Advent Technologies (ADN) 10-Q 20 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 18, 2021
Cover [Abstract]
Entity Registrant Name	Advent Technologies Holdings, Inc.
Entity Central Index Key	0001744494
Current Fiscal Year End Date	--12-31
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Address, State or Province	MA
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		46,128,745

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 124,974,831	$ 515,734
Accounts receivable	1,138,454	421,059
Due from related parties	0	67,781
Contract assets	745,513	85,930
Inventories	812,744	107,939
Prepaid expenses and Other current assets	4,121,554	496,745
Total current assets	131,793,096	1,695,188
Goodwill and intangibles, net	5,178,771	0
Property and equipment, net	317,996	198,873
Total Assets	137,289,863	1,894,061
Current liabilities:
Trade and other payables	1,462,789	881,394
Due to related parties	0	1,114,659
Deferred income from grants, current	306,917	158,819
Contract liabilities	44,185	167,761
Other current liabilities	2,956,116	904,379
Income tax payable	199,653	201,780
Total current liabilities	4,969,660	3,428,792
Warrant Liability	23,350,695	0
Deferred income from grants, non-current	67,848	182,273
Other long-term liabilities	193,719	76,469
Total liabilities	28,581,922	3,687,534
Commitments and contingent liabilities
Stockholders' equity/(deficit)
Common stock ($0.0001 par value per share; Shares authorized: 110,000,000 at March 31, 2021 and December 31, 2020; Issued and outstanding: 46,105,947 and 25,033,398 at March 31, 2021 and December 31, 2020, respectively)	4,611	2,503
Preferred stock ($0.0001 par value per share; Shares authorized: 1,000,000 at March 31, 2021 and December 31, 2020; nil issued and outstanding at March 31 2021 and December 31, 2020	0	0
Additional Paid in Capital	118,568,449	10,993,762
Accumulated Other Comprehensive Income	130,725	111,780
Accumulated Deficit	(9,995,844)	(12,901,518)
Total stockholders' equity/(deficit)	108,707,941	(1,793,473)
Total liabilities and stockholders' equity/(deficit)	$ 137,289,863	$ 1,894,061

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Stockholders' equity/(deficit)
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	110,000,000	110,000,000
Common stock, shares issued (in shares)	46,105,947	25,033,398
Common stock, shares outstanding (in shares)	46,105,947	25,033,398
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Revenue, net	$ 1,489,292	$ 100,266
Cost of revenues	(347,342)	(66,037)
Gross profit / (loss)	1,141,950	34,229
Income from grants	38,453	228,764
Research and development expenses	(29,082)	(51,269)
Administrative and selling expenses	(7,921,858)	(302,669)
Amortization of intangibles	(186,760)	0
Operating Loss	(6,957,297)	(90,945)
Finance costs	(10,280)	(2,523)
Change fair value of warrant liability	9,765,625	0
Foreign exchange differences, net	23,955	(18,587)
Other income / (expense)	83,671	(104,561)
Income / (Loss) before income tax	2,905,674	(216,616)
Income tax expense	0	0
Net income/(loss)	$ 2,905,674	$ (216,616)
Net income / (loss) per share, basic (in dollars per share)	$ 0.08	$ (0.01)
Weighted Average shares outstanding, basic (in shares)	37,769,554	14,979,803
Net income / (loss) per share, diluted (in dollars per share)	$ 0.07	$ (0.01)
Weighted Average shares outstanding, diluted (in shares)	40,987,346	14,979,803

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME / (LOSS) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME / (LOSS) [Abstract]
Net Income / (loss)	$ 2,905,674	$ (216,616)
Other comprehensive income / (loss), net of tax effect:
Foreign currency translation adjustment	18,945	(49,841)
Total other comprehensive income / (loss)	18,945	(49,841)
Comprehensive income / (loss)	$ 2,924,619	$ (266,457)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY / (DEFICIT) - USD ($)		Preferred Stock [Member]Series A [Member]	Preferred Stock [Member]Series Seed [Member]	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Deficit [Member]	Accumulated OCI [Member]	Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		$ 315	$ 2,108	$ 888	$ 8,811,647	$ (9,767,619)	$ 118,859	$ (833,802)
Beginning balance (in shares)		314,505	2,108,405	888,184
Retroactive application of recapitalization		$ (315)	$ (2,108)	$ 592	1,831	0	0	0
Retroactive application of recapitalization (in shares)		(314,505)	(2,108,405)	13,915,109
Adjusted balance, beginning of period at Dec. 31, 2019		$ 0	$ 0	$ 1,480	8,813,478	(9,767,619)	118,859	(833,802)
Adjusted balance, beginning of period (in shares) at Dec. 31, 2019		0	0	14,803,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock	[1]	$ 0	$ 0	$ 223	1,429,782	0	0	1,430,005
Issuance of preferred stock (in shares)	[1]	0	0	2,225,396
Net (loss) / Profit		$ 0	$ 0	$ 0	0	(216,616)	0	(216,616)
OCI		0		0	0	0	(49,841)	(49,841)
Ending balance at Mar. 31, 2020		$ 0	$ 0	$ 1,703	10,243,260	(9,984,235)	69,018	329,746
Ending balance (in shares) at Mar. 31, 2020		0	0	17,028,689
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		$ 845	$ 2,096	$ 3,017	10,990,307	(12,901,518)	111,780	(1,793,473)
Beginning balance (in shares)		844,037	2,095,592	3,017,057
Retroactive application of recapitalization		$ (845)	$ (2,096)	$ (513)	3,454	0	0	0
Retroactive application of recapitalization (in shares)		(844,037)	(2,095,592)	22,016,341
Adjusted balance, beginning of period at Dec. 31, 2020		$ 0	$ 0	$ 2,504	10,993,761	(12,901,518)	111,780	(1,793,473)
Adjusted balance, beginning of period (in shares) at Dec. 31, 2020		0	0	25,033,398
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Business Combination and PIPE financing		$ 0	$ 0	$ 2,107	107,574,688	0	0	107,576,795
Business Combination and PIPE financing (in shares)		0	0	21,072,549
Net (loss) / Profit		$ 0	$ 0	$ 0	0	2,905,674	0	2,905,674
OCI		0		0	0	0	18,945	18,945
Ending balance at Mar. 31, 2021		$ 0	$ 0	$ 4,611	$ 118,568,449	$ (9,995,844)	$ 130,725	$ 108,707,941
Ending balance (in shares) at Mar. 31, 2021		0	0	46,105,947
[1]	Issuance of convertible preferred stock has been retroactively restated to give effect to the recapitalization transaction.

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS [Abstract]
Net Cash used in Operating Activities	$ (12,196,101)	$ (341,666)
Cash Flows from Investing Activities:
Purchases of property and equipment	(77,112)	(34,699)
Acquisition of a subsidiary, net of cash acquired	(3,975,940)	0
Net Cash used in Investing Activities	(4,053,052)	(34,699)
Cash Flows from Financing Activities:
Business Combination and PIPE financing, net of issuance costs paid	140,693,116	0
Proceeds of issuance of preferred stock	0	1,430,005
Repayment of Loan	0	(487,708)
Net Cash provided by Financing Activities	140,693,116	942,297
Net increase (decrease) in cash and cash equivalents	124,443,963	565,932
Effect of exchange rate changes on cash and cash equivalents	15,134	7,893
Cash and cash equivalents at the beginning of the period	515,734	1,199,015
Cash and cash equivalents at the end of the period	$ 124,974,831	$ 1,772,840

Basis of presentation

Basis of presentation	3 Months Ended
	Mar. 31, 2021
Basis of presentation [Abstract]
Basis of presentation	1. Basis of presentation (a) Overview On February 4, 2021 (“Closing Date”), AMCI Acquisition Corp. (“AMCI”), consummated the previously announced business combination (the “Business Combination”) pursuant to that certain merger agreement (the “Agreement and Plan of Merger”), dated October 12, 2020, by and among AMCI, AMCI Merger Sub Corp., a Delaware corporation and newly formed wholly-owned subsidiary of AMCI (“Merger Sub”), AMCI Sponsor LLC (the “Sponsor”), solely in the capacity as the representative from and after the effective time of the Business Combination for the stockholders of AMCI (the “Purchaser Representative”), Advent Technologies, Inc., a Delaware corporation (“Legacy Advent”), and Vasillios Gregoriou, solely in his capacity as the representative from and after the effective time for the Legacy Advent stockholders (the “Seller Representative”), as amended by Amendment No. 1 and Amendment No. 2 to the Agreement and Plan of Merger, dated as of October 19, 2020 and December 31, 2020, respectively, by and among AMCI, Merger Sub, Sponsor, Legacy Advent, and Seller Representative. In connection with the closing of the Business Combination (the “Closing”), AMCI acquired 100% of the stock of Legacy Advent (as it existed immediately prior to the Closing) and its subsidiaries. On the Closing Date, and in connection with the closing of the Business Combination, AMCI changed its name to Advent Technologies Holding, Inc. (the "Company" or "Advent"). Legacy Advent was deemed the accounting acquirer in the Business Combination based on an analysis of the criteria outlined in Accounting Standards Codification ("ASC") 805. This determination was primarily based on Legacy Advent's stockholders prior to the Business Combination having a majority of the voting interests in the combined company, Legacy Advent's operations comprising the ongoing operations of the combined company, Legacy Advent's board of directors comprising a majority of the board of directors of the combined company, and Legacy Advent's senior management comprising the senior management of the combined company. Accordingly, for accounting purposes, the Business Combination was treated as the equivalent of Legacy Advent issuing stock for the net assets of AMCI, accompanied by a recapitalization. The net assets of AMCI are stated at historical cost, with no goodwill or other intangible assets recorded. While AMCI was the legal acquirer in the Business Combination, because Legacy Advent was deemed the accounting acquirer, the historical financial statements of Legacy Advent became the historical financial statements of the combined company, upon the consummation of the Business Combination. As a result, the unaudited condensed consolidated financial statements included in this report reflect (i) the historical operating results of Legacy Advent prior to the Business Combination; (ii) the results of the Company (combined results of AMCI and Legacy Advent) following the closing of the Business Combination; (iii) the assets and liabilities of Legacy Advent at their historical cost; and (iv) Company’s equity structure for all periods presented. In accordance with guidance applicable to these circumstances, the equity structure has been restated in all comparative periods up to the Closing Date, to reflect the number of shares of the Company's common stock, $0.0001 par value per share ("Common Stock") issued to Legacy Advent's stockholders in connection with the recapitalization transaction. As such, the shares and corresponding capital amounts and earnings per share related to Legacy Advent Preferred Stock (“Preferred Series A” and “Preferred Series Seed”) and Legacy Advent common stock prior to the Business Combination have been retroactively restated as shares reflecting the exchange ratio established in the Business Combination Agreement. Activity within the statement of changes in stockholders' equity / (deficit) for the issuances of Legacy Advent's Preferred Stock, were also retroactively converted to Legacy Advent common stock. (Note 3) On February 18, 2021, the Company, entered into a Membership Interest Purchase Agreement with Bren-Tronics, Inc. (“Seller”) and UltraCell, LLC, a Delaware limited liability company and a direct wholly-owned subsidiary of Seller (“UltraCell”) (the “Purchase Agreement”). See Note 3 “Business Combination” (b) Unaudited Condensed Consolidated Financial Statements The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) and pursuant to the regulations of the U.S. Securities and Exchange Commission (“SEC”). The unaudited financial information reflects, in the opinion of management, all adjustments, consisting of normal recurring adjustments, considered necessary for a fair statement of the Company's financial position, results of operations and cash flows for the periods indicated. The results reported for the interim period presented are not necessarily indicative of results that may be expected for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's audited consolidated financial statements as of and for the year ended December 31, 2020 included in the Current Report on Form 8-K filed with the SEC on February 9, 2021 (the “Original Form 8-K”), as amended by Amendment No. 1 to Form 8-K, filed with the SEC on February 9, 2021 (“Amendment No. 1”), as further amended by Amendment No. 2 to Form 8-K, filed with the SEC on March 26, 2021 (“Amendment No. 2”) and as further amended by Amendment No 3 to Form 8-K, filed with the SEC on May 20, 2021 (“Amendment No. 3,” and, the Original Form 8-K, as so amended by Amendment No. 1, Amendment No. 2 and Amendment No. 3, the “Super Form 8-K”). The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. Intercompany accounts and transactions have been eliminated. Certain prior period balances have been reclassified to conform to the current period presentation in the unaudited condensed consolidated financial statements and the accompanying notes. Share and per share amounts are presented on a post-conversion basis for all periods presented, unless otherwise specified. (c) Going Concern The unaudited condensed consolidated financial statements have been prepared by management in accordance with GAAP, assuming that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. Accordingly, these financial statements do not include any adjustments that may result in the event the Company is unable to continue as a going concern. Beginning in March 2020, the COVID-19 pandemic and the measures imposed to contain this pandemic have disrupted and are expected to continue to impact the Company’s business. The magnitude of the impact of the COVID-19 pandemic on the Company’s productivity, results of operations and financial position, and its disruption to the Company’s business (fuel cells sales timeline, realization of income from grants received) will depend in part, on the length and severity of these restrictions and on the Company’s ability to conduct business in the ordinary course. As of the date of this Quarterly Report on Form 10-Q, the Company’s existing cash resources are sufficient to support planned operations for the next 12 months. As a result, management believes that the Company's existing financial resources are sufficient to continue operating activities for at least one year past the issuance date of the unaudited condensed consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies: There have been no significant changes from the significant accounting policies disclosed in Note 2 of the “Notes to Consolidated Financial Statements” included in the Super Form 8-K. The Company is an “emerging growth company,” as defined in Section 2(a) of the Securities Act, as modified by the Jumpstart our Business Startups Act of 2012, (the “JOBS Act”). As an emerging growth company (“EGC”), the JOBS Act allows the Company to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are applicable to private companies. The Company elected to use this extended transition period under the JOBS Act until such time the Company is no longer considered to be an EGC. The Company applied the following new accounting policies: (a) Business acquisitions, Goodwill and Intangible Assets The Company allocates the fair value of purchase consideration transferred in a business acquisition to the tangible assets acquired, liabilities assumed, and intangible assets acquired based on their estimated fair values. The excess of the fair value of purchase consideration transferred over the fair values of these identifiable assets and liabilities is recorded as goodwill. In case the fair value of purchase consideration transferred is below fair values of these identifiable assets and liabilities, the Company recognizes a gain from a bargain purchase. Such valuations require management to make significant estimates and assumptions, especially with respect to intangible assets. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired licenses, trade names, in process research and development ("R&D"), useful lives and discount rates, patents, customer clientele, customer contracts and know-how. Management's estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, the Company may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period, any subsequent adjustments are recorded in the consolidated statement of operations. For significant acquisitions, the Company obtains independent appraisals and valuations of the intangible (and certain tangible) assets acquired and certain assumed obligations. The Company analyzes each acquisition individually and all acquisitions within each reporting period in aggregate to determine if those are material acquisitions in the context of ASC 805-10-50. The estimated fair values and useful lives of identified intangible assets are based on many factors, including estimates and assumptions of future operating performance and cash flows of the acquired business, estimates of cost avoidance, the nature of the business acquired, the specific characteristics of the identified intangible assets and our historical experience and that of the acquired business. The estimates and assumptions used to determine the fair values and useful lives of identified intangible assets could change due to numerous factors, including product demand, market conditions, regulations affecting the business model of our operations, technological developments, economic conditions and competition. We conduct a goodwill impairment analysis annually in the fourth fiscal quarter, as of October 1, and as necessary if changes in facts and circumstances indicate that the fair value of our reporting units may be less than their carrying amounts. When indicators of impairment do not exist and certain accounting criteria are met, we are able to evaluate goodwill impairment using a qualitative approach. When necessary, our quantitative goodwill impairment test consists of two steps. The first step requires that we compare the estimated fair value of our reporting units to the carrying value of the reporting unit’s net assets, including goodwill. If the fair value of the reporting unit is greater than the carrying value of its net assets, goodwill is not considered to be impaired and no further testing is required. If the fair value of the reporting unit is less than the carrying value of its net assets, we would be required to complete the second step of the test by analyzing the fair value of its goodwill. If the carrying value of the goodwill exceeds its fair value, an impairment charge is recorded. Currently, we identify one reporting unit. (b) Warrants The Company may issue or assume common stock warrants with debt, equity or as a standalone financing instruments that are recorded as either liabilities or equity in accordance with the respective accounting guidance. Warrants recorded as equity are recorded at their relative fair value or fair value determined at the issuance date and remeasurement is not required. Warrants recorded as liabilities are recorded at their fair value, within warrant liability on the consolidated balance sheets, and remeasured on each reporting date with changes recorded in revaluation of warrant liability on the Company's consolidated statements of operations. (c) Fair Value of Financial Instruments As a result of the Business Combination, the Company assumed a warrant liability (the "Warrant Liability") related to previously issued 3,940,278 warrants, each exercisable to purchase one share of common stock at an exercise price of $11.50 per share, originally sold to AMCI Sponsor LLC (the “Sponsor”) in a private placement consummated in connection with AMCI’s Initial Public Offering (the “Private Placement Warrants”) and the 400,000 warrants, each exercisable to purchase one share of common stock at an exercise price of $11.50 per share, converted from the Sponsor’s non-interest bearing loan to the Company of $400,000 in connection with the closing of the Business Combination (the “Working Capital Warrants”) (Note 10). The Private Placement Warrants and the Working Capital Warrants have substantially the same terms as the 22,052,077 warrants, each exercisable to purchase one share of common stock at an exercise price of $11.50 per share, issued by AMCI in its Initial Public Offering (the “Public Warrants”). The Warrant Liability was remeasured to its fair value at each reporting period and upon settlement. The change in fair value was recognized in revaluation of warrant liability on the consolidated statements of operations. The change in fair value of the Warrant Liability was as follows: Warrant Liability Estimated fair value at February 4, 2021 33,116,321 Change in estimated fair value (9,765,625 ) Estimated fair value at March 31, 2021 23,350,695 The estimated fair value of the Private Placement Warrants and the Working Capital Warrants (each as defined below) is determined using Level 3 inputs by using the Black-Scholes model. The application of the Black-Scholes model requires the use of a number of inputs and significant assumptions including volatility. Significant judgment is required in determining the expected volatility of our common stock. Due to the limited history of trading of our common stock, we determined expected volatility based on a peer group of publicly traded companies. The following table provides quantitative information regarding Level 3 fair value measurements inputs as their measurement dates: Stock price 13.39 Exercise price (strike price) 11.50 Remaining term (in years) 4.84 Volatility 40 % Risk-free interest rate 0.63 % The Company performs routine procedures such as comparing prices obtained from independent source to ensure that appropriate fair values are recorded. (d) Earnings / (Loss) Per Share Earnings / (Loss) Per Share is computed by dividing earnings / (loss) by the weighted average number of common shares outstanding during the period. Diluted earnings / (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted at the beginning of the periods presented, or issuance date, if later. The treasury stock method is used to compute the dilutive effect of warrants. (e) Recent Accounting pronouncements Recently issued accounting pronouncements not yet adopted In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. In July 2018, ASU 2018-10, Codification Improvements to Topic 842, Leases, was issued to provide more detailed guidance and additional clarification for implementing ASU 2016-02. Furthermore, in July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements, which provides an optional transition method in addition to the existing modified retrospective transition method by allowing a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Additionally, ASU 2019-01, Codification Improvements to Topic 842, Leases and ASU 2020-02, Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842), provided additional clarifications for implementing ASU 2016.02. The new lease standard was originally effective for the private entities on January 1, 2021, with early adoption permitted. Following the issuance of ASU 2020-05, Effective Dates for Certain Entities (Topic 842), the effective date of Leases was deferred for private entities (the “all other” category) to fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early application continues to be permitted which means that an entity may choose to implement Leases before those deferred effective dates. The Company is currently evaluating the effect of the adoption of this guidance on the consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments, which, amends the requirement on the measurement and recognition of expected credit losses for financial assets held. Furthermore, amendments, ASU 2019-10 and ASU 2019-11 provided additional clarification for implementing ASU 2016-13. ASU 2016-13 is effective for the Company beginning January 1, 2023, with early adoption permitted. The Company is currently in the process of evaluating the effect of this guidance on the consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is intended to simplify various aspects related to accounting for income taxes. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. ASU 2019-12 is effective for the Company beginning January 1, 2022, with early adoption permitted. The Company is currently evaluating the effects of this guidance on the Company's financial statements.

Business Combination

Business Combination	3 Months Ended
	Mar. 31, 2021
Business Combination [Abstract]
Business Combination	3. Business Combination (a) AMCI Acquisition Corp. As detailed in Note 1 on February 4, 2021, the Company and AMCI consummated the Business Combination pursuant to the terms of the merger agreement, with Advent Legacy surviving the merger as a wholly-owned subsidiary of AMCI. Immediately prior to the closing of the Business Combination, all shares of outstanding preferred stock Series A and preferred stock Series Seed of Legacy Advent were automatically converted into shares of the Legacy Advent's common stock. Upon the consummation of the Business Combination, each share of Legacy Advent common stock issued and outstanding was canceled and converted into the right to receive the amount of shares as determined based on the merger consideration of $250 million minus the estimated consolidated indebtedness of Legacy Advent and its subsidiaries as of the consummation of the Business Combination, net of their estimated consolidated cash and cash equivalents (“Closing Net Indebtedness”) divided by $10.00. The Closing Net Indebtedness was based solely on estimates determined shortly prior to the closing and was not subject to any post-closing true-up or adjustment. Upon the closing of the Business Combination, AMCI's certificate of incorporation was amended and restated to, among other things, authorize the issuance of 111,000,000 shares, of which 110,000,000 shares are shares of common stock, par value $0.0001 per share and 1,000,000 shares are shares of undesignated preferred stock, par value $0.0001 per share. In connection with the execution of the Business Combination Agreement, AMCI entered into separate subscription agreements (each, a "Subscription Agreement") with a number of investors (each a "Subscriber"), pursuant to which the Subscribers agreed to purchase, and AMCI agreed to sell to the Subscribers, an aggregate of 6,500,000 shares of common stock (the "PIPE Shares"), for a purchase price of $10.00 per share and an aggregate purchase price of $65.0 million, in a private placement pursuant to the subscription agreements (the "PIPE"). The PIPE investment closed simultaneously with the consummation of the Business Combination. The Business Combination is accounted for as a reverse recapitalization in accordance with GAAP. Under this method of accounting, AMCI was treated as the "acquired" company for financial reporting purposes. See Note 1 "Basis of Presentation" in the accompanying unaudited condensed consolidated financial statements for further details. Accordingly, for accounting purposes, the Business Combination was treated as the equivalent of Legacy Advent issuing stock for the net assets of AMCI, accompanied by a recapitalization. The net assets of AMCI are stated at historical cost, with no goodwill or other intangible assets recorded. The following table reconciles the elements of the Business Combination to the consolidated statement of cash flows and the consolidated statement of changes in equity for the three month ended March 31, 2021: Recapitalization Cash- AMCI’s trust and cash (net of redemptions) $ 93,310,599 Cash – PIPE plus interest 65,000,118 Less transaction costs and advisory fees paid (17,617,601 ) Less non-cash warrant liability assumed (33,116,321 ) Net Business Combination and PIPE financing $ 107,576,795 The number of shares of common stock issued immediately following the consummation of the Business Combination: Recapitalization Class A Common A stock of AMCI, outstanding prior to Business Combination 9,061,136 Less Redemption of AMCI shares (1,606 ) Class B Common Stock of AMCI, outstanding prior to Business Combination 5,513,019 Shares issued in PIPE 6,500,000 Business Combination and PIPE financing shares 21,072,549 Legacy Advent Shares 25,033,398 Total shares of Common Stock immediately after Business Combination 46,105,947 (b) UltraCell, LLC On February 18, 2021 (the “acquisition date”), pursuant to the terms and conditions of the Purchase Agreement, the Company acquired 100% of the issued and outstanding membership units of UltraCell from Bren-Tronics, Inc. The results of UltraCell’s operations have been included in the unaudited condensed consolidated financial statements since the acquisition date. UltraCell is an entity specialized in lightweight fuel cells for the portable power market with mature products and cutting-edge technology. The acquisition consideration transferred totaled $6.0 million, of which $4.0 million was cash and $2 million was the fair value of the contingent consideration. The contingent consideration arrangement required the Company to pay $2 million of additional cash to UltraCell’s former holders of membership interests, if UltraCell entered into certain customer arrangements for sales of products prior to June 30, 2021. The estimated fair values of the assets acquired and liabilities assumed at the acquisition date was $5.5 million, resulting in the recognition of provisional goodwill of $0.5 million. The Company is in the process of obtaining third-party valuations of certain intangible assets; thus, the provisional measurements of intangible assets and goodwill are subject to change. The provisional value of $5 million of intangibles relates to trademarks, patents, customer relationships, customer contracts and know-how. Those intangibles mainly relate to definite-live intangible assets with estimated useful lives that vary between 3-10 years, with the exception of contract backlogs which are amortized over the remaining period of the contracts assumed based on income approach. During the period from acquisition and up to March 31, 2021, the Company has recognized in the condensed consolidated statement of operations amortization for those intangibles of $0.2 million.

Related party disclosures

Related party disclosures	3 Months Ended
	Mar. 31, 2021
Related party disclosures [Abstract]
Related party disclosures	4. Related party disclosures: The amounts included in the accompanying consolidated balance sheets and consolidated statements of operations are as follows: March 31, 2021 December 31, 2020 Due to related parties Unpaid compensation cost Unpaid compensation cost Vassilios Gregoriou $ - $ 613,971 Christos Kaskavelis - 75,160 Emory Sayre De Castro - 425,528 Total $ - $ 1,114,659 March 31, 2021 December 31, 2020 Due from related parties Prepayment Prepayment Charalampos Antoniou $ - $ 67,781 Total $ - $ 67,781 The outstanding balances as of December 31, 2020 due to/from Company’s executives and officers relating to unpaid compensation and prepaid services have been settled during the first quarter of 2021. The Company executives, Vassilis Gregoriou, Christos Kaskavelis, Emory Sayre De Castro, James Coffey and William Hunter, each received a signing bonus and transaction bonus upon the consummation of the merger in an aggregate amount of $5.6 million, which is included in administrative and selling expenses in the statement of operations for the first quarter of 2021.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2021
Inventories [Abstract]
Inventories	5. Inventories: Inventories consist of the following: March 31, 2021 December 31, 2020 Raw materials and supplies $ 812,744 $ 107,939 Total $ 812,744 $ 107,939

Prepaid expenses and Other curr

Prepaid expenses and Other current assets	3 Months Ended
	Mar. 31, 2021
Prepaid expenses and Other current assets [Abstract]
Prepaid expenses and Other current assets	6. Prepaid expenses and Other current assets: Prepaid expenses and Other current assets are analyzed as follows: March 31, 2021 December 31, 2020 VAT receivable $ 287,523 $ 259,831 Grants receivable 91,182 95,064 Other current assets 891,168 140,126 Prepaid Expenses 2,851,681 1,724 Total $ 4,121,554 $ 496,745 Prepaid expenses as of March 31, 2021 mainly include prepayments to insurers for director’s and officer’s insurance services. Other current assets as of March 31, 2021 include amounts provided as guarantees for leases (Note 15) and prepayments to suppliers.

Property and equipment, net

Property and equipment, net	3 Months Ended
	Mar. 31, 2021
Property and equipment, net [Abstract]
Property and equipment, net	7. Property and equipment, net: During the three-month period ended March 31, 2021, $77,112 additions to property and equipment concern machinery, office and other equipment and the remaining additions to the account relate to property and equipment acquired from UltraCell (Note 3). There are no collaterals or other commitments on the Company’s property and equipment.

Trade and other payables

Trade and other payables	3 Months Ended
	Mar. 31, 2021
Trade and other payables [Abstract]
Trade and other payables	8. Trade and other payables: December 31, March 31, 2021 December 31, 2020 Trade payables and other payables $ 1,462,789 $ 881,394 Total $ 1,462,789 $ 881,394 Trade payables include balances of suppliers and consulting service providers.

Other current liabilities

Other current liabilities	3 Months Ended
	Mar. 31, 2021
Other current liabilities [Abstract]
Other current liabilities	9. Other current liabilities: Other current liabilities of the Company are analyzed as follows: March 31,2021 December 31, 2020 Accrued expenses for legal and consulting fees $ 837,606 $ 814,965 Other accruals and short-term payables 118,510 89,414 Contingent Consideration 2,000,000 - Total $ 2,956,116 $ 904,379

Private Placement Warrants and

Private Placement Warrants and Working Capital Warrants	3 Months Ended
	Mar. 31, 2021
Private Placement Warrants and Working Capital Warrants [Abstract]
Private Placement Warrants and Working Capital Warrants	10. Private Placement Warrants and Working Capital Warrants: In connection with the Business Combination, the Company has assumed 3,940,278 Private Placement Warrants issued upon AMCI’s Initial Public Offering. In addition, upon the closing of the Business Combination, the working capital loan provided by AMCI’s Sponsor to AMCI was converted into 400,000 Working Capital Warrants, which were also assumed. The terms of the Working Capital Warrants are the same as those of the Private Placement Warrants. As of March 31, 2021, the Company had 4,340,278 Private Placement Warrants and Working Capital Warrants outstanding. Each Private Placement Warrant and Working Capital Warrant entitles the registered holder to purchase one share of Common Stock at a price of $11.50 per share, subject to adjustment, at any time commencing 30 days after the completion of the Business Combination. The Public Warrants will expire five years after the completion of a Business Combination or earlier upon redemption or liquidation. The Private Placement Warrants and Working Capital Warrants are identical to the Public Warrants, except that the Private Placement Warrants and Working Capital Warrants and the common stock issuable upon the exercise of those warrants will not be transferable, assignable or salable until 30 days after the completion of a Business Combination, subject to certain limited exceptions. Additionally, the Private Placement Warrants and Working Capital Warrants will be exercisable on a cashless basis and be non-redeemable so long as they are held by the initial purchasers or their permitted transferees. If those warrants are held by someone other than the initial purchasers or their permitted transferees, they will be redeemable by the Company and exercisable by such holders on the same basis as the Public Warrants. As of March 31, 2021, Private Placement Warrants and Working Capital Warrants are held by its initial purchasers. According to the provisions of the Private Placement Warrants and Working Capital Warrants warrant agreements, the exercise price and number of shares of common stock issuable upon exercise of those warrants may be adjusted in certain circumstances including in the event of a stock dividend, or recapitalization, reorganization, merger or consolidation. Private Placement Warrants and Working Capital Warrants are classified as liabilities in accordance with the Company’s evaluation of the provisions of ASC 815- 40-15, which provides that a warrant is not indexed to the issuer’s common stock if the terms of the warrant require an adjustment to the exercise price upon a specified event and that event is not an input to the fair value of the warrant with a fixed exercise price and fixed number of underlying shares.

Stockholders' Equity _ (Deficit

Stockholders' Equity / (Deficit)	3 Months Ended
	Mar. 31, 2021
Stockholders' Equity / (Deficit) [Abstract]
Stockholders' Equity / (Deficit)	11. Stockholders’ Equity / (Deficit): Shares Authorized As of March 31, 2021, the Company had authorized a total of 111,000,000 shares for issuance with 110,000,000 shares designated as common stock, par value $0.0001 per share and 1,000,000 shares designated as preferred stock, par value $0.0001 per share. Public Warrants In connection with the Business Combination, the Company has assumed Public Warrants issued upon AMCI’s Initial Public Offering. As of March 31, 2021, the Company had 22,052,077 Public Warrants outstanding. Each Public Warrant entitles the registered holder to purchase one share of Common Stock at a price of $11.50 per share, subject to adjustment, at any time commencing 30 days after the completion of the Business Combination. The Public Warrants will expire five years after the completion of a Business Combination or earlier upon redemption or liquidation. Once the warrants become exercisable, the Company may redeem the Public Warrants: –in whole and not in part; –at a price of $0.01 per warrant; –upon not less than 30 days’ prior written notice of redemption; –if, and only if, the reported last sale price of the Company’s common stock equals or exceeds $18.00 per share for any 20 trading days within a 30-trading day period ending three business days before the Company sends the notice of redemption to the warrant holders; and –if, and only if, there is a current registration statement in effect with respect to the shares of common stock underlying such warrants. If the Company calls the Public Warrants for redemption, management will have the option to require all holders that wish to exercise the Public Warrants to do so on a “cashless basis,” as described in the warrant agreement. The exercise price and number of shares of common stock issuable upon exercise of the warrants may be adjusted in certain circumstances including in the event of a stock dividend, or recapitalization, reorganization, merger or consolidation. However, the warrants will not be adjusted for issuance of common stock at a price below its exercise price. In addition, the warrant agreement provides that in case of a tender offer or exchange that involves 50% or more of the Company’s stockholders, the Public Warrants may be settled in cash, equity securities or other assets depending on the kind and amount received per share by the holders of the common stock in such consolidation or merger that affirmatively make such election. Public Warrants are classified in equity in accordance with the Company’s evaluation of the provisions of ASC 480 and ASC 815. The Company analyzed the terms of the Public Warrants and concluded that there are no terms that provide that the warrant is not indexed to the issuer’s common stock. The Company also analyzed the tender offer provision discussed above, and considering that upon the Closing of the Business Combination the Company has a single class of common shares, concluded that the exception discussed in ASC 815-40-25 applies, and thus equity classification is not precluded.

Revenue, net

Revenue, net	3 Months Ended
	Mar. 31, 2021
Revenue, net [Abstract]
Revenue, net	12. Revenue, net: Revenue, net is analyzed as follows: Three months period ended March, 31 2021 March, 31,2020 Sales of goods $ 1,489,292 $ 100,266 Total revenue from contracts with customers $ 1,489,292 $ 100,266 As at March 31, 2021 and December 31, 2020 contract assets were $ 745,513 and $85,930, respectively. Also, the Company has recognized contract liabilities of $44,185 and $167,761 has at March 31, 2021 and December 31, 2020, respectively.

Fair value measurement

Fair value measurement	3 Months Ended
	Mar. 31, 2021
Fair value measurement [Abstract]
Fair value measurement	13. Fair value measurement: The carrying amounts reflected in the consolidated balance sheets of cash and cash equivalents, accounts receivables, net, other current assets, trade and other payables, due from/to related parties, other current liabilities, income tax payable and convertible promissory notes, approximate their respective fair values due to the short maturity of these instruments.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Taxes [Abstract]
Income Taxes	14. Income Taxes To calculate the interim tax provision, at the end of each interim period the Company estimates the annual effective tax rate and applies that to its ordinary quarterly earnings. The effect of changes in the enacted tax laws or rates is recognized in the interim period in which the change occurs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and judgments including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in foreign jurisdictions, permanent differences between book and tax amounts, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained, or the tax environment changes.

Commitments and contingencies

Commitments and contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and contingencies [Abstract]
Commitments and contingencies	15. Commitments and contingencies: 15.1 Litigations The Company is subject to legal and regulatory actions that arise from time to time in the ordinary course of business. The assessment as to whether a loss is probable or reasonably possible, and as to whether such loss or a range of such loss is estimable, often involves significant judgment about future events. On December 17, 2020, a purported shareholder class action complaint was filed by Dillon Frey against AMCI in the Supreme Court of the State of New York, County of New York, alleging that the proposed Business Combination with Advent is both procedurally and substantively unfair and seeking to maintain the action as a class action and enjoin the Business Combination, among other things, without stating a specific amount of damages. The complaint does not provide detail as to how the proposed Business Combination is unfair, either procedurally or substantively, and we believe it has no merit. On February 10, 2021, a notice of voluntary discontinuance of the complaint was filed in the Supreme Court of the State of New York, County of New York. There is no material pending or threatened litigation against the Company that remains outstanding as of March 31, 2021. 15.2 Operating Leases On February 5, 2021, the Company entered into a lease agreement by and among the Company, in its capacity as Tenant, and BP Hancock LLC, a Delaware limited liability company, in its capacity as Landlord. The lease provides for the rental by the Company of office space at 200 Clarendon Street, Boston, MA 02116 for use as the Company’s executive offices. Under the terms of the lease, the Company leases 6,041 square feet at an initial fixed annual rent of $456,095.50. The term of the lease is for five years (unless terminated as provided in the lease) and is expected to commence in April 2021. The Company provided security in the form of a security deposit in the amount of $114,023.88 which is included in Other current assets. On March 8, 2021, the Company entered into a lease for 21,401 square feet as a product development and manufacturing center at Hood Park in Charlestown, MA. Under the terms of the lease, the Company will pay an initial fixed annual rent of $1,498,070.00. The lease has a term of eight years and five months, with an option to extend for five years, and is expected to commence in June 2021. The Company is obliged to provide security in the form of a security deposit in the amount of $750,000.00 before commencement of the lease.

Net income _ (loss) per share

Net income / (loss) per share	3 Months Ended
	Mar. 31, 2021
Net income / (loss) per share [Abstract]
Net income / (loss) per share	16. Net income / (loss) per share Net income (loss) per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period totaled to 46,105,947. The following table sets forth the computation of the basic and diluted net loss per share for the three months ended March 31, 2021 and 2020. Three-months ended March 31, Numerator: 2021 2020 Net income / (loss) $ 2,905,674 $ (216,616 ) Denominator: Weighted average shares outstanding, basic 37,769,554 14,979,803 Dilutive effect of common stock issuable from assumed exercise of warrants 3,217,792 - Weighted average shares outstanding, diluted 40,987,346 14,979,803 Net income / (loss) per share: Basic $ 0.08 $ (0.01 ) Diluted $ 0.07 $ (0.01 ) Basic net income / (loss) per share is computed by dividing net income/ (loss) for the periods presented by the weighted-average number of common shares outstanding during these periods. Diluted net income /(loss) per share is computed by dividing the net income /(loss), by the weighted average number of common shares outstanding for the periods, adjusted for the dilutive effect of shares of common stock equivalents resulting from the assumed exercise of the Public Warrants, Private Placements Warrants and Working Capital Warrants. The treasury stock method was used to calculate the potential dilutive effect of these common stock equivalents. Potentially dilutive shares were excluded from the computation of diluted net income / (loss) when their effect was antidilutive.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	17. Subsequent Events Subsequent to March 31, 2021 certain warrantholders exercised their options to purchase an additional 22,798 shares at $11.50. These exercises generated $262,177 in additional proceeds to the Company and increased our shares outstanding by 22,798 shares.

Basis of presentation (Policies

Basis of presentation (Policies)	3 Months Ended
	Mar. 31, 2021
Basis of presentation [Abstract]
Overview	(a) Overview On February 4, 2021 (“Closing Date”), AMCI Acquisition Corp. (“AMCI”), consummated the previously announced business combination (the “Business Combination”) pursuant to that certain merger agreement (the “Agreement and Plan of Merger”), dated October 12, 2020, by and among AMCI, AMCI Merger Sub Corp., a Delaware corporation and newly formed wholly-owned subsidiary of AMCI (“Merger Sub”), AMCI Sponsor LLC (the “Sponsor”), solely in the capacity as the representative from and after the effective time of the Business Combination for the stockholders of AMCI (the “Purchaser Representative”), Advent Technologies, Inc., a Delaware corporation (“Legacy Advent”), and Vasillios Gregoriou, solely in his capacity as the representative from and after the effective time for the Legacy Advent stockholders (the “Seller Representative”), as amended by Amendment No. 1 and Amendment No. 2 to the Agreement and Plan of Merger, dated as of October 19, 2020 and December 31, 2020, respectively, by and among AMCI, Merger Sub, Sponsor, Legacy Advent, and Seller Representative. In connection with the closing of the Business Combination (the “Closing”), AMCI acquired 100% of the stock of Legacy Advent (as it existed immediately prior to the Closing) and its subsidiaries. On the Closing Date, and in connection with the closing of the Business Combination, AMCI changed its name to Advent Technologies Holding, Inc. (the "Company" or "Advent"). Legacy Advent was deemed the accounting acquirer in the Business Combination based on an analysis of the criteria outlined in Accounting Standards Codification ("ASC") 805. This determination was primarily based on Legacy Advent's stockholders prior to the Business Combination having a majority of the voting interests in the combined company, Legacy Advent's operations comprising the ongoing operations of the combined company, Legacy Advent's board of directors comprising a majority of the board of directors of the combined company, and Legacy Advent's senior management comprising the senior management of the combined company. Accordingly, for accounting purposes, the Business Combination was treated as the equivalent of Legacy Advent issuing stock for the net assets of AMCI, accompanied by a recapitalization. The net assets of AMCI are stated at historical cost, with no goodwill or other intangible assets recorded. While AMCI was the legal acquirer in the Business Combination, because Legacy Advent was deemed the accounting acquirer, the historical financial statements of Legacy Advent became the historical financial statements of the combined company, upon the consummation of the Business Combination. As a result, the unaudited condensed consolidated financial statements included in this report reflect (i) the historical operating results of Legacy Advent prior to the Business Combination; (ii) the results of the Company (combined results of AMCI and Legacy Advent) following the closing of the Business Combination; (iii) the assets and liabilities of Legacy Advent at their historical cost; and (iv) Company’s equity structure for all periods presented. In accordance with guidance applicable to these circumstances, the equity structure has been restated in all comparative periods up to the Closing Date, to reflect the number of shares of the Company's common stock, $0.0001 par value per share ("Common Stock") issued to Legacy Advent's stockholders in connection with the recapitalization transaction. As such, the shares and corresponding capital amounts and earnings per share related to Legacy Advent Preferred Stock (“Preferred Series A” and “Preferred Series Seed”) and Legacy Advent common stock prior to the Business Combination have been retroactively restated as shares reflecting the exchange ratio established in the Business Combination Agreement. Activity within the statement of changes in stockholders' equity / (deficit) for the issuances of Legacy Advent's Preferred Stock, were also retroactively converted to Legacy Advent common stock. (Note 3) On February 18, 2021, the Company, entered into a Membership Interest Purchase Agreement with Bren-Tronics, Inc. (“Seller”) and UltraCell, LLC, a Delaware limited liability company and a direct wholly-owned subsidiary of Seller (“UltraCell”) (the “Purchase Agreement”). See Note 3 “Business Combination”
Unaudited Condensed Consolidated Financial Statements	(b) Unaudited Condensed Consolidated Financial Statements The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) and pursuant to the regulations of the U.S. Securities and Exchange Commission (“SEC”). The unaudited financial information reflects, in the opinion of management, all adjustments, consisting of normal recurring adjustments, considered necessary for a fair statement of the Company's financial position, results of operations and cash flows for the periods indicated. The results reported for the interim period presented are not necessarily indicative of results that may be expected for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's audited consolidated financial statements as of and for the year ended December 31, 2020 included in the Current Report on Form 8-K filed with the SEC on February 9, 2021 (the “Original Form 8-K”), as amended by Amendment No. 1 to Form 8-K, filed with the SEC on February 9, 2021 (“Amendment No. 1”), as further amended by Amendment No. 2 to Form 8-K, filed with the SEC on March 26, 2021 (“Amendment No. 2”) and as further amended by Amendment No 3 to Form 8-K, filed with the SEC on May 20, 2021 (“Amendment No. 3,” and, the Original Form 8-K, as so amended by Amendment No. 1, Amendment No. 2 and Amendment No. 3, the “Super Form 8-K”). The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. Intercompany accounts and transactions have been eliminated. Certain prior period balances have been reclassified to conform to the current period presentation in the unaudited condensed consolidated financial statements and the accompanying notes. Share and per share amounts are presented on a post-conversion basis for all periods presented, unless otherwise specified.
Going Concern	(c) Going Concern The unaudited condensed consolidated financial statements have been prepared by management in accordance with GAAP, assuming that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. Accordingly, these financial statements do not include any adjustments that may result in the event the Company is unable to continue as a going concern. Beginning in March 2020, the COVID-19 pandemic and the measures imposed to contain this pandemic have disrupted and are expected to continue to impact the Company’s business. The magnitude of the impact of the COVID-19 pandemic on the Company’s productivity, results of operations and financial position, and its disruption to the Company’s business (fuel cells sales timeline, realization of income from grants received) will depend in part, on the length and severity of these restrictions and on the Company’s ability to conduct business in the ordinary course. As of the date of this Quarterly Report on Form 10-Q, the Company’s existing cash resources are sufficient to support planned operations for the next 12 months. As a result, management believes that the Company's existing financial resources are sufficient to continue operating activities for at least one year past the issuance date of the unaudited condensed consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Business acquisitions, Goodwill and Intangible Assets	(a) Business acquisitions, Goodwill and Intangible Assets The Company allocates the fair value of purchase consideration transferred in a business acquisition to the tangible assets acquired, liabilities assumed, and intangible assets acquired based on their estimated fair values. The excess of the fair value of purchase consideration transferred over the fair values of these identifiable assets and liabilities is recorded as goodwill. In case the fair value of purchase consideration transferred is below fair values of these identifiable assets and liabilities, the Company recognizes a gain from a bargain purchase. Such valuations require management to make significant estimates and assumptions, especially with respect to intangible assets. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired licenses, trade names, in process research and development ("R&D"), useful lives and discount rates, patents, customer clientele, customer contracts and know-how. Management's estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, the Company may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period, any subsequent adjustments are recorded in the consolidated statement of operations. For significant acquisitions, the Company obtains independent appraisals and valuations of the intangible (and certain tangible) assets acquired and certain assumed obligations. The Company analyzes each acquisition individually and all acquisitions within each reporting period in aggregate to determine if those are material acquisitions in the context of ASC 805-10-50. The estimated fair values and useful lives of identified intangible assets are based on many factors, including estimates and assumptions of future operating performance and cash flows of the acquired business, estimates of cost avoidance, the nature of the business acquired, the specific characteristics of the identified intangible assets and our historical experience and that of the acquired business. The estimates and assumptions used to determine the fair values and useful lives of identified intangible assets could change due to numerous factors, including product demand, market conditions, regulations affecting the business model of our operations, technological developments, economic conditions and competition. We conduct a goodwill impairment analysis annually in the fourth fiscal quarter, as of October 1, and as necessary if changes in facts and circumstances indicate that the fair value of our reporting units may be less than their carrying amounts. When indicators of impairment do not exist and certain accounting criteria are met, we are able to evaluate goodwill impairment using a qualitative approach. When necessary, our quantitative goodwill impairment test consists of two steps. The first step requires that we compare the estimated fair value of our reporting units to the carrying value of the reporting unit’s net assets, including goodwill. If the fair value of the reporting unit is greater than the carrying value of its net assets, goodwill is not considered to be impaired and no further testing is required. If the fair value of the reporting unit is less than the carrying value of its net assets, we would be required to complete the second step of the test by analyzing the fair value of its goodwill. If the carrying value of the goodwill exceeds its fair value, an impairment charge is recorded. Currently, we identify one reporting unit.
Warrants	(b) Warrants The Company may issue or assume common stock warrants with debt, equity or as a standalone financing instruments that are recorded as either liabilities or equity in accordance with the respective accounting guidance. Warrants recorded as equity are recorded at their relative fair value or fair value determined at the issuance date and remeasurement is not required. Warrants recorded as liabilities are recorded at their fair value, within warrant liability on the consolidated balance sheets, and remeasured on each reporting date with changes recorded in revaluation of warrant liability on the Company's consolidated statements of operations.
Fair Value of Financial Instruments	(c) Fair Value of Financial Instruments As a result of the Business Combination, the Company assumed a warrant liability (the "Warrant Liability") related to previously issued 3,940,278 warrants, each exercisable to purchase one share of common stock at an exercise price of $11.50 per share, originally sold to AMCI Sponsor LLC (the “Sponsor”) in a private placement consummated in connection with AMCI’s Initial Public Offering (the “Private Placement Warrants”) and the 400,000 warrants, each exercisable to purchase one share of common stock at an exercise price of $11.50 per share, converted from the Sponsor’s non-interest bearing loan to the Company of $400,000 in connection with the closing of the Business Combination (the “Working Capital Warrants”) (Note 10). The Private Placement Warrants and the Working Capital Warrants have substantially the same terms as the 22,052,077 warrants, each exercisable to purchase one share of common stock at an exercise price of $11.50 per share, issued by AMCI in its Initial Public Offering (the “Public Warrants”). The Warrant Liability was remeasured to its fair value at each reporting period and upon settlement. The change in fair value was recognized in revaluation of warrant liability on the consolidated statements of operations. The change in fair value of the Warrant Liability was as follows: Warrant Liability Estimated fair value at February 4, 2021 33,116,321 Change in estimated fair value (9,765,625 ) Estimated fair value at March 31, 2021 23,350,695 The estimated fair value of the Private Placement Warrants and the Working Capital Warrants (each as defined below) is determined using Level 3 inputs by using the Black-Scholes model. The application of the Black-Scholes model requires the use of a number of inputs and significant assumptions including volatility. Significant judgment is required in determining the expected volatility of our common stock. Due to the limited history of trading of our common stock, we determined expected volatility based on a peer group of publicly traded companies. The following table provides quantitative information regarding Level 3 fair value measurements inputs as their measurement dates: Stock price 13.39 Exercise price (strike price) 11.50 Remaining term (in years) 4.84 Volatility 40 % Risk-free interest rate 0.63 % The Company performs routine procedures such as comparing prices obtained from independent source to ensure that appropriate fair values are recorded.
Earnings / (Loss) Per Share	(d) Earnings / (Loss) Per Share Earnings / (Loss) Per Share is computed by dividing earnings / (loss) by the weighted average number of common shares outstanding during the period. Diluted earnings / (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted at the beginning of the periods presented, or issuance date, if later. The treasury stock method is used to compute the dilutive effect of warrants.
Recent Accounting Pronouncements	(e) Recent Accounting pronouncements Recently issued accounting pronouncements not yet adopted In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. In July 2018, ASU 2018-10, Codification Improvements to Topic 842, Leases, was issued to provide more detailed guidance and additional clarification for implementing ASU 2016-02. Furthermore, in July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements, which provides an optional transition method in addition to the existing modified retrospective transition method by allowing a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Additionally, ASU 2019-01, Codification Improvements to Topic 842, Leases and ASU 2020-02, Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842), provided additional clarifications for implementing ASU 2016.02. The new lease standard was originally effective for the private entities on January 1, 2021, with early adoption permitted. Following the issuance of ASU 2020-05, Effective Dates for Certain Entities (Topic 842), the effective date of Leases was deferred for private entities (the “all other” category) to fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early application continues to be permitted which means that an entity may choose to implement Leases before those deferred effective dates. The Company is currently evaluating the effect of the adoption of this guidance on the consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses of Financial Instruments, which, amends the requirement on the measurement and recognition of expected credit losses for financial assets held. Furthermore, amendments, ASU 2019-10 and ASU 2019-11 provided additional clarification for implementing ASU 2016-13. ASU 2016-13 is effective for the Company beginning January 1, 2023, with early adoption permitted. The Company is currently in the process of evaluating the effect of this guidance on the consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is intended to simplify various aspects related to accounting for income taxes. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. ASU 2019-12 is effective for the Company beginning January 1, 2022, with early adoption permitted. The Company is currently evaluating the effects of this guidance on the Company's financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Change in Fair Value of Warrant Liability	The change in fair value of the Warrant Liability was as follows: Warrant Liability Estimated fair value at February 4, 2021 33,116,321 Change in estimated fair value (9,765,625 ) Estimated fair value at March 31, 2021 23,350,695
Fair Value Measurements Input	The following table provides quantitative information regarding Level 3 fair value measurements inputs as their measurement dates: Stock price 13.39 Exercise price (strike price) 11.50 Remaining term (in years) 4.84 Volatility 40 % Risk-free interest rate 0.63 %

Business Combination (Tables)

Business Combination (Tables)	3 Months Ended
	Mar. 31, 2021
Business Combination [Abstract]
Reconciles the Elements of Business Combination to Consolidated Statements	The following table reconciles the elements of the Business Combination to the consolidated statement of cash flows and the consolidated statement of changes in equity for the three month ended March 31, 2021: Recapitalization Cash- AMCI’s trust and cash (net of redemptions) $ 93,310,599 Cash – PIPE plus interest 65,000,118 Less transaction costs and advisory fees paid (17,617,601 ) Less non-cash warrant liability assumed (33,116,321 ) Net Business Combination and PIPE financing $ 107,576,795
Common Stock Issued Following the Consummation of Business Combination	The number of shares of common stock issued immediately following the consummation of the Business Combination: Recapitalization Class A Common A stock of AMCI, outstanding prior to Business Combination 9,061,136 Less Redemption of AMCI shares (1,606 ) Class B Common Stock of AMCI, outstanding prior to Business Combination 5,513,019 Shares issued in PIPE 6,500,000 Business Combination and PIPE financing shares 21,072,549 Legacy Advent Shares 25,033,398 Total shares of Common Stock immediately after Business Combination 46,105,947

Related party disclosures (Tabl

Related party disclosures (Tables)	3 Months Ended
	Mar. 31, 2021
Related party disclosures [Abstract]
Related Party Transactions	The amounts included in the accompanying consolidated balance sheets and consolidated statements of operations are as follows: March 31, 2021 December 31, 2020 Due to related parties Unpaid compensation cost Unpaid compensation cost Vassilios Gregoriou $ - $ 613,971 Christos Kaskavelis - 75,160 Emory Sayre De Castro - 425,528 Total $ - $ 1,114,659 March 31, 2021 December 31, 2020 Due from related parties Prepayment Prepayment Charalampos Antoniou $ - $ 67,781 Total $ - $ 67,781

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2021
Inventories [Abstract]
Inventories	Inventories consist of the following: March 31, 2021 December 31, 2020 Raw materials and supplies $ 812,744 $ 107,939 Total $ 812,744 $ 107,939

Prepaid expenses and Other cu_2

Prepaid expenses and Other current assets (Tables)	3 Months Ended
	Mar. 31, 2021
Prepaid expenses and Other current assets [Abstract]
Prepaid expenses and Other current assets	Prepaid expenses and Other current assets are analyzed as follows: March 31, 2021 December 31, 2020 VAT receivable $ 287,523 $ 259,831 Grants receivable 91,182 95,064 Other current assets 891,168 140,126 Prepaid Expenses 2,851,681 1,724 Total $ 4,121,554 $ 496,745

Trade and other payables (Table

Trade and other payables (Tables)	3 Months Ended
	Mar. 31, 2021
Trade and other payables [Abstract]
Trade and Other Payables	December 31, March 31, 2021 December 31, 2020 Trade payables and other payables $ 1,462,789 $ 881,394 Total $ 1,462,789 $ 881,394

Other current liabilities (Tabl

Other current liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Other current liabilities [Abstract]
Other Current Liabilities	Other current liabilities of the Company are analyzed as follows: March 31,2021 December 31, 2020 Accrued expenses for legal and consulting fees $ 837,606 $ 814,965 Other accruals and short-term payables 118,510 89,414 Contingent Consideration 2,000,000 - Total $ 2,956,116 $ 904,379

Revenue, net (Tables)

Revenue, net (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue, net [Abstract]
Revenue, Net	Revenue, net is analyzed as follows: Three months period ended March, 31 2021 March, 31,2020 Sales of goods $ 1,489,292 $ 100,266 Total revenue from contracts with customers $ 1,489,292 $ 100,266

Net income _ (loss) per share (

Net income / (loss) per share (Tables)	3 Months Ended
	Mar. 31, 2021
Net income / (loss) per share [Abstract]
Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the basic and diluted net loss per share for the three months ended March 31, 2021 and 2020. Three-months ended March 31, Numerator: 2021 2020 Net income / (loss) $ 2,905,674 $ (216,616 ) Denominator: Weighted average shares outstanding, basic 37,769,554 14,979,803 Dilutive effect of common stock issuable from assumed exercise of warrants 3,217,792 - Weighted average shares outstanding, diluted 40,987,346 14,979,803 Net income / (loss) per share: Basic $ 0.08 $ (0.01 ) Diluted $ 0.07 $ (0.01 )

Basis of presentation (Details)

Basis of presentation (Details) - $ / shares	Mar. 31, 2021	Feb. 04, 2021	Dec. 31, 2020
Basis of Presentation [Abstract]
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
AMCI Acquisition Corp. [Member]
Basis of Presentation [Abstract]
Acquired percentage		100.00%
Common stock, par value (in dollars per share)		$ 0.0001

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details)	2 Months Ended	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares	Mar. 31, 2021USD ($)Reportingunit$ / sharesshares	Mar. 31, 2020USD ($)
Summary of Significant Accounting Policies [Abstract]
Number of reporting units | Reportingunit		1
Changes in Fair Value of Warrant Liabilities [Roll Forward]
Change in estimated fair value		$ 9,765,625	$ 0
Warrant [Member]
Fair Value Measurements [Abstract]
Remaining term	4 years 10 months 2 days	4 years 10 months 2 days
Stock Price [Member] | Warrant [Member]
Fair Value Measurements [Abstract]
Measurement input	13.39	13.39
Exercise Price [Member] | Warrant [Member]
Fair Value Measurements [Abstract]
Measurement input	11.50	11.50
Volatility [Member] | Warrant [Member]
Fair Value Measurements [Abstract]
Measurement input	0.4	0.4
Risk-free interest rate [Member] | Warrant [Member]
Fair Value Measurements [Abstract]
Measurement input	0.0063	0.0063
Warrant Liabilities [Member]
Warrants [Abstract]
Warrants issued (in shares) | shares		3,940,278
Changes in Fair Value of Warrant Liabilities [Roll Forward]
Estimated fair value at beginning balance	$ 33,116,321
Change in estimated fair value	(9,765,625)
Estimated fair value at ending balance	$ 23,350,696	$ 23,350,696
Common Stock [Member] | Warrant Liabilities [Member]
Warrants [Abstract]
Number of shares called by each warrant (in shares) | shares	1	1
Exercise price (in dollars per share) | $ / shares	$ 11.50	$ 11.50
Private Placement Warrants [Member]
Warrants [Abstract]
Warrants issued (in shares) | shares		22,052,077
Number of shares called by each warrant (in shares) | shares	1	1
Exercise price (in dollars per share) | $ / shares	$ 11.50	$ 11.50
Fair Value Measurements [Abstract]
Remaining term	5 years	5 years
Private Placement Warrants [Member] | Common Stock [Member]
Warrants [Abstract]
Number of shares called by each warrant (in shares) | shares	1	1
Exercise price (in dollars per share) | $ / shares	$ 11.50	$ 11.50
Working Capital Warrants [Member]
Warrants [Abstract]
Warrants issued (in shares) | shares		400,000
Number of shares called by each warrant (in shares) | shares	1	1
Exercise price (in dollars per share) | $ / shares	$ 11.50	$ 11.50
Fair Value Measurements [Abstract]
Remaining term	5 years	5 years
Working Capital Warrants [Member] | Common Stock [Member]
Warrants [Abstract]
Number of shares called by each warrant (in shares) | shares	1	1
Exercise price (in dollars per share) | $ / shares	$ 11.50	$ 11.50
Sponsor [Member]
Warrants [Abstract]
Non-interest bearing loan		$ 400,000

Business Combination, AMCI Acqu

Business Combination, AMCI Acquisition Corp (Details) - USD ($)	Feb. 04, 2021	Mar. 31, 2021	Dec. 31, 2020
Business Combination, Description [Abstract]
Common stock, shares authorized (in shares)		110,000,000	110,000,000
Common stock, par value (in dollars per share)		$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)		1,000,000	1,000,000
Preferred stock, par value (in dollars per share)		$ 0.0001	$ 0.0001
Consummation of Business Combination [Abstract]
Common stock, shares outstanding (in shares)		46,105,947	25,033,398
AMCI Acquisition Corp. [Member]
Business Combination, Description [Abstract]
Merger consideration	$ 250,000,000
Purchase price (in dollars per share)	$ 10
Authorized issuance of shares (in shares)	111,000,000
Common stock, shares authorized (in shares)	110,000,000
Common stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares authorized (in shares)	1,000,000
Preferred stock, par value (in dollars per share)	$ 0.0001
Goodwill	$ 0
Intangible assets	$ 0
Business Combination to consolidated statements [Abstract]
Proceeds from issuance of common stock		$ 93,310,599
Less transaction costs and advisory fees paid		(17,617,601)
Less non-cash warrant liability assumed		$ (33,116,321)
Consummation of Business Combination [Abstract]
Common stock, shares outstanding (in shares)		46,105,947
Less Redemption of AMCI shares (in shares)		(1,606)
AMCI Acquisition Corp. [Member] | Legacy [Member]
Consummation of Business Combination [Abstract]
Common stock, shares outstanding (in shares)		25,033,398
AMCI Acquisition Corp. [Member] | PIPE [Member]
Business Combination, Description [Abstract]
Purchase price (in dollars per share)	$ 10
Business Combination to consolidated statements [Abstract]
Proceeds from issuance of common stock		$ 65,000,118
Net Business Combination and PIPE financing		$ 107,576,795
Consummation of Business Combination [Abstract]
Common stock, shares outstanding (in shares)		21,072,549
Common stock, shares issued (in shares)		6,500,000
AMCI Acquisition Corp. [Member] | Class A Common Stock [Member]
Consummation of Business Combination [Abstract]
Common stock, shares outstanding (in shares)		9,061,136
AMCI Acquisition Corp. [Member] | Class B Common Stock [Member]
Consummation of Business Combination [Abstract]
Common stock, shares outstanding (in shares)		5,513,019

Business Combination, UltraCell

Business Combination, UltraCell LLC (Details) - USD ($)	Feb. 18, 2021	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Business Combination, Description [Abstract]
Amortization of intangibles			$ 186,760	$ 0
UltraCell LLC [Member]
Business Combination, Description [Abstract]
Acquired percentage	100.00%
Merger consideration	$ 6,000,000
Payments to acquire businesses, gross	4,000,000
Fair value of contingent consideration	2,000,000
Additional cash required to pay contingent consideration	2,000,000
Assets acquired and liabilities assumed	5,500,000
Goodwill	500,000
Provisional value of intangibles	$ 5,000,000
Amortization of intangibles		$ 200,000
UltraCell LLC [Member] | Minimum [Member]
Business Combination, Description [Abstract]
Useful lives of assets	3 years
UltraCell LLC [Member] | Maximum [Member]
Business Combination, Description [Abstract]
Useful lives of assets	10 years

Related party disclosures (Deta

Related party disclosures (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Due to Related Parties [Abstract]
Unpaid compensation cost	$ 0	$ 1,114,659
Due from Related Parties [Abstract]
Prepayment	0	67,781
Related Party Transaction [Abstract]
Related party transaction amount	5,600,000
Vassilios Gregoriou [Member]
Due to Related Parties [Abstract]
Unpaid compensation cost	0	613,971
Christos Kaskavelis [Member]
Due to Related Parties [Abstract]
Unpaid compensation cost	0	75,160
Emory Sayre De Castro [Member]
Due to Related Parties [Abstract]
Unpaid compensation cost	0	425,528
Charalampos Antoniou [Member]
Due from Related Parties [Abstract]
Prepayment	$ 0	$ 67,781

Inventories (Details)

Inventories (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Inventories [Abstract]
Raw materials and supplies	$ 812,744	$ 107,939
Total	$ 812,744	$ 107,939

Prepaid expenses and Other cu_3

Prepaid expenses and Other current assets (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Prepaid expenses and Other current assets [Abstract]
VAT receivable	$ 287,523	$ 259,831
Grants receivable	91,182	95,064
Other current receivables	891,168	140,126
Prepaid Expenses	2,851,681	1,724
Total	$ 4,121,554	$ 496,745

Property and equipment, net (De

Property and equipment, net (Details)	3 Months Ended
	Mar. 31, 2021USD ($)
Property and equipment, net [Abstract]
Addition to property and equipment	$ 77,112

Trade and other payables (Detai

Trade and other payables (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Trade and other payables [Abstract]
Trade payables and other payables	$ 1,462,789	$ 881,394
Total	$ 1,462,789	$ 881,394

Other current liabilities (Deta

Other current liabilities (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Other current liabilities [Abstract]
Accrued expenses for legal and consulting fees	$ 837,606	$ 814,965
Other accruals and short-term payables	118,510	89,414
Contingent Consideration	2,000,000	0
Total	$ 2,956,116	$ 904,379

Private Placement Warrants an_2

Private Placement Warrants and Working Capital Warrants (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Private Placement Warrant [Member]
Private Placement Warrants [Abstract]
Warrants issued (in shares)	22,052,077
Warrants outstanding (in shares)	4,340,278
Number of shares called by each warrant (in shares)	1
Exercise price (in dollars per share) | $ / shares	$ 11.50
Period to exercise warrants after business combination	30 days
Warrants expiration period	5 years
Period not to transfer, assign or sell warrants	30 days
Working Capital Warrants [Member]
Private Placement Warrants [Abstract]
Warrants issued (in shares)	400,000
Warrants outstanding (in shares)	4,340,278
Number of shares called by each warrant (in shares)	1
Exercise price (in dollars per share) | $ / shares	$ 11.50
Period to exercise warrants after business combination	30 days
Warrants expiration period	5 years
Period not to transfer, assign or sell warrants	30 days
Initial Public Offering [Member] | Private Placement Warrant [Member]
Private Placement Warrants [Abstract]
Warrants issued (in shares)	3,940,278

Stockholders' Equity _ (Defic_2

Stockholders' Equity / (Deficit) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Stockholders' Equity (Deficit) [Abstract]
Shares authorized (in shares)	111,000,000
Common stock, shares authorized (in shares)	110,000,000	110,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Public Warrants [Member]
Warrants [Abstract]
Warrants outstanding (in shares)	22,052,077
Number of shares called by each warrant (in shares)	1
Exercise price of warrant (in dollars per share)	$ 11.50
Period to exercise warrants after business combination	30 days
Expiration period of warrants	5 years
Warrant redemption price (in dollars per share)	$ 0.01
Notice period to redeem warrants	30 days
Share price (in dollars per share)	$ 18
Threshold trading days	20 days
Threshold consecutive trading days	30 days
Public Warrants [Member] | Minimum [Member]
Warrants [Abstract]
Percentage of company's stockholders	50.00%

Revenue, net (Details)

Revenue, net (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Disaggregation of Revenue [Abstract]
Revenue from contracts with customers	$ 1,489,292	$ 100,266
Contract assets	745,513		$ 85,930
Contract liabilities	44,185		$ 167,761
Sales of Goods [Member]
Disaggregation of Revenue [Abstract]
Revenue from contracts with customers	$ 1,489,292	$ 100,266

Commitments and contingencies (

Commitments and contingencies (Details)	Mar. 08, 2021USD ($)ft²	Feb. 04, 2021USD ($)ft²
Operating Leases [Abstract]
Area of leased space | ft²	21,401	6,041
Annual rent	$ 1,498,070	$ 456,095.50
Lease contract term	8 years 5 months	5 years
Term of option to extend lease	5 years
Security deposit	$ 750,000
Other Current Assets [Member]
Operating Leases [Abstract]
Security deposit		$ 114,023.88

Net income _ (loss) per share_2

Net income / (loss) per share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net income / (loss) per share [Abstract]
Net income (loss) per share weighted-average number of common stock outstanding (in shares)	46,105,947
Numerator [Abstract]
Net Income / (loss)	$ 2,905,674	$ (216,616)
Denominator [Abstract]
Weighted average shares outstanding, basic (in shares)	37,769,554	14,979,803
Dilutive effect of common stock issuable from assumed exercise of warrants (in shares)	3,217,792	0
Weighted average shares outstanding, diluted (in shares)	40,987,346	14,979,803
Net income / (loss) per share [Abstract]
Basic (in dollars per share)	$ 0.08	$ (0.01)
Diluted (in dollars per share)	$ 0.07	$ (0.01)

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member]	2 Months Ended
	May 20, 2021USD ($)$ / sharesshares
Subsequent Event [Abstract]
Warrantholders exercised options to purchase additional shares (in shares)	22,798
Exercise price (in dollars per share) | $ / shares	$ 11.50
Proceeds from exercise of warrants | $	$ 262,177
Increase in shares outstanding (in shares)	22,798