Ambri

The company emerged from bankruptcy in July 2024 after its assets were sold to a consortium of existing lenders.¹ In October 2025, Ambri shut down permanently due to insufficient capital for factory operations.²

Timeline

Money raised

Ambri raised $35 million in Series C funding in April 2014.⁹¹⁰¹³ The Series C round was led by Elemental Impact and Khosla Ventures, with participation from KLP Enterprises, Building Insurance Bern, Bill Gates, and Total.⁹¹³ Ambri raised $17 million in an undisclosed stage funding round in December 2018.⁹ In August 2021, Ambri secured $144 million in financing led by Reliance New Energy Solar and Paulson & Co., with participation from Bill Gates, Fortistar, Goehring & Rozencwajg Associates, and Japan Energy Fund.⁹¹¹¹⁴ Reliance New Energy Solar invested $50 million for 42.3 million shares of preferred stock in the 2021 round.⁹ In 2023, Ambri attempted to raise a $300 million Series F round, but the lead investor backed out.⁴ Ambri then sought a $50 million bridge loan from existing investors, but Reliance declined to participate, leaving an $8 million gap.⁴ In August 2024, Ambri raised $11 million in a Series A round at a $400 million valuation.⁹

Investors named in the sources: Bill Gates^15910111314, Khosla Ventures⁵⁹¹⁰¹³, Elemental Impact⁹, Reliance Industries¹⁹¹¹¹⁴, Japan Energy Fund⁹¹¹¹⁴, Fortistar⁹¹¹¹⁴, Paulson & Co.⁹¹¹¹⁴, Goehring & Rozencwajg Associates⁹¹¹¹⁴, KLP Enterprises⁵⁹¹⁰¹³, Building Insurance Bern⁵⁹¹³, Total⁵¹³.

What happened

Ambri was founded in 2010 by MIT professor Donald Sadoway and David Bradwell.¹⁴⁹¹³ The company developed liquid metal batteries based on calcium anodes, molten salt electrolyte, and solid antimony particles in the cathode.¹ Ambri's technology was licensed from MIT.⁹¹³ In 2013, Ambri opened a prototype cell manufacturing facility in Marlborough, Massachusetts.¹³ In April 2014, Ambri raised $35 million in Series C funding to deliver commercial systems and build an initial commercial-scale manufacturing plant.⁹¹³

In September 2015, Ambri cut a quarter of its staff and pushed back commercial sales because a battery seal showed disappointing results in high-temperature tests.⁵ Ambri had originally planned to start shipping commercial batteries in 2015 or early 2016.⁵ In December 2018, Ambri raised $17 million in an undisclosed stage funding round.⁹ In August 2021, Ambri secured $144 million in financing led by Reliance New Energy Solar and Paulson & Co.⁹¹¹¹⁴ The 2021 funding was intended to commercialize the technology, scale operations, and build a domestic manufacturing facility.⁹¹¹¹⁴

As part of the 2021 transaction, Reliance New Energy Solar was selected as Ambri's strategic partner to develop and manufacture batteries in India.⁹¹⁴ Ambri also entered into a long-term antimony supply agreement with Perpetua Resources.⁹¹⁴ In June 2022, Ambri announced expansion of manufacturing capacity with a new facility in Massachusetts.³ In September 2022, Ambri deployed a Liquid Metal battery system for Microsoft at a data center.¹³ In 2022, Ambri signed an agreement with Reliance to deploy a pilot battery system in India, but the pilot system never shipped due to Ambri's fundraising struggles.⁴

In 2023, Ambri attempted to raise a $300 million Series F round, but the lead investor backed out at the last minute.⁴ Ambri then sought a $50 million bridge loan from existing investors, but Reliance New Energy Solar declined to participate, leaving an $8 million gap.⁴ Without the additional capital, Ambri could not cover the initial phases of its manufacturing expansion.⁴ In November 2023, Ambri laid off about two-thirds of its workforce.⁴ Ambri filed for Chapter 11 bankruptcy in May 2024.¹⁴⁷

The bankruptcy filing was in part to get out from under a ten-year lease on its Massachusetts facility.⁴ At the time of bankruptcy, Ambri had a pipeline of MOUs totaling around $1.7 billion.⁴ In July 2024, Ambri completed the sale of its assets to a consortium of existing lenders and emerged from Chapter 11.¹³ The sale was conducted under Section 363 of the Bankruptcy Code.¹ After emerging from bankruptcy, David Bradwell became CEO, and Donald Sadoway remained Chief Scientific Advisor.¹

In August 2024, Ambri raised $11 million in a Series A round at a $400 million valuation.⁹ In October 2025, Ambri announced it was shutting down after 15 years due to insufficient capital for factory operations.² The auction included battery testing equipment, furnaces, electron microscopes, welding systems, and other manufacturing assets.¹⁶

Legal outcomes

• filedAmbri filed for Chapter 11 bankruptcy protection in the US Bankruptcy Court for the District of Delaware in May 2024.¹⁴
• settledThe bankruptcy case was resolved through a sale of assets under Section 363 of the Bankruptcy Code, completed in July 2024.¹

Where the founders are now

After emerging from bankruptcy in July 2024, David Bradwell assumed the position of CEO, having been CTO since Ambri was launched.¹ Donald Sadoway remained Chief Scientific Advisor.¹

Lessons, as others put them

"We almost got there, but we didn’t."Adam Briggs, chief commercial officer at Ambri⁴

"As we embark on this fresh start with a stronger balance sheet and new capital, we are focused on positioning Ambri to play a leading role in the long duration energy storage market for the benefit of our stakeholders."David Bradwell, CEO of Ambri¹

Sources

1. Liquid metal startup Ambri back in business after Chapter 11 bankruptcy, Energy-Storage.News, 2024-08-02
2. Ambri, Bill Gates-backed battery startup, to shut down, bizjournals.com, Oct 3, 202
3. Home - Ambri, Ambri
4. How liquid-metal battery maker Ambri ended up on the auction block, Latitude Media, 2024-05-10
5. Battery startup Ambri lays off staff, pushes back commercial sales | Fortune, Fortune, Sep 11, 20
7. The cleantech companies that didn’t make it through 2024, Canary Media, Dec 12, 20
9. Ambri Valuation, Funding & Investors | Multiples, multiples.vc, Sep 18, 20
10. Khosla Ventures, Bill Gates and KLP Enterprises back Ambri, Venture Capital Journal, 2014-05-01
11. Bill Gates-Backed Battery Storage Tech Company Ambri Raises $144 Million, ESG Today, 2021-08-10
13. Ambri Raises $35 Million in Series C Round, prnewswire.com, 2014-04-30
14. Ambri LLC Secures $144M Financing for Battery Technology for Daily Cycling Long Duration Energy Storage Applications - Ambri, Ambri, 2021-08-09
16. Ambri Auction | Heritage Global Partners, Heritage Global Partners

How this case file was put together

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