Ambri’s liquid metal battery digs up $144 million in storage investment gold rush

Upholding the new tradition of raising massive amounts of capital for unproven and uncommercialized energy storage technologies, Ambri just landed a $144 million financing round led by Reliance New Energy Solar (part of Reliance, India’s largest private-sector firm), along with Paulson & Co.

Ambri’s liquid-metal long-duration energy storage technology is based on the research of Donald Sadoway, MIT professor of materials chemistry, and inspired by the economies of scale facilitated by breakthroughs in electrometallurgy and the aluminum smelter.

Bill Gates, Ambri’s largest shareholder and a profligate energy storage investor, also invested in this round, bringing the long-in-the-tooth startup to a total of more than $200 million in funding since 2010.

Ambri claims its liquid-metal battery can break through the asserted ​“cost, longevity and safety barriers” its press release attributes to lithium-ion batteries, the industry’s dominant technology.

When Ambri was founded, the lithium-ion price point to beat was around $1,000 per kilowatt-hour. But today’s lithium-ion batteries have plunged to the $100-per-kilowatt-hour range while being deployed at gigawatt-hour scale, and with a decade of field data now under their belt.

Brave long-duration storage entrepreneurs now face a lithium-ion juggernaut while sailing in uncharted regulatory waters.

Promises, promises

Ambri pledged in a 2016 interview to deploy at least one 500-kilowatt-hour commercial storage system in 2018. It did not deliver on that promise.

After ​“pausing” commercialization in 2016 to address a technical problem with the seals on its high-temperature battery cells, the company returned with a new chemistry. The original design used magnesium and antimony separated by a salt. The company’s most recent press release cites a design based on ​“calcium and antimony electrode-based cells.”

In 2018, the company announced plans to ship its 10-foot-cube commercial units in 2020 for proof-of-concept field deployments. It failed to deliver on those plans.

Ambri now aspires to scale up its manufacturing capabilities to develop batteries for projects ​“from 10 megawatt-hours to over 2 gigawatt-hours.”

Ambri claims its high-temperature batteries ​“are more economical than lithium-ion batteries, capable of operating safely in any climatic condition without requiring supplemental air conditioning and meant to last for over 20 years with minimal degradation.”

The company now alleges that it is ​“securing customers for large-scale projects with commercial operation dates in 2023 and beyond.”

Battery unicorns

Ambri joins a growing crop of revenue-free battery unicorns.

ESS makes what it terms a ​“flow battery” that moves electrons with a liquid mixture of iron and salt. ESS announced in May that it would go public by merging with a special-purpose acquisition company (SPAC).

Form Energy is building iron-air batteries and just announced a $200 million Series D raise led by global steel and mining giant ArcelorMittal.

Zinc battery company Eos just raised $100 million in convertible notes from Koch Strategic Platforms; it also raised money from a SPAC merger in November.

The heady combination of solid-state batteries, celebrity VC investors and SPAC financing has allowed QuantumScape to land $1 billion in the bank and a valuation of $10 billion even though it has not reached the preproduction phase of manufacturing and won’t garner significant revenue until late in this decade.

SES builds a ​“hybrid lithium metal” battery; it expects to list as a $3.6 billion company and raise more than $400 million in a SPAC.

Julian Spector covered Form Energy’s technology, David Roberts covered the economics of long-duration energy storage, and your humble narrator enumerated the technologies and players in the zero-billion-dollar LDES market.

Over the years, bankruptcies have thinned out the LDES ecosystem. As Canary’s Spector reported: Aquion’s saltwater battery play went underwater; Alevo closed down its mysterious operation; LightSail ran out of cash for its compressed air storage concept.

Many decarbonization models posit that long-duration energy storage is a critical component of a carbon-free future; it can help integrate renewables and balance the grid. Lee Kasten, a power system operator in the Western Electricity Coordinating Council, suggests that we should rely on software and markets, not hardware:

Don’t build a battery that costs a billion dollars, only works 2 percent of the time and only moves around 100 [gigawatt-hours] of electricity. Build an energy-imbalance market or an extended day-ahead market for $50 million or $100 million that moves around hundreds of gigawatts of electricity. Give all consumers price signals, and then watch the flexible consumers adapt to those price signals using software to manage existing loads.

(Lead photo: Dan-Cristian Pădureț/Unsplash)