Can solid state batteries power up for the next generation of EVs?

Lithium-ion batteries power almost every new phone, laptop and electric vehicle. But unlike processors or solar panels, which have improved exponentially, lithium-ion batteries have inched along with only incremental gains.

For the last decade, developers of solid state battery systems have promised products that are vastly safer, lighter and more powerful. Those promises largely evaporated into the ether - leaving behind a vapor stream of disappointing products, failed startups and retreating release dates.

For the last decade, developers of solid state battery systems have promised products that are vastly safer, lighter and more powerful.

A new wave of companies and technologies are finally maturing and attracting the funding necessary to feed batteries' biggest market: transportation. Electric vehicles account for about 60% of all lithium-ion batteries made today, and IDTechEx predicts that solid state batteries will represent a $6 billion industry by 2030.

Electric vehicles have never been cooler, faster or cleaner, yet they still account for only around one in 25 cars sold around the world (and fewer still in the United States). A global survey of 10,000 drivers in 2020 by Castrol delivered the same perennial complaints that EVs are too expensive, too slow to charge and have too short a range.

Castrol identified three tipping points that EVs would need to drive a decisive shift away from their internal combustion rivals: a range of at least 300 miles, charging in just half an hour and costing no more than $36,000.

Theoretically, solid state batteries (SSB) could deliver all three.

There are many different kinds of SSB but they all lack a liquid electrolyte for moving electrons (electricity) between the battery's positive (cathode) and negative (anode) electrodes. The liquid electrolytes in lithium-ion batteries limit the materials the electrodes can be made from, and the shape and size of the battery. Because liquid electrolytes are usually flammable, lithium-ion batteries are also prone to runaway heating and even explosion. SSBs are much less flammable and can use metal electrodes or complex internal designs to store more energy and move it faster - giving higher power and faster charging.

If you run the calculations, you can get really amazing numbers and they're very exciting," Amy Prieto, founder and CTO of solid state Colorado-based startup Prieto Battery said in a recent interview. It's just that making it happen in practice is very difficult."

Prieto, who founded her company in 2009 after a career as a chemistry professor, has seen SSB startups come and go. In 2015 alone, Dyson acquired Ann Arbor startup Sakti3 and Bosch bought Berkeley Lab spin-off SEEO in separate automotive development projects. Both efforts failed, and Dyson has since abandoned some of Sakti3's patents.

Prieto Battery, whose strategic investors include Stout Street Capital and Stanley Ventures, venture arm of toolmaker Stanley Black & Decker, pioneered an SSB with a 3D internal architecture that should enable high power and good energy density. Prieto is now seeking funding to scale up production for automotive battery packs. The first customer for these is likely to be electric pickup maker Hercules, whose debut vehicle, called Alpha, is due in 2022. (Fisker also says that it is developing a 3D SSB for its debut Ocean SUV, which is expected to arrive next year.)

Another Colorado SSB company is Solid Power, which has had investments from auto OEMs including BMV, Hyundai, Samsung and Ford, following a $20 million Series A in 2018. Solid Power has no ambitions to make battery packs or even cells, according to CEO Doug Campbell, and is doing its best to use only standard lithium-ion tooling and processes.

Once the company has completed cell development in 2023 or 2024, it would hand over full-scale production to its commercialization partners.

It simply lowers the barrier to entry if existing producers can adopt it with minimal pain," Campbell said.

QuantumScape is perhaps the highest profile SSB maker on the scene today. Spun out from Stanford University a decade ago, the secretive QuantumScape attracted funding from Bill Gates and $300 million from Volkswagen. In November, QuantumScape went public via a special purpose acquisition company at a $3.3 billion valuation. It then soared in value over 10 times after CEO Jagdeep Singh claimed to have solved the short lifetime and slow charging problems that have plagued SSBs.