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.
The players
“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.
“It took us about five years to find the material and then another five years to figure out to make it high volume with high quality,” he told TechCrunch at the time. QuantumScape’s initial claims, which were backed by performance data, were made on the basis of a single-layer cell hundreds of times smaller and much less complex than a full automotive battery pack. Since then, QuantumScape has announced the first successful tests of 4-layer cells.
“If what they are showing is real, it is a major breakthrough in fundamental science,” Prieto said. “They don’t need to care if people are arguing about whether they can scale up because they have so much in the bank they’ll probably be able to solve most problems.”
Other promising startups working on SSBs include Ilika in the U.K., Ion Storage Solutions in Maryland and BrightVolt in Indiana.
Who’s investing
Many traditional VCs are funding SSBs. QuantumScape alone attracted Breakthrough Energy Ventures, Khosla Ventures, Kleiner Perkins, Fidelity Management & Research, Prelude Ventures, Lightspeed Venture Partners and Capricorn Investment Group.
Other companies listed here have been funded by Samsung Venture Investment, Sanoh Industrial, Solvay Stand Up for Start-Ups, Emerald Technology Ventures, Donnelley, Rho Capital Partners, Helmet Capital, Texas Instruments, Ignite Group, Boeing, Total Carbon Neutrality Ventures and Franklin Templeton Investments.
Alongside VCs and the new SPAC vehicles, the U.S. government has also been an active investor into SSB research.
The IONICS program at the Department of Energy’s research agency ARPA has pumped $6.7 million into Massachusetts-based Ionic Materials’ effort to build a highly conductive solid polymer electrolyte. Its $65 million Series C in 2018 included Renault-Nissan-Mitsubishi and Sun co-founder Bill Joy.
24M, another IONICS ARPA recipient, hopes to bridge the gap between lithium-ion and SSBs, using a semi-solid electrolyte that promises to be cheaper and safer than today’s batteries. Boston-based 24M, funded by Northbridge Venture Partners, CRV and Itochu Corp., is licensing its technology to European battery maker FREYR, which is about to go public through a SPAC.
PolyPlus Battery got $8.6 million from IONICS to bond a super-smooth glass surface to lithium electrodes to avoid the formation of dendrites, tiny metal fibers that can short-circuit SSBs. PolyPlus was spun out of the Lawrence Berkeley National Laboratory in 1991, and in 2019 entered a strategic partnership with SK Innovation. This South Korean company is one of the five largest manufacturers of lithium-ion EV batteries today, supplying Hyundai and Kia.
Where the action is
Any future SSB production will likely happen very close to automakers. Despite all the development work happening in the U.S., only around 8% of current EV batteries — all of which are the traditional lithium-ion batteries — are produced in the country, and Bloomberg NEF expects that to drop further to just 6% by 2025.
Perhaps the best-known lithium-ion battery hotspot in the U.S. is the massive “Gigafactory” located in Sparks, Nevada — the product of a partnership between cell supplier Panasonic and electric automaker Tesla. Panasonic is conducting basic research into SSBs, however it has invested most of its resources into improving its lithium-ion battery cells. Last July the company announced new battery technology for the “2170” lithium-ion cells it produces and supplies to Tesla, a change that improves energy density by 5% and reduces costly cobalt content.
Despite Tesla’s activity and visibility in the U.S., China remains the powerhouse for electric transportation and home to nearly half of the planet’s EVs. The country’s influence, regulatory framework and available supplier base has prompted Tesla to diversify — a shift that occurred after the automaker built and began producing electric vehicles at its factory in Shanghai. Tesla’s Shanghai Gigafactory uses batteries from LG Energy Solution and the world’s largest battery maker, CATL.
While Tesla has never publicly talked about using SSBs in its vehicles, its supplier CATL has been working on the technology for a decade. It’s unclear how close they are to bringing such a battery to market, but the company is reportedly targeting solid-state batteries with energy densities about a third higher than lithium-ion packs today.
China contains at least one other possible SSB adopter. Chinese EV company NIO announced it would offer a 150 kWh SSB in its cars from 2022, possibly to be supplied by the little-known Beijing Welion New Energy Technology Co. In Japan, Nissan is working on its own SSB, and Toyota has promised to be the first major car company to sell an SSB-equipped EV “in the early 2020s,” with a prototype to be unveiled later this year. While GM is pushing its Ultium lithium ion battery technology, it has also said it is exploring SSBs.
Legacy automakers still remain solidly in lithium-ion territory even as they invest in SSB R&D. LG Energy Solution supplies li-ion batteries to Renault and Volkswagen, while Samsung SDI’s batteries power Audi and BMW.
In the near term, a trade dispute, not new technology is likely to make the biggest waves in the automotive industry. South Korea’s SK recently lost a trade secret dispute with LG at the International Trade Commission, effectively banning the company from supplying EV batteries in the U.S. for the next 10 years.
Prieto is hopeful that U.S. innovation will bring some of the manufacturing back onshore. “As we’re building new battery plants to meet growing demand, we need to make improvements in those manufacturing facilities,” she told TechCrunch. “Our hope is that they’re built here in the U.S. with state of the art automation, but also a highly skilled workforce.”
“I’m not seeing any viable American cell producers emerging today,” warns Campbell. “But with the change in presidential administration, we’re seeing a little bit of momentum around the possibility of public-private partnerships to keep elements of manufacturing here in the United States.”
Solid-state niches
SSBs are starting to prove their worth outside traditional consumer vehicles, although they have yet to be produced reliably in large volumes. That means SSBs are, for now, showing up in niche or low-volume applications first.
Bolloré, a French conglomerate originally founded in the 19th century, has demonstrated how to build domestic verticals using SSBs. Starting in 2011, it integrated its solid state batteries, which are made in France and Canada, into thousands of custom-made EVs for its Autolib’ car-sharing scheme in a handful of European cities. Although that service ended in 2018, Bolloré’s Blue Solutions subsidiary is now selling SSB-powered city buses, over 400 of which are already in operation worldwide.
Daimler is also using the Blue Solutions battery in its eCitaro G articulated buses, claiming an energy density 25% higher than lithium-ion packs, although its charging rate is slower.
SSBs are carving out success in other niches, too. Sion Power, a spin-off from Brookhaven National Laboratory in the 1980s, is about to supply SSBs to Thales Alenia Space-France for a high-altitude surveillance airship called Stratobus. The extremely energy dense packs could allow the solar-powered aircraft to remain aloft for up to two years. Sion is also working on SSBs for eVTOL air taxis and drones.
Cuberg, another Stanford spin-out, has built an SSB that enables small drones to fly for 70% longer, while Cymbet, based in Montana and Texas, claims to have made the world’s smallest SSB for chip-scale applications.
Future bets versus near-term progress
However, even as SSBs are maturing, lithium-ion technologies continue to advance. Sila Nanotechnologies has developed a silicon-based anode to replace graphite in lithium-ion batteries. While the energy density boost (20%) is not as impressive as that from SSBs, the new anode should be much easier to integrate into existing processes and factories. A recent $590 million Series F round from Coatue, T. Rowe Price, 8VC and others pushed Sila’s valuation to $3.3 billion.
Amprius Technologies, a spin-out from Stanford University, is also developing silicon anodes in the form of tiny nanowires.
In a white paper last year, Sila CEO Gene Berdichevsky predicted that the most innovative period for lithium-ion technologies is only just beginning. “Solid state batteries are likely to be irrelevant … a niche player at best,” he wrote. “Lithium-ion won’t be everything, but lithium-ion will be everything that matters.”
Corie Cobb, a professor in clean energy at the University of Washington, also doubts SSBs will arrive as quickly as some boosters predict. “We are still far away from full-scale production of solid state batteries,” she told TechCrunch. “Solid-state batteries will require a major, if not complete, redesign of today’s production lines to reach the manufacturing efficiency needed for low-cost, long-range electric vehicles.”
Nevertheless, Prieto believes the future looks bright for solid state. “Up until now, a lot of the discovery of new materials has been trial and error,” she says. “But we are on the cusp of some pretty incredible discoveries, using major improvements in computational science and machine learning algorithms to accelerate that process.”
Your next electric car almost certainly won’t have an SSB inside it. But as the market for EVs shifts to include commercial vehicles, aerospace, off-roaders and microtransit, the commercial future for SSBs is finally looking a little more solid.
Update: The article has been updated to add that QuantumScape has had successful tests of 4-layer cells.