Solid-state batteries
Batteries that swap liquid electrolytes for solid materials promise to charge faster, last longer, and (crucially) run cooler.
The rise of the lithium-ion battery, which powers everything from the smallest personal electronics to gargantuan energy storage systems, has been nothing short of revolutionary. But as anyone who’s boarded a plane in the last decade could tell you, storing and pumping out energy by moving charged lithium ions through a liquid electrolyte soup has its drawbacks, not least that the batteries have a troubling tendency to catch fire. Enter the solid-state battery, which swaps liquid for a solid ceramic or polymer, creating power packs that charge faster, last longer, cram more energy into smaller spaces, and (crucially) run cooler. A new generation of companies aim to bring such batteries to market, and if their bets pan out, the tech could substantially ease the shift away from fossil fuels.
Solid-state batteries have been “just a few years away” for more than a decade now. In laboratories, the technology works. But there have been challenges. In designs that pair the solid electrolyte with a lithium-metal anode (the side of the battery that releases electrons into an electrical circuit), needlelike filaments called dendrites tend to grow during charging, and they eventually push through the electrolyte and short the cell. Solid electrolytes are supposed to physically block the formation of dendrites, but many of them crack as the treelike projections break through like roots in a concrete foundation.
Then there’s the problem of manufacturing at scale. Mass production requires large quantities of defect-free sheets of ceramic-like material to make the electrolytes as well as dry rooms for assembly, since those electrolytes have a tendency to react with water. Would-be manufacturers quote a range of potential prices for solid-state batteries, but most expect them to fall in line with lithium-ion packs sometime in the mid-2030s.
Nascent as the technology is, solid-state batteries have already seen high-profile missteps. But one of America’s most advanced solid-state-battery companies says it’s closing in on being able to bring its product to market. The Bill Gates–backed QuantumScape launched in Silicon Valley in 2010 and built its battery around a class of ceramic materials that it says is compatible with lithium—meaning no dendrite formation. “We spent, then, like 10 years learning how to process it to satisfy all of the other requirements,” says Tim Holme, QuantumScape’s cofounder and chief technology officer. In 2025, the startup announced a proprietary, large-scale manufacturing method for quickly producing and heat-treating the ceramic electrolytes used in its batteries. “Nobody has ever done this in the field of ceramics before,” Holme claims. For 10,000 years, producing ceramics has involved slowly cooking the starting materials in an oven over the course of days. “We figured out a way to shorten that down to several minutes,” he says.
Plenty of other companies are pushing the tech forward as well. Toyota, the world’s biggest automaker, launched a research program on solid-state batteries way back in 2010. It’s now partnering with the global energy and petroleum company Idemitsu Kosan on a pilot plant, promising cars that can travel up to 745 miles after charging 10 minutes or less—a huge leap, if it works out. In China, CATL, the giant behind roughly 40% of the global battery market, is aggressively pursuing solid-state batteries too, pumping nearly $2.6 billion into a research program in 2024 alone. Mercedes, meanwhile, equipped one of its EQS sedans with solid-state batteries last fall; after driving nonstop for 750 miles, the car still had some range to spare.
Will the tech gain traction? Investing in vehicle batteries makes sense given the size of the potential market. But any little uptick in cost typically gets passed on to buyers, so the first solid-state EV batteries will inevitably be more expensive.
Grid storage buyers, who are working to meet the increasing demands posed by data centers, may also hesitate to purchase new technologies that still haven’t come down the cost curve. Then again, the promise of energy storage that lasts longer than lithium-ion’s typical eight hours could make them easier to persuade.
Some companies are taking a page from a playbook employed by outfits pursuing fusion: Focus on near-term markets with better margins to help fund development and bring down costs. Solid-state firms including California-based Solid Energies and Arizona-headquartered Sion Power are looking at selling batteries to the aviation industry or the military. “Those are sectors that are less sensitive to cost, and they typically require lower volumes as well,” says Evelina Stoikou, head analyst for battery technologies and supply chains at the consultancy BloombergNEF. “It’s a good way to prove your concept, then go through and fund the pilot plant where you can make t