How solid-state batteries can transform electric cars
More range, less weight, faster charging time -- you name it.
- 5G Technician, ETA International
We haven't perfected lithium-ion batteries for electric cars but the race is already on to replace them. Solid-state batteries are getting the most buzz as the heir apparent: Their proponents promise they'll deliver longer range, faster charging and more affordable electric cars compared to today's top EVs like the Tesla Model 3 and Chevy Bolt.
A solid-state battery is exactly that: A tightly compressed arrangement of hard materials rather than the slightly mushy stew that makes up a typical lithium-ion (li-ion) battery. That solid state composition and construction yields an electrochemical device that promises a lot of improvements:
- Greater energy density. This could mean an EV with two or more times the current range, or possibly an EV with the same range but with a much smaller, lighter and less expensive battery that charges faster.
- Faster charging. Estimates of an 80% charge in 15 minutes get bandied about a lot with solid state, performance that would be on par or a bit faster than today's best li-ion applications.
- Longer life. Solid-state tech is a key part of GM's plan to produce a million-mile life battery, changing the equation of EV affordability and reducing concerns about mountains of toxic batteries that need recycling after 100,000 to 150,000 miles.
- Thermal stability. Solid-state designs promise less likelihood of thermal runaway, which can cause a fire. Li-ion batteries have developed a nasty reputation for this.
But of course there's a catch, or two, with solid-state:
- Expansion and contraction. Solid-state batteries are sensitive to these natural changes batteries undergo as they charge and discharge. Such movement can corrupt the tight, precise arrangement of solid-state materials and cause the battery to fail if not controlled or designed for such behavior.
- Dendrites. These are invasive, root-like structures that can grow in a solid-state battery, breaking up the precise division of material layers and causing the battery to fail.
- Expense. As new tech, solid-state batteries are still fabulously expensive until they reach greater scale and manufacturing refinement.
Who's in the hunt? Perhaps most talked about is QuantumScape, which VW has notably invested in. Expectations are that they will produce a solid-state battery for a VW EV as soon as 2024. Toyota says it will have a very limited production vehicle using a solid-state battery by 2025, in partnership with Panasonic, which is Tesla's partner on traditional li-ion batteries at the Gigafactory.
Who says there are no vehicles using solid-state batteries yet? Bollore of France produces buses that use solid-state lithium-metal-polymer batteries under controlled onboard conditions.
Bollore of France has solid-state battery vehicles on the road, but they're buses, not passenger cars. Such managed fleets allow for infrastructure and a usage cycle that can run the batteries under very specific conditions, but Bollore is targeting a passenger car version by 2026.
Solid Power sees the challenge a bit differently, aiming to design a solid-state battery that can be produced on the same production lines as today's li-ion batteries to leverage the huge current and planned investments in them. They have attracted investment from BMW and Ford in this approach that seeks a financially efficient migration to new technology.
The solid-state battery is a few years away from its moment, but if these bets pay out the technology might roughly double the still struggling palatability of an EV over vehicles using existing li-ion technology.