What is a solid-state battery, and does it compare to the traditional lithium-ion ones?
A solid-state battery is an alternative way to provide energy in electric vehicles. The traditional lithium-ion packs use liquid electrolytes to move Li+ ions throughout the battery. However, this is considered a potentially unsafe method of providing power to the car as it can increase temperatures, which could cause a fire.
With a solid-state battery, though, lithium moves from one end to the other using solid materials, which doesn't generally cause the temperature to rise. It also has the potential for a greater energy density than lithium-ion batteries.
Are the solid-state batteries really that safe?
Research results suggest that it goes both ways, but it depends on the scenario. For example, during external heating tests (like fire), the solid-state battery didn't produce any heat, the same for an internal short-circuit scenario.
However, when it comes to mechanical failure, the solid-state battery becomes as hot as the traditional lithium-ion one, making it just as unsafe when temperatures begin to rise. These conditions come up when the battery gets crushed or punctured, which could essentially happen when the vehicle collides with another object.
For the most part, solid-state technology is the safer option because electrolytes stay firm in most situations, with a smaller chance of breaking. But, it's by far not considered invincible. It would need some kind of fail-safe measure to keep temperatures from rising should those electrolytes break.
Can you improve them to increase safety?
Ultimately, the best safeguard for solid-state batteries is to eliminate lithium metal. Researchers say that the batteries become more dangerous when lithium is present within the construction. More research needs to be done, but finding other solid materials to use in production would likely offer more safety in the long run.
They've also tested adding a small amount of liquid electrolytes to the solid-state batteries. The findings suggest that it would generate 1/5th the heat lithium packs do when a fire is present. It also would increase the performance of the battery as well. But, you still run the risk of the electrolytes failing.
Toyota plans to add them to its hybrid vehicles, while Ford and BMW are turning to solid-state power for a future supply of solid-state batteries. That sure sounds promising, but it might be a while before they can be considered really solid enough to use on a massive scale.
Keeping your electric vehicle safe