China's New Big Bet: Batteries Powered by Sea Salt

China leads the world in the production of lithium-ion batteries, which power most of the electric vehicles now running. It's possible that nations looking to catch up could turn to alternatives such as sodium-ion batteries—but as the BBC reports, China is leading the way on this burgeoning technology as well. For now, the batteries are being used primarily in the nation's massive electric scooter market—about 55 million are sold annually—and the plan is to keep scaling up production and capabilities. Details:

• Sodium is cheaper and far more abundant than lithium—about 400 times so—making it more sustainable and less vulnerable to global supply chain disruptions. It can be extracted from sea salt.

• Sodium-ion batteries charge quickly, perform well in cold weather, and are less likely to overheat, making them a safe and practical choice for small vehicles. While they hold less energy than lithium batteries, that tradeoff matters less for short-distance urban travel.
• For longer travel, that currently presents a problem, given that "range is a big deciding factor for people when they buy an EV," says Phate Zhang of EV news outlet CnEVPost.
• Most scooters are currently powered by lead-acid batteries, which are cheaper than sodium-ion alternatives—for now. Things could change as production is scaled up.
• Leading Chinese companies such as CATL and BYD are already investing heavily in sodium-ion tech, betting that it could soon power not just scooters but low-speed vehicles and stationary energy storage systems as well.