What is a lithium-ion battery?

Lithium-ion (Li-ion) batteries are a relatively new type of rechargeable energy storage cell, with widespread distribution beginning in the 1990s. They can store far more energy than older lead-acid or nickel-metal-hydride cells, making them ideally suited to powering electric cars, enabling driving ranges of 400 miles or more in the most advanced models.

They work by shuttling lithium ions – positively charged lithium atoms that have lost an electron – through an electrolyte between the battery's cathode and anode. This draws electrons through the electric car's circuits and drives its electric motor, or the process can be reversed to recharge the battery.

EVs normally use hundreds of individual lithium-ion cells assembled into a pack, with an electronic battery management system (BMS) to closely monitor and balance each cell's charge and condition. The battery pack in an EV will be warrantied for several years but should last far longer than this period with careful ownership. At the end of their useful lives, lithium-ion cells are easily recyclable, with 95% of the battery's mass able to be recovered and reused in new cells.