Definition: lithium ion

A rechargeable battery technology introduced in 1991 that provides greater charge per pound than nickel metal hydride. In 1993, Toshiba introduced the first notebook in the U.S. with a Li-ion battery. Since then, it has become the most popular battery technology for notebooks, cellphones and other handheld devices.

Lithium-ion batteries also power electric vehicles. Although it has less than 10% of lithium reserves, as of 2025, China has roughly 70% of the lithium refining market and 60% of the EV car battery market. See electric vehicle.

Shallow Discharges Are Best
Nickel-based batteries require full discharges before recharging to keep the battery healthy. In contrast, lithium-ion batteries thrive on frequent, shallow discharges. See lithium polymer, lithium iron phosphate and batteries.

High-Performance Lithium Ion

Using a patented technology, this lithium-ion battery from the early 2000s delivered 183 watt hours per kilogram (Wh/kg) compared to about 115 for standard lithium ion. It added up to 16 hours of extra running time.