lithiumion

Lithium-ion, often written lithium-ion, refers to a family of rechargeable battery technologies in which lithium ions move between the anode and cathode during charging and discharging. A typical cell uses a graphite anode, a lithium metal oxide cathode, an organic electrolyte containing a lithium salt, and a porous separator. The cells are packaged into modules and assembled into devices or larger energy systems.

During discharge, lithium ions travel from the anode to the cathode through the electrolyte, while electrons flow through an external circuit to power devices. Charging reverses the ion flow. The performance depends on chemistry; common cathodes include lithium cobalt oxide (LiCoO2), NMC (nickel manganese cobalt oxide), NCA (nickel cobalt aluminum oxide), and LFP (lithium iron phosphate).

Lithium-ion batteries offer high energy density, relatively light weight, and low self-discharge, contributing to long device runtimes and compact electric vehicles. They require a battery management system to monitor voltage, current, and temperature to prevent overcharge, overheating, and short circuits. Safety incidents are typically linked to mechanical damage, thermal runaway, or improper charging.

The technology entered commercial use in the 1990s, with Sony among the early manufacturers. Since then, various chemistries have been developed to balance energy density, power, lifetime, and safety, leading to a wide range of performance profiles suited to different applications.

Applications include portable electronics, electric vehicles, and grid energy storage. Environmental considerations involve resource extraction, particularly cobalt and lithium, and end-of-life recycling and repurposing.