litiumkoboltoxid

Litiumkoboltoxid, known in English as lithium cobalt oxide (LiCoO2), is a layered transition metal oxide used as a cathode material in many lithium-ion batteries. The compound combines lithium ions with cobalt oxide in a layered rock-salt-like structure. During charging, lithium ions are extracted from the lattice and cobalt changes oxidation state from Co3+ to Co4+ to balance charge.

The crystal structure is a layered arrangement where lithium and cobalt occupy alternating layers. Deintercalation of Li+ during charging is accompanied by oxidation of cobalt from Co3+ to Co4+. The material offers good electronic conductivity and, with surface coatings, improved cycling stability, making it a historically common choice for cathodes.

Synthesis is typically by solid-state reaction of lithium carbonate or lithium hydroxide with cobalt oxide at high temperatures (roughly 700–900 C), followed by controlled cooling. Doping and surface coatings are used to improve stability, rate capability, and safety.

Applications and performance: LiCoO2 offers high energy density and long cycle life in appropriate cells; theoretical capacity is about 274 mAh/g, with practical energy density around 140–170 Wh/kg. Its capacity fades with deep cycling, and high states of charge can cause structural degradation of the layered lattice. Consequently, LiCoO2 is often used in combination with other materials or in cobalt-containing chemistries, while newer cells increasingly move toward cobalt-reduced or cobalt-free cathodes.

Safety and environmental: cobalt compounds can be toxic, requiring proper handling and regulation. LiCoO2 can decompose at elevated temperatures, and damaged or abused cells pose thermal risk. Cobalt mining raises environmental and social concerns, making recycling and supply diversification important.