LITHIUM-ION BATTERY AND APPARATUS

The present application provides a lithium-ion battery and an apparatus, the lithium-ion battery includes an electrode assembly and an electrolytic solution, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separation film. A positive electrode active material in the positive electrode sheet includes LiCoMOQ, and the positive electrode active material is a mixture of large particles LiCoMOQand small particles LiCoMOQ; an average particle size D50 of the large particles LiCoMOQis 10 μm-17 μm, and an average particle size D50 of the small particles LiCoMOQis 2 μm-7 μm. The electrolytic solution contains an additive A that is a polynitrile six-membered nitrogen-heterocyclic compound with a relatively low oxidation potential. The lithium-ion battery has superb cycle performance and storage performance, especially under high-temperature and high-voltage conditions.