Stable nanostructured cathode with polycrystalline Li-deficient Li _0.28Co_0.29Ni_0.30Mn_0.20O₂ for lithium-ion batteries

The lithium-ion battery, a major renewable power source, has been widely applied in portable electronic devices and extended to hybrid electric vehicles and all-electric vehicles. One of the main issues for the transportation application is the need to develop high-performance cathode materials. Here we report a novel nanostructured cathode material based on air-stable polycrystalline Li_0.28Co_0.29Ni_0.30Mn _0.20O₂ thin film with lithium deficiency for high-energy density lithium-ion batteries. This film is prepared via a method combining radio frequency magnetron sputtering and annealing using a crystalline and stoichiometric LiCo_1/3Ni_1/3Mn_1/3O₂ target. This lithium-deficient Li_0.28Co_0.29Ni _0.30Mn_0.20O₂ thin film has a polycrystalline nanostructure, high tap density, and higher energy and power density compared to the initial stoichiometric LiCo_1/3Ni_1/3Mn _1/3O₂. Such a material is a promising cathode candidate for high-energy lithium-ion batteries, especially thin-film batteries.