A novel concentration-gradient Li[Ni0.83Co0.07Mn0.10]O2 cathode material for high-energy lithium-ion batteries

Abstract

A novel concentration-gradient Li[Ni_0.83Co_0.07Mn_0.10]O₂ cathode material was successfully synthesized viaco-precipitation, in which the core Li[Ni_0.9Co_0.05Mn_0.05]O₂ was encapsulated completely with a stable concentration-gradient layer having reduced Ni content. The electrochemical and thermal properties of the concentration-gradient Li[Ni_0.83Co_0.07Mn_0.10]O₂ were studied and compared to those of the core Li[Ni_0.9Co_0.05Mn_0.05]O₂ material alone. The concentration-gradient material had a superior lithium intercalation stability and thermal stability compared to the core material. The high capacity was delivered from the Ni-rich core Li[Ni_0.9Co_0.05Mn_0.05]O₂, and the improved thermal stability was achieved by the Ni-depleted concentration-gradient layer with outer surface composition of Li[Ni_0.68Co_0.12Mn_0.20]O₂. The concentration-gradient materials open a new era for the development of advanced Li-ion batteries with high energy density, long cycle life, and improved safety.