Facile oxidant-assisted treatment to improve the cyclic performance of Li-rich cathode materials

Abstract

Li-rich cathode materials for lithium-ion batteries have garnered increased attention owing to their large discharge capacity and high operating voltage. However, rapid voltage attenuation and cycle capacity deterioration hinder the commercial applications of these materials. In this study, hydrogen peroxide was used as an oxidant to pre-treat a carbonate precursor for the oxidation of metal ions. The synthesized materials exhibited a large discharge capacity, stable cycle performance and good rate performance. It was found that the spinel phase formed in the materials during preparation can prevent the phase transformation and significantly enhance cycling ability. Furthermore, increased Ni3+ and Mn4+ contents were beneficial in improving the cyclic performance. An appropriate increase in the Ni3+ content can effectively increase the operating voltage, successfully suppress the voltage attenuation, and effectively improve the structural stability of the material. Here, Ni3+ acts as a stable ion to inhibit the formation of Mn3+ and leads to the formation of increased amounts of Mn4+ to stabilize the material structure.