Stable interface Co3O4-coated LiNi0.5Mn1.5O4 for lithium-ion batteries

Abstract

The spinel LiNi0.5Mn1.5O4 (LNMO) has received much attention as a cathode material in high energy density lithium-ion battery thanks to its high working voltage. It is recognized that its interface instability issues, especially for the Fd-3m phase with superior conductivity, Co3O4 is employed as an interface coating to stabilize the surface structure of LNMO. A series of test results demonstrated that the side-reaction between LNMO and electrolyte interface is greatly reduced, and as a result, the formation of cathode electrolyte interfacial (CEI) film is inhibited, and the structural change and manganese dissolution are also alleviated. The modified LNMO shows super rate performance and excellent cycle retention. Specifically, the LNMO material coated with 0.8 wt% Co presents a discharge capacity of 120 mA h g−1 at a rate of 10 C with a capacity retention rate of 95.8% after 300 cycles.