A new modification strategy for improving the electrochemical performance of high-nickel cathode material: V2O5 particles anchored on rGO sheets as a dual coating layer

Abstract

Nickel-rich material has the advantages of high energy density and low cost, so it is an attractive cathode material. However, the defects such as fast capacity drop and low capacity at high rates hinder its commercial application. Herein, to solve the problems and obtain nickel-rich material with high performance, a novel dual conductive layer is designed and coated on the surface of LiNi0.84Co0.11Mn0.05O2 material. The uniform hybrid coating layer is composed of vanadium pentoxide (V2O5) and reduced graphene oxide (rGO). The V2O5 could facilitate the Li+ intercalation/deintercalation process of the nickel-rich cathode material and stabilize its layered structure after reacting with surface lithium residuals, and the rGO with excellent electronic conductivity is helpful to facilitate the transfer of electrons. Therefore, the V2O5/rGO hybrid coating layer not only prevents the surface against corrosion by electrolyte, but also improves the electronic and ionic conductivity of the material. The results showed that the cycling and rate performances of the designed material are more superior than those of the pristine material. The designed material performed an outstanding capacity of 145.7 mAh g−1 at 10 C, and the capacity retention was 90.43% at 1 C after 100 cycles, which is much higher than the pristine material. This work provides an effective strategy for improving the electrochemical performances of nickel-rich cathode materials.