Deep surface modification with silicon improves the cycling stability of nickel-rich LiNi0.83Co0.06Mn0.11O2 cathode

Abstract

Nickel-rich and cobalt-poor Li[Ni0.83Co0.06Mn0.11]O2 (NCM83) cathode is more effective than normal Li[Ni0.83Co0.11Mn0.06]O2 for high energy density lithium-ion battery applications. However, its capacity degradation caused by the structural instability and large phase transition resistance during cycling critically hinders the commercialization. Herein, we report that a deep surface modification of NCM83 with silicon can maximally balance the high conductivity and the good structural stability to improve its electrochemical performance and long cycling stability. The electrochemical results showed that the capacity retention of the resultant sample Si-NCM83 was remarkably increased at 0.1 C (210.3 mA h g−1) from 85.8% to 96.3% after 500 cycles compared with NCM83. The greatly improved cycle life of Si-NCM83 was attributed to the cycling stability achieved by the reduction of anisotropic volume change, microcracks from structural stress, and the uniform long rod-shaped primary particles, which lead to the acceleration of the diffusion of lithium-ions.