An effective modification strategy enhancing the structure stability and electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode material for lithium-ion batteries

Abstract

LiNixCoyMn1−x-yO2 (NCM) (x ≥ 0.5) have received more and more attention due to high energy density, which have been widely utilized in the fields of mobile electronic equipment and new energy vehicles. Nevertheless, these materials suffer severe capacity attenuation and inferior rate performance, hindering their commercialization. In this work, we design an effective strategy: co-modification of Nb doping and LiBO2 coating (NB-NCM) to stabilize the internal structure, reduce cation mixing, alleviate external side reactions and improve electrochemical performance. Material characterizations and electrochemical measurements were operated to comprehensively value the effect of co-modification on the structure, topography and electrochemical properties of NCM materials. As a result, Nb is doped into the bulk of the material and the surface of particle is uniformly coated with LiBO2. In addition, for the NB-NCM electrode, the discharge capacity retained 90.90% at 0.5 C rate after 50 cycles, which proves that co-modification is an effective method to stabilize structure and enhance electrochemical performance.