Graphene-analogous structural MoS2 modification to improve electrochemical properties of Ni-rich layered oxide cathode material for lithium-ion batteries

Abstract

Ni-rich cathode material attracts a substantial amount of attention due to its high specific capacity, superior energy density and low cost. Nonetheless, there are still a few intrinsic issues which need to be solved including rate performance, cycling stability, elevated-temperature performance, etc. In this paper, the graphene-analogous structural MoS2 with chemical stability and acceptable conductivity is purposefully introduced to modify LiNi0.8Co0.1Mn0.1O2 cathode material via a facile wet-chemical approach followed by low-temperature reaction. In addition, lithium-active MoS2 coating layer can provide an interconnected and stable tunnel for the insertion and extraction of lithium ions. Characterizations by X-ray diffraction, X-ray photoelectron spectroscopy, Raman, scanning electron microscopy and transmission electron microscopy demonstrate that MoS2 coating layer is uniformly deposited on the surface of LiNi0.8Co0.1Mn0.1O2 material. The electrochemical results indicate that the modified cathode material displays excellent structure stability, superior rate performance and outstanding cycling properties.