Nanocomposite of ultrasmall Co3O4 nanoparticles deposited on ultrathin MoS2 surfaces for excellent performance anode materials in lithium ion batteries

Abstract

A novel nanocomposite, ultrasmall Co3O4 nanoparticles decorated on ultrathin surface of MoS2 nanosheets, namely MoS2/Co3O4, was synthesized as an anode material for lithium ion battery. The discharge capacity of MoS2/Co3O4 nanocomposite reached 1100.0mAhg−1 after 50 cycles at 200mAg−1, much higher than the pure Co3O4 nanoparticles. Moreover, it could maintain reversible capacity of 946.6mAhg−1 even after 50 cycles at a high current density of 500mAg−1. While increasing the current densities step by step from 100 to 200, 500, and 800mAg−1, the capacities of MoS2/Co3O4 nanocomposite are 1474.9, 1209.9, 952.6 and 801.9mAhg−1, respectively. The excellent electrochemical performance resulted from the designed nanocomposite composed of uniformly distributed ultrasmall Co3O4 nanoparticles and ultrathin MoS2 nanosheets, which maximally utilized electrochemical active MoS2 nanosheets and Co3O4 nanoparticles for lithium ion batteries. Moreover, this composite structure may provide more extra spaces for the storage of lithium ions and help to accommodate the volume change through a synergistic interaction between two active materials.