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

A novel nanocomposite, ultrasmall Co 3 O 4 nanoparticles decorated on ultrathin surface of MoS 2 nanosheets, namely MoS 2 /Co 3 O 4 , was synthesized as an anode material for lithium ion battery. The discharge capacity of MoS 2 /Co 3 O 4 nanocomposite reached 1100.0   mAh   g −1 after 50 cycles at 200   mA   g −1 , much higher than the pure Co 3 O 4 nanoparticles. Moreover, it could maintain reversible capacity of 946.6   mAh   g −1 even after 50 cycles at a high current density of 500   mA   g −1 . While increasing the current densities step by step from 100 to 200, 500, and 800   mA   g −1 , the capacities of MoS 2 /Co 3 O 4 nanocomposite are 1474.9, 1209.9, 952.6 and 801.9   mAh   g −1 , respectively. The excellent electrochemical performance resulted from the designed nanocomposite composed of uniformly distributed ultrasmall Co 3 O 4 nanoparticles and ultrathin MoS 2 nanosheets, which maximally utilized electrochemical active MoS 2 nanosheets and Co 3 O 4 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.