3D Heterogeneous Co3O4@Co3S4 Nanoarrays Grown on Ni Foam as a Binder-Free Electrode for Lithium-Ion Batteries

Abstract

Co3O4@Co3S4 nanoarrays on Ni foam (abbreviated as Co3O4@Co3S4 NAs) were prepared by using a facile synthesis method, which involves hydrothermal preparation, low-temperature thermal decomposition of Co(OH)y(CO3)0.5(2-y) ⋅ 11H2O, and sulfurization. The material exhibited good electrical conductivity, high specific capacity, and cycling stability with a reversible capacity of 1050 mAh g−1 at 200 mA g−1 after 40 cycles and an initial coulombic efficiency of 82.25 %. At a high current density (1500 mA g−1), the capacity reached up to 808.1 mAh g−1. The excellent lithium-storage performance of Co3O4@Co3S4 NAs can be ascribed to the synergistic effect between Co3O4 and Co3S4, along with the contribution of the Ni foam. The method described in this paper can be extended to enhance the electrochemical performance of other metal oxides.