Hollow Concave Zinc-Doped Co₃O₄ Nanosheets/Carbon Composites as Ultrahigh Capacity Anode Materials for Lithium-Ion Batteries

Composition-structure strategy is an effective method to improve the electrochemical performance of lithium-ion batteries (LIBs). Ideal active materials combined with unique structure can lead to potential candidates for next-generation LIB anode materials. In this research, we designed a hollow concave Zn-doped Co₃O₄ nanosheets/carbon composites as active electrodes for LIBs. The hollow concave structure could shorten the path length of Li⁺ and electron transfer. The interconnected Co₃O₄ nanosheets could construct a conductive network and enhance the composites’ conductivity. Moreover, defects produced by Zn doping in the Co₃O₄ phase improves the electronic structure of Co₃O₄, endowing superior electrochemical performances for the doped Co₃O₄-based composites. As expected, the optimized hollow concave Zn-doped Co₃O₄/C composites exhibited high specific capacities with stable cyclability (750 mA h g⁻¹ at 500 mA g⁻¹ after 300 cycles) and excellent rate performances (723.5 mA h g⁻¹ at 3.0 A g⁻¹).