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)).

Automated summary

The hollow concave Zn-doped Co3O4/C composites designed in this research exhibit high specific capacities and stable cyclability, as well as excellent rate performances for lithium-ion batteries. The unique structure and defect production by Zn doping in the Co3O4 phase play significant roles in improving the electrochemical performance of the composites.