Core–Shell Co2VO4/Carbon Composite Anode for Highly Stable and Fast-Charging Sodium-Ion Batteries

• DOI: 10.1021/acsami.1c16035
• Publication Date: 2021-11-09T21:52:10Z
• Authors: Cong Wang; Zhenyu Wang; Decheng Zhao; Jinghui Ren; Shupei Liu; Hao Tang; Peng Xu; Fei Gao; Xiangan Yue; Han Yang; Chunming Niu; Weishen Chu; Di Wang; Xiang Liu; Zhoulu Wang; Yutong Wu; Yi Zhang
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

Sodium-ion batteries (SIBs) are promising candidates for large-scale energy storage systems due to the abundance and wide distribution of sodium resources. Various solutions have been successfully applied to revolve the large-ion-size-induced battery issues at the mid-to-low current density range. However, the fast-charging properties of SIBs are still in high demand to accommodate the increasing energy needs at large to grid scales. Herein, a core-shell Co2VO4/carbon composite anode is designed to tackle the fast-charging problem of SIBs. The synergetic effect from the stable spinel structure of Co2VO4, the size of the nanospheres, and the carbon shell provide enhanced Na+ ion diffusion and electron transfer rates and outstanding electrochemical performance. With an ultrahigh current density of 5 A g-1, the Co2VO4@C anode achieved a capacity of 135.1 mAh g-1 and a >98% capacity retention after 2000 cycles through a pseudocapacitive dominant process. This study provides insights for SIB fast-charging material design and other battery systems such as lithium-ion batteries.