Construction of VS<sub>2</sub>/VO<i><sub>x</sub></i> Heterostructure via Hydrolysis‐Oxidation Coupling Reaction with Superior Sodium Storage Properties
Yuxiang Zhang, Yangziyu Chen, Yan Jiang, Jing Wang, Xiangyi Zheng, Bo Han, Kaisheng Xia, Qiang Gao, Zhao Cai, Chenggang Zhou, Ruimin Sun
Abstract
Abstract Heterostructure engineering is one of the most promising modification strategies for reinforcing Na + storage of transition metal sulfides. Herein, based on the spontaneous hydrolysis‐oxidation coupling reaction of transition metal sulfides in aqueous media, a VO x layer is induced and formed on the surface of VS 2 , realizing tight combination of VS 2 and VO x at the nanoscale and constructing homologous VS 2 /VO x heterostructure. Benefiting from the built‐in electric field at the heterointerfaces, high chemical stability of VO x , and high electrical conductivity of VS 2 , the obtained VS 2 /VO x electrode exhibits superior cycling stability and rate properties. In particular, the VS 2 /VO x anode shows a high capacity of 878.2 mAh g −1 after 200 cycles at 0.2 A g −1 . It also exhibits long cycling life (721.6 mAh g −1 capacity retained after 1000 cycles at 2 A g −1 ) and ultrahigh rate property (up to 654.8 mAh g −1 at 10 A g −1 ). Density functional theory calculations show that the formation of heterostructures reduces the activation energy for Na + migration and increases the electrical conductivity of the material, which accelerates the ion/electron transfer and improves the reaction kinetics of the VS 2 /VO x electrode.