关键词: 二硫化钨, 钠离子电池, 纳米结构, 复合材料, 电化学

Abstract:

Tungsten disulfide (WS₂), as a typical two-dimensional transition metal sulfide with a wide layer spacing (6.2Å，1Å=0.1nm) and a multi-electron conversion reaction sodium storage mechanism, is a sodium ion battery anode material with high theoretical specific capacity and fast sodium ion reaction kinetics. However, in its actual sodium storage process, the electronic conductivity inherent in the 2H phase structure of WS₂ is poor, and the large phase structure transformation and volume change are brought about by the conversion reaction, as well as the dissolution and shuttle effect of the reduced intermediate product polysulfide (NaS _x, 0<x<2) and the low conductivity of the reduced product sodium sulfide (NaS₂) during the charging and discharging process, leading to the less than ideal actual electrochemical performance of WS₂. To address the above problems, this paper introduced the basic structural features of WS₂, briefly described the main synthetic methods and modifications that existed, and researchers has used hydrothermal/solvent thermal and high-temperature sulfidation methods for nanostructure design, compounding with carbon materials, and introducing a second phase to build a heterogeneous structure to enhance the electrochemical performance of WS₂. Finally, the main modification methods of WS₂ materials and the achieved results are summarized. In the future research direction of WS₂ sodium storage materials, the combination of various modification strategies such as nanostructure design, compounding with carbon materials, constructing heterojunctions, doping with heterophase atoms and increasing active sites to fabricate high magnification performance WS₂ materials that can achieve fast charging and discharging with stable structure is the focus of research.

Key words: tungsten disulfide, sodium-ion batteries, nanostructure, composites, electrochemistry