A multifunctional layered Ti3C2Tx/VS2 composite sulfur host for promoting the conversion of lithium polysulfides in lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries show promise in meeting the requirements of high energy density and cost-effective energy storage systems. However, they are hindered by slow reaction kinetics and lithium polysulfide (LiPS) shuttling. In this research, a multifunctional sulfur host, Ti3C2Tx/VS2, is developed by incorporating VS2 onto the surface of few-layer Ti3C2Tx using a self-assembly method. The presence of VS2 sheets can prevent the re-stacking of Ti3C2Tx sheets. The Ti3C2Tx/VS2 composite exhibits high electronic conductivity, strong adsorption and anchoring of LiPSs by Ti3C2Tx, and excellent electrocatalytic activity due to VS2. Additionally, carbon nanotubes (CNTs) are used as both conductive agents and binders in the cathode to promote electron/ion transport and improve structural stability. These characteristics can accelerate redox kinetics and mitigate LiPS shuttling. The Ti3C2Tx/VS2/S composite cathode demonstrates a high initial capacity of 1382.7 mA h g(-1) and excellent cycling stability, maintaining a reversible capacity of 806.6 mA h g(-1) after 150 cycles at 0.1C. Moreover, 3D printing technology is utilized to manufacture 3D grid electrodes with a high sulfur loading of 10.05 mg cm(-2). The 3D-printed composite cathode maintains an areal capacity of 7.13 mA h cm(-2) after 100 cycles at 0.05C.