The practical application of lithium–sulfur (Li–S) batteries is severely hampered by the polysulfide shuttle effect and sluggish sulfur redox kinetics. To address these challenges, a Schottky heterostructure catalyst (2H-VS2/V2C) with a built-in electric field (BIEF) was constructed by epitaxially anchoring semiconducting 2H-VS2 nanoflowers onto metallic V2C MXene substrates via a two-step hydrothermal method. This effectively synergizes the strong adsorption capability of V2C with the catalytic activity of 2H-VS2. The BIEF at the heterointerface significantly enhances electron and ion transport as well as accelerates the conversion kinetics of sulfur species. Consequently, Li–S batteries equipped with 2H-VS2/V2C modified separators achieve a specific capacity of 804.2 mAh g–1 at 5 C, demonstrating an excellent rate capability. Moreover, they exhibit outstanding cycling stability, with a capacity decay rate of only 0.037% per cycle over 1000 cycles at 1 C. Notably, they maintain excellent electrochemical properties even at high sulfur loadings of 4 mg cm–2 and at 0 °C. This work provides an effective interfacial engineering strategy to improve Li–S battery performance and offers guidance for the design of advanced heterostructure catalysts.
Wu et al. (Wed,) studied this question.