MXene@Montmorillonite heterostructure with fast lithium‐ion transport and polysulfide conversion kinetics assisting high‐capacitive lithium‐sulfur batteries

Abstract Lithium‐sulfur batteries are one of the most promising next‐generation energy storage systems, while their real application is largely limited by the shuttle effect of lithium polysulfides (LiPSs). Herein, an interlayer based on a heterostructure consisting of MXene and two‐dimensional montmorillonite (MXene@MMT) is developed via an electrostatic self‐assembly strategy. Such a heterostructure possesses strong adsorption ability for LiPSs and can accelerate the conversion reaction from liquid LiPSs to solid Li 2 S in virtue of its strong adsorption, high conductivity, and good catalytic activity. Furthermore, this heterostructure not only effectively blocks the migration of polysulfides, but also provides low energy barrier and rich pathways for Li + transport. Ultimately, the as‐assembled Li–S batteries with the MXene@MMT based interlayer deliver a high initial discharge capacity of 1375.5 mAh g −1 at 0.1C and long‐term cycling stability with 500 mAh g −1 remaining over 500 cycles under a high rate of 2C. In a practical demonstration, the as‐sembled soft pack battery achieved an initial discharge capacity of 733 mAh g −1 at 0.1C and still retained a high capacity of 402 mAh g −1 after 100 cycles.