Anchoring VS2/SnS2 Heterojunction on V2CT x MXene for Exceptional Rate Performance and Stable Low-Temperature Lithium Storage for Lithium-Ion Batteries

Abstract

The development of electrode materials with high reversible capacity and robust structural stability is crucial for advancing lithium-ion batteries (LIBs). However, their practical application is frequently limited by sluggish ion and electron transport kinetics. Herein, we report a rational structural design to fabricate a bimetallic sulfide heterostructure composite (VS2/SnS2/V2CTx) anchored onto V2CTx MXene nanosheets. The intimately coupled VS2/SnS2 heterointerface is proposed to enable possible interfacial charge redistribution, which may contribute to accelerated charge transfer kinetics. Meanwhile, the conductive MXene scaffold enhances the overall electrode conductivity and effectively accommodates volume fluctuation during cycling, which is a typical advantage of MXene/chalcogenide composite electrodes. When tested as an LIB anode, the composite achieves a high reversible capacity of 811 mA h g−1 at 0.1 A g−1 along with outstanding cycling stability. A full cell assembled with this material and a commercial LiFePO4 cathode exhibits a capacity of 245 mA h g−1 at 0.1 C and retains remarkable capacity retention after 100 cycles at −20 °C. This work provides fundamental insights into designing high-performance metal sulfide-based anodes via synergistic heterojunction and scaffold engineering.