Construction of highly conductive MoS2/MoO2/reduced graphene oxide nanocomposites for ultralong-life hybrid Mg2+/Li+ batteries

Abstract

Hybrid Mg2+/Li+ batteries (MLIBs) are a promising battery system that combines the advantages of fast lithium-ion kinetics and dendrite-free magnesium deposition. Layered molybdenum disulfide (MoS2) has gained increasing interest due to larger layer spacing and weak van der Waals forces in MLIBs. However, poor intrinsic electronic conductivity hinders its practical application. Here, a highly conductive MoS2/MoO2/reduced graphene oxide (MoS2/MoO2/rGO) composite synthesized via a facile hydrothermal method is employed as a high-performance cathode material for MLIBs. The high electrical conductivity (7.5 ×10−3 S cm−1) and large specific surface area of MoS2/MoO2/rGO facilitate the rapid transport of interfacial electrons and provide abundant active sites for Mg2+/Li+ storage. The optimized MoS2/MoO2/rGO composite exhibits a high discharge capacity (297.3 mAh g−1) and excellent rate performance. Moreover, the composite electrode delivers ultra-long cycle life over 5000 cycles at 1000 mA g−1, with a capacity degradation rate of only 0.007 % per cycle. The results offer valuable insights for the development of highly conductive MoS2-based composites.