Nitrogen-doped carbon-coated molybdenum disulfide composites grown on modified graphite: Stable structure and rapid ion diffusion promote ultra-long lifespan in lithium-ion batteries

Molybdenum disulfide (MoS 2 ) has a unique layered structure, and its large interlayer spacing facilitates the insertion and extraction of lithium ions. However, due to the instability of its electrode material structure and slow electron/ion diffusion rate, it exhibits poor cycling stability and low rate performance, which limits its application in lithium-ion batteries. Therefore, optimizing the design of high-performance molybdenum disulfide based materials for lithium-ion battery anodes remains a major challenge in current research. This article uses polyvinylpyrrolidone (PVP) as a soft template and graphite ball milled with PVP as a hard template to synthesize a nitrogen doped carbon coated MoS 2 composite material (MoS 2 /PG) grown on graphite by hydrothermal method. In the prepared composite material, MoS 2 exhibits a flower ball shape with a diameter of about 230 nm. Through the connection of the interface carbon layer, MoS 2 can grow uniformly and firmly on the graphite surface. This structure plays a crucial role at the microscale, not only promoting the ordered growth of MoS 2 on the surface of modified graphite, but also providing stable mechanical support for it. This small particle size and unique growth structure play an important role in its excellent electrochemical performance, as they not only provide rapid electron transfer and ion diffusion, but also effectively alleviate the volume change of MoS 2 during repeated charge and discharge processes. The MoS 2 /PG electrode exhibits excellent cycling and high rate performance, maintaining a specific capacity of 345.21 mAh g −1 after 1000 cycles at a current density of 1 A g −1 , with a capacity retention rate of up to 80.77 %; At a cycle rate of 5 C, the average specific capacity is 364.44mAh g −1 .