Modification And Electrochemical Study Of In-situ Growth Of Metal Sulfides On Kapok Fiber

Molybdenum disulfide（Mo S₂）,which has a two-dimensional layered structure,has unique intercalation chemistry,and has promising applications for energy conversion and storage,but molybdenum disulfide has shown poor cycling stability in practical studies.The various biomass carbon materials reported so far have attracted attention for their green,renewable and low-cost advantages.Most importantly,most biomass carbon materials can inherit the complex microstructure of their precursors,which can improve the structural stability of metal sulfide/biomass carbon composites.The dispersion of Mo S₂ in a carbonaceous matrix can effectively solve the problems of poor electrical conductivity,structural damage during cycling,and the shuttle effect of polysulphides during electrochemical processes.Based on the above background,this paper proposes the idea of"double protection structure",using the natural structure of biomass kapok fiber as the basic template,using each component of the biomass material as a carbon skeleton,building a heterojunction structure by stacking different two-dimensional composites,and further modifying the kapok fiber by⁶⁰Co-γ-ray irradiation technology.better loading of nanomaterials.The main research of this paper is as follows:（1）The kapok fiber is a space-limited microreactor with heterogeneous structures anchored inside and outside,forming a unique“hollow tube covered Mo S₂/Mxene”composite for efficient utilization of the heterogeneous structure.The composite electrode has better rate characteristics and longer cycling performance than pure Mo S₂ and Mxene.This work provides a versatile strategy for the preparation of other types of hybrid anode materials.Based on these advantages,the composites have a higher specific capacity than pure Mo S₂ with superior rate performance(specific capacities of 639.3,409.5,386.2,372 and 338,422.8 and 434.7 m Ah g^-1 at current densities of 0.05,0.1,0.2,0.5,1,0.1 and 0.05 A g^-1,respectively)（2）The use of irradiation to optimize the modification of kapok fibers produces undulating structures,generating a wealth of reactive sites,thereby increasing the strength of the fiber-substrate interface bond,effectively resolving the stress concentration between kapok fibers and the substrate,and effectively promoting the loading and attachment of nanomaterials on kapok fibers.The optimized electrode has excellent cycling stability.The internal structural changes of the fibers after irradiation were characterized using Shanghai synchrotron radiation,Density functional theory（DFT）calculations elucidated the binding energy enhancement mechanism between Mo S₂ andγ-kapok fiber,nanoindentation techniques confirmed the rational design of the electrode stress dispersion structure,and finite element theory calculations confirmed the effectiveness of stress dispersion in suppressing the volume expansion effect.This work provides a structurally stable material with long cycle life.