Configuring single-layer MXene nanosheet onto natural wood fiber via C-Ti-C covalent bonds for high-stability Li-S batteries  

作　　者：Yangyang Chen Yu Liao Ying Wu Lei Li Zhen Zhang Sha Luo Yiqiang Wu Yan Qing 

机构地区：[1]College of Materials Science and Technology,Central South University of Forestry and Technology,Changsha 410004,Hunan,China

出　　处：《Journal of Energy Chemistry》2024年第8期701-711,I0016,共12页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(31890771);the Young Elite Scientists Sponsorship Program from the National Forestry and Grassland Administration of China(2019132614);the Science and Technology Innovation Program of Hunan Province(2022RC3054);the Hunan Provincial Innovation Foundation for Postgraduate(CX20230758)。

摘　　要：Lithium-sulfur batteries(LSBs)are considered promising candidates for next-generation battery technologies owing to their outstanding theoretical energy density and cost-effectiveness.However,the low conductivity and polysulfide shuttling effect of S cathodes severely hamper the practical performance of LSBs.Herein,in situ-generated single layer MXene nanosheet/hierarchical porous carbonized wood fiber(MX/PCWF)composites are prepared via a nonhazardous eutectic activation strategy coupled with pyrolysis-induced gas diffusion.The unique architecture,wherein single layer MXene nanosheets are constructed on carbonized wood fiber walls,ensures rapid polysulfide conversion and continuous electron transfer for redox reactions.The C-Ti-C bonds formed between MXene and PCWF can considerably expedite the conversion of polysulfides,effectively suppressing the shuttle effect.An impressive capacity of 1301.1 m A h g^(-1)at 0.5 C accompanied by remarkable stability is attained with the MX/PCWF host,as evidenced by the capacity maintenance of 722.6 m A h g^(-1)after 500 cycles.Notably,the MX/PCWF/S cathode can still deliver a high capacity of 886.8 m A h g^(-1)at a high S loading of 5.6 mg cm^(-2).The construction of two-dimensional MXenes on natural wood fiber walls offers a competitive edge over S-based cathode materials and demonstrates a novel strategy for developing high-performance batteries.

关 键 词：Lithium-sulfur batteries S cathodes MXene nanosheets Wood fiber C-Ti-C bonds 

分 类 号：TM912[电气工程—电力电子与电力传动]