Enhancing electrochemical conversion of lithium polysulfide by 1T-rich MoSe_(2) nanosheets for high performance lithium-sulfur batteries

查看全文 作　　者：Ruilong [1]Li;Zhe [1]Bai;Wensuo [1]Hou;Zeyu [1]Wu;Pingli [1]Feng;Yu [1]Bai;Kening [1]Sun;Zhenhua [1]Wang 机构地区：[1]Beijing Key Laboratory of Chemical Power Source and Green Catalysis,School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 100081,China 出　　处：《Chinese Chemical Letters》索引2023年第34卷第11期,共7页 基　　金：supported by the National Natural Science Foundation of China(No.22179007). 摘　　要：The sluggish conversion kinetics and shuttle effect of lithium polysulfides(LiPSs)severely hamper the commercialization of lithium-sulfur batteries.Numerous electrocatalysts have been used to address these issues,amongst which,transition metal dichalcogenides have shown excellent catalytic performance in the study of lithium-sulfur batteries.Note that dichalcogenides in different phases have different catalytic properties,and such catalytic materials in different phases have a prominent impact on the performance of lithium-sulfur batteries.Herein,1T-phase rich MoSe_(2)(T-MoSe_(2))nanosheets are synthesized and used to catalyze the conversion of LiPSs.Compared with the 2H-phase rich MoSe_(2)(H-MoSe_(2))nanosheets,the T-MoSe_(2) nanosheets significantly accelerate the liquid phase transformation of LiPSs and the nucleation process of Li2S.In-situ Raman and X-ray photoelectron spectroscopy(XPS)find that T-MoSe_(2) effectively captures LiPSs through the formation of Mo-S and Li-Se bonds,and simultaneously achieves fast catalytic conversion of LiPSs.The lithium-sulfur batteries with T-MoSe_(2) functionalized separators display a fantastic rate performance of 770.1 mAh/g at 3 C and wonderful cycling stability,with a capacity decay rate as low as 0.065%during 400 cycles at 1 C.This work offers a novel perspective for the rational design of selenide electrocatalysts in lithium-sulfur chemistry. 关 键 词：MoSe_(2) Functionalized separator Lithium-sulfur battery Phase Catalytic conversion