文献类型：期刊文献

英文题名：Electron delocalization-enhanced sulfur reduction kinetics on an MXene-derived heterostructured electrocatalyst

作者：Li, Yunmeng[1];Zuo, Yinze[2];Li, Xiang[1];Zhang, Yongzheng[1];Ma, Cheng[3];Cheng, Xiaomin[4,5];Wang, Jian[4,5,6];Wang, Jitong[1];Lin, Hongzhen[4,5];Ling, Licheng[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Key Lab Specially Funct Polymer Mat & Related Tech, Minist Educ, Shanghai 200237, Peoples R China;[2]Fuzhou Univ, Inst New Energy Mat & Engn, Coll Mat Sci & Engn, Fuzhou 350108, Peoples R China;[3]East China Univ Sci & Technol, Sch Mat Sci & Engn, Key Lab Specially Funct Polymer Mat & Related Tech, Minist Educ, Shanghai 200237, Peoples R China;[4]Chinese Acad Sci, i Lab, Suzhou 215123, Peoples R China;[5]Chinese Acad Sci, Suzhou Inst Nanotech & Nanobion, CAS Key Lab Nanophoton Mat & Device, Suzhou 215123, Peoples R China;[6]Helmholtz Inst Ulm HIU, D-89081 Ulm, Germany

年份：2024

卷号：17

期号：8

起止页码：7153

外文期刊名：NANO RESEARCH

收录：;EI(收录号：20242016102267);WOS:【SCI-EXPANDED(收录号:WOS:001223469500001)】；

基金：This work was financially supported by the National Natural Science Foundation of China (No. U1710252), the Natural Science Foundation of Jiangsu Province (BK. 20210130), Innovative and Entrepreneurial Doctor in Jiangsu Province (No. JSSCBS20211428), China Postdoctoral Science Foundation (No. 2023M731084), Shanghai Sailing Program of China (No. 23YF1408900) and the Fundamental Research Funds for the Central Universities (No. JKD01231701). J. W. acknowledged the funding provided by the Alexander von Humboldt Foundation and the basic funding of the Helmholtz Association. Dr. Y. Z. Z. thanks the Shanghai Super Postdoctoral Incentive Program. We also thank the support from Nano-X, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences.

语种：英文

外文关键词：delocalized electron; lithium sulfur batteries; MXene-based heterostructures; catalytic desolvation; multi-catalytic sites

摘要：Lithium-sulfur (Li-S) batteries mainly rely on the reversible electrochemical reaction of between lithium ions (Li+) and sulfur species to achieve energy storage and conversion, therefore, increasing the number of free Li+ and improving the Li+ diffusion kinetics will effectively enhance the cell performance. Here, Mo-based MXene heterostructure (MoS2@Mo2C) was developed by partial vulcanization of Mo2C MXene, in which the introduction of similar valence S into Mo-based MXene (Mo2C) can create an electron delocalization effect. Through theoretical simulations and electrochemical characterisation, it is demonstrated that the MoS2@Mo2C heterojunction can effectively promote ion desolvation, increase the amount of free Li+, and accelerate Li+ transport for more efficient polysulfide conversion. In addition, the MoS2@Mo2C material is also capable of accelerating the oxidation and reduction of polysulfides through its sufficient defects and vacancies to further enhance the catalytic efficiency. Consequently, the Li-S battery with the designed MoS2@Mo2C electrocatalyst performed for 500 cycles at 1 C and still maintained the ideal capacity (664.7 mAhg-1), and excellent rate performance (567.6 mAhg-1 at 5 C). Under the extreme conditions of high loading, the cell maintained an excellent capacity of 775.6 mAhg-1 after 100 cycles. It also retained 838.4 mAhg-1 for 70 cycles at a low temperature of 0 degrees C, and demonstrated a low decay rate (0.063%). These results indicate that the delocalized electrons effectively accelerate the catalytic conversion of lithium polysulfide, which is more practical for enhancing the behaviour of Li-S batteries.