Atomic Manganese Manipulating Polysulfide Speciation Pathway for Room-Temperature Na-S Batteries  

作　　者：Hong Zhang Mingli Wang Xiang-Long Huang Songtao Lu Ke Lu Xiaohong Wu 

机构地区：[1]School of Chemistry and Chemical Engineering,Harbin Institute of Technology,Harbin,Heilongjiang 150001 [2]Institutes of Physical Science and Information Technology,Anhui University,Hefei,Anhui 230601 [3]Institute of Fundamental and Frontier Sciences,University of Electronic Science and Technology of China,Chengdu 610054

出　　处：《CCS Chemistry》2024年第9期2289-2304,共16页中国化学会会刊（英文）

基　　金：financially supported by the Natural Scientific Foundation of China(grant nos.22109001 and 22208335);the Postdoctoral Fellowship Program of CPSF(grant no.GZB20230950);the Heilongjiang Postdoctoral Science Foundation(grant no.LBH-Z23187);the Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Soochow University(grant no.KJS2308);startup funds provided to H.Z.from the Harbin Institute of Technology.

摘　　要：Sluggish polysulfide redox kinetics,especially the high energy barrier of rate-determining short-chain polysulfide conversion and the high activation barrier of Na_(2)S decomposition during sulfur recovery,compromise the full potential of rechargeable Na-S electrochemistry.Herein we construct the hierarchical sandwich-structured carbon matrix with atomically dispersed Mn-N4 Lewis acidic sites,taking advantage of their bidirectional electrocatalytic behavior toward interface-mediated reversible sulfur redox.Experimental and theoretical results reveal that the spatial confinement and catalytic effects facilitated via strong Lewis acid-base electron interactions synergistically manipulate the low kinetically direct Na_(2)S_(4) to Na_(2)S conversion,and the formation of Mn-S bond minimizes the energy barrier of Na_(2)S electrochemical activation during battery recharging,thereby rendering a reversible and tunable polysulfide speciation pathway.Furthermore,the degradation of the Na-S cell is due to the depletion of metal anode rather than the loss of active sulfur species and/or aggregation of inactive dead sulfur.As expected,the S@Mn/NC cathode delivers outstanding rate capability and ultrahigh cycling stability.Simultaneously,a proof-of-concept pouch cell was also demonstrated capable of delivering an energy density up to 840 Wh kgcathode−1.The tunable sulfur redox electrochemistry invoked by the bidirectional monodispersed Mn catalytic hot spots facilitates the efficient polysulfide speciation for practical Na-S cells.

关 键 词：single-atom manganese catalysts polysulfide manipulation reaction kinetics bidirectional catalysts sodium-sulfur batteries 

分 类 号：O64[理学—物理化学]