摘要
Lithium-sulphur(Li-S)batteries are currently considered as next-generation battery technology.Sulphur is an attractive positive electrode for lithium metal batteries,mainly due to its high capacity(1675 m Ah g^(-1))and high specific energy(2600 Wh kg^(-1)).The electrochemical reaction of lithium with sulphur in non-aqueous electrolytes results in the formation of electrolyte soluble intermediate lithium-polysulphides.The dissolved polysulphides shuttle to the anode and get reduced at the anode resulting in Li metal corrosion.The solubility of polysulphide gradually reduces the amount of sulphur in the cathode,thereby limiting the cycle life of Li-S batteries.Several strategies have been proposed to improve the cycling stability of Li-S batteries.A unique approach to eliminate the polysulphide shuttle is to use ultramicroporous carbon(UMC)as a host for sulphur.The pore size of UMC which is below 7A,is the bottleneck for carbonate solvents to access sulphur/polysulphides confined in the pores,thereby preventing the polysulphide dissolution.This perspective article will emphasise the role of UMC host in directing the lithiation mechanism of sulphur and in inhibiting polysulphide dissolution,including the resulting parasitic reaction on the lithium anode.Further,the challenges that need to be addressed by UMC-S based Li-S batteries,and the strategies to realise high power density,high Coulombic efficiency,and resilient Li-S batteries will be discussed.
基金
partly funded by the German Research Foundation(DFG)under Project ID 390874152(POLiS Cluster of Excellence,EXC2154)。
作者简介
Corresponding author:Helen Maria Joseph,(M.Helen)obtained her Ph.D.from Indian Institute of Technology.Madras in 2009.Prior to joining Swansea University as a project officer,she has been a research scientist at Helmholtz Institute Ulm(HIU),Karlsruhe Institute of Technology(KIT).Germany.Her research interests include electrochemical energy storage and conversion technologies(batteries and fuel cells),electrocatalysis(methanol oxidation),materials(nano materials.organic-inorganic hybrid materials,nanocomposite membranes).and surface chemitry,email:helen.mariajoseph@swansea.ac.uk;Prof.Dr.Maximilian Fichtner is director at the H elmholtz-Institute Ulm(HIU)for Electrochemical Energy Storage,professor for Solid State Chemistry at the UIm University and head of the Research Unit"Energy Storage Systems"at the Institute of Nanotech-nology,Karlsruhe Institute of Technology.He is scien-tific director of CELEST(Center for Electrochemical Energy Storage Ulm-Karlsruhe)and spokesperson of the German Excellence Cluster on battery research,entitled“Energy Sterage Beyend Lithium(POLiS)"and has been scientific coordinator of several European collaborative projects on batteries and on hydrogen storage.His current research interest is on resource and sustainability issues,novel principles for energy storage and the synthesis and investigation of related storage materials.He is author and co-author of more than 280 research papers and book chapters.20 patent applications and editor of a book on magnesium batteries.
