N-doped carbon-embedded TiN nanowires as a multifunctional separator for Li–S batteries with enhanced rate capability and cycle stability

摘要

Lithium-sulfur(Li-S)batteries have attracted considerable attention as next-generation energy storage devices owing to their high theoretical specific capacity and safety.However,the commercialization of Li-S batteries is hindered by critical issues,including the migration of the dissolved lithium polysulfides(LiPSs)from the sulfur electrode to the lithium metal anode,resulting in poor cycling stability.Here,we report a multifunctional interlayer configured with an N-doped carbon framework and titanium nitride nanowires on a polypropylene separator(NC/TiN NWs@PP)to suppress the polysulfide shuttling problem.NC/TiN NWs@PP can be obtained by electrospinning and the subsequent scalable solution-based vacuum filtration.The one-dimensional structure of the TiN NWs can shorten the Li-ion diffusion distance with large electrode/electrolyte interfaces.Furthermore,the N-doped carbon framework in the NWs enables facile electron transportation and allows the suppression of the shuttle effect to improve the electrochemical reaction kinetics.The Li-S battery with a NC/TiN NWs@PP separator exhibited enhanced cycling stability and rate capability,indicating that this could be a new research direction for Li-S batteries.