Enhanced electrochemical performance of lithium-sulphur battery by negating polysulphide shuttling and interfacial resistance through aluminium nanolayer deposition on a polypropylene separator

摘要

Shuttling of lithium polysulphides and the formation of lithium dendrites are the key challenges that impede the commercialization of high-capacity lithium-sulphur batteries. Here, we report on a binder-free novel aluminium nanolayer-coated polypropylene separator prepared by radio frequency magnetron sputtering technique for shuttle-free lithium metal battery applications. A symmetric cell with a modified separator exhibits smooth lithium striping and plating cycles at higher current density under room temperature conditions for an extended time period of 1550h, suggesting better safety and protection of lithium anode from dendrite formation. Coin cells assembled with sulphurized cathode and Li metal as anode in a liquid electrolyte medium using a surface-modified separator display significantly improved specific initial discharge capacity with reasonable reversible discharge capacity and high Coulombic efficiency after 100 galvanostatic cycles at a cycling rate of 0.1C. This result suggests that the aluminium nanolayer-coated separator can effectively help in reduction of polysulphide crossover during the electrochemical process.