Protection of Lithium Anode by a Highly Porous PVDF Membrane for High-Performance Li-S Battery

Abstract

The Li-S battery is considered as the next-generation energy storage solution largely because of its high energy density. However, the lithium metal anode has suffered from the "shuttle effect" of soluble polysulfide species and the formation of dendrites that cause quick performance decay and safety issues. Here, a poly(vinylidene fluoride) (PVDF) membrane that contains a hierarchical porous structure was introduced as a protection layer to insulate the lithium anode from polysulfide shuttling and dendrite formation. The PVDF protected Li-S battery showed a capacity of around 850 mAh g-1 and a Coulombic efficiency of 98% over 200 cycles at 0.5 C. Both performances are significantly improved from the normal Li-S batteries. The PVDF membrane is stable, easy to coat, and scalable, which offers a convenient, affordable, yet effective strategy for achieving commercialization of high energy density and safe Li-S batteries.