Stable cycling of lithium sulfide cathodes through strong affinity with a bifunctional binder

Abstract

Rechargeable lithium–sulfur batteries have attracted great interest in recent years because of their high theoretical specific energy, which is several times that of current lithium-ion batteries. Compared to sulfur, fully-lithiated Li₂S represents a more attractive cathode material because it enables pairing with safer, lithium metal-free anodes. Here, we demonstrate stable and high-performance Li₂S cathodes by using ab initio simulations to guide our rational selection of poly(vinylpyrrolidone) binder which exhibits strong affinity with both Li₂S and lithium polysulfides. A high discharge capacity of 760 mA h g⁻¹ of Li₂S (∼1090 mA h g⁻¹ of S) was achieved at 0.2 C with stable cycling over prolonged 500 charge/discharge cycles.