Scalable, flexible and fire-retardant janus membranes for simultaneously inhibiting dendrite growth and catalyzing polysulfide conversion in lithium-sulfur batteries

Shuttle effect of lithium polysulfides (LiPSs) and the problems arising from lithium dendrites impede the practical applications of Li-S batteries. Herein, a scalable and fire-retardant janus membrane (C@OPBI-CeO2//GF) with glass fiber membrane (GF) as substrate and hierarchically porous C@OPBI-CeO2 membrane as the cathode has been constructed. The cathode membrane with porous conductive networks can replace the conventional Al foil and significantly promote Li+ and electron transportation. Meanwhile, the doped CeO2 nanoparticles in the membrane can trap and catalyze LiPSs transformation. The interwoven GF membrane allows the uniform distribution of Li+ on Li plate by redistributing the Li+ flux. It also facilitates the rapid diffusion of Li+ and promotes the reversible Li plating and stripping processes against dendrite growth. Furthermore, the introduction of OPBI and GF improve the structural stability and high temperature resistance of the membrane which are of great significance to realize the commercial application of Li-S batteries. The batteries assembled with the janus membrane have a specific capacity of 620 mA h g − 1 after 550 cycles at a current density of 1 C, and still deliver a capacity of 720 mA h g − 1 after 100 cycles even at a high sulfur loading of 5 mg cm−2.