LAUSR

Lithium-sulfur (Li-S) battery has received intense interest as next-generation electrochemical energy storage systems because of its high specific energy and natural abundance potential. However, its practical reality is seriously limited by the safety concerns from heterogeneous lithium deposition and the so-called "shuttle effect". Herein, this work reports a novel gel-polymer-inorganic separator specifically for the lithium-sulfur battery, which could enable homogeneous lithium deposition and inhibit the diffusion of polysulfides, simultaneously. The composite separator exhibits a superior electrochemical performance up to 500 cycles at 0.5 C with the capacity retention of 718.2 mAh g-1. It is worth noting that the corresponding fade rate for 1000 cycles was 0.04 %/cycle even tested at 2 C. This outstanding cycling stability can be attributed to the strong anchoring effect of polar carboxymethylcellulose sodium (CMC) to polysulfides, which is confirmed by the permeation experiments and XPS analyses. Besides, the Al2O3 coating layer on the anode side could achieve relatively uniform lithium deposition and inhibit the growth of dendrite to some extent. As a result, this study may pave a novel strategy for the effective design of separator toward the practical reality of high-performance lithium-sulfur battery.