| Summary: | As a promising candidate for high-energy-density rechargeable lithium metal batteries, Li/FeS<sub>2</sub> batteries still suffer from the large volume change and severe shuttle effect of lithium polysulfides during cycling. To improve the electrochemical performance, great efforts have been made to modify FeS<sub>2</sub> cathodes by constructing various nanocomposites. However, energy density is sacrificed, and these materials are not applicable at a large scale. Herein, we report that the electrochemical performance of commercial FeS<sub>2</sub> can be greatly enhanced with the application of a double-layer MoS<sub>2</sub>-CNTs-PVA (MCP)/PVA separator fabricated by electrospinning. The assembled Li/FeS<sub>2</sub> batteries can still deliver a high discharge capacity of 400 mAh/g after 200 cycles at a current density of 0.5 C. The improved cycling stability can be attributed to the strong affinity towards lithium polysulfides (LiPSs) of the hydroxyl-rich PVA matrix and the unique double-layer structure, in which the bottom layer acts as an electrical insulation layer and the top layer coupled with MoS<sub>2</sub>/CNTs provides catalytic sites for LiPS conversion.
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