Abstract
As a promising candidate for high-energy-density rechargeable lithium metal batteries, Li/FeS(2) 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(2) 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(2) can be greatly enhanced with the application of a double-layer MoS(2)-CNTs-PVA (MCP)/PVA separator fabricated by electrospinning. The assembled Li/FeS(2) 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(2)/CNTs provides catalytic sites for LiPS conversion.