Multifunctional flame‐retardant co‐based interlayer for improving lithium−sulphur batteries performance

Abstract

AbstractLithium–sulphur batteries (LSBs) have elicited great interest due to their remarkably high energy density. However, challenges such as the dissolution of lithium polysulfides (LiPSs), low reaction kinetics, and safety concerns associated with LSBs impede large‐scale application. In this work, a multifunctional Co‐HP‐GC interlayer was prepared using evaporation, refluxing, and impregnation procedures. Notably, after ignition, this interlayer retained its structural integrity, indicative of excellent flame retardancy and thermal stability. Furthermore, the addition of cobalt atoms augmented the cyclic performance of the batteries by expediting the redox kinetics of LiPSs transformation and electron transfer at the interface. The electrodeposition capacity of Li2S cathode with Co‐HP‐GC interlayer reached up to 199.2 mAh g−1, higher than the 155.7 mAh g−1 achieved with a graphene oxide/carbonized fibre paper (G‐CCP) interlayer. This, in turn, curtails the shuttle effect whilst improving sulphur utilization. LSBs possessing a Co‐HP‐GC interlayer demonstrated superior cyclic and rate performance. At 0.5 C, the initial specific capacity of the battery fitted with a Co‐HP‐GC interlayer was 915.8 mAh g−1, with the rate of attenuation reduced by approximately half. The strategy integrates the multifunctional flame‐retardant interlayer into various battery systems, demonstrating wide‐ranging potential applicability within the realm of LSBs.