Durable Conductive Webs as Multifunctional Binder for the High-Performance Lithium-Sulfur Battery

Because of its high theoretical energy density, the Li-S battery (LSB) is regarded as one of the most promising next-generation energy-storage devices. However, LSBs undergo extreme electrochemical and physical changes in S during charge cycling, which limit battery performance. Here, we design a multifunctional polymer binder based on robust conductive webs comprising ring-opened poly(vinylpyrrolidone) (PVP) connected with reduced graphene oxide (rGO). By forming an intermolecular structure in the simultaneous reduction of GO and ring-opening of PVP, the PVP-rGO web provides high affinity to Li polysulfides, mechanical robustness, and facile electron transfer, which can overcome the performance issues of LSBs. The prepared Li-S cell with the PVP-rGO web as binder presents the remarkable specific capacity of 374 mAh g(-1) at 7 C and stable cycling performance with low capacity decay per cycle over 500 cycles at both 1 and 5 C.