Durable Conductive Webs as Multifunctional Binder for the High-Performance Lithium–Sulfur Battery
Sungsik Choi, Soochan Kim, Misuk Cho, Youngkwan Lee
Abstract
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.