Lignocellulose-based gel polymer electrolyte composited by a special additive of elemental sulfur with outstanding performances in lithium–sulfur batteries

Abstract

Gel polymer electrolyte (GPE) based on polymer matrix of lignocellulose and gelatinized potato starch is prepared, and elemental sulfur is introduced as an additive for the first time. The polymer matrix has shown excellent performances including liquid electrolyte uptake, tensile strength and thermal stability. The ionic conductivity and electrochemical stability window of the corresponding GPE are improved with the introduction of the elemental sulfur. Furthermore, the addition of elemental sulfur can be reduced into short-chain Li2S and Li2S2 on the surface of lithium anode to further elevate the capacity of battery. Meanwhile, the short-chain Li2S and Li2S2 in the solid electrolyte interphase (SEI) film on the surface of lithium metal can improve SEI’s mechanical properties and the interface compatibility between GPE and lithium metal. The multi-component synergistic effect of GPE provides the battery with superior cycle stability and excellent electrochemical performances. Bio-based GPE will exhibit a promising and alternative way for the practical application of lithium–sulfur batteries.