Development of a lithium-oxygen battery with an improved redox mediator applicable to gel polymer electrolytes

Abstract

Lithium-oxygen batteries (LOBs) are next-generation electrochemical power sources with significantly high capacities and energy densities. In particular, Li2O2 produced during charging exhibits a low electrical conductivity and insolubility, which leads to low energy efficiency in LOBs. Thus, various catalysts are studied to solve essential problems such as the sluggish decomposition rate of Li2O2. In this study, a redox polymeric catalyst (RPC-FePc) is fabricated on an air electrode by combining iron(Ⅱ) phthalocyanine (FePc) as the redox mediator and polyvinylidene fluoride as the binder. The RPC-FePc applied to liquid electrolyte- and gel polymer electrolyte-based LOBs exhibit improved electrochemical properties, that is, increased cycling efficiencies and a reduced IR drop, compared to an RPC-free LOB. © 2022 The Korean Society of Industrial and Engineering Chemistry