Interfacial construction of Li2O2 for a performance-improved polymer Li-O-2 battery

Compared with conventional nonaqueous Li-O-2 batteries using organic liquid electrolytes, polymer Li-O-2 batteries have been considered as ideal alternatives based on the consideration of safety issues. However, high interfacial resistances and severe overpotential build-up during cycling remain unsolved problems for their future application. Much less attention has been devoted to the interfacial chemistries in polymer Li-O-2 batteries. In this study, interfacial engineering was elaborately carried out for the design and construction of a Li-O-2 battery with the aim of decreasing the overpotential and achieving a highly efficient polymer Li-O-2 battery. A dramatically decreased overpotential (terminal voltage of charge lower than 4 V vs. Li/Li+) was obtained in a polymer Li-O-2 battery assembled with a stable redox mediator decorated polymer electrolyte and a high catalytic RuO2@reduced graphene oxide based cathode for the first time. The feasibility study demonstrated that interfacial construction could be used as a promising alternative strategy for the development of a polymer Li-air battery.