Na–CO2 battery with NASICON-structured solid-state electrolyte

Utilizing CO2 as cathode gas, Na–CO2 battery has been intensively studied due to its potential application in the exploration of Mars, where CO2 takes up 96% of the atmosphere. However, evaporation of the flammable liquid electrolyte restricts the practical application of the Na–CO2 battery. Herein, a solid-state Na–CO2 battery has been fabricated with the help of a plastic crystal electrolyte and kinetically stable interphase. The succinonitrile-based plastic crystal electrolyte interphase makes an intimate contact between Na3Zr2Si2PO12(NZSP) and cathode, thereby promotes the interfacial charge transfer. Simultaneously, the kinetically stable interphase on the anode side is revealed by the cooperation of theoretical calculation and experiments. The kinetically stable interphase protects the NZSP from the continuous interfacial parasitic reaction. The as-proposed solid-state Na–CO2 battery delivers a life span of 50 cycles at 100 mA g−1 with a potential gap of 1.4 V. This study makes solid-state electrolyte Na–CO2 battery an attractive prospect in future applications.