• This review focuses on the design principles and basic characteristics of electrolytes, as well as how to construct a stable electrode–electrolyte interface. Perspectives on how electrolytes influence CO2 redox pathways are consolidated and proposed.
• The electrochemical reaction mechanism and interfacial evolution of nonaqueous metal–CO2 batteries in different electrolyte systems are highlighted.
• The electrode/electrolyte interface challenges encountered by nonaqueous metal–CO2 batteries are thoroughly discussed, along with corresponding optimization strategies.
• The review provides a comprehensive understanding of electrolytes and interface engineering toward practical applications of next-generation metal–CO2 batteries.