Understanding Electrolytes and Interface Chemistry for Sustainable Nonaqueous Metal-CO₂ Batteries

Metal-carbon dioxide (CO₂) batteries hold great promise for reducing greenhouse gas emissions and are regarded as one of the most promising energy storage techniques due to their efficiency advantages in CO₂ recovery and conversion. Moreover, rechargeable nonaqueous metal-CO₂ batteries have attracted much attention due to their high theoretical energy density. However, the stability issues of the electrode-electrolyte interfaces of nonaqueous metal-CO₂ (lithium (Li)/sodium (Na)/potassium (K)-CO₂) batteries have been troubling its development, and a large number of related research in the field of electrolytes have conducted in recent years. This review retraces the short but rapid research history of nonaqueous metal-CO₂ batteries with a detailed electrochemical mechanism analysis. Then it focuses on the basic characteristics and design principles of electrolytes, summarizes the latest achievements of various types of electrolytes in a timely manner and deeply analyzes the construction strategies of stable electrode-electrolyte interfaces for metal-CO₂ batteries. Finally, the key issues related to electrolytes and interface engineering are fully discussed and several potential directions for future research are proposed. This review enriches a comprehensive understanding of electrolytes and interface engineering toward the practical applications of next-generation metal-CO₂ batteries.