Metal-CO2 Batteries at the Crossroad to Practical Energy Storage and CO2 Recycle

Metal-CO2 batteries show great promise in meeting the growing energy, chemical, and environmental demands of daily life and industry, because of their advantages of high flexibility and efficiency in both energy storage and CO2 recycle applications. It has been a trend that Li/Na-CO2 and Zn/Al-CO2 systems show different developments to achieve practical energy storage (e.g., high electricity supply) and CO2 recycling (e.g., flexible chemical production), respectively, which is often neglected. This inhibits the application of metal-CO2 batteries in maximizing energy supply and value-added CO2 conversion. This progress report presents a critically selected overview of the individual developments of metal-CO2 batteries with emphasis on diverse fundamental origins, performance advantages, and the future of these two systems. Furthermore, the reaction pathways, particularly for catalytic materials, for the Li/Na-CO2 and Zn/Al-CO2 systems are discussed. Finally, the challenges of these two systems along with a hybrid Li/Na-CO2 battery design that may simultaneously provide high operating voltages and flexible chemicals are outlined.