Rechargeable Al-CO 2 Batteries for Reversible Utilization of CO 2 .

The excessive emission of CO2 and the energy crisis are two major issues facing humanity. Thus, the electrochemical reduction of CO2 and its utilization in metal-CO2 batteries have attracted wide attention because the batteries can simultaneously accelerate CO2 fixation/utilization and energy storage/release. Here, rechargeable Al-CO2 batteries are proposed and realized, which use chemically stable Al as the anode. The batteries display small discharge/charge voltage gaps down to 0.091 V and high energy efficiencies up to 87.7%, indicating an efficient battery performance. Their chemical reaction mechanism to produce the performance is revealed to be 4Al + 9CO2 ↔ 2Al2 (CO3 )3 + 3C, by which CO2 is reversibly utilized. These batteries are envisaged to effectively and safely serve as a potential CO2 fixation/utilization strategy with stable Al.