High-Efficiency Rechargeable Fe-CO₂ Battery: A Route for Effective CO₂ Conversion and Energy Storage

Abstract

Because of their high theoretical energy density, metal-CO 2 batteries based on Li, Na, or K have attracted increasing attention recently for meeting the growing demands of CO 2 recycling and conversion into electrical energy. However, the scarcity of active anode material resources, high cost, as well as safety concerns of Li, Na, and K create obstacles for practical applications. Herein, we demonstrate for the first time a highefficiency (η = 77.2%) rechargeable Fe-CO 2 battery that is composed of iron (Fe) anode and MoS 2 -catalysts deposited carbon cathode. MoS 2 catalysts are crucial to the successful acceleration of reaction kinetics of Fe during charge and discharge with a minimum overpotential of the cell. The Fe-CO 2 cell has a higher initial specific capacity of 12,500 mA h g −1 with an average discharge potential of 0.65 V and operates reversibly with a lower overpotential than that of Li-CO 2 batteries with a cutoff capacity of 500 mA h g −1 . Our Fe-CO 2 battery can effectively convert CO 2 greenhouse gas into electrical energy by consuming 1 ton of CO 2 with usage of 1.23 tons of iron.