Redox-active metal–organic framework as an anode-active material for rechargeable aqueous manganese dioxide batteries with very high-rate capabilities

Abstract

Rechargeable aqueous manganese-based batteries are attracting considerable attention because they consist of Earth-abundant elements, are environmentally friendly, and exhibit high theoretical capacity. To avoid deteriorating battery performance owing to dendrite formation on the zinc anode surface, organic-manganese dioxide batteries using redox-active organic materials as the anode-active material feature dendrite-free and highly durable charge storage. However, organic anode-active materials usually suffer from poor counterion diffusion, and their low conductivity prevents electron conduction to the interior of the materials, rechargeable aqueous organic-manganese dioxide batteries exhibiting a discharge capacity close to the theoretical capacity and high coulombic efficiency have not been previously achieved. In the current work, we fabricated a novel rechargeable aqueous metal–organic framework (MOF)-manganese dioxide battery with a redox-active MOF as the anode-active material, which provided pores for efficient ion diffusion and a small particle size to promote electron conduction throughout the material. The developed battery exhibited a discharge capacity close to theoretical capacity (>99% of the theoretical capacity), high coulombic efficiency (99%), and high-rate capabilities, while maintaining high cyclability.