High specific capacity and mechanism of a metal-organic framework based cathode for aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage due to their high safety and low cost but the reported cathode materials still suffer from limited specific capacities and poor cycle performance. Herein, the Mn-based metal-organic framework (MOF), MOF-73, is used for the first time to make a novel cathode for AZIBs and its great capacity enhancement mechanism is investigated. Results show that MOF-73 can render a voltage plateau of similar to 1.45 V and induce manganese ions to co-contribute a high-specific capacity of 815 mA h g-1 (0.84 mA h cm-2). This work sheds light on the fundamentals of the electrochemical zinc energy storage of MOFs while holding great promise for exploring novel MOFs as cathodes for AZIBs. MOF-73 is explored as a novel cathode for aqueous zinc-ion batteries, and a co-contribution zinc ion storage mechanism is illustrated.