Cobalt-Doped Layered MnO2 Thin Film Electrochemically Grown on Nitrogen-Doped Carbon Cloth for Aqueous Zinc-Ion Batteries

The layered manganese dioxide (δ-type MnO 2 ) film electrodeposited on carbon cloth (CC) functioned as a cathode in aqueous zinc-ion batteries. Battery performance was notably improved by doping MnO 2 layers with cobalt and the CC surface with nitrogen. The δ-MnO 2 interlayer accommodated Zn 2+ ions in the as-deposited state and thus could act as an intercalation host during the discharging process. The Co-doped MnO 2 film on the nitrogen-doped CC delivered a discharge capacity as high as 280 mA h g –1 at a specific current of 1.2 A g –1 for 600 charge/discharge cycles, while the discharge capacity did not exceed 30 mA h g –1 even at a specific current as high as 10.5 A g –1 . These values are superior to those observed in the absence of doping, demonstrating the positive impact of Co- and N-doping into the MnO 2 layers and the CC substrate on the cycling stability and rate capability.