A comparison study of MnO(2) and Mn(2)O(3) as zinc-ion battery cathodes: an experimental and computational investigation

The high specific capacity, low cost and environmental friendliness make manganese dioxide materials promising cathode materials for zinc-ion batteries (ZIBs). In order to understand the difference between the electrochemical behavior of manganese dioxide materials with different valence states, i.e., Mn(iii) and Mn(iv), we investigated and compared the electrochemical properties of pure MnO(2) and Mn(2)O(3) as ZIB cathodes via a combined experimental and computational approach. The MnO(2) electrode showed a higher discharging capacity (270.4 mA h g(−1) at 0.1 A g(−1)) and a superior rate performance (125.7 mA h g(−1) at 3 A g(−1)) than the Mn(2)O(3) electrode (188.2 mA h g(−1) at 0.1 A g(−1) and 87 mA h g(−1) at 3 A g(−1), respectively). The superior performance of the MnO(2) electrode was ascribed to its higher specific surface area, higher electronic conductivity and lower diffusion barrier of Zn(2+) compared to the Mn(2)O(3) electrode. This study provides a detailed picture of the diversity of manganese dioxide electrodes as ZIB cathodes.