Joint Influence of Nitrogen Doping and Oxygen Vacancy on Manganese Dioxide as a High-Capacity Cathode for Zinc-Ion Batteries
Zining Zhang, Li Song, Bin Zhao, Xiaole Zhang, Xinyu Wang, Zhongsheng Wen, Shijun Ji, Juncai Sun
Abstract
Increasing active sites and defect control are both effective ways to enhance electrochemical performance. We introduce N doping and oxygen vacancy into electrolytic MnO2 simultaneously by a simple wet ball milling for the first time. The nanocomposites (named NEG) exhibit a high capacity of 360 mA h g–1 under 0.1 A g–1 current density which is much higher than the capacity in the theory of MnO2 (308 mA h g–1). By comparing the density functional theory calculations with the experimental data, we verify the adsorption between H+/Zn2+ and oxygen vacancies and identify that the oxygen vacancy-containing N-doped MnO2 has a much stronger adsorption effect on H+, which makes a major impact on the capacity storage. The study on the introduction of N dopants and oxygen vacancies might provide a novel idea in the development of manganese-based oxide electrode materials.