A simple physical mixing method for MnO2/MnO nanocomposites with superior Zn2+ storage performance
(1. School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China;
2. University Lille, CNRS UMR 8520-IEMN, Lille, F-59000, France)
2. University Lille, CNRS UMR 8520-IEMN, Lille, F-59000, France)
Abstract: MnO2/MnO cathode material with superior Zn2+ storage performance is prepared through a simple physical mixing method. The MnO2/MnO nanocomposite with a mixed mass ratio of 12:1 exhibits the highest specific capacity (364.2 mA·h/g at 0.2C), good cycle performance (170.4 mA·h/g after 100 cycles) and excellent rate performance (205.7 mA·h/g at 2C). Analysis of cyclic voltammetry (CV) data at various scan rates shows that both diffusion- controlled insertion behavior and surface capacitive behavior contribute to the Zn2+ storage performance of MnO2/MnO cathodes. And the capacitive behavior contributes more at high discharge rates, due to the short paths of ion diffusion and the rapid transfer of electrons.
Key words: zinc-ion battery; MnO2/MnO cathode material; physical mixing method; reaction kinetics