Cerium-doped porous K-birnessite manganese oxides microspheres as pseudocapacitor electrode material with improved electrochemical capacitance

Cerium-doped nanosheet-based porous δ-MnO2 microspheres have been successfully prepared via a simple hydrothermal process. Electrochemical measurements showed that appropriate amount of cerium doping can significantly increase the speicific capacitance of δ-MnO2. It is found that 1.5% cerium-doped manganese oxides exhibit the best specific capacitance of 382.38 F g−1 at a current density of 1 A g−1. In terms of ion transport kinetics, cerium doping can shorten the diffusion path length and increase the ion transfer rate by changing the partical size, porosity density and conductivity of manganese oxides materials.