Controlled growth of MnO2 via a facile one-step hydrothermal method and their application in supercapacitors

MnO2 is successfully synthesized by one-step hydrothermal process. By varying reaction temperature and time, the shape control of MnO2 structures have been achieved, which produces flower-like, urchin-like and nanorod-like structures. The effects of the reaction temperature and time on the morphology and electrochemical performance are investigated. The morphology of MnO2 is shown to play a dominate role in the electrochemical performance. The flower-like MnO2 shows a high specific capacitance of 495 F g−1 at current density of 1 A g−1, and 91% retention after 1000 charge-discharge cycles, which is promising for application in supercapacitors.