Facile Preparation of MnO2 with Large Surface Area in a Rotor Stator Reactor for Supercapacitors

Facile preparation of MnO2 with large specific surface area was explored in a rotor-stator reactor (RSR). The MnO2 product was characterized by FESEM, TEM, XRD, XPS, TG, FTIR and automated surface area and pore size analyzer. The electrochemical performance of the as-prepared MnO2 nanospheres as an electrode material for supercapacitors was investigated using three-electrode and two-electrode methods. The results show that the MnO2 nanospheres were well dispersed and had a surface area of 337.01 m(2) g(-1). The specific capacitance was as high as 320.7 F g(-1) at 0.3 A g(-1) and 477.5 F g(-1) at 5 mV s(-1). The as-prepared MnO2 also exhibited good stability with 107.4 % capacitance retention after 1000 cycles. Moreover, the MnO2//active carbon asymmetric supercapacitor in 1 M Na2SO4 electrolyte showed a maximum energy density of 27.23 W h kg(-1) and correspondingly power density was 225 W kg(-1).