MnO2@polypyrrole composite with hollow microsphere structure for electrode material of supercapacitors

In this work, a new MnO2@polypyrrole mesoporous composite with hollow microsphere structure is synthesized using PS (polystyrene) beads as the hard template. In 1 M Na2SO4 solution, it exhibits a specific capacitance value of 295F g−1 at the current density of 1 A g−1. After 20,000 charge/discharge cycles at the current density of 10 A g−1, the capacitance retention rate is 100%. The MnO2@H-PPy (1:4)-based asymmetric supercapacitor shows a specific capacitance of 63F g−1 in a potential window of 0 to + 2.2 V at the current density of 1 A g−1. The energy density is 42 Wh kg−1 and the power density is 1100 W kg−1, which proved to be a promising candidate for the electrode materials in supercapacitor applications.