Preparation of Flexible Substrate Electrode for Supercapacitor With High-Performance MnO₂ Stalagmite Nanorod Arrays

A large-area MnO₂ stalagmite nanorod arrays (SNAs) growing vertically on flexible substrates were successfully fabricated by an easy heat-electrodeposition method. The large specific capacitance (646.4 F g^-1 at 500 mA g^-1) and excellent rate capability (42.3% retention with 40 times of increase) indicate that the prepared MnO₂ SNAs flexible electrode has outstanding electrochemical performance. Furthermore, after 5,000 repetitions of CV tests, the overall specific capacitance could retain ~101.2% compared with the initial value meant a long cycling life. These outstanding properties could be ascribed to the effective conductive transport path between Ni substrate and MnO₂ nanorods, and owing to the stalagmite like structure of MnO₂ nanorods, the exposed sufficient active sites are beneficial to the electrolyte infiltration.