Controllable Synthesis of Nanostructured MnO2 as Electrode Material of Supercapacitors

In this study, MnO2 with different nanostructures (nanorods, nanospheres, nanoflowers, nanolychee) were obtained using a facile chemical method by adding different amounts of sulfuric acid for application in supercapacitors. Structure, morphology and composition were examined by X-ray diffractometer, Brunauer-Emmett-Teller, Fourier transform infrared, etc. Electrochemistry performances were tested by Autolab and LANHE CT2001A test system. Results indicated that the nanoflower MnO2 (F-MnO2) exhibited largest specific surface area, which was 83.17 m(2) g(-1) Electrode materials were tested in different electrolytes, including 6.0 M KOH, 1.0 M LiNO3 and 1.0 M LiOH. The F-MnO2 electrode material displayed the best electrochemical properties, and its specific capacitance was 171 F g(-1) at 1 A g(-1). Moreover, F-MnO2 electrode material showed splendid cycling durability was 130.9% of original value after 1000 cycles. These results demonstrated that the F-MnO2 electrode material should be a promising candidate for application in supercapacitors.