1 Research Center of Graphene Applications, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China 2 Jiangxi Power Transmission & Transformation Construction Company, Nanchang 330200, China
Two types of ultrathin-flaky δ-MnO2 electrode materials (denoted as δ-MnO2-A and δ-MnO2-B) were synthesized through the reduction of potassium permanganate with manganese acetate and ethanol separately.The crystalline structure, chemical component, microstructure and pore size distribution of these nano-materials were determined by XRD, XPS, SEM/TEM and BET analysis.The electrochemical test demonstrates two δ-MnO2 electrode materials own similar specific capacitance and rate capability.Comparing to δ-MnO2-A, however, electrode material δ-MnO2-B contains a higher potassium and manganese vacancy content, and the lamellar structure of δ-MnO2-B is more legible and stable, therefore it displays a much more superior cycling stability.In 0.5mol/L Na2SO4 electrolyte, the specific capacitance of δ-MnO2 reaches 227F·g-1(1mV·s-1) and the capacitance retention rate is achieved 87.6% after 5000 cycles at 100mV·s-1.
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2019, Vol. 47 
), 王楠1, 彭思侃1, 王晨1, 吴广明2, 戴圣龙1
