Direct and environmentally benign synthesis of manganese oxide/graphene composites from graphite for electrochemical capacitors

作者：Lee Hae Min; Jeong Gyoung Hwa; Kang Doo Won; Kim Sang Wook; Kim Chang Koo^*

来源：Journal of Power Sources, 2015, 281: 44-48.

DOI：10.1016/j.jpowsour.2015.01.155

• Manganese oxide
• Graphene
• Electrochemical capacitor
• Environmentally benign
• Specific capacitance
• Cycling stability

We develop a direct and environmentally benign method to prepare manganese oxide (Mn3O4)/graphene composites via one-step hydrothermal synthesis from graphite without using strong acids and toxic reducing agents. Structural and morphological analyses reveals that the irregularly shaped Mn3O4 nanoparticles are well-dispersed on the graphene flakes. Cyclic voltammetry and galvanostatic charge discharge tests indicate that the charge-storing mechanism of the Mn3O4/graphene composites is pseudocapacitive. The Mn3O4/graphene composite exhibits a specific capacitance of 367 F/g at a current density of 5 A/g. After 3000 charge discharge cycles, the Mn3O4/graphene electrode retains 91.8% of its initial specific capacitance. From electrochemical impedance spectra, it is evident that the changes in both the equivalent series resistance and charge-transfer resistance of the Mn3O4/graphene electrode before and after 3000 charge discharge cycles are small, indicating good cycling and electrochemical stability of the Mn3O4/graphene electrode.

• 出版日期2015-5-1