Fabrication,characterization and electrochemical behavior of <i>δ</i>-MnO₂ nanoflakes

• Main Authors: CHEN Xiang, YAN Shao-jiu, WANG Nan, PENG Si-kan, WANG Chen, WU Guang-ming, DAI Sheng-long
• Format: Article
• Language: zho
• Published: Journal of Materials Engineering 2019-02-01
• Series: Journal of Materials Engineering
• Subjects: manganese dioxide; lamellar nanoflake; supercapacitor; energy storage electrode material
• Online Access: http://jme.biam.ac.cn/CN/Y2019/V47/I2/49

Two types of ultrathin-flaky <i>δ</i>-MnO₂ electrode materials (denoted as <i>δ</i>-MnO₂-A and <i>δ</i>-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 <i>δ</i>-MnO₂ electrode materials own similar specific capacitance and rate capability.Comparing to <i>δ</i>-MnO₂-A,however,electrode material <i>δ</i>-MnO₂-B contains a higher potassium and manganese vacancy content,and the lamellar structure of <i>δ</i>-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 <i>δ</i>-MnO₂ reaches 227F&#183;g^-1(1mV&#183;s^-1) and the capacitance retention rate is achieved 87.6% after 5000 cycles at 100mV&#183;s^-1.