α型二氧化锰的制备及电化学性能研究

Preparation and electrochemical properties of α-MnO_2

选用过硫酸钾(K_2S_2O_8)和一水合硫酸锰(MnSO_4·H_2O)为原材料,通过液相共沉淀法制得MnO_2,用X射线衍射和扫描电镜对制得的MnO_2进行结构形貌表征。结果表明,在控制溶液p H值为l,反应温度为60℃,反应时间为22 h的条件下,制得的四方晶系α-MnO_2微球的表面具有明显的纳米刺结构特征。将所制得的四方晶系α-MnO_2用于超级电容器的电极材料,以6 mol/L的KOH作为电解质溶液,研究其恒电流充放电、循环伏安及交流阻抗等电化学性能,当扫描速度为5 m V/s时,其比容量为156.0 F/g。

Electrode material of MnO_2 microspheres were synthesized via a simple liquid phase co- precipitation method by using K_2S_2O_8 and Mn SO_4·H_2O as raw material. The products were characterized by XRD and SEM. Results show that the α-MnO_2 in tetragonal system with obvious nanothorn structure are obtained under the conditions of p H value of l,reaction temperature of 60 ℃ and reaction time of 22 h. The obtained α-MnO_2 was then applied as the electrode material for supercapacitors,with 6 mol/L KOH as electrolyte solution,the electrochemical characterization was carried out using galvanostatic charge- discharge cycling,cyclic voltammetry and impedance spectroscopy. Its specific capacitance is 156.0 F/g at the scanning rate of 5 m V/s.