超级电容器电极材料纳米α-MnO_2的制备及性能研究

Studies on Preparation and Electrochemical Properties of Nanosized α-MnO_2 as of Supercapacitor Electrode Materials

用溶胶-凝胶法和沉淀法制备了具有纳米结构的α-MnO2,分别对其进行X-射线衍射(XRD)、扫描电镜(SEM)、循环伏安(CV)等测试,结果发现溶胶-凝胶法所合成的材料是由粒径为60nm的微粒组成,沉淀法所合成的材料粒径在80nm范围.并研究了不同配比的α-MnO2和活性炭组成的复合电极在各种浓度的电解液中的循环伏安性能,发现当电极中α-MnO2质量百分含量为40%～60%时,在0.5mol/LNa2SO4、2.0mol/L(NH4)2SO4、1.0mol/LKCl溶液中的比电容较高,其中在2.0mol/L(NH4)2SO4溶液中的比电容最高可达108.26F/g.

In this paper,α-MnO_(2 )was synthesized by sol-gel and coprecipitation techniques, respectively. XRD, SEM and cyclic voltammetry have been used to characterize the performances of the materials. The results showed that the material formed by sol-gel method was comprised of 60 nm particles, and the material formed by coprecipitation was consisted of 80 nm particles. The specific capacitance of the materials were investigated in 0.5 mol/LNa_(2)SO_(4), 2.0 mol/L (NH_(4))_(2)SO_(4) and 1.0 mol/L KCl electrolytes by cyclic voltammetry. Results indicated α-MnO_(2 )composite electrodes mixing active carbon at 40%～60% had high specific capacitance, especially the maximal specific capacity (108.26 F/g) could be obtained in 2.0 mol/L (NH_(4))_(2)SO_(4) electrolyte.