多孔不锈钢基二氧化锰薄膜电极的制备及电容特性

Fabrication and Capacitive Characteristics of a Porous Stainless Steel-supported MnO_2 Thin Film Electrode

用电化学方法制备了一种多孔不锈钢基二氧化锰薄膜电极。在不锈钢基体上以聚乙二醇辛基苯基醚(Triton X-100)在水溶液中形成的液晶作掩膜,通过电化学腐蚀制备了多孔基体电极,用恒电位方法在基体上沉积二氧化锰薄膜。用扫描电子显微镜对二氧化锰薄膜电极形貌进行了考察,循环伏安法和充放电曲线法测试了二氧化锰薄膜电极的电容。结果表明,腐蚀后的不锈钢基体呈现多孔特征,孔分布无规律,孔径大小从几十纳米到几百纳米不等,沉积的二氧化锰呈颗粒状,直径为80～90 nm。扫描速率为20 mV/s,沉积电量0.4 C/cm2时,循环伏安法测得的二氧化锰薄膜电极的质量比电容达400 F/g;沉积电量4～5 C/cm2时,面积比电容达到320×10-3F/cm2,此时的质量比电容仍保持在200 F/g左右。实验结果表明,多孔不锈钢基二氧化锰薄膜电极在超级电容器领域有潜在的应用前景。

One porous stainless steel-supported manganese dioxide thin film electrode,fabricated by electrochemical method was evaluated as a potential electrode for electrochemical capacitors.The porous stainless steel substrate electrode was obtained by mask electrolysis in the sodium chloride solution containing a lyotropic liquid crystalline phase of p-tert-alkylphenoxy poly（oxyethylene） ether（Triton X-100）.Manganese dioxide film was electrodeposited on porous stainless steel substrate under a potentiostatic mode.Liquid crystalline phases were examined using XP-330C polarizing microscope at room temperature.The surface morphologies of the electrode were characterized by SEM.The capacity of manganese oxide film electrode was investigated by cycle voltammetry and constant-current charge-discharge method in potassium sulfate solutions.The results showed that stainless steel exhibited a highly porous surface morphology with an irregular pore size in a range of tens nanometer to hundreds nanometer after electrochemical erosion with liquid crystal mask.The deposited manganese oxide film consisted of spherical particles with an average size of 80～90 nm.The manganese oxide film electrode presents a specific capacitance of 400 F/g when the charge consumed is 0.4 C/cm2 in electro deposition.The highest capacitance of 320×10-3 F/cm2 could be obtained by cycle voltammetry at a scan rate of 20 mV/s,corresponding to a specific capacitance of 200 F/g.The porous stainless steel-supported manganese dioxide electrode shows promising applications in electrochemical super capacitors.