超细氧化钌超电容器电极材料的制备

Prepatation of Ultra-Fine Ruthenium Oxide as an Electrode Material for Electrochemical Capacitors

本文采用利用氯化钌和碳酸氢氨为反应前驱体,溶胶凝胶方法制备了超细氧化钌材料。将材料在250℃下加热脱水处理后,材料具有良好的表面特性和最大电化学比容量570F·g-1。当脱水温度在300℃以上时,氧化钌材料明显晶化,同时材料比容量迅速降低。本文还测试了不同温度处理后材料的等效串联电阻和法拉第电化学阻抗特性,实验证明250℃条件下处理的电极材料具有最低的等效串联阻抗和良好的功率特性。当制备氧化钌过程中掺加适量碳纳米管形成复合材料时,电极材料的功率特性得到明显的改善。

The ruthenium oxide has been formed by a sol-gel process. The active electrode material was obtained by mixing aqueous solution of RuCl3 . xH(2)O and NH4HCO3. The fine hydrous ruthenium oxide powder with satisfactory electrochemical characteristic was obtained by annealing the powder at 250degreesC. The crystalline structure and the electrochemical properties of the powder have been studied as a function of the annealing temperature. At lower annealing temperatures, the powder is in an amorphous phase with a lower active surface area and poor electrochemical capacitance. When the ruthenium oxide was annealed at 250degreesC, the active surface area of the material is improved and the capacitance is calculated to be 570F . g(-1). when the annealing temperature exceeded 300degreesC, the typical crystalline phase was formed, and the specific capacitance dropped rapidly. The resistivity and the faradic impedance of the pellet made from RuO2 powder have also been studied. The lowest resistance was attained when the annealing temperature is 250degreesC. A capacitor was made with electrodes comprised of ruthenium oxide and 1mol . L-1 KOH electrolyte. It was also found that the addition of carbon nanotubes in ruthenium oxide can improve the power characteristics of electrode materials.