(中南大学 材料科学与工程学院,长沙 410083)
摘 要: 以RuCl3·3H2O水溶液为电沉积液,采用直流−示差脉冲组合电沉积技术,通过后续热处理工艺制备超级电容器用钽基RuO2·nH2O薄膜电极材料。用X射线衍射仪 (XRD)、红外光谱仪 (FTIR)、差热分析仪 (DTA)、扫描电镜 (SEM)和电化学分析仪,研究前驱体RuCl3·cH2O转化为RuO2·nH2O的物相演变行为以及微观组织形貌和循环伏安性能。结果表明:随着热处理温度升高,前驱体RuCl3·cH2O通过4步反应转变成RuO2·nH2O薄膜;该薄膜经历从无定形向晶体结构的转变。经300 ℃热处理的RuO2·nH2O薄膜电极材料的单位面积质量为2.5 mg/cm2,比电容达到512 F/g;当电压扫描速率从5 mV/s增加到250 mV/s 时,其比电容下降34%。
关键字: 水合氧化钌;薄膜材料;热处理;超级电容器;物相演变
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract:As a good electrode material for supercapacitor, RuO2·nH2O film was deposited on tantalum foils in aqueous solution of RuCl3·3H2O by galvanostatic-differential pulse voltammetry and heat treatment. The phase transition, surface morphology and cyclic voltammetric performance from precursor RuCl3·cH2O to amorphous and crystalline RuO2·nH2O of the developed film were studied with X-ray diffractometer (XRD), infrared spectrometer (FTIR), differential thermal analyzer (DTA), scanning electron microscope (SEM) and electrochemical analyzer, respectively. The results show that the precursor RuCl3·3H2O film transforms into RuO2·nH2O through four reactions, including one from amorphous to crystal phase change with the increase of temperature. After being heat treated at 300 ℃, surface mass of the RuO2·nH2O film electrode material is 2.5 mg/cm2 with a specific capacitance of 512 F/g. The specific capacitance of the RuO2·nH2O film decreases by 38% when the voltage scan rate increases from 5 mV/s to 250 mV/s.
Key words: RuO2·nH2O; film material; heat treatment; supercapacitor; phase evolution