微型超级电容器PPy/GO-RuO_2复合膜电极的制备与电化学性能

Preparation and Electrochemical Performance of PPy/GO-RuO_2 Film Electrode for Micro-supercapacitor

为了解决氧化钌(RuO2)沉积电位过高,难以在三维微结构金属集流体上直接沉积的问题,提出采用分步电沉积方法在微三维结构镍(Ni)集流体上制备RuO2复合膜电极,即先在三维微结构Ni集流体上沉积聚吡咯/氧化石墨烯(PPy/GO)薄膜作为基底,经热处理后,在基底上二次沉积出RuO2颗粒,最后再对RuO2复合薄膜进行二次热处理。扫描电子显微镜(SEM)观察显示,随着热处理温度的升高,薄膜表面多孔结构增多,达到了提高膜电极结构孔隙分布的目的。能量分散谱(EDS)和X射线光电子能谱分析(XPS)表明,薄膜中无定形RuO2·x H2O的存在保证了膜电极的大比容量。电化学性能测试结果表明,经105℃处理后的膜电极电化学性能最佳,比电容为28.5 m F/cm2,能量密度为0.04 Wh/m2,功率密度为14.25 W/m2。采用分步电沉积方法制备出的RuO2复合薄膜是一种良好的MEMS超级电容器电极材料。

To address the issue that RuO2 was difficult to deposit directly on the micro-3D-structure metal current col- lector due to its high deposition potential, this study was engaged to prepare RuO2 composite film by the fractional electro-deposition method. PPy/GO film was firstly deposited on nickel current collector as substrate, then RuO2 parti- cles were deposited on the substrate after heat-treatment, finally the RuO2 composite film was carried on a second heat-treatment. By means of scanning electron microscope （SEM）, it can be found that the porous structures of RuO2 composite film multiply with the increase of heat-treatment temperature, so that the pore structure of the membrane electrode is improved. By means of X-ray energy dispersive spectroscope （EDS） and X-ray photoelectron spectroscope （XPS）, the results indicate that there exists amorphous RuO2＂xH20 in the film, which ensures the great specific capac- ity of the membrane electrode. The electrochemical testing results indicate that the electrochemical performance of membrane electrode is optimal when heat-treatment temperature reaches 105℃, with specific capacitance of 28.5 mF/cm2, energy density of 0.04 Wh/m2 and power density of 14.25 W/mz. The RuO2 composite film prepared by using step-by-step electro-deposition method is a type of excellent electrode material for micro-supercapacitor.