石墨烯超级电容器的性能研究与优化

发布时间：2018-06-23 09:02

本文选题：超级电容器 + 石墨烯　；参考：《北京交通大学》2014年硕士论文

【摘要】：石墨烯的高电导率和高比表面积的特性使其非常适合做超级电容器的电极,如何实现高质量石墨烯的量产是现今研究的热点。本文以改进的Hummers法制备氧化石墨,通过管式炉高温还原法制备石墨烯,并对所得产物进行XRD、SEM、TEM表征和BET比表面积测试,测得石墨烯比表面积高达853m2/g。泡沫镍和铝箔是两种常用的集流体材料,铝箔相比于泡沫镍拥有更高的电导率,但是铝箔表面过于光滑不利于活性物质粘附,本文制备了基于石墨烯的双电层的超级电容器；并通过电化学方法对铝箔表面进行刻蚀来提升超级电容器性能。具体研究内容如下： (1)分别采用1.Omol/L和1.5mol/L的Na2SO4溶液做超级电容器的电解液,并对比两种超级电容器的电化学性能,结果证明1.0mol/L的Na2SO4溶液更适合做超级电容器电解液。 (2)分别采用泡沫镍和铝箔做集流体制备超级电容器并测试两者的电化学性能,结果表明泡沫镍比未经刻蚀的铝光箔拥有更好的电化学性能,因此可以考虑对铝箔进行电化学刻蚀来提升铝箔超级电容器的电化学性能。 (3)通过对铝箔进行电化学刻蚀,分析刻蚀溶液的浓度比、时间以及电流密度对电容性能的影响来找出相对优化的刻蚀工艺：在刻蚀条件为HCl、H2SO4浓度比为3：1,刻蚀电流密度为70mA/cm2,刻蚀时间为140s时所得到的铝箔具备最佳的电容性能。
[Abstract]:Graphene is suitable for supercapacitor because of its high conductivity and high specific surface area. Graphite oxide was prepared by modified Hummers method and graphene was prepared by high temperature reduction in tube furnace. The obtained products were characterized by XRDX SEMTEM and BET specific surface area. The specific surface area of graphene was up to 853 m2 / g. Foamed nickel and aluminum foil are two common fluid-collecting materials. Aluminum foil has higher conductivity than foamed nickel, but the surface of aluminum foil is too smooth and not conducive to the adhesion of active substances. In this paper, a double-layer supercapacitor based on graphene was prepared. The surface of aluminum foil was etched by electrochemical method to improve the performance of supercapacitor. The main contents of the study are as follows: (1) the electrolyte of supercapacitor was made by using 1.Omol / L and 1.5 mol / L Na _ 2SO _ 4 solution, and the electrochemical performance of the two supercapacitors was compared. The results show that 1.0 mol / L Na _ 2SO _ 4 solution is more suitable for supercapacitor electrolyte. (2) supercapacitors are prepared by using foamed nickel and aluminum foil as collector and their electrochemical properties are tested. The results show that foamed nickel has better electrochemical performance than unetched aluminum foil. Therefore, electrochemical etching of aluminum foil can be considered to improve the electrochemical performance of aluminum foil supercapacitor. (3) through electrochemical etching of aluminum foil, the concentration ratio of etching solution is analyzed. The effects of time and current density on the capacitance performance were found out. The optimum etching process was obtained under the conditions of HClH2SO4 concentration ratio of 3: 1, etching current density of 70 Ma / cm 2 and etching time of 140 s. The results show that the aluminum foil has the best capacitive performance when the etching condition is 3: 1, the current density is 70 Ma / cm 2, and the etching time is 140 s.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53

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