發(fā)布時間：2018-02-25 05:01

  本文關(guān)鍵詞： 超級電容器 石墨烯 宏觀體 孔結(jié)構(gòu) 表面化學 二氧化錳　出處：《天津大學》2014年博士論文　論文類型：學位論文

【摘要】：超級電容器作為一種綠色儲能器件，其性能主要依賴于電極材料。石墨烯作為sp2雜化碳質(zhì)材料的基元單位，具有獨特的二維結(jié)構(gòu)和優(yōu)異的物化特性，使得其在超級電容器領(lǐng)域具有巨大的應(yīng)用潛力。盡管目前石墨烯的結(jié)構(gòu)特征和物化性質(zhì)可以得到有效調(diào)控，然而其作為超級電容器電極材料的實際比電容均與理論值存在一定差距，能量密度偏低。針對這些不足，本論文主要以石墨烯基碳質(zhì)材料作為超級電容器電極材料，，探討其電化學儲能機理，可控構(gòu)建結(jié)構(gòu)獨特的電極材料，使其性能得以優(yōu)化，組裝高性能超級電容器。 在石墨烯基碳質(zhì)電極材料儲能機制方面：（1）論文以兩種極限結(jié)構(gòu)石墨烯基碳質(zhì)材料作為模板電極材料，考察了它們在水系電解液中的電化學特性，提出表面化學是影響完全外表面無孔炭電化學性能的決定因素，孔結(jié)構(gòu)決定了完全內(nèi)表面微孔炭的電化學行為，孔結(jié)構(gòu)和表面化學協(xié)同影響其電容特性。（2）全面考察了微觀結(jié)構(gòu)、比表面積和含氧官能團對層次孔石墨烯宏觀體電化學性能的影響，通過提高電極材料表面含氧官能團的濃度，可增加電極材料的親水特性，降低電解質(zhì)離子的擴散阻力，提高電極材料的比電容和倍率性能。 在超級電容器電極材料可控制備及應(yīng)用方面：（1）以結(jié)構(gòu)致密但孔隙發(fā)達的高密度多孔石墨烯宏觀體直接作為超級電容器電極材料，其表現(xiàn)出超高體積比電容，并組裝了高體積能量密度超級電容器。依據(jù)相同的脫水機制，以石墨烯宏觀體作為支撐骨架，均勻負載金屬氧化物納米粒子，利用溶液浸漬法制備了超高密度的RuO2/石墨烯復(fù)合宏觀體，二者的協(xié)同儲能效應(yīng)確保了該復(fù)合材料具有超高體積能量密度和功率密度。（2）以三維結(jié)構(gòu)石墨烯水凝膠作為反應(yīng)物和模板，在溫和條件下，發(fā)展了新型反應(yīng)性模板法，制備了三維多孔MnO2納米材料，該材料表現(xiàn)出良好的電化學性能，其優(yōu)異的倍率性能大大拓展了MnO2的應(yīng)用范圍。通過調(diào)整反應(yīng)物的摩爾比，可以獲得三維結(jié)構(gòu)MnO2/石墨烯復(fù)合宏觀體。
[Abstract]:As a kind of green energy storage device, the performance of supercapacitor mainly depends on the electrode material. As the unit of sp2 hybrid carbon material, graphene has unique two-dimensional structure and excellent physical and chemical properties. It has great potential for application in the field of supercapacitors, although the structure and physicochemical properties of graphene can be effectively regulated at present. However, the actual specific capacitance of the supercapacitor electrode material is far from the theoretical value and the energy density is low. In view of these shortcomings, the graphene based carbonaceous material is mainly used as the electrode material of the supercapacitor in this paper. The mechanism of electrochemical energy storage was discussed, and the electrode material with unique structure was constructed, which made the performance optimization and assembled high performance supercapacitor. In the aspect of energy storage mechanism of graphene based carbon electrode materials, two kinds of limit structure graphene based carbon materials were used as template electrode materials to investigate their electrochemical characteristics in aqueous electrolyte. It is suggested that surface chemistry is the decisive factor affecting the electrochemical performance of porous carbon on the complete outer surface. The pore structure determines the electrochemical behavior of the microporous carbon on the complete inner surface, and the pore structure and surface chemistry synergistically affect the capacitance characteristics of the carbon. The effect of specific surface area and oxygen-containing functional groups on the electrochemical properties of macroporous graphene macrobodies was investigated. By increasing the concentration of oxygen-containing functional groups on the surface of electrode materials, the hydrophilicity of electrode materials was increased and the diffusion resistance of electrolyte ions was reduced. The specific capacitance and rate performance of electrode materials are improved. In the field of controllable preparation and application of electrode materials for supercapacitors, the macroporous graphene with dense structure but well developed pores is directly used as electrode material for supercapacitor, which shows ultra-high volume specific capacitance. A high volume energy density supercapacitor was assembled. According to the same dehydration mechanism, the graphene macrostructure was used as the support skeleton, and the metal oxide nanoparticles were uniformly loaded. The ultrahigh density RuO2 / graphene composite macrostructure was prepared by solution impregnation method. The synergistic energy storage effect between the two materials ensures that the composite has ultra-high volume energy density and power density. The novel reactive template method has been developed under mild conditions using three-dimensional graphene hydrogels as reactants and templates. Three-dimensional porous MnO2 nanomaterials have been prepared. The materials exhibit good electrochemical properties, and their excellent rate performance greatly expands the scope of application of MnO2. By adjusting the molar ratio of reactants, Three dimensional structure MnO2 / graphene composite macrostructure can be obtained.
【學位授予單位】：天津大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TQ127.11;TM53

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本文編號：1533072