石墨烯及其在活性炭基超级电容器中的性能与应用

发布时间：2018-01-15 11:42

本文关键词：石墨烯及其在活性炭基超级电容器中的性能与应用　出处：《宁波大学》2014年硕士论文　论文类型：学位论文

【摘要】：本论文研究探索石墨烯的合成、表征、改性及其在超级电容器中的应用。采用金属焰还原法及化学氧化还原制备高导电性能石墨烯，并将其作为导电剂与活性炭复合使活性炭基超级电容能获得更优异的性能。（1）通过研究YP型活性炭与8B型活性炭超级电容器在6M KOH水系，1MEt4NBF4/PC有机系及EMI-TFSI离子液体电解液中的比电容、等效串联电阻及倍率性能等电化学性能，我们发现与8B型活性炭相比，YP型活性炭有着较为优异的倍率性能，这与YP型活性炭的中孔含量、电解液离子尺寸、碳粒粒径、表面含氧官能团及石墨微晶结构有着最为直接的关系。（2）采用金属镁与干冰燃烧热反应制备出少层石墨烯。少层石墨烯是在反应生成的氧化镁基底上沉积生长而成。少层石墨烯作为超级电容器的电极材料时，因不可逆团聚的影响，其比电容仅稍低。然而，当应用少层石墨烯做导电填充剂时，其与活性炭的复合电极材料可以得到较高的比电容，这是一种提高活性炭电极材料的电容性能的新设计。（3）此外，我们研究比较了石墨烯、单壁碳纳米管、乙炔黑及石墨等碳素材料作为活性炭电极的导电剂时，它们对活性炭基超级电容器的电化学性能的影响及机理。借助超声辅助制备复合材料时，石墨烯与活性炭内部产生分布的三维孔洞结构对提高超级电容器的性能有极大的好处，导致石墨烯与活性炭复合结构一方面有助于改善电解液的浸润；另一方面，微波石墨烯贡献了比电容并提高了活性炭电极的导电性。（4）采用非化学反应交联剂，，即交联剂与氧化石墨烯不发生化学作用，制备了石墨烯气凝胶。当采用聚四氟乙烯等粘结高分子聚合物时，通过控制其与氧化石墨烯的质量比，可成功制得氧化石墨烯溶胶，然后经过冷冻干燥、还原得到石墨烯气凝胶。与通过化学交联反应生成的石墨烯气凝胶相比，该石墨烯气凝胶具有更好的电化学性能。
[Abstract]:In this paper, the synthesis, characterization, modification and application in supercapacitors of graphene were studied. High conductive graphene was prepared by metal flame reduction and chemical redox. The supercapacitor based on activated carbon can obtain better performance when it is used as conductive agent and activated carbon. Through the study of YP type activated carbon and 8B type activated carbon supercapacitor in 6m KOH water system. 1Electrochemical properties of MEt4NBF4 / PC organic system and EMI-TFSI ionic liquid electrolyte, such as specific capacitance, equivalent series resistance and rate performance, were found to be compared with 8B type activated carbon. YP type activated carbon has excellent rate performance, which is directly related to the mesoporous content of YP type activated carbon, the ionic size of electrolyte, the particle size of carbon particle, the oxygen functional group on the surface and the structure of graphite microcrystal. (2) the low layer graphene was prepared by the combustion heat reaction of magnesium and dry ice. The low layer graphene was deposited on the reactive magnesium oxide substrate, and the low layer graphene was used as the electrode material of the supercapacitor. Due to irreversible agglomeration, its specific capacitance is only slightly lower. However, when the less layer graphene is used as conductive filler, the composite electrode material with activated carbon can get higher specific capacitance. This is a new design to improve the capacitance performance of activated carbon electrode materials. In addition, we studied and compared carbon materials such as graphene, single-walled carbon nanotubes, acetylene black and graphite as conductive agents for activated carbon electrodes. Their effect on the electrochemical properties of activated carbon based supercapacitors and their mechanism. The three-dimensional pore structure in graphene and activated carbon has great benefits to improve the performance of supercapacitors, which leads to the composite structure of graphene and activated carbon, on the one hand, to improve the infiltration of electrolyte. On the other hand, microwave graphene contributes specific capacitance and improves the conductivity of activated carbon electrode. The graphene aerogel was prepared by using non-chemical crosslinking agent, that is, the crosslinking agent did not react chemically with graphene oxide, when the polymer was bonded with polytetrafluoroethylene (PTFE). By controlling the mass ratio of graphene oxide to graphene oxide, the graphene oxide sol can be prepared successfully, and then freeze-dried, then reduced to a graphene aerogel, which is compared with the graphene aerogel produced by chemical crosslinking reaction. The graphene aerogel has better electrochemical properties.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TQ127.11;TM53

【相似文献】