本文選題：石墨烯 + 活性炭��； 參考：《燕山大學》2014年碩士論文

【摘要】：石墨烯作為碳材料的又一新同素異形體，具有巨大的研究、應用開發(fā)價值，有望成為超級電容器理想的電極材料。然而石墨烯基超級電容器有著其自身存在的問題有待研究。首先便不同的制備方法所獲得的產(chǎn)物在形貌上存在著較大的差異，對石循環(huán)穩(wěn)定性有著較大的影響；其次在制備過程中，片層之間存在的作用力使產(chǎn)物會發(fā)生團聚現(xiàn)象，實際獲得的石墨烯的比表面積要遠低于理論值，如何減少團聚且構(gòu)建具備多級結(jié)構(gòu)的石墨烯，從而使其提供的比容量盡可能向理論值靠近便成為當前研究的熱點；最后制備石墨烯的成本就目前來說較高，而為了使石墨烯能夠成為商業(yè)化應用的超級電容器電極材料，探索石墨烯和其它材料的復合材料便成為了可能的出路。本論文主圍繞石墨烯基超級電容器主要展開以下研究工作。 采用水合肼處理和熱膨脹兩種不同的方法制備還原氧化石墨烯并對其循環(huán)穩(wěn)定性加以研究。采用水合肼處理制備的產(chǎn)物rGO-Hz具有良好的循環(huán)穩(wěn)定性；而采用熱膨脹方法制備的產(chǎn)物rGO-T循環(huán)穩(wěn)定性較差。分析了rGO-T循環(huán)穩(wěn)定性較差的原因，是因為在循環(huán)過程當中，含氧官能團的消去使得rGO-T贗電容不斷減少，且片層間發(fā)生團聚，最終導致其循環(huán)穩(wěn)定性較差。 制備GO包覆的PS球作為前驅(qū)體并在不同溫度下進行熱處理得到具備多級結(jié)構(gòu)的石墨烯。當熱處理溫度為700℃時，獲得的樣品HG7在0.5A/g的電流密度下比電容為162F/g，當電流密度提高至16A/g時，，其比電容仍然能達到112F/g，并且在各個電流密度下的比電容保持率都能達到90%以上；其拐點頻率和等效內(nèi)阻分別為12.598Hz和0.465，具有較快的電容響應速度和良好的導電性。 通過控制KAC和GO的質(zhì)量比進行水熱反應實現(xiàn)還原氧化石墨烯與活性炭復合材料的制備。當KAC與GO的質(zhì)量比為2:1時，產(chǎn)物GKAC2的協(xié)同效應達到最大，具有最佳的電容行為和導電性的同時，比電容也達到最大值。電流密度為2A/g時，產(chǎn)物GKAC2在水系環(huán)境和有機體系下的比電容分別為205F/g和175F/g，當電流密度提高至16A/g時，其比電容分別為152F/g和143F/g。此外，產(chǎn)物GKAC2在有機體系下的功率密度和能量密度相比于水系環(huán)境下都有所提升，在1mol/LTEABF4/AN為電解液的有機體系，樣品在16A/g的電流密度下功率密度和能量密度分別達到9.1kW/kg和26.3Wh/kg。因此制備石墨烯和活性炭的復合材料過程中，在提升石墨烯性能的同時大大降低了其生產(chǎn)成本。
[Abstract]:Graphene, as a new isomorphism of carbon materials, has great research and development value, and is expected to be an ideal electrode material for supercapacitors. However, graphene-based supercapacitors have their own problems to be studied. First of all, the products obtained by different preparation methods have great differences in morphology, which have a great influence on the stability of the stone cycle. Secondly, during the preparation process, the products will be agglomerated by the force between the layers. The specific surface area of graphene obtained is much lower than the theoretical value. How to reduce agglomeration and construct graphene with multilevel structure, so as to make the specific capacity of graphene as close as possible to the theoretical value has become the focus of current research. At last, the cost of preparing graphene is relatively high. In order to make graphene become a commercial electrode material for supercapacitor, it is possible to explore the composite materials of graphene and other materials. In this thesis, the following research work is mainly carried out around graphene-based supercapacitors. The redox graphene was prepared by hydrazine hydrate treatment and thermal expansion, and its cycle stability was studied. The products prepared by hydrazine hydrate treatment have good cyclic stability, while those prepared by thermal expansion method have poor cycle stability. The reason for the poor stability of rGO-T cycle is that the elimination of oxygen functional groups leads to the decrease of rGO-T pseudo-capacitance and the aggregation between the layers, which leads to the poor cycle stability of rGO-T. Go coated PS spheres were prepared as precursors and heat treated at different temperatures to obtain graphene with multilevel structure. When the heat treatment temperature is 700 鈩

本文編號：2062142