以石墨烯與活化的介相碳微球複合材料為電極在超級電容器之應用

Application of Graphene and Activated Mcmb Composites as Electrode Materials for Supercapacitors

黃振家(Chen-Chia Huang) ； 陳冠銘(Kuan-Ming Chen)

《技術學刊》 29卷3期 (2014/09) Pp. 199-206

摘要

本研究以氧化石墨經過熱還原膨脹法製備石墨烯（G1），並與經KOH活化的介相碳微球（MCMB）依不同的比例共同混摻，作為超級電容器之電極材料，研究其電化學性能的表現。碳材之孔洞特性以氮氣吸附儀測量；以X光粉末繞射儀（XRD）、掃描式電子顯微鏡（FE-SEM）及顯微拉曼光譜儀（Raman）分析石墨烯和活化的MCMB（KM）層間距變化、表面型態及晶體結構。電化學實驗使用電壓電流儀檢測混摻材料於循環伏安法、計時電位法及交流阻抗譜的電化學性能。實驗結果顯示，當摻入KM重量比率為66%（KM-G1-2）時，於掃描速率與電流密度為5mVs^(-1)與0.5Ag^(-1)，其比電容分別為126Fg^(-1)與130Fg^(-1)。在高電流密度10Ag^(-1)時，不同比例的混摻材料比電容近乎相似，顯示電化學反應只在電極材料的表面層進行。

關鍵字

墨烯 ； 介相碳微球 ； 超級電容器

並列摘要

In this study, graphene sheets (G1) were prepared by thermal reduction of graphite oxide. The carbonaceous composites were prepared by blending the G1 with KOH activated mesophase carbon microbeads (MCMB) by various ratios and were used as electrode materials for supercapacitors. The texture characteristics of carbonaceous composites were determined by using nitrogen adsorption and desorption analysis. The morphology and crystal structures of graphene were observed by XRD, FE-SEM, and Raman spectroscopy. The electrochemical characterizations are performed by cyclic voltammetry, galvanostatic charge/discharge and AC impedance in a three-electrode system. The specific capacitances of the activated MCMB (KM) and graphene composite (KM-G1-2) with 33% graphene were determined as 126 and 130Fg^(-1), at a scan rate of 5mVs^(-1) and current density of 0.5Ag^(-1), respectively. At a high current density of 10Ag^(-1), however, the specific capacitances of the composites with different mixing ratios are almost the same. This implies that the electrochemical reaction is only occurred in the surface layers of the electrode materials.

並列關鍵字

graphene ； MCMB ； supercapacitor