Le Fevre Lewis W, Cao Jianyun, Kinloch Ian A, Forsyth Andrew J, Dryfe Robert A W
School of Electronic and Electrical Engineering University of Manchester Sackville Street, Manchester M13 9PL UK.
School of Chemistry University of Manchester Oxford Rd Manchester M13 9PL UK.
ChemistryOpen. 2019 Apr 2;8(4):418-428. doi: 10.1002/open.201900004. eCollection 2019 Apr.
A comparison of the performance of graphene-based supercapacitors is difficult, owing to the variety of production methods used to prepare the materials. To the best of our knowledge, there has been no systematic investigation into the effect of the graphene production method on the supercapacitor performance. In this work, we compare graphene produced through several routes. This includes anodic and cathodic electrochemically exfoliated graphene, liquid phase exfoliated graphene, graphene oxide, reduced graphene oxide, and graphene nanoribbons. Graphene oxide exhibited the highest capacitance of approximately 154 F g in 6 M KOH at 0.5 A g attributed to oxygen functional groups giving an additional pseudocapacitance and preventing significant restacking; however, the capacitance retention was poor, owing to the low conductivity. In comparison, the anodic electrochemically exfoliated graphene exhibited a capacitance of approximately 44 F g, the highest of the 'pure' graphene materials, which all exhibited superior capacitance retention, owing to their higher conductivity. The cyclability of all of the materials, with the exception of reduced graphene oxide (70 %), was found to be greater than 95 % after 10 000 cycles. These results highlight the importance of matching the graphene production method with a specific application; for example, graphene oxide and anodic electrochemically exfoliated graphene would be best suited for high energy and power applications, respectively.
由于制备材料所采用的生产方法多种多样，因此很难对基于石墨烯的超级电容器的性能进行比较。据我们所知，尚未对石墨烯生产方法对超级电容器性能的影响进行系统研究。在这项工作中，我们比较了通过几种途径生产的石墨烯。这包括阳极和阴极电化学剥离石墨烯、液相剥离石墨烯、氧化石墨烯、还原氧化石墨烯和石墨烯纳米带。氧化石墨烯在6M KOH中、0.5A g电流密度下表现出约154F g的最高电容，这归因于氧官能团提供了额外的赝电容并防止了显著的重新堆叠；然而，由于电导率低，电容保持率较差。相比之下，阳极电化学剥离石墨烯表现出约44F g的电容，是“纯”石墨烯材料中最高的，由于其较高的电导率，所有这些材料都表现出优异的电容保持率。除还原氧化石墨烯（70%）外，所有材料在10000次循环后的循环稳定性均大于95%。这些结果突出了将石墨烯生产方法与特定应用相匹配的重要性；例如，氧化石墨烯和阳极电化学剥离石墨烯分别最适合高能量和高功率应用。
