Capacitance of edge-free three-dimensional graphene: New perspectives on the design of carbon structures for supercapacitor applications
Capacitance of edge-free three-dimensional graphene: New perspectives on the design of carbon structures for supercapacitor applications
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无边三维石墨烯的电容：超级电容器应用碳结构设计的新视角
DOI：
10.1016/j.electacta.2022.141009
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发表时间：
2022
影响因子：
6.6
通讯作者：
Nishihara Hirotomo
中科院分区：
文献类型：
--
作者：
Tang Rui;Nomura Keita;Inoue Kazutoshi;Kotani Motoko;Kyotani Takashi;Nishihara Hirotomo
目前扩大超级电容器应用范围的目标是将其能量密度（E）提高到20 Wh kg−1以上。在这方面，无边缘碳材料由于其在有机电解质中的高工作电压（U）而显示出相当大的潜力;然而，其电容（C）仍然有限。在这项研究中，我们合成了无边缘的三维（3D）石墨烯材料与不同数量的石墨烯堆叠层（nstack）。这些碳材料具有相似的孔形态和无边缘结构，因为分别应用了模板法和在1800 °C下退火。这些功能allowedCto保持不受孔径效应，润湿性，寄生副反应，和赝电容。我们的研究结果表明，增加nstack略有增加的arealC;然而，这样的增加不能补偿的减少在C归因于比表面积的减少。我们还证实了3D石墨烯材料的C具有量子起源，这导致了“蝴蝶形”的循环伏安曲线;我们还成功地量化了量子电容（CQ），以完整地理解C的起源。基于这些知识，我们估计这种3D石墨烯材料一旦优化CQ，就可以产生43 Wh kg− 1的高E。
The current target for expanding the application scope of supercapacitors is to increase their energy density (E) beyond 20 Wh kg−1. In this regard, edge-free carbon materials show considerable potential because of their high working voltage (U) in organic electrolytes; however, their capacitance (C) remains limited. In this study, we synthesized edge-free three-dimensional (3D) graphene materials with different numbers of graphene stacking layers (nstack). These carbon materials have similar pore morphologies and an edge-free structure because a template method and annealing at 1800 °C were applied, respectively. These features allowedCto remain unaffected by the pore size effect, wettability, parasitic side reactions, and pseudocapacitance. Our results suggested that increasingnstackslightly enhances the arealC; however, such an increase cannot compensate for the decrease inCattributed to the decrease in the specific surface area. We also confirmed that theCof 3D graphene materials has a quantum origin, which results in a “butterfly shaped” cyclic voltammetry curve; we also successfully quantified the quantum capacitance (CQ) for the complete understanding of the origin ofC. Based on this knowledge, we estimated that this 3D graphene material can yield a highEof 43 Wh kg−1onceCQis optimized.