Complementary Effects of Pore Accessibility and Decoordination on the Capacitance of Nanoporous Carbon Electrochemical Supercapacitors
Complementary Effects of Pore Accessibility and Decoordination on the Capacitance of Nanoporous Carbon Electrochemical Supercapacitors
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DOI：
10.1021/acs.jpcc.5b10712
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发表时间：
2015-12
影响因子：
3.7
通讯作者：
S. Varanasi;Amir H. Farmahini;S. Bhatia
中科院分区：
文献类型：
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作者：
S. Varanasi;Amir H. Farmahini;S. Bhatia
本文采用恒压Gibbs系综为基础的大正则蒙特卡罗模拟，以已知原子结构的三种不同的微孔碳电极和1-乙基-3-甲基咪唑四氟化硼（EMI-BF4）为电解质，说明了纳米超级电容器中配位和可达孔体积的相互作用。我们证明了反离子配位数随着孔径的减小而减小，并且这种趋势对于所考虑的电极是相似的，尽管它们的结构不同，这表明孔形状对这种关系不太重要，至少对于这里所研究的碳。可以看出，低配位离子和（或）完全配位离子诱导的电荷最大，而高配位离子诱导的电荷较少，这与最近的MD模拟结果一致，表明高约束度（DOC）的离子比低DOC的离子诱导的电荷更多。我们的研究结果表明，不同孔隙体积的电极可以表现出相似的…
We illustrate here the interplay of decoordination and accessible pore volume in nanosized supercapacitors, using constant voltage Gibbs ensemble based grand canonical Monte Carlo simulations for three different microporous carbon electrodes of known atomistic structure and 1-ethyl-3-methylimidazolium boron tetrafluoride (EMI-BF4) as electrolyte. We demonstrate that the counterion coordination number decreases with pore size, and this trend is similar for the electrodes considered, despite their different structures, suggesting that the pore shape is less important to this relation, at least for the carbons examined here. It is seen that ions with low coordination and/or completely decoordinated ions induce maximum charge, while those with higher coordination induce less, in accordance with recent MD simulation results which demonstrate that ions in high degree of confinement (DOC) induce more charge than those in low DOC. Our results indicate that electrodes with different pore volumes can exhibit simila...