A statistical mechanics study on relationship between nanopore size and energy storage in supercapacitors
A statistical mechanics study on relationship between nanopore size and energy storage in supercapacitors
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超级电容器纳米孔径与储能关系的统计力学研究
DOI：
10.1016/j.jpcs.2020.109705
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
S. Zhou
中科院分区：
文献类型：
--
作者：
S. Zhou
应用经典密度泛函理论方法，研究了圆柱孔电极相对于盐离子的相对尺寸对微分电容Cd-表面电荷强度曲线的影响| σ|以及储能密度E与外加电压U的关系，主要结论如下。(i)溶剂粒度总是试图促进Cd-σ曲线从钟形到骆驼形的变化;假定圆柱形孔是浅的，具有约化半径（如R = 1.5），并且在对称和高价离子的存在下，Cd-σ曲线总是呈现骆驼形，无论电解质体积浓度是多少。(ii)对于足够小的圆柱形孔（如R_（max）= 1.5），对称高价电解质在零表面电荷两侧诱导出一个极高的骆驼形Cd-σ曲线峰。(iii)对称的高价（2：2和3：3）电解质有助于提高E值，无论圆柱形孔半径是多少，E值几乎与电解质体积浓度无关。(iv)只有当施加的电压超过某个下限电压时，孔径对单个孔E值的影响才变得可观察到，该下限电压与离子价态正相关。超过下限电压后，只有当R_（max）= 1.5时，E-U曲线才呈现饱和趋势，而当R_（max）= 1.5时，E随U的增长速度越来越快。小孔饱和现象的深层原因是当σ值超过某一临界值时，共离子吸附量趋于零，之后表面电位随σ值急剧增加。
By applying classical density functional theory approach, one study is done on the impacts of the relative size (compared to that of the salt ions) of the cylindrical pore electrode on the curves of differential electrical capacitance C d vs surface charge strength| σ| and energy storage density E vs applied voltage U, main conclusions are summarized as follows.(i) Solvent granularity always tries to facilitate a change of the C d-σ curve from bell-shaped to camel shape; given that the cylindrical pore is shallow with reduced radius such as R∗= 1.5 and in the presence of symmetrical and higher valence ion the C d-σ curve always assumes camel shape, whatever the electrolyte bulk concentration is.(ii) For sufficiently small cylindrical pore such as R∗= 1.5, symmetrical high valence electrolyte induces one extremely high peak of the camel-shaped C d-σ curve at both sides of zero surface charge.(iii) Symmetrical high valence (2: 2 and 3: 3) electrolytes help in raising the E value, which is almost independent on the electrolyte bulk concentration, whatever the cylindrical pore radius is.(iv) Influence of the pore size on the single pore E value becomes observable only when the applied voltage exceeds some lower limit voltage, which is positively correlated with the ion valence. After exceeding the lower limit voltage, the curve of E versus U display saturation trend only for smaller pore such as R∗= 1.5; whereas for larger pore, increase rate of E with U becomes faster and faster. The deep reason for the small pore saturation phenomena is that the co-ion adsorption capacities go to zero when the σ value exceeds some critical value after which the surface potential increases steeply with the σ value.
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单个无限长圆柱形孔内形成的双电层电容
DOI：
10.1088/1742-5468/aaddb1
发表时间：
2018-10
期刊：
J. Stat. Mech.-Theory E
影响因子：
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作者：
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DOI：
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期刊：
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影响因子：
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作者：
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Tomohiko Hayashi;Tomoaki Matsuda;T. Nagata;M. Katahira;M. Kinoshita
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影响因子：
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影响因子：
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