Analysis of non-uniform charge/discharge and rate effects in porous carbon capacitors containing sub-optimal electrolyte concentrations
Analysis of non-uniform charge/discharge and rate effects in porous carbon capacitors containing sub-optimal electrolyte concentrations
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DOI：
10.1016/s0022-0728(00)00207-2
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发表时间：
2000-09-08
影响因子：
4.5
通讯作者：
Marincic, N
中科院分区：
文献类型：
--
作者：
Pell, WG;Conway, BE;Marincic, N
通过循环伏安法和在不同速率下进行的放电/放电程序，研究了一系列3 V非水双层电容器的内部电解质电阻对电荷接受和传递的影响。所获得的数据使Ragone图构建的电容器模块的性能。使用2000 m2 g-1的碳和含有四氟硼酸四乙基铵的无水碳酸丙烯酯作为电解质，以1.0、0.4、0.2和0.08 M四种浓度构建了一系列四个电容器模块。选择较低的浓度是为了故意引入电解质饥饿，从而能够研究这些条件对电容器模块的放电/再充电行为的影响。在稀溶液中，由于离子在电容器电极基质的相应负表面和正表面处从电解质本体吸附，通过电解质的阳离子和阴离子的再分布，电解质饥饿可以在充电时变得增强。这种效应的大小取决于与装置中可用的总电解质离子浓度和充电终止时获得的电位相关的吸附电荷容量。(C)2000 Elsevier Science B. V.保留所有权利。
The effects of internal electrolyte resistance on the acceptance and delivery of charge by a series of 3 V, non-aqueous, double-layer capacitors have been investigated by cyclic voltammetry and de charging/discharging procedures conducted at different rates. The data obtained enable Ragone plots to be constructed for the performance of the capacitor modules. A series of four capacitor modules have been constructed using 2000 m(2) g(-1) carbon and containing tetraethylammonium tetrafluoroborate in dry propylene carbonate as electrolyte at four concentrations: 1.0, 0.4, 0.2 and 0.08 M. The lower concentrations are chosen to introduce electrolyte starvation deliberately and thus to be able to investigate the effects of such conditions on the discharge/recharge behaviour of the capacitor modules. In dilute solutions, electrolyte starvation can become enhanced on charge by redistribution of cations and anions of the electrolyte due to adsorption of the ions at respective negative and positive surfaces of the capacitor electrode matrices, from the electrolyte bulk. The magnitude of such effects depends on the adsorption charge capacity in relation to the total electrolyte ion concentrations available in the device and to the potential attained at the termination of charging. (C) 2000 Elsevier Science B.V. All rights reserved.