Improvement in the capacitance of a carbon electrode prepared using water-soluble polymer binder for a capacitive deionization application
Improvement in the capacitance of a carbon electrode prepared using water-soluble polymer binder for a capacitive deionization application
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DOI：
10.1016/j.electacta.2009.12.084
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发表时间：
2010-03-01
影响因子：
6.6
通讯作者：
Choi, Jae-Hwan
中科院分区：
文献类型：
--
作者：
Park, Byeong-Hee;Choi, Jae-Hwan
增加碳电极的润湿表面积对于提高电容去离子性能是非常重要的。为了增加碳电极的润湿性，我们通过使用水溶性聚合物粘合剂聚乙烯醇（PVA）来制备碳电极。比较了PVA键合碳电极与另一种使用疏水粘合剂聚偏氟乙烯（PVdF）制备的碳电极的电化学性能。电化学方法-循环伏安法，计时电流法，和电阻抗谱-被用来表征电极的电化学性能。正如所预期的那样，基于接触角测量，证实了PVA结合的电极比PVdF结合的电极更易弯曲。根据循环伏安分析，我们发现PVdF键合电极的比电容为74.4-80.3 Fg（-1），PVA键合电极的比电容为89.6-99.8 Fg（-1），这取决于电位，表明比电容增加了13.3-30.1%。据观察，交流信号穿透PVA键合的碳电极的微孔比PVdF键合的更深，导致更高的电容。这归因于交流信号能够使更多的内表面位点带电的事实，因为PVA结合的电极中的微孔可以由于PVA粘合剂而被润湿。(C)2010爱思唯尔有限公司版权所有。
It is very important to increase the wetted surface area of a carbon electrode for high capacitive deionization performance. To increase the wettability of a carbon electrode, we fabricated carbon electrodes by using water-soluble polymer binder, polyvinyl alcohol (PVA). The electrochemical properties of the PVA-bonded carbon electrode were compared with another that was prepared using hydrophobic binder, polyvinylidene fluoride (PVdF). Electrochemical methods - cyclic voltammetry, chronoamperometry, and electrical impedance spectroscopy - were used to characterize the electrochemical properties of the electrodes. As might be expected, it was confirmed that the PVA-bonded electrode was more wettable than the PVdF-bonded one, based on contact angle measurements. From the cyclic voltammetric analysis, we found that the specific capacitance was 74.4-80.3 Fg(-1) for the PVdF-bonded electrode and 89.6-99.8 Fg(-1) for the PVA-bonded electrode, depending on the potential, indicating a 13.3-30.1% increase in specific capacitance. It was observed that the ac-signal penetrated micropores of the PVA-bonded carbon electrode more deeply than the PVdF-bonded one, resulting in a higher capacitance. This was attributed to the fact that the ac-signal was able to charge more inner surface sites because micropores in the PVA-bonded electrode could be wetted due to the PVA binder. (C) 2010 Elsevier Ltd. All rights reserved.