Performance optimization of carbon electrodes for capacitive deionization by potentiostatic analysis
Performance optimization of carbon electrodes for capacitive deionization by potentiostatic analysis
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DOI：
10.1016/j.electacta.2019.134898
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发表时间：
2019-12
影响因子：
6.6
通讯作者：
Aranzazu Carmona-Orbezo;Lewis W. Le Fevre;R. Dryfe
中科院分区：
文献类型：
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作者：
Aranzazu Carmona-Orbezo;Lewis W. Le Fevre;R. Dryfe
电容去离子是一种通过在两个多孔电极之间施加电势来淡化水的方法。以往的报道一般认为，两个电极的外加电势通常被一分为二，电极的活性质量对某一CDI系统的海水淡化性能起着重要的作用。本文用恒电位法测定了电池的电化学稳定电位窗口(ESPW)，从而找到了由活性碳电极和浓氯化钠水溶液电解液制成的电池电极对的最佳质量比。结果表明，电极不发生法拉第降解的正极−为0.4V，负极ESPW为0.6V，质量平衡比为m+/m-1=2.22。然后将这些参数应用于CDI电池，在该电池中，与等效质量情况相比，系统在质量平衡条件下运行时，盐吸附容量提高了65%，充电效率提高了58%。
Capacitive deionization is a method in which water is desalinated by the application of a potential between two porous electrodes. Previous reports generally consider that the applied potential is usually divided in half for both electrodes and that the active mass of the electrodes plays an important role on the desalination performance obtained from a certain CDI system. In this work, a potentiostatic method for the determination of the electrochemical stable potential window (ESPW) was used, and thus an optimised mass ratio for the electrode pairings, of a cell made with activated carbon electrodes and a concentrated NaCl aqueous electrolyte, was found. The obtained results demonstrate that the ESPW in which the electrodes would not suffer from Faradaic degradation is 0.4 V for the positive electrode and −0.6 V for the negative electrode, leading to a mass balance ratio of m+/m- = 2.22. These parameters were then applied to a CDI cell, in which an improvement of 65% of the salt adsorption capacity and of 58% for charge efficiency was obtained when the system was operated with the mass balanced conditions, compared to the equivalent mass case.