Comparing energy demands and longevities of membrane-based capacitive deionization architectures
Comparing energy demands and longevities of membrane-based capacitive deionization architectures
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比较基于膜的电容去离子架构的能源需求和寿命
DOI：
10.1039/d2ew00188h
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Gorski, Christopher A.
中科院分区：
文献类型：
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作者：
Pothanamkandathil, Vineeth;Gorski, Christopher A.
几种电容去离子（CDI）电池架构采用离子交换膜来控制接触电极的电解质的化学性质。在这里，我们通过实验研究了将碳电极暴露于盐水电解质或含有可溶性氧化还原活性化合物的电解质如何影响去离子能量需求和超过150小时的长期稳定性。我们特别比较了将20 mM NaCl去除到15 mM所需的能量需求（W h L−1）与50%水回收率作为生产率（L m−2 h−1）的函数。相对于传统的膜电容去离子（MCDI）电池，在电极上流动的盐电解质不影响能量需求，但增加了电极的盐吸附容量和重复循环的容量保持率。将电极暴露于含有氧化还原活性化合物的电解质中，使电池的行为类似于电渗析系统，大大降低了能量需求，并在50小时的操作中表现出显着的稳定性。这些实验结果表明，在接触电极的电解质中使用再循环的可溶性氧化还原活性化合物来平衡电荷，比通过进行电容性充电/放电反应的电极平衡电荷时，会导致更节能的苦咸水去离子。
Several capacitive deionization (CDI) cell architectures employ ion-exchange membranes to control the chemistry of the electrolyte contacting the electrodes. Here, we experimentally examined how exposing carbon electrodes to either a saline electrolyte or an electrolyte containing a soluble redox-active compound influenced deionization energy demands and long-term stability over ∼50 hours. We specifically compared the energy demands (W h L−1) required to deionize 20 mM NaCl to 15 mM with a 50% water recovery as a function of productivity (L m−2 h−1). Relative to a conventional membrane capacitive deionization (MCDI) cell, flowing saline electrolyte over the electrodes did not affect energy demands but increased electrode salt adsorption capacities and capacity retention over repeated cycles. Exposing the electrodes to an electrolyte containing a redox-active compound, which made the cell behave similarly to an electrodialysis system, dramatically reduced energy demands and showed remarkable stability over 50 hours of operation. These experimental results indicate that using a recirculated soluble redox-active compound in the electrolyte contacting the electrodes to balance charge leads to far more energy efficient brackish water deionization than when charge is balanced by the electrodes undergoing capacitive charging/discharging reactions.