Electrochemical Desalination Using Intercalating Electrode Materials: A Comparison of Energy Demands
Electrochemical Desalination Using Intercalating Electrode Materials: A Comparison of Energy Demands
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DOI：
10.1021/acs.est.9b07311
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发表时间：
2020-03-17
影响因子：
11.4
通讯作者：
Gorski, Christopher A.
中科院分区：
文献类型：
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作者：
Pothanamkandathil, Vineeth;Fortunato, Jenelle;Gorski, Christopher A.
一种用于淡化微咸水的方法是使用从水中电化学去除盐离子的电极材料。最近的研究发现，钠嵌入电极材料（即，可逆地将Na+离子插入其结构中的材料）在较小或类似的电压窗口上具有比碳基电极材料更高的比盐存储容量（mg（盐）/g（材料））。这些观察结果导致了这样的假设，即电化学脱盐系统的能量需求可以通过用嵌入电极代替碳基电极来降低。为了测试该假设并直接比较嵌入材料，我们检查了被认为能够在电化学流动电池中钠嵌入的九种电极材料，其关于体积能量需求（W. h. L-1）和作为生产率的函数的热力学效率（即，海水淡化速率，L·m（-2）·h（-1））。我们还研究了材料的电荷存储容量如何在50个循环中变化。当我们假设没有能量回收发生时（即，当电池在循环期间产生电功率时没有能量被回收），并且当我们假设完全能量回收时表现出类似的效率。在所有材料中，六氰合铁酸镍表现出最低的能量需求，并且在50次循环中表现出最高的稳定性。
One approach for desalinating brackish water is to use electrode materials that electrochemically remove salt ions from water. Recent studies found that sodium-intercalating electrode materials (i.e., materials that reversibly insert Na+ ions into their structures) have higher specific salt storage capacities (mg(salt)/g(material)) than carbon-based electrode materials over smaller or similar voltage windows. These observations have led to the hypothesis that energy demands of electrochemical desalination systems can be decreased by replacing carbon-based electrodes with intercalating electrodes. To test this hypothesis and directly compare intercalation materials, we examined nine electrode materials thought to be capable of sodium intercalation in an electrochemical flow cell with respect to volumetric energy demands (W.h.L-1) and thermodynamic efficiencies as a function of productivity (i.e., the rate of water desalination, L.m(-2).h(-1)). We also examined how the materials' charge-storage capacities changed over 50 cycles. Intercalation materials desalinated brackish water more efficiently than carbon-based electrodes when we assumed that no energy recovery occurred (i.e., no energy was recovered when the cell produced electrical power during cycling) and exhibited similar efficiencies when we assumed complete energy recovery. Nickel hexacyanoferrate exhibited the lowest energy demand among all of the materials and exhibited the highest stability over 50 cycles.