Abstract Capacitive deionization (CDI) is an electrochemical ion removal technique that could offer a lower energy or more selective alternative to reverse osmosis for water treatment applications. Over a dozen CDI cell architectures have been developed, but few studies have directly compared these designs for performance metrics such as ion adsorption rate and energy efficiency. Two of the most popular cell architectures include flow-by CDI, in which a feed stream flows parallel to two charged porous electrodes, and flow-through electrode CDI, in which the feed stream flows perpendicular to the electrodes. In this study, flow-by and flow-through CDI architectures were compared using commercially available electrode materials. Experimentally observed salt adsorption capacity (SAC), average salt adsorption rate (ASAR), and charge efficiency (Λ) was then compared to theoretical models over a range of voltage conditions (0.2–1.2 V), charge cycle times (1–60 min), and flow rates (10–30 mL min- 1). Cell architecture affected the SAC, ASAR, Λ, electrode stability, and oxidation rates for a given electrode material. Flow-by CDI tended to have higher SAC and better charge efficiency than flow-through CDI, yet flow-through CDI demonstrated a higher ASAR, particularly for shorter half-cycle times.

中文翻译：

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流通式和流通式电容去离子的直接比较

摘要 电容去离子 (CDI) 是一种电化学离子去除技术，可为水处理应用提供更低能量或更选择性的反渗透替代方案。已经开发了十多种 CDI 电池架构，但很少有研究直接比较这些设计的性能指标，如离子吸附率和能源效率。两种最流行的电池结构包括流通式 CDI，其中进料流平行于两个带电多孔电极流动，以及流通式电极 CDI，其中进料流垂直于电极流动。在这项研究中，使用市售电极材料比较了流通式和流通式 CDI 架构。实验观察盐吸附容量（SAC）、平均盐吸附率（ASAR）、然后将充电效率 (Λ) 与一系列电压条件 (0.2–1.2 V)、充电循环时间 (1–60 分钟) 和流速 (10–30 mL min-1) 的理论模型进行比较。电池结构影响给定电极材料的 SAC、ASAR、Λ、电极稳定性和氧化速率。流通式 CDI 往往比流通式 CDI 具有更高的 SAC 和更好的充电效率，但流通式 CDI 表现出更高的 ASAR，尤其是对于较短的半周期时间。