Abstract Capacitive deionization (CDI) is a fast-emerging technology typically applied to brackish water desalination and ion selective separations. In a typical cell, feedwater is desalinated via ion electrosorption into micropore electric double layers (EDLs) of charging porous carbon electrodes. Several studies have previously demonostrated that oxidizing the cathode via a nitric acid pretreatment enhances the cell’s salt adorption capacity (SAC). It was recently reported that oxidized cathodes can degrade rapidly during cell cycling, yet the mechanisms and mitigation strategies remain unknown. Here, we experimentally characterize the performance and degradation of nitric acid-oxidized commercial carbon cloth cathodes. For a full cycle time (FCT) of 100 min and 1 V applied, we observed a 42.5% reduction of SAC by the 100th cycle, and measured a reduction in cathode micropore chemical charge concentration at pH = 7 from -1.5 M to -0.25 M after cycling. We further found that cell charging time and electrode mass are major determinants of degradation rate, for example, reducing FCT to 30 min and 10 min allows for SAC decay of only ∼14% and

中文翻译：

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表征和减轻电容去离子循环过程中氧化阴极的降解

摘要 电容去离子 (CDI) 是一种新兴的技术，通常应用于苦咸水淡化和离子选择性分离。在典型的电池中，给水通过离子电吸附脱盐进入带电多孔碳电极的微孔双电层 (EDL)。之前的几项研究表明，通过硝酸预处理氧化阴极可增强电池的盐吸附能力 (SAC)。最近有报道称，氧化阴极在电池循环过程中会迅速降解，但其机制和缓解策略仍然未知。在这里，我们通过实验表征硝酸氧化商业碳布阴极的性能和降解。对于 100 分钟和 1 V 的完整循环时间 (FCT)，我们观察到到第 100 个循环时 SAC 减少了 42.5%，并测量了在 pH = 7 时，循环后阴极微孔化学电荷浓度从 -1.5 M 减少到 -0.25 M。我们进一步发现，电池充电时间和电极质量是降解率的主要决定因素，例如，将 FCT 减少到 30 分钟和 10 分钟只允许 SAC 衰减约 14% 和