Understanding the material property origins of performance decay in carbon electrodes is critical to maximizing the longevity of capacitive deionization (CDI) systems. This study investigates the cycling stability of electrodes fabricated from six commercial and two post-processed activated carbons. We find that the capacity decay rate of electrodes in half cells is positively correlated with the specific surface area and total surface acidity of the activated carbons. We also demonstrate that half-cell cycling stability is consistent with full cell desalination performance durability. Additionally, our results suggest that increase in internal resistance and physical pore blockage resulting from extensive cycling may be important mechanisms for the specific capacitance decay of activated carbon electrodes in this study. Our findings provide crucial guidelines for selecting activated carbon electrodes for stable CDI performance over long-term operation and insight into appropriate parameters for electrode performance and longevity in models assessing the techno-economic viability of CDI. Finally, our half-cell cycling protocol also offers a method for evaluating the stability of new electrode materials without preparing large, freestanding electrodes.

中文翻译：

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活性炭电极在电容去离子中的性能损失：机理和材料性能预测指标

了解碳电极性能下降的物质属性起因对于最大化电容去离子（CDI）系统的使用寿命至关重要。这项研究调查了由六种商用和两种后处理活性炭制成的电极的循环稳定性。我们发现，半电池中电极的容量衰减率与活性炭的比表面积和总表面酸性呈正相关。我们还证明了半电池循环稳定性与全电池淡化性能的耐久性是一致的。此外，我们的研究结果表明，广泛的循环导致内部电阻的增加和物理孔的堵塞可能是该研究中活性炭电极的比电容衰减的重要机制。我们的发现为选择活性炭电极以确保长期CDI性能稳定提供了关键指导，并在评估CDI技术经济可行性的模型中深入了解了电极性能和寿命的适当参数。最后，我们的半电池循环方案还提供了一种无需准备大型独立电极即可评估新电极材料稳定性的方法。