标题： 水污染对采用基于LiFSI电解质的双碳锂离子电容器老化的影响 显示英文标题

标题： The Effect of Water Contamination on the Aging of a Dual-Carbon Lithium-Ion Capacitor Employing LiFSI-Based Electrolyte

摘要： 制造电化学储能器件需要大量的能量来干燥电池组件，以确保最佳性能。 开发新型耐水材料将在成本节约和可持续性方面取得巨大进展。 尽管普遍认为水会降低电池性能，但关于可容忍的最大水分污染量的研究很少，而且大多数研究使用了电解质盐$\mathrm{LiPF_6}$，这种盐在暴露于湿度时不可避免地分解。 在本工作中，探讨了非水解盐 LiFSI 在基于活性炭（AC）和预锂化石墨（Gr）的锂离子电容器中的性能潜力。 故意添加不同量的水（950、2300 和 6000 ppm），并系统研究其对 AC 和 Gr 电极的电化学性能和老化的影响。 虽然添加 950 ppm 水对容量保持率没有明显影响（2000 次循环后为 96%），但添加 2300 ppm 水或 6000 ppm 水则显示出明显的容量衰减，这归因于锂库存的显著损失以及由于水与锂化石墨反应引起的电阻增加。 事后分析显示，水分别促进了 LiFSI 在 AC 和锂化石墨上的氧化和还原分解。 随着水浓度的增加，观察到 Gr 上的 SEI 显著增厚。 显示英文摘要

摘要： Fabricating electrochemical energy storage devices demands significant energy for drying cell components to ensure optimal performance. The development of new, water-tolerant materials would represent a tremendous advance in cost savings and sustainability. Although it is generally established that water deteriorates cell performance, there are few systematic studies on the maximum amount of tolerable water contamination, and most of the studies employed the electrolyte salt $\mathrm{LiPF_6}$, which inevitably decomposes upon exposure to humidity. In this work, the potential of using the non-hydrolyzing salt LiFSI is explored with respect to its performance in Li-ion capacitor cells based on activated carbon (AC) and pre-lithiated graphite (Gr). Water is deliberately added in various amounts (950, 2300, and 6000 ppm), and its effect on the electrochemical performance and aging of AC and Gr electrodes is systematically studied. While the addition of 950 ppm water has no evident impact on capacity retention (96% after 2000 cycles), the addition of 2300 ppm water or 6000 ppm water shows a distinct capacity fade, attributed to a significant loss of lithium inventory and increased resistivity due to irreversible reactions of the water with lithiated Gr. Post-mortem analysis reveals that water promotes the oxidative and reductive decomposition of LiFSI on AC and lithiated Gr, respectively. A significant thickening of the SEI on Gr is observed as the water concentration is increased.