Constructing a stable passivation film at the negative electrode–electrolyte interface is an effective strategy for optimizing the high voltage stability of propylene carbonate-based electrochemical double-layer capacitors (EDLC). However, the role of passivation film composition in determining high voltage performance is still being established. Herein, the effect of passivation film composition on the energy storage mechanism and high voltage performance is investigate. The modified passivation film inhibits the specific adsorption of anions; thus, the energy storage mechanism is altered to ionic exchange from co-ion desorption. This mechanism inhibits solvents from entering the inner Helmholtz plane, thus effectively reducing solvent decomposition and inhibiting rapid thickening of the passivation film. As expected, the floating stabilization time of EDLC utilizing this electrolyte at 3.3 V increases to 2090 h, which is 4.6 times longer than that for those utilizing commercial electrolyte. This work provides a new perspective for the development of high voltage EDLC.

中文翻译：

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稳定的钝化膜诱导的双电层离子交换机制提高了超级电容器的高压性能


在负极-电解质界面构建稳定的钝化膜是优化碳酸丙烯酯基电化学双电层电容器 （EDLC） 高压稳定性的有效策略。然而，钝化膜成分在决定高压性能方面的作用仍在确定中。本文研究了钝化膜成分对储能机制和高压性能的影响。改性钝化膜抑制了阴离子的特异性吸附;因此，储能机制从共离子解吸转变为离子交换。这种机制抑制溶剂进入亥姆霍兹内平面，从而有效减少溶剂分解并抑制钝化膜的快速增厚。正如预期的那样，使用这种电解质的 EDLC 在 3.3 V 下的浮动稳定时间增加到 2090 小时，是使用市售电解质的 EDLC 的 4.6 倍。这项工作为高压 EDLC 的发展提供了新的视角。