Liu Huazhen, Hwang Jinkwang, Matsumoto Kazuhiko, Hagiwara Rika
Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
ACS Appl Mater Interfaces. 2023 Jul 26;15(29):35062-35071. doi: 10.1021/acsami.3c06812. Epub 2023 Jul 13.
The development of sodium-ion batteries utilizing sulfonylamide-based electrolytes is significantly encumbered by the corrosion of the Al current collector, resulting in capacity loss and poor cycling stability. While ionic liquid electrolytes have been reported to suppress Al corrosion, a recent study found that pitting corrosion occurs even when ionic liquids are employed. This study investigates the effects of temperature and Na salt concentration on the Al corrosion behavior in different sulfonylamide-based ionic liquid electrolytes for sodium-ion batteries. In the present work, cyclic voltammetry measurements and scanning electron microscopy showed that severe Al corrosion occurred in ionic liquids at high temperatures and low salt concentrations. X-ray photoelectron spectroscopy was employed to identify the different elemental components and verify the thickness of the passivation layer formed under varied salt concentrations and temperatures. The differences in the corrosion behaviors observed under the various conditions are ascribed to the ratio of free [FSA] to Na-coordinating [FSA] in the electrolyte and the stability of the newly formed passivation layer. This work aims at augmenting the understanding of Al corrosion behavior in ionic liquid electrolytes to develop advanced batteries.
利用基于磺酰胺的电解质的钠离子电池的发展受到铝集流体腐蚀的严重阻碍，导致容量损失和循环稳定性差。虽然据报道离子液体电解质可抑制铝的腐蚀，但最近的一项研究发现，即使使用离子液体也会发生点蚀。本研究调查了温度和钠盐浓度对不同基于磺酰胺的钠离子电池离子液体电解质中铝腐蚀行为的影响。在本工作中，循环伏安法测量和扫描电子显微镜表明，在高温和低盐浓度下，离子液体中会发生严重的铝腐蚀。采用X射线光电子能谱来识别不同的元素成分，并验证在不同盐浓度和温度下形成的钝化层的厚度。在各种条件下观察到的腐蚀行为差异归因于电解质中游离[FSA]与钠配位[FSA]的比例以及新形成的钝化层的稳定性。这项工作旨在加深对离子液体电解质中铝腐蚀行为的理解，以开发先进的电池。
