Corrosion of current collectors is one of the most significant issues to tackle in rechargeable magnesium batteries where chloride-abundant electrolytes are commonly used since it can affect the electrochemical performance and the safety of battery system seriously. Here we investigate 1-butyl-1-methylpyrrolidinium chloride ionic liquid as an effective corrosion inhibitor of the current collector in an electrolyte containing magnesium chloride complex. We find that adding just 0.2 wt.% ionic liquid increases the anodic stability of common current collectors by 0.1–0.3 V while maintaining the coulombic efficiencies for Mg deposition and stripping at over 98%. In particular, analytical studies of the passive film formed on 316L stainless steel show that the inhibitor efficiently prevents the formation of corrosion pits and preserves the protective property of the passive film upon repeated anodic scans. Furthermore, the inhibitor enables almost 100% efficiencies in the full cell cycling with Mo₆S₈ cathode, reflecting higher anodic stability of the current collectors in the electrolyte containing the inhibitor. We propose that the formation of an adsorbed layer of the ionic liquid as a plausible corrosion inhibition mechanism.

中文翻译：

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1-丁基-1-甲基吡咯烷鎓氯化物作为氯化镁复合电解质中不锈钢集电器的有效腐蚀抑制剂

集流体的腐蚀是可再充电镁电池中最重要的问题之一，在镁电池中，氯化物常用于电解液，因为它会严重影响电化学性能和电池系统的安全性。在这里，我们研究了1-丁基-1-甲基吡咯烷鎓氯化物离子液体作为一种有效的缓蚀剂，该缓蚀剂在含有氯化镁配合物的电解质中。我们发现仅添加0.2 wt。％的离子液体可将普通集电器的阳极稳定性提高0.1-0.3 V，同时将Mg沉积和剥离的库仑效率保持在98％以上。尤其是，对316L不锈钢上形成的钝化膜的分析研究表明，该抑制剂有效地防止了腐蚀坑的形成，并在重复进行阳极扫描后保留了钝化膜的保护性能。此外，该抑制剂可在Mo的整个细胞循环中实现近100％的效率₆ S ₈阴极，反映了含抑制剂的电解质中集电器的更高的阳极稳定性。我们提出形成离子液体的吸附层作为合理的腐蚀抑制机理。