Motivated by the potential of ionic liquids (ILs) to replace traditional aqueous electrolytes in Zn-air batteries, we investigated the effects arising from mutual interactions between O₂ and Zn(TFSI)₂ as well as the influence of H₂O impurities in the oxygen reduction/oxygen evolution reaction (ORR/OER) and in Zn deposition/dissolution on a glassy carbon (GC) electrode in the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide (BMP-TFSI) by differential electrochemical mass spectrometry. This allowed us to determine the number of electrons transferred per reduced/evolved O₂ molecule. In O₂ saturated neat BMP-TFSI the ORR and OER were found to be reversible, in Zn²⁺containing IL Zn deposition/stripping proceeds reversibly as well. Simultaneous addition of O₂ and Zn²⁺ suppresses Zn metal deposition, instead ZnO₂ is formed in the ORR, which is reversible only after excursions to very negative potentials (−1.4 V). The addition of water leads to an enhancement of all processes described above, which is at least partly explained by a higher mobility of O₂ and Zn²⁺ in the water containing electrolytes. Consequences for the operation of Zn-air batteries in these electrolytes are discussed.

中文翻译：

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用于金属-空气电池的离子液体电解质：O2、Zn2+ 和 H2O 杂质之间的相互作用

受离子液体 (IL) 在锌空气电池中取代传统水性电解质的潜力的启发，我们研究了 O2 和 Zn(TFSI)2 之间相互作用产生的影响以及 H2O 杂质对氧还原/氧析出反应 (ORR/OER) 和在离子液体 N-丁基-N-甲基吡咯烷鎓双 (三氟甲磺酰基)-酰亚胺 (BMP-TFSI) 中通过差示电化学质谱法在玻璃碳 (GC) 电极上沉积/溶解锌。这使我们能够确定每个还原/进化的 O 2 分子转移的电子数。在 O 2 饱和的纯 BMP-TFSI 中，发现 ORR 和 OER 是可逆的，在含有 Zn 2⁺ 的 IL 中，Zn 沉积/剥离也可逆地进行。同时添加 O₂ 和 Zn²⁺ 抑制 Zn 金属沉积，相反，氧化锌在 ORR 中形成，只有在偏移到非常负的电位 (-1.4 V) 后才可逆。添加水导致上述所有过程的增强，这至少部分是由于O 2 和Zn 2⁺ 在含电解质的水中具有更高的迁移率。讨论了在这些电解质中锌空气电池运行的后果。