One of the holy grails in research and development focused on rechargeable magnesium batteries is development of “conventional” electrolyte solutions that are compatible with both anode and cathode and support highly reversible magnesium electrochemical activity. In the last couple of years, MgTFSI₂, a “simple” salt, attracted considerable attention owing to its high solubility in a range of relevant solvents and apparent compatibility with magnesium anode and cathode materials. Nonetheless, questions were raised regarding the validity of the chemical and electrochemical inertness attributed to the TFSI anion, in particular when electrochemistry of magnesium is in the spotlight. Here, we demonstrate the impact of the TFSI anion on the intercalation kinetics of Mg ions into V₂O₅. The importance of this work is the fact that V₂O₅ is considered to be the most attractive high-voltage/high-capacity cathode for secondary Mg batteries, while MgTFSI₂ is considered a very important electrolyte for the same systems.

中文翻译：

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阴离子对可充电镁电池阴极电化学活性的影响：以V ₂ O _5为例

专注于可充电镁电池的研究和开发中的一项圣战是开发与阳极和阴极兼容并支持高度可逆的镁电化学活性的“常规”电解质溶液。在过去的几年中，“ MgTFSI _2”（一种简单的盐）由于在各种相关溶剂中的高溶解度以及与镁阳极和阴极材料的明显相容性而备受关注。尽管如此，人们仍对TFSI阴离子的化学和电化学惰性的有效性提出了疑问，特别是当镁的电化学成为人们关注的焦点时。在这里，我们证明了TFSI阴离子对Mg离子嵌入V ₂ O的嵌入动力学的影响₅。这项工作的重要性在于事实，即V ₂ O ₅被认为是二次Mg电池最具吸引力的高压/高容量阴极，而MgTFSI ₂被认为是同一系统中非常重要的电解质。