Mohammad Irshad, Blondeau Lucie, Leroy Jocelyne, Khodja Hicham, Gauthier Magali
Université Paris-Saclay, CEA, CNRS, NIMBE, LEEL, 91191 Gif-sur-Yvette, France.
Université Paris-Saclay, CEA, CNRS, NIMBE, LICSEN, 91191 Gif-sur-Yvette, France.
Molecules. 2021 Sep 21;26(18):5721. doi: 10.3390/molecules26185721.
Achieving the full potential of magnesium-ion batteries (MIBs) is still a challenge due to the lack of adequate electrodes or electrolytes. Grignard-based electrolytes show excellent Mg plating/stripping, but their incompatibility with oxide cathodes restricts their use. Conventional electrolytes like bis(trifluoromethanesulfonyl)imide ((Mg(TFSI)) solutions are incompatible with Mg metal, which hinders their application in high-energy Mg batteries. In this regard, alloys can be game changers. The insertion/extraction of Mg in alloys is possible in conventional electrolytes, suggesting the absence of a passivation layer or the formation of a conductive surface layer. Yet, the role and influence of this layer on the alloys performance have been studied only scarcely. To evaluate the reactivity of alloys, we studied InSb as a model material. Ex situ X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy were used to investigate the surface behavior of InSb in both Grignard and conventional Mg(TFSI)/DME electrolytes. For the Grignard electrolyte, we discovered an intrinsic instability of both solvent and salt against InSb. XPS showed the formation of a thick surface layer consisting of hydrocarbon species and degradation products from the solvent (THF) and salt (CHMgCl-(CH)AlCl). On the contrary, this study highlighted the stability of InSb in Mg(TFSI) electrolyte.
由于缺乏合适的电极或电解质，充分发挥镁离子电池（MIBs）的全部潜力仍然是一项挑战。基于格氏试剂的电解质表现出优异的镁电镀/脱镀性能，但其与氧化物阴极的不相容性限制了它们的使用。像双（三氟甲磺酰）亚胺（（Mg（TFSI））溶液这样的传统电解质与镁金属不相容，这阻碍了它们在高能镁电池中的应用。在这方面，合金可能会带来变革。在传统电解质中，镁可以在合金中嵌入/脱出，这表明不存在钝化层或形成了导电表面层。然而，关于该层对合金性能的作用和影响，人们几乎没有进行过研究。为了评估合金的反应活性，我们研究了InSb作为模型材料。采用非原位X射线光电子能谱（XPS）和电化学阻抗谱来研究InSb在格氏试剂和传统Mg（TFSI）/ DME电解质中的表面行为。对于格氏试剂电解质，我们发现溶剂和盐对InSb都存在内在不稳定性。XPS显示形成了一个厚表面层，该表面层由烃类物质以及来自溶剂（THF）和盐（CHMgCl - (CH)AlCl）的降解产物组成。相反，这项研究突出了InSb在Mg（TFSI）电解质中的稳定性。
