Improving halide-containing magnesium-ion electrolyte performance via sterically hindered alkoxide ligands

JOURNAL OF POWER SOURCES

卷:362

Article

Nist-Lund, Carl A.^1,2  Herb, Jake T.^1,2  Arnold, Craig B.^2,3 

[1] Princeton Univ, Dept Chem, Princeton, NJ 08540 USA

[2] Princeton Univ, Princeton Inst Sci & Technol Mat, Princeton, NJ 08540 USA

[3] Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08540 USA

关键词: Magnesium-ion batteries;    Electrodeposition;    Electrolytes;    Alkoxides;   

DOI  :  10.1016/j.jpowsour.2017.07.045

来源: Elsevier

【 摘 要 】

While homoleptic magnesium dialkoxides (MgR2, R = alkoxide) have shown promise as precursors for magnesium-ion electrolytes, the effect of ligand steric bulk on the performance of electrolytes based on these compounds is not fully understood. Increasing steric hindrance, studied via R groups with additional phenyl moieties, produces electrolytes with sequentially lower deposition overpotentials (less than -90 mV), higher purity Mg deposits (ca. 100% Mg), and lower overall cell impedances. The two largest alkoxide ligands show consistent cycling behavior and low stripping and plating overpotentials over 200 constant-current plating/stripping cycles. A deep-red visual change and the presence of large solubilized magnesium particulates above 450 rim in size is observed in an electrolyte containing magnesium bis(triphenylmethoxide) and aluminum chloride in contact with an abraded magnesium anode. Further morphological and impedance characterization show that this electrolyte system rapidly activates the magnesium metal anode surface to produce low overpotentials and, as such, is a candidate for further investigation. (C) 2017 Elsevier B.V. All rights reserved.

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