Water scavengers controlled electrolyte performance and sulfur cathode for magnesium-ion batteries

• Published in: Ionics Vol. 27; no. 10; pp. 4295 - 4305
• Main Authors: Mesallam, Medhat, Sheha, E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2021; Springer Nature B.V
• Subjects: Anodes; Anodic protection; Aqueous electrolytes; Buffer layers; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Conducting polymers; Contaminants; Difluorides; Electrochemical analysis; Electrochemistry; Electrolytes; Electrolytic cells; Energy Storage; Galvanic corrosion; Magnesium; Magnesium chloride; Magnesium perchlorates; Nonaqueous electrolytes; Optical and Electronic Materials; Original Paper; Polyvinylidene fluorides; Renewable and Green Energy; Scavengers; Buffer layer; Magnesium-sulfur battery; Water scavenger; Electrolyte additives
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-021-04229-0

Realizing practical magnesium-ion batteries (MIBs) is hindered by parasitic formation processes on the surface of the magnesium anode from contaminants typically from the electrolyte. Aiming to address this issue, we investigate the addition of water scavengers like hexamethyldisilazane (HMDS) and 2,2-dimethoxypropane (DMP) into a non-aqueous electrolyte-based magnesium perchlorate. The addition of water scavengers greatly reduces the overpotential of Mg deposition/dissolution, improves the ionic transfer number, and enhances the electrochemical performance of the electrolyte. In addition, a buffer layer interface from ionic conductive polymer–based magnesium chloride and polyvinylidene difluoride (PVDF) was applied between the liquid electrolyte and magnesium anode to protect the surface of the Mg anode from the direct contact with the liquid electrolyte to further inhibit Mg metal corrosion. The Mg symmetric cells deliver low overpotential compared with the liquid electrolytes by introducing the buffer layer, with and without scavengers. The value of the ion transference increased compared with analogs of liquid electrolytes. Mg-S coin cell assembled with an electrolyte-based HMDS can deliver a high initial discharge/charge specific capacity of ~ 520/530 mAhg −1 .