Electrolyte Based on Easily Synthesized, Low Cost Triphenolate–Borohydride Salt for High Performance Mg(TFSI)2-Glyme Rechargeable Magnesium Batteries

Hebié Seydou (1, 2) , Hoang Phuong Khanh Ngo (1, 2) , Jean-Claude Leprêtre (1, 2) , Cristina Iojoiu (1, 2) , Laure Cointeaux (1, 2) , Romain Berthelot (1, 3) , Fannie Alloin (1, 2)

1 RS2E - Réseau sur le stockage électrochimique de l'énergie
2 LEPMI - Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces
3 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

A new class of electrolyte based on TFSI– and triphenolate–borohydride anions was designed and produced which fulfill all requirements of easy synthesis, high ionic conductivity, wide potential window, and noncorrosion of Al current collector. The electrolyte composed of magnesium triphenolate borohydride and Mg(TFSI)2 in glyme simultaneously displays a high conductivity of 5.5 mS cm–1 at 25 °C and a reversible Mg plating/stripping with high current density and Coulombic efficiency at room temperature. By addition of a slight amount of MgCl2 to this electrolyte, a Coulombic efficiency of 90% in an SS/Mg cell, stable cycling performance, and a wide anodic potential of 3.4 V vs Mg2+/Mg on Al current collector can be reached. Reversible and efficient Mg insertion/deinsertion with a high capacity of 94 mAh g–1 and 96% Coulombic efficiency was obtained in a Mo6S8 Chevrel cathode phase

Domaines: Chimie

Hebié Seydou, Hoang Phuong Khanh Ngo, Jean-Claude Leprêtre, Cristina Iojoiu, Laure Cointeaux, et al.. Electrolyte Based on Easily Synthesized, Low Cost Triphenolate–Borohydride Salt for High Performance Mg(TFSI)2-Glyme Rechargeable Magnesium Batteries. ACS Applied Materials & Interfaces, 2017, ⟨10.1021/acsami.7b06022⟩. ⟨hal-01588924⟩