A Novel and Highly Efficient Indolyl-Based Electrolyte for Mg Batteries

Magnesium-based batteries are one of the most promising candidates as postlithium electrochemical energy storage devices. Despite considerable research progress, suitable electrolytes supporting long-term reversible stripping/deposition of magnesium metal in a low content or halide-free electrolyte are still of great interest. Moreover, the electrolytes should possess certain properties to be a good match with candidate cathode materials. Herein, the electrochemical performance of a novel indolyl-based electrolyte is presented. Theoretical modeling combined with NMR analysis identifies the magnesium species in the electrolyte. Reversible stripping/deposition of Mg metal in indolyl-based electrolyte shows long-term cycling with high coulombic efficiency of >99.5% and yields dendrite-free magnesium deposition in compact and smooth layers. The X-ray diffraction shows different preferential structural orientations depending on the electrode substrate. Finally, a proof-of-concept MgMo6S8 full cell using the newly developed electrolyte is proposed.

Automated summary

This study presents the electrochemical performance of a novel indolyl-based electrolyte, which exhibits long-term cycling and high coulombic efficiency for the reversible stripping/deposition of magnesium metal. The electrolyte also enables dendrite-free magnesium deposition in compact and smooth layers. Additionally, a proof-of-concept MgMo6S8 full cell using the newly developed electrolyte is proposed.