Facile and Economic Synthesis of Robust Non-Nucleophilic Electrolyte for High-Performance Rechargeable Magnesium Batteries

A cost-effective and highly efficient electrolyte with a wide electrochemical window, high reversibility of Mg plating/stripping, non-/low-corrosivity, good compatibility with cathode materials, and tolerance of trace water and impurity is crucial for the commercialization of rechargeable magnesium batteries. In this work, a novel boron-centered non-nucleophilic electrolyte that meets all the above requirements is prepared via a facile and economic approach from the raw materials B(TFE)(3)/MgCl2/CrCl3/Mg (BMCM). The as-prepared BMCM electrolyte is mainly composed of tetracoordinated anions [B(TFE)(4)](-) and solvated cations [Mg-2(mu-Cl)(2)(DME)(4)](2+). The BMCM electrolyte demonstrates attractive electrochemical performance, with a low overpotential (similar to 139 mV), a high Coulombic efficiency (similar to 97%), a high anodic stability (similar to 3.5 V vs Mg/Mg2+), and a long-term (more than 500 h) cycling stability. Moreover, BMCM shows good compatibility with the CuS cathode material. The CuS vertical bar BMCM vertical bar Mg full cell delivers a discharge specific capacity of 231 mAh g(-1) (at 56 mA g(-1)), which can retain similar to 88% even after 100 cycles. Importantly, the BMCM electrolyte is cost-effective and tolerant of trace impurity and water, which has great potential to be commercialized. This work is expected to promote the development of practical rechargeable magnesium batteries.

Automated summary

In this study, a novel boron-centered non-nucleophilic electrolyte with excellent electrochemical performance and compatibility with anode materials has been prepared, which is of great significance for the commercialization of rechargeable magnesium batteries.