Strong anion receptor-assisted boron-based Mg electrolyte with wide electrochemical window and non-nucleophilic characteristic

Herein we present a strong anion receptor-assisted Mg-ion electrolyte, which is synthesized from tris(2H-hexafluoroisopropyl) borate (THFPB) and MgO in 1,2-dimethoxyethane (DME). The as-prepared borate magnesium oxide complex (BMOC) electrolyte delivers exceptional electrochemical performances, including extremely high anodic stability (up to 4.2   V vs. Mg), non-corrosivity to stainless steel and aluminium foils , and reasonable ionic conductivity of 1.74   ×   10 −   4   S   cm −   1 . In addition, by virtue of the non-nucleophilic characteristic of the BMOC electrolyte, S   ||BMOC   ||Mg cells have been assembled, which show a high stable discharge capacity of 1030   mAh   g −   1 for 15   cycles and one well-defined voltage plateau of ≈   1.1   V vs. Mg, yielding a desirable energy density beyond 1100   Wh   kg −   1 based on the weight of sulfur in cathodes.