Novel liquid lithium borates characterized with high lithium ion transference numbers

A series of lithium borates with two oligoether chains and two electron withdrawing groups directly bonded to the ate complex center were prepared. Ionic conductivity as high as 4.5×10−5 S/cm was achieved at 30 °C for Salt A(n=7.2). Lithium borates exhibited much higher ionic conductivities than corresponding lithium aluminates, which was explained by the partial charges on oxygen atoms obtained from MOPAC calculation and by the results of fitting Vogel–Tammann–Fulcher (VTF) equation to conductivity data. Lithium borates also exhibited high lithium ion transference numbers (T+) and satisfactory electrochemical stabilities. They were considered as promising materials for lithium battery application.