Studies on lithium bis(oxalato)-borate/propylene carbonate-based electrolytes for Li-ion batteries

Lithium bis(oxalato)-borate (LiBOB) is a promising salt for Li-ion batteries owing to its various characteristics such as non-fluorine, non-toxicity, low cost, and safety. It has the unique merits such as the stability at high temperature and the film-forming characteristics in propylene carbonate (PC)-based electrolyte. In this work, the utilization of PC as the basal solvent and dimethyl carbonate, gamma-butyrolactone and ethylene carbonate as co-solvents for LiBOB have been investigated. The results indicate that the co-solvent has conducive effects on the conductivities, viscosities, and battery performance. The conductivity and viscosity of 0.7 mol L-1 LiBOB in PC+GBL+EC+DMC (1:1:1:1, v/v) are 6.22 mS cm(-1) and 3.74 mPa s, respectively, and it is very stable in 0-5 V range. The capacity of Li/LiFePO4 battery is about 160 mAh g(-1) at 0.5 A degrees C. Moreover, the battery has exhibited the excellent rate performance.