Electrochemical performances of two kinds of ternary electrolyte mixtures with lithium bis(oxalate)borate

Conductivities (??) of PC (propylene carbonate)/EMC (ethyl methyl carbon ate)/DMC (dimethyl carbonate) and EC (ethylene carbonate)/EMC/DMC solutions of lithium bis(oxalate)borate (LiBOB) were experimentally determined at a temperature (??) range from ?40.0 to 60.0°C. Under such experimental conditions, the effect factors on the ??, such as the salt molar concentrations (m), and the volume ratio of solvent compositions, were also investigated. The results showed that, in wide ?? range, the higher ?? were obtained with 0.7 mol L^?1 LiBOB in PC/EMC/DMC and 0.6 mol L^?1 LiBOB in EC/EMC/DMC and with a volume ratio of 1: 1: 1 and 1: 1: 2, respectively. When used in LiFePO₄/Li cells, compared to the cell with the electrolyte system of 1.0 mol L^?1 LiPF₆-EC/EMC/DMC (1: 1: 1), LiBOB cells with PC/EMC/DMC and EC/EMC/DMC electrolyte systems with the same volume mixture solvent compositions exhibit several advantages, such as more stable cycle performance, higher mean voltage, excellent large current discharge capability, more capacity retention at high temperature, and more stable storage performance, etc. This study not only shows that LiBOB is a very promising alternative salt for lithium ion chemistry, but also provides appropriate solvent to improve LiBOB??s electrochemical performance.