Abstract

A series of new room temperature molten salt electrolyte based on lithium oxalyldifluoroborate (LiODFB) and 2-Oxazolidinone (C₃H₅NO₂, OZO) for EDLCs were synthesized by a facile and fast route. The investigation of the electrochemical characteristics of LiODFB-OZO molten salt electrolytes and the evaluation of LiODFB-OZO complex as electrolyte for EDLCs shows that the resulting molten salt exhibits excellent thermal stability, high ionic conductivity (up to ∼ 12.8 mS cm^–1), a wide electrochemical stability window (∼ 3.8 V) and lower electron-transfer resistance (∼ 4.8 Ω).The EDLCs with the LiODFB-OZO complex electrolyte can be charged up to 3.0 V. At 30°C the EDLCs with LiODFB-OZO complex electrolyte based on activated carbon electrodes deliver a stable specific capacitance of ∼ 83.9 F g^–1; At 70°C, they can deliver stable capacities of up to ∼ 106.1 F g^–1 (current density, 1 mA cm^–2). It is reasonable to assume that LiODFB-OZO complex system has some advantages as electrolyte for EDLCs with high energy density and high-power density, especially at elevated temperatures.