A novel electrolyte used in high working voltage application for electrical double-layer capacitor using spiro-(1,1 ')-bipyrrolidinium tetrafluoroborate in mixtures solvents

作者：Yu, Xuewen; Wang, Jing; Wang, Chenglin; Shi, Zhiqiang^*

来源：Electrochimica Acta, 2015, 182: 1166-1174.

DOI：10.1016/j.electacta.2015.09.013

• spiro-(1,1')-bipyrrolidinium
• tetrafluoroborate
• solvent systems
• ionic conductivity
• high working voltage
• spiral cylindrical capacitor

This paper is addressed on studying the electrolytes for electrical double layer capacitors with relatively high ionic conductivity and electrochemical stability for high energy density application. A systematic analysis of the electrochemical characteristics has been presented using spiro-(1,1')-bipyrrolidinium tetrafluoroborate (SBP-BF4) with 1.5 mol L-1 (M) in variety of solvent compositions including propylene carbonate (PC), ethylene carbonate (EC) and dimethyl carbonate (DMC), while the solvent mixtures are PC + DMC (1:1 in volume) and PC + DMC + EC (1:1:1 in volume). The physical properties and electrochemical performance of SBP-BF4-based electrolytes are improved by tuning solvent mixtures compositions for high working voltage application. The binary solvent system of PC + DMC electrolyte exhibits lowest viscosity of about 3.14 mPa s, while the ternary solvent system of PC + DMC + EC electrolyte exhibits highest conductivity of about 18.08 mS cm(-1). The SBP-BF4/PC-based electrolytes display excellent upper voltage hold capability about 3.5 V. The binary solvent system exhibits superior rate performance, when the charge cut-off voltage is lower than 3.2 V. The ternary solvent system exhibits superior rate performance than that of other two solvent systems electrolytes, when the charge cut-off voltage is higher than 3.2 V. The maximum energy density and power density of EDLCs using the ternary solvent system electrolyte are 41.5 Wh kg(-1) and 17.0 kW kg(-1), respectively. The spiral cylindrical capacitors based on ternary solvent system electrolyte exhibits better cycle performance than that of other two solvent system electrolytes at the high working voltages.

• 出版日期2015-11-10
• 单位天津工业大学