The physicochemical (e.g., density, viscosity, ionic conductivity, and self-diffusion coefficient) and electrochemical (e.g., electrochemical window and electric double-layer capacitor performance) properties of two new types of room-temperature ionic liquids, 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate (EMIm-FAP) and 1-ethyl-3- methylimidazolium tetracyanoborate (EMIm-TCB), were investigated and compared. EMIm-FAP showed a wider electrochemical window with a carbon working electrode compared with EMIm-TCB, in spite of lower viscosity, larger self-diffusion coefficients and higher ionic conductivity. Also, the electric double-layer capacitor using EMIm-FAP shows better cycle reversibility and higher charge/discharge voltage operation (over 3 V) than that using EMIm-TCB.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry