Measurement of low frequency relative permittivity of room temperature molten salts by triangular waveform voltage

Abstract

We present a low-cost experimental method for measuring cell resistance and capacitance independently. In this technique a triangular waveform voltage excitation is adopted. Conductivity calibration is straightforward. However, it is demonstrated that a specific calibration procedure needs to be followed to obtain correct relative permittivity values for highly conductive liquids. It is also required to measure conductivity in order to measure relative permittivity for highly conductive liquids. Using this technique, the relative permittivities of room temperature molten salt 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF4) were measured. To our knowledge, this is the first ever directly measured low frequency relative permittivity value of highly conducting EMImBF4 and BMImBF4.