Sp 150 potentiostat

All the electrochemical measurements were carried out using Biologic (SP-150) Potentiostat. The ZnO-V₂O₅ coated PET fiber was used as a working electrode, Ag/AgCl electrode in 0.2 M KCl as a reference electrode, and a Pt wire electrode as a counter electrode with different concentrations of NaOH and HCl as electrolytes. Prior to the electrochemical test, an electrode was prepared by thoroughly mixing active material (ZnO/V₂O₅), carbon black, and PVDF in a mass ratio of 80:10:10. The prepared sample was coated on the ZnO seed layered PET fiber using a dip coater. The fabricated electrode was dried in a vacuum oven at 60 °C and finally used as an electrochemical sensor.

Specific conductivities of the pure ionic liquid and binary solutions with lithium salts were obtained by impedance spectroscopy using a sealed commercial conductivity probe (WTW, Weilheim, Germany) consisting of two rectangular platinized platinum electrodes fused into glass with a nominal cell constant of 0.5 cm⁻¹. The actual cell constant was determined prior to the experiments using commercial conductivity standards. The impedance spectra were obtained with an SP-150 potentiostat (Biologic, Seysinnet-Pariset, France) by applying voltages of 5, 10 and 15 mV and frequencies from 200 kHz to 1 Hz in 50 logarithmic steps. The electrolyte resistance for the three voltages was averaged. Temperature was controlled by immersing the conductivity probe in a Proline RP 1845 thermostat (LAUDA, Lauda-Königshofen, Germany). The specific conductivity $\kappa$ was calculated as the actual cell constant divided by the electrolyte resistance $R$ . From the specific conductivity and density, the molar conductivity was calculated using Equation (5), with M the molar mass of the sample.
$${\Lambda }_{\mathrm{M}}=\frac{\kappa M}{\rho }.$$