IMPEDANCE OF THE INTERFACE - ELECTRODE-VERTICAL-BAR-FROZEN ELECTROLYTE CONTAINING REDOX-ACTIVE IONS

Impedance spectra of the frozen electrolyte (CH3)(4)NF . 4H(2)O contai ning a 1:1 mixture of K3Fe(CN)(6) and K4Fe(CN)(6), placed between gold electrodes, have been measured over a wide temperature range, includi ng above and below the melting point of the electrolyte. For temperatu res about 40K below the melting point of (CH3)(4)NF . 4H(2)O, the impe dance spectra, obtained in the frequency range from below 10(-2) Hz to over 10(5) Hz, seem to be dominated by charge transport to the electr odes. At these temperatures the interfacial reaction is controlled by the transport of redox active ions both in liquid and frozen electroly tes. However, at temperatures not far below the electrolyte melting po int, the low frequency part of the spectra contains a contribution fro m restricted diffusion. A simplified model of the studied interface, w ith the segregation of redox active ions from bulk frozen electrolyte into the thin layer near the electrode surface and pores in the bulk e lectrolyte, is proposed.