Electrical impedance spectroscopy of a PET chip sandwiched between two disk electrodes: understanding the contribution of the polymer/electrode interface

Mohamed Kechadi (1) , Lila Chaal (1) , Vincent Vivier (2) , Bernard Tribollet (2) , Jean Gamby (3, 2)

1 LECVE - Laboratoire d'Electrochimie, Corrosion et de Valorisation Energétique [Université de Béjaïa]
2 LISE - Laboratoire Interfaces et Systèmes Electrochimiques
3 LPN - Laboratoire de photonique et de nanostructures

This work is devoted to the understanding of the dielectric impedance response of a semi-crystalline polyethylene terephthalate (PET) membrane sandwiched between two disk electrodes under alternate voltage excitation in the frequency range between 1 MHz and 25 mHz. Experimental results obtained for various PET thicknesses (36, 50 and 100 mm) highlighted the influence of the contact resistance at the electrode/polymer interface. For a better understanding of the PET/electrode interface behaviour, the experiments were compared with simulations performed for three different descriptions: the direct use of electrical equivalent circuits, an analytical model accounting for a power-law distribution of resistivity, and a numerical model (finite element simulations of the whole cell). The results highlight that the resistivity distribution obtained using the power-law model provided an appropriate description of the system in the frequency range investigated while the use of the CPE model is only consistent for low-frequencies (below 1 Hz).

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux

Mohamed Kechadi, Lila Chaal, Vincent Vivier, Bernard Tribollet, Jean Gamby. Electrical impedance spectroscopy of a PET chip sandwiched between two disk electrodes: understanding the contribution of the polymer/electrode interface. Physical Chemistry Chemical Physics, 2016, 18, pp.20583-20590. ⟨10.1039/c6cp03042d⟩. ⟨hal-01358834⟩