Electroanalytical features of non-uniformly doped conducting poly-3-(3,4,5-trifluorophenyl)thiophene films

Two parallel diffusion paths model for interpretation of PITT and EIS responses from non-uniform intercalation electrodes

“…1 as an example) confirmed the dependence of the short time and the long time s d on the particle size and thickness of the electrodes (see details in [6]). A later work on impedance characterization of poly(trifluorophenyl)thiophene (PTFPT) films [35] revealed the same two characteristic features of the Nyquist plots for these polymeric electrodes (as found for Li-graphite electrodes) [6], namely, the deviation of the complex-plane impedance from the Warburg line at relatively high frequencies, and the need for two different values of s d in order to model and simulate the impedance spectra of the polymeric electrodes. In this case, however, we could not assume an orientation effect (similar to that observed for graphite electrodes) to be responsible for such behavior.…”

“…In contrast to a serial combination of FSW and FLW, the parallel combination of two FSWs fits the structural impedance modeling of the chemical or the geometric inhomogeneities of the electroactive films. Our previous EIS studies related to lithiated graphite intercalation electrodes [6] and doped conducting polymer electrodes [35], showed that the EIS spectra for both intercalation and doping electrodes can be nicely simulated by two alternative models, as depicted in Fig. 2.…”

Three-electrode cell set-up electrical equivalent circuit applied to impedance analysis of thin polyaniline film modified electrodes

“…5b, Z x is defined as the sum of Z WE and R s , the last comprising electrolyte solution resistance formed between surface of WE and end of HL capillary of RE. According to a common picture appearing from literature on polymer films [26,[30][31][32], Z WE (ix) of PANI modified electrode in Fig. 5c is defined as a parallel combination of not ideal capacitive impedance, Z c (ix), and impedance of the polymer film, Z f (ix).…”

“…Not ideal capacitive impedance Z c (ix) described by Eq. (4c) as a two-parameter function (Q, a) with a < 1, could originate from either interfacial phenomena [11][12][13][14][24][25][26][27][28][29][30][31][32] or from the bulk of porous film exhibiting anomalous transport of charges [35]. Whereas R f in Eq.…”

“…5c is defined as a parallel combination of not ideal capacitive impedance, Z c (ix), and impedance of the polymer film, Z f (ix). Under assumption that polymer films could be segmented to a number (n) of parallel sections with different charge transport properties [31,32], Z f (ix) in Fig. 5d is defined by a resistance and parallel connection of n transmission line elements terminated by capacitance [33].…”