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Equivalent circuit ideally polarizable electrode

The simplest model is the connection of resistor and capacitor in either series or parallel. Figure 4.2a shows the connection of a resistor and a capacitor in series. This equivalent circuit is the simplest model for an ideal polarizable electrode, with the assumption that neither the charge transfer on the electrode surface nor the diffusion limitations are present. [Pg.144]

An ideally polarizable electrode behaves as an ideal capacitor because there is no charge transfer across the solution/electrode boundary. In this case, the equivalent electrical model consists of the solution resistance, R, in series with the double-layer capacitance, Cdi. An analysis of such a circuit was presented in Section I.2(i). [Pg.167]

Capacitance measurements have become an important method in electrochemistry. Combinations of resistance and capacitance elements, the so-called equivalent circuits, describe the electrochemical properties of the double layer. In the case of an ideally polarizable electrode, the equivalent circuit is a linear combination of a double layer capacitance and an Ohmic electrolyte resistance (Figure 4.9a). The equivalent circuit of an... [Pg.114]

Figure 4.9 (a) Equivalent circuit of an ideally polarizable electrode, electrolyte resistance and... [Pg.115]

In Chap. 2 we saw the responses of electrical circuits containing the elements R, C, and L. Because these are linear elements, their impedance is independent of the ac amplitude used. However, in electrochemical systems, we do not have such elements we have solution-electrode interfaces, redox species, adsorption, etc. In this and the following chapters, we will learn how to express the electrochemical interfaces and reactions in terms of equations that, in particular cases, can be represented by the electrical equivalent circuits. Of comse, such circuits are only the electrical representations of physicochemical phenomena, and electrical elements such as resistance, capacitance, or inductance do not exist physically in cells. However, such a presentation is useful and helps in our understanding of the physicochemical phenomena taking place in electrochemical cells. Before presenting the case of electrochemical reactions, the case of an ideally polarizable electrode will be presented. [Pg.85]

F ure 3.44 Equivalent circuit of metal-elecirolyte interface for (a) an electrode with charge transfer reaction, showing the double layer capacitance and the charge transfer resistance and for (b) an ideally polarizable electrode with infinite charge transfer resistance. [Pg.100]

Fig. 1. Schema of an electrolytic cell with a working electrode W, auxiliary electrode A, and the corresponding equivalent circuit for the case of an ideally polarizable electrode. Fig. 1. Schema of an electrolytic cell with a working electrode W, auxiliary electrode A, and the corresponding equivalent circuit for the case of an ideally polarizable electrode.
Fig. 10. The complex impedance plot for several simple electrode processes at the electrode and their equivalent circuits (A) Ideally polarizable electrode. (B) Diffusion-controlled fast redox reaction. (C) Irreversible electrode reaction. (D) Quasi-reversible electrode reaction. Arrows indicate the increasing frequency. Fig. 10. The complex impedance plot for several simple electrode processes at the electrode and their equivalent circuits (A) Ideally polarizable electrode. (B) Diffusion-controlled fast redox reaction. (C) Irreversible electrode reaction. (D) Quasi-reversible electrode reaction. Arrows indicate the increasing frequency.
A strong adsorption on the electrode surface under the conditions of a rapid establishment of the adsorption equilibrium leads to a change in the double-layer capacity. In such cases the equivalent circuit and the frequency dependence is the same as for an ideally polarizable electrode. [Pg.18]

Here is more impedance study the simplest cell. In a real-life experiment, one can only work with a complete circuit, which consists of at least two electrodes. Now, to test our newly acquired impedance knowledge on a real-life problem, let s consider a circuit consisting of two identical electrodes. Draw its equivalent circuit and make a try at its impedance expression. Try harder to imagine its Cole-C ole plot You may also use a computer to simulate the situation by using reasonable parameters. To make the situation less complicated, we assume the interface is ideally polarizable. (Kang)... [Pg.673]

Impedance spectroscopy a single interface. Draw the equivalent circuits for the following electrode/electrolyte interfaces, then derive their impedance expression and explain what their Cole-Cole plot will look like (a) An ideally polarizable interface between electrode and electrolyte, (b) An ideally nonpolarizable interface between electrode and electrolyte, (c) A real-life electrode/... [Pg.673]

If one studies an (almost) ideally polarizable interphase, such as the mercury electrode in pure acids, there is no need to measure at high frequency. In this case the equivalent circuit is a resistor and a capacitor in series. The accuracy of measurement is actually enhanced by making measurements at lower frequencies, since the impedance of the capacitor is higher. The high accuracy and resolution offered by modem instmmentation allows measurement in such cases in very dilute solutions or in poorly conducting nonaqueous media, which could not have been performed until about a decade ago. [Pg.433]

III.l [see also Eq. (17) and Fig. 2], and that in the presence of a faradaic reaction [Section III. 2, Fig. 4(a)] are found experimentally on liquid electrodes (e.g., mercury, amalgams, and indium-gallium). On solid electrodes, deviations from the ideal behavior are often observed. On ideally polarizable solid electrodes, the electrically equivalent model usually cannot be represented (with the exception of monocrystalline electrodes in the absence of adsorption) as a smies connection of the solution resistance and double-layer capacitance. However, on solid electrodes a frequency dispersion is observed that is, the observed impedances cannot be represented by the connection of simple R-C-L elements. The impedance of such systems may be approximated by an infinite series of parallel R-C circuits, that is, a transmission line [see Section VI, Fig. 41(b), ladder circuit]. The impedances may often be represented by an equation without simple electrical representation, through distributed elements. The Warburg impedance is an example of a distributed element. [Pg.201]

Figure 27.11. (a) Equivalent electric circuit and (b) impedance complex plane plot for an ideally polarizable porous electrode. [Pg.284]


See other pages where Equivalent circuit ideally polarizable electrode is mentioned: [Pg.100]    [Pg.101]    [Pg.438]    [Pg.9]    [Pg.179]   
See also in sourсe #XX -- [ Pg.115 ]




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