Circuit Elements

impedance.circuit_elements.A(p, f)[source]

defines a semi-infinite Warburg element

Notes

\[Z = \frac{A_W}{\sqrt{ 2 \pi f}} (1-j)\]
impedance.circuit_elements.C(p, f)[source]

defines a capacitor

\[Z = \frac{1}{C \times j 2 \pi f}\]
impedance.circuit_elements.E(p, f)[source]

defines a constant phase element

Notes

\[Z = \frac{1}{Q \times (j 2 \pi f)^\alpha}\]

where \(Q\) = p[0] and \(\alpha\) = p[1].

impedance.circuit_elements.G(p, f)[source]

defines a Gerischer Element

Notes

\[Z = \frac{1}{Y \times \sqrt{K + j 2 \pi f }}\]
impedance.circuit_elements.K(p, f)[source]

An RC element for use in lin-KK model

Notes

\[Z = \frac{R}{1 + j \omega \tau_k}\]
impedance.circuit_elements.L(p, f)[source]

defines an inductor

\[Z = L \times j 2 \pi f\]
impedance.circuit_elements.R(p, f)[source]

defines a resistor

Notes

\[Z = R\]
impedance.circuit_elements.T(p, f)[source]

A macrohomogeneous porous electrode model from Paasch et al. [1]

Notes

\[Z = A\frac{\coth{\beta}}{\beta} + B\frac{1}{\beta\sinh{\beta}}\]

where

\[A = d\frac{\rho_1^2 + \rho_2^2}{\rho_1 + \rho_2} \quad B = d\frac{2 \rho_1 \rho_2}{\rho_1 + \rho_2}\]

and

\[\beta = (a + j \omega b)^{1/2} \quad a = \frac{k d^2}{K} \quad b = \frac{d^2}{K}\]

[1] G. Paasch, K. Micka, and P. Gersdorf, Electrochimica Acta, 38, 2653–2662 (1993) doi: 10.1016/0013-4686(93)85083-B.

impedance.circuit_elements.W(p, f)[source]

defines a blocked boundary Finite-length Warburg Element

Notes

\[Z = \frac{R}{\sqrt{ T \times j 2 \pi f}} \coth{\sqrt{T \times j 2 \pi f }}\]

where \(R\) = p[0] (Ohms) and \(T\) = p[1] (sec) = \(\frac{L^2}{D}\)

impedance.circuit_elements.num_params(n)[source]

decorator to store number of parameters for an element

impedance.circuit_elements.p(parallel)[source]

adds elements in parallel

Notes

\[Z = \frac{1}{\frac{1}{Z_1} + \frac{1}{Z_2} + ... + \frac{1}{Z_n}}\]
impedance.circuit_elements.s(series)[source]

sums elements in series

Notes

\[Z = Z_1 + Z_2 + ... + Z_n\]