Warburg Impedance

The Warburg impedance
W
is the diffusional impedance for 1D linear diffusion. This Demonstration shows the Randles equivalent circuit, taking into account the electrolyte resistance
R
e
, the charge transfer resistance
R
ct
, and the double layer capacitance
C
dl
. Various shapes of the impedance diagram can be obtained when changing the parameter
λ
.

Details

The Warburg impedance is the diffusional impedance for the diffusion layer of infinite thickness, which is characterized for the macroelectrode.
The Warburg impedance is given by
W(ω)=
R
ct
λ
ω
, where
λ
is the relative parameter of the charge transfer
k
and the diffusion coefficient
D
,
λ
=
k
f
D
o
+
k
b
D
R
,
where
k
f
,
k
b
are heterogeneous kinetics on the electrode and
D
O
,
D
R
are the diffusion coefficients of the species oxidant and reductant.
With Warburg impedance, one can describe an electrochemical cell for the macroelectrode by the Randles equivalent circuit:

External Links

Electrochemical Impedance

Permanent Citation

Quang-Dao Trinh
​
​"Warburg Impedance"​
​http://demonstrations.wolfram.com/WarburgImpedance/​
​Wolfram Demonstrations Project​
​Published: December 9, 2010