Problem 1

Assume a system that has two identical electrodes, and is comprised of a Cu/Li conducting electrolyte/Cu symmetric cell. There is no charge transfer process at the electrode/electrolyte interface. Electrode size is 1 cm2, the electrolyte resistance is 100 ohms, and the double layer capacitance is 10 uF/cm2.

a) Draw the equivalent circuit of the full cell.

b) Draw the Nyquist plot and the bode plot of the full cell based on following parameters.

c) Draw the Bode plot of this cell in the frequency range of 10 10^5 Hz.

d) Determine the characteristic frequency corresponding to |Z| = |Z|, where Z and Z are the real and the imaginary part of the complex impedance, respectively.

e) Now consider a Li/electrolyte interface. The electrode size is 1 cm2, the exchange current density is 1 10^-2 A/cm2 (n=1), and the double layer capacitance is 50 uF/cm2. Draw the corresponding Nyquist plot. What is the characteristic frequency of the semicircle?