Cyclic Voltammetry & Impedance Kinetics Protocol
Electrochemical characterization of electrodes: baseline subtraction, Dunn’s capacitive/diffusion separation, and Nyquist EIS equivalent circuit fitting.
Scientific Principles & Procedural Takeaways
Dunn’s Method: i(V) = k1*v + k2*v^(1/2) separates surface capacitive charge (k1*v) from solid-state diffusion (k2*v^(1/2)).
EIS Nyquist Plot: High-frequency semicircle diameter gives charge transfer resistance (Rct); low-frequency slope yields Warburg impedance.
Settings & Acquisition Nuances
Scan rates (5 to 100 mV/s), potential window, electrolyte concentration, reference electrode potential offset.
Common Artifacts & Prevention
Uncompensated solution resistance (Ru) distorting redox peak potentials. Apply 85-90% iR-compensation on the potentiostat.
📥 Starter Practice Datasets
Example Practice Data: Cyclic Voltammetry Potential-Current (CSV)
Pedagogical starter cyclic voltammetry potential vs current array for practicing specific capacitance integration.