Impedance analysers apply a small alternating perturbation over a wide frequency range and resolve a system into its resistive, capacitive and diffusional contributions. NewRoad supplies Bio-Logic impedance instrumentation, both as dedicated analysers and as EIS capability integrated into potentiostats and battery cyclers.
A small sinusoidal voltage or current is applied at each frequency and the amplitude and phase of the response are measured. Plotting the complex impedance as Nyquist and Bode diagrams and fitting an equivalent circuit separates charge transfer resistance, double layer capacitance, film properties and diffusion, each of which dominates a different frequency window.
