Popular topics · Modelling and fitting (ZFit, ZSim)

How do I learn impedance fitting with ZFit? (Five-part video series)

Five short tutorial videos on the ZFit tool in EC-Lab and BT-Lab, from the impedance of single elements to fitting tips; applicable to data from single- and multichannel potentiostats and battery cyclers.

Key points

1. Impedance of single elements: R, C, L, CPE (Q), Warburg and diffusion elements.
2. Typical equivalent circuits and their Nyquist shapes.
3. Choosing an equivalent circuit and creating it with the text or graphic editor.
4. The fitting window: initial values, minimisation method, weighting and results.
5. ZFit tips: forcing the sign of a parameter, multiple attempts, checking the results.

Figures

**Figure 1.** ZFit results window: parameter values, standard errors and goodness of fit via χ².

**Figure 2.** EC-Lab equivalent circuit editor: circuit library, text and graphic editing, impedance expression.

Images: Bio-Logic Science Instruments; taken from the source article.

Videos

ZFit tutorial 1: Impedance of single elementsWatch on YouTube

ZFit tutorial 2: Typical equivalent circuitsWatch on YouTube

ZFit tutorial 3: Choose and create an equivalent circuitWatch on YouTube

ZFit tutorial 4: Description of the fitting windowWatch on YouTube

ZFit tutorial 5: Tips and tricksWatch on YouTube

Related application notes

What is an equivalent circuit, and how is it built and fitted with Z Fit? Battery AN14
How are several impedance diagrams fitted simultaneously with Z Fit? Corrosion AN45
How are potential-dependent EIS (SPEIS) and automatic sequential Z Fit performed? Battery AN18

Related curriculum module: Electrochemical Impedance Spectroscopy (EIS)