EIS Plotting: Nyquist and Bode Visualization

After completing EIS data extraction, the first thing to do is usually “look at the plots to assess data quality.”

This Workflow batch-plots the extracted *_eis.csv files as Nyquist and Bode diagrams, helping you quickly identify sample differences, outliers, and test stability. It also supports exporting Origin projects for subsequent formatting and publication-quality figure preparation.

Prerequisites

First run EIS Extraction: CHI Instrument Data Preprocessing or In-Situ EIS Extraction: Donghua Instrument to ensure the directory contains standardized *_eis.csv files.

Steps

1. Select input directory: Select the output directory from EIS Extraction: CHI Instrument Data Preprocessing.
2. The system automatically identifies all *_eis.csv files and batch-generates plots.
3. The output directory is the input directory itself; files can be viewed directly after processing.

Generated Plots

1) Nyquist Plot

• X-axis: $Z'$
• Y-axis: $-Z''$
• Used for observing charge transfer impedance, diffusion behavior, and overall morphology before equivalent circuit fitting

2) Bode Plot

• Modulus plot: $|Z|$ vs. frequency (logarithmic axis)
• Phase plot: Phase vs. frequency (logarithmic axis)
• Convenient for comparing response mechanisms across different frequency ranges

Output

Each sample produces:

• *_nyquist_matplotlib.png
• *_bode_matplotlib.png
• *_eis_plots.opju (single-sample Origin project)

Additionally:

• eis_plots_merged.opju (multi-sample merged Origin project)

Recommended Next Steps

• EIS/DRT Analysis: Mapping Frequency-Domain Impedance to Relaxation Time Distribution: Further DRT analysis based on the same batch of *_eis.csv