The echemsuite.cyclicvoltammetry module

The echemsuite.cyclicvoltammetry module is dedicated to the analysis of data deriving from cyclic-voltammetry experiments.

Supported file types

The module currently supports GAMRY .DTA files, Biologic .mpt files and CH instruments .txt ASCII files.

Structure of the module

The echemsuite.cyclicvoltammetry module is articulated in a single sub-module named read_input. The module is resposible to load the experimental files, parse them and allow an easy access to the user. The core element of the module is the CyclicVoltammetry class that represents the digital equivalent of a cyclic-voltammetry experiment.

Basic operation of the module

An instance of a CyclicVoltammetry object can be created directly form an experimental file according to the syntax:

from echemsuite.cyclicvoltammetry import CyclicVoltammetry

cv = CyclicVoltammetry("../utils/cv_sample.DTA")

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
Cell In[1], line 1
----> 1 from echemsuite.cyclicvoltammetry import CyclicVoltammetry
      3 cv = CyclicVoltammetry("../utils/cv_sample.DTA")

ImportError: cannot import name 'CyclicVoltammetry' from 'echemsuite.cyclicvoltammetry' (unknown location)

The number of cycles loaded can be accessed using the __len__ attribute according to:

ncycles = len(cv)
print(f"The loaded experiment contains {ncycles} cycles")

The CyclicVoltammetry class allows easy access to each cycles in the experiment thanks to the built-in __getitem__ attribute. To access the current and potential values associated with a given cycle, it is sufficient to access the desired index using the square brakets notation. As an example, the following code can be used to access the current I and the potential V associated to the first CV cycle (index 0):

I, V = cv[0]
print(I)

The CyclicVoltammetry class also provides a simple __iter__ method returning for each cycle the series containing the current and potential values associated to each cycle. As an example:

for index, (I, V) in enumerate(cv):
    print(f"Cycle {index}: {I}")

Example: A simple script to plot the experimental data

The following scipt can be used to plot the experimental data associated to a CV experiment. The data will be plotted using the matplotlib library.

# Import all the required packages
import matplotlib.pyplot as plt
from echemsuite.cyclicvoltammetry import CyclicVoltammetry

# Load the data to plot
cv = CyclicVoltammetry("../utils/cv_sample.DTA")

# Setup a figure and set a global font size
fig = plt.figure(figsize= (8, 8))
plt.rcParams.update({'font.size': 18}) 

# Plot all the cycles contained in the cyclic-voltammetry experiment
for index, (current, voltage) in enumerate(cv):
    plt.plot(voltage, [1e6*i for i in current], label=f"{index}")

# Set the axis labels
plt.xlabel(r"V vs $\mathrm{V}_\mathrm{ref}$ [$V$]", size=22)
plt.ylabel(r"I [$\mu A$]", size=22)

# Add a legend to the plot
plt.legend(title="Cycle")

# Setup a grid
plt.grid(which="major", c="#DDDDDD")
plt.grid(which="minor", c="#EEEEEE")

# Render the plot
plt.tight_layout()
plt.show()