M.A.P.L.E. Lab

EDLC Model

This page provides Matlab codes and experimental data described in the paper. The codes are given in the zip file below. Download and save the PDF files as m files to use them. Note that running the same codes in FORTRAN or C++ may be more faster or efficient. The estimation algorithm used may not converge or provide global optima for all the problems.

N. A. Choudhury, P. W. C. Northrop, A. C. Crothers, S. Jain, and V. R. Subramanian, "Chitosan hydrogel-based electrode binder and electrolyte membrane for EDLCs: experimental studies and model validation," J. Appl. Electrochem., 42 (11), 935-943 (2012) . 

Supercapacitors have a very high power density, which allows them to be charged and discharged in applications that occur on the order of seconds, for example, in regenerative braking in hybrid electric vehicles.

The electrical double layer capacitor (EDLC) is a type of supercapacitor which relies on very high surface area electrodes to achieve a very high capacitance. This allows a double layer of positive and negative charge to develop at the electrode electrolyte interface. In this paper, Choudhury, et al. constructed EDLCs using a chitosan based electrode binder and electrolyte membrane. Chitosan is developed from chitin, a naturally occurring and abundant polymer. Chitosan has the advantage of being non-toxic, biodegradable, and cost-effective, hence its use in this study. 

The included codes estimate two parameters, specific capacitance and separator resistance, across the life of a chitosan based EDLC. The file, EDLC_Simulation.m is the main file used and can be run independently. It reads experimental data from the text files and returns the estimated parameter at each cycle.

vCell.m is a function file of the capacitor model used. It inputs a parameter vector and a time vector and returns the predicted discharge of the capacitor. Vres.m is a function file which calculates and returns the difference between the model predicted curve (from vCell.m) and the experimental data. The m-files are posted as a single pdf file titled EDLC_Simulation.pdf in the zip file below.

TempTime.txt is a vector of the experimental times that data is measured. Note that it resets to zero at each experimental step. TempVolt.txt is a vector of experimentally measured voltages. TempStep.txt records the condition under which of each data point was sampled (charge, discharge, or relaxation), while TempNumber.txt lists the cycle numbers.

EDLC_Simulation.zip

Please feel free to contact Dr. Venkat Subramanian for any comments.

List of other models:

• Polymer Electrolyte Fuel Cell Model
• Electrical Double Layer Capacitor Model
• Semianalytical method of lines
• Separation of variables for composite electrodes
• False Transient Method of Lines
• Single particle model for lithium-ion batteries