Reports

This page includes:

• Final Report

• Executive Summary

• Final Poster

• All Presentations Made to MAE 156B Class

• Individual Component Reports

Each file can be seen as a PDF for easy viewing and also in editable form as a doc and in ppt files

Subpages:

• Budget Sheet

• Programs/Code

Final Report 

Executive Summary 

UC San Diego’s Electrochemical Materials Science Research Lab led by Professor Ping Liu studies nanomaterials via impedance. This lab specifically tests nanoporous, metal-salt composites. For the metal component of the nanocomposite cell, the lab uses one of the following metals: copper, cobalt, or iron. For the salt component of the nanocomposite cell, the lab uses one of the following salts: lithium sulfate, chloride, or bromide. The current lab process is to heat up or synthesize this nanocomposite by placing the nanomaterial cell into a convection oven to observe the changes in its impedance spectra. The process described is known as the sintering process. This requires a lab staff member to constantly check if the target impedance spectra has been met via the Gamry (a potentiostat instrument), and increase the temperature of the oven as needed until the material reaches a quasi-steady-state equilibrium. A standard run of the experiment takes about 10-20 hours and requires manual adjustments, making the process daunting and non-efficient from the experimenter’s perspective. 

The objective of this project is to automate the heating process for a metal-salt nanocomposite material given a target impedance spectra. Our controller makes data analysis and the sintering process more efficient for the lab in terms of time and result replication. Our system eliminates the lab’s current trial-and-error method when analyzing a material’s impedance spectra. The implementation of a multi-controller system was necessary to regulate the oven temperature and impedance over time. Statistical analysis methods such as variance and least squared error were used to compare the changes in the imaginary component of the impedance spectra to narrow down the quasi-steady state equilibrium of the material, giving us a metric to compare the impedance spectrum with. 

To replicate the experimental procedure conducted at the UC San Diego Sustainable Power and Energy Center, the team set up a DIY oven, which includes a commercial PID controller with a USB output, a standard toaster oven, a solid-state relay, and a K-type thermocouple cable. For validation of the DIY oven, the team conducted experiments and gathered impedance data with a reversible metal-salt composite cell provided by the sponsor’s laboratory. A prototype was built and set up to find the equilibrium of a given nanocomposite material using variance. For our testing method, we have a nanocomposite material (FeCl/LiCl) connected to the Gamry device inside the oven, with our oven set at 30℃ and cooled with a fan to keep the oven heat from overheating. The MATLAB code asks for user input from the Gamry instrument and the desired setpoint temperature. As the test is running, the MATLAB code will read the variance for every four impedance spectras given by the Gamry. Our desired metric for successful equilibrium is a variance value of 0.2. After a set amount of time, the full results will be given indicating whether or not equilibrium was achieved during an experimental trial. After the experimental trial, we obtained the following variance values over 20 impedance graphs generated: 0.3923, 0.2966, 0.3116, and 0.3180. After the second variance, a new temperature was set to ensure our material reached the desired spectra. Our experiment concluded when a least squared error of 0.7 was obtained indicating that our material reached equilibrium as well as the desired impedance spectra.

Presentations 

Individual Component Analysis