Graduation Semester and Year
Spring 2025
Document Type
Thesis
Degree Name
Master of Science in Electrical Engineering
Department
Electrical Engineering
First Advisor
David Wetz
Abstract
As technology continues to evolve, the demand for more reliable and longer-lasting batteries is growing rapidly in the electronics industry. Batteries are vital for powering a wide range of technologies, from smartphones and consumer electronics to automotive systems and high-end tools used across multiple sectors. Lithium-ion batteries (LIBs) have helped bridge the power and energy gap that these different technologies require while achieving sufficient efficiency and reliability to make carrying them around feasible and long lasting. To further enhance the performance and longevity of a these devices, a deeper understanding of the degradation mechanisms occurring inside LIBs is crucial. The sealed nature of these technologies makes this extremely difficult but the research performed here aims to study how changes in internal pressure can serve as an indicator for age related degradation of LIBs. To test the correlation between internal pressure and degradation, various lithium iron phosphate (LiFePO4) cells were punctured in an inert environment and then placed custom chambers that have been designed to hermetically seal the commercially procured cells from the outside atmosphere. After a certain number of cycles performed at high C rates, the degradation of the cells and their pressure evolution behavior were analyzed using electrochemical impedance spectroscopy (EIS), capacity fade, gas chromatography-mass spectroscopy and scanning electron microscope imaging (SEM). This thesis describes the experimental methods undertaken and the results obtained from a few experiments.
Keywords
Lithium ion, Internal Pressure, lithium iron phosphate, electrochemical impedance spectroscopy, capacity fade, degradation mechanisms
Disciplines
Electrical and Electronics
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Garcia, Kayla, "Correlation of Internal Pressure to the Fundamental Aging Mechanism of Li-Ion Batteries" (2025). Electrical Engineering Theses. 394.
https://mavmatrix.uta.edu/electricaleng_theses/394