Date of Award
1-1-2022
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Chemical Engineering
Specialization
Materials Science
Department
Chemical Engineering
First Advisor
Arijit Bose
Abstract
Lithium-ion batteries (LIBs) with solid electrolytes show promise as a safer and more thermally stable alternative to those with liquid carbonate electrolytes. Despite their advantages, solid electrolytes exhibit poor lithium-ion conductivity at room temperature and poor contact with electrode surfaces; both issues must be overcome if solid electrolytes are to replace liquid electrolytes. Additionally, several corrosion mechanisms exist within the electrolyte system, of poly(ethylene oxide) and bis(trifluoromethane) sulfonimide lithium salt, leading to cathode damage for high voltage cathodes and loss of lithium. This work demonstrates that manufacturing and design optimizations exist which can minimize and overcome these issues.
Many methods attempt to create polymer cells through a process where the cathode and anode are mixed with polymer electrolyte. While this is convenient and reduces the footprint of the electrolyte, any electrode material surrounded by polymer is partially or completely isolated from the electrochemical reaction. Conductive carbon black may be added to the polymer to enhance electron conductivity, but this decreases the overall power and energy density of the battery cell. Instead, this work: first, investigates the material properties of common carbon black particles; second, investigates the connections between carbon black and the coating conditions used to create carbon-containing electrodes; and third, proposes a one method to infiltrate existing electrodes with polymer electrolyte to reduce interfacial resistance and improve lithium-ion transport and a second method to passivate and protect cathode materials from corrosion and degradation at high voltage. A tape casting method coats suspended polymer electrolyte onto existing, calendared electrodes and lowers the resistance at the interface, as seen through successful cycling data. After a pre-cycling process to passivate the cathode material and limit corrosion, a safe, high-power polymer electrolyte battery cell is realized. The passivation is also shown to protect aluminum from liquid electrolytes using the highly corrosive LiTFSI lithium salt from polyethylene oxide-based polymer electrolytes.
Recommended Citation
Sullivan, Joseph Patrick, "Development of a Safe Lithium-ion Battery with a Polymer Electrolyte" (2022). Open Access Dissertations. Paper 1480.
https://digitalcommons.uri.edu/oa_diss/1480
Terms of Use
All rights reserved under copyright.
Comments
This dissertation contains Controlled Unclassified Information (CUI) and is not available.