Can batteries take the heat? Investigating the electrode-electrolyte interface for solid-state battery performance at elevated temperatures

Solid-state batteries consisting of solid electrolytes and high voltage cathodes present new possibilities toward safer and more efficient batteries that can operate at elevated temperatures (>60°C) while requiring little to no external cooling mechanisms. In this dissertation, the failure mechanisms of solid-state batteries constructed from high voltage cathodes and inorganic solid-state electrolytes at an array of temperatures ranging from 24°C to 100°C was investigated by studying their cycling performance. One of the most fundamental indicators of electrochemical performance degradation of solid-state batteries at elevated temperatures was studied in detail; the electrode electrolyte interfacial charge transfer resistance. Possible degradation mechanisms were explored at the electrode and electrolyte materials after electrochemical testing. A correlation between elevated temperature, capacity retention, and battery state of charge was found. Mainly, it was found that capacity retention decreases with overall increase in operating temperature and state of charge, due to an increase in the cathode electrolyte interfacial resistance, possibly originating from deposition of side reaction products such as In2O3, as well as phase transitions at the cathode surface that impede Li-ion transport at elevated temperatures. Furthermore, the potential impacts of solid-state battery implementation for electrothermal systems in electric vehicles was also investigated based on preliminary findings at elevated temperatures. Lastly, materials modification at the electrode scale was also explored for improving cycling performance, with emerging prospects for both cathode surface treatment to decrease the growth in interfacial resistance and anode pre-alloying to increase the available Li content. Future work regarding these modifications to further improve performance is suggested.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Kwon, Patrick J

Contributors dc:contributor

• Braun, Paul V
• Krogstad, Jessica A
• Perry, Nicola H
• Miljkovic, Nenad

• Batteries
• Solid-state
• Elevated Temperature
• Li-ion
• Lithium-ion

Statement dc:rights

• Copyright 2024 Patrick Kwon

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/125753

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F125753