“TEMPERATURE-DEPENDENT ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS) LITHIUM THIONYL CHLORIDE AND LI-ION BATTERIES”
By Gökberk Katırcı
Advisor: Assoc. Prof. Burak Ülgüt
Bilkent University, Chemistry Department
Date: 22.05.2024
Time: 16:00 (4 p.m.) Turkish Time (UTC +03:00)
Place: Zoom Meeting as follows:
Topic: Gökberk Katırcı’s Ph.D. Defense
Time: May 22, 2024 04:00 PM Istanbul
This is an online seminar. To obtain event details please send a message to department.
All are cordially invited.
Abstract:
Batteries are one of the most researched and developed energy storage systems in recent years due to their utilization in portable and mobile devices. Therefore, operando and in-situ characterization of batteries should be properly performed to understand the electrochemical processes. For this purpose, Electrochemical impedance spectroscopy (EIS) based techniques have been utilized in this thesis. EIS is an in-situ, non-destructive characterization technique that has been widely used in recent years.
In this talk, EIS of lithium thionyl chloride batteries (with different internal geometries) are investigated in terms of temperature-dependent processes and architecture. Thereafter, the electrochemical processes will be independently analyzed via the Arrhenius relations and their activation energies are calculated. Consequently, the impedance responses of both geometries (spiral and bobbin-type) are investigated. Moreover, temperature dependent EIS of symmetric (Li/Li and LFP/LFP) and battery-type (Li/LFP) cells are investigated. Similarly, the activation energies of different electrodes are calculated and compared within these cell structures. Lastly, a quick state-of-health (SoH) and capacity estimation processes are presented.