SUBJECT: M.S. Thesis Presentation
   
BY: Kun Ryu
   
TIME: Thursday, April 27, 2023, 12:15 p.m.
   
PLACE: Love Building, 210
   
TITLE: Enhancing Low-Temperature Electrochemical Performance of Lithium Secondary Batteries
   
COMMITTEE: Dr. Seung Woo Lee, Chair (Mechanical Engineering)
Dr. Marta Hatzell (Mechanical Engineering)
Dr. Peter Hesketh (Mechanical Engineering)
 

SUMMARY

The application of lithium (Li) secondary batteries in extreme environments, such as deep-sea explorations and space missions, requires stable operation under low-temperature conditions. However, the low-temperature performance of conventional Li-ion batteries (LIBs) employing graphite anode is limited by the diffusion-controlled charge storage mechanism, which can cause the sluggish diffusion of Li-ions into the layered anode structure at low temperatures. In addition, the performance of next generation Li metal batteries (LMBs) using Li metal as the anode under sub-zero temperatures is also highly dependent on the electrolyte properties and electrode/electrolyte interface stability. This study provides two strategies to enable stable operations of LIBs and LMBs under low temperatures. First, balancing the diffusive and capacitive charge storing characteristics to enhance the charge storage capability of LIB anodes under low temperature conditions. Second, introducing a low-cost and effective additive into conventional electrolytes to improve Li thermodynamic stability and to generate the stable SEI layer on Li metal anode at low temperatures. Optimization of the diffusive and capacitive charge storage mechanism and additive engineering will provide scientific insights into enhancing the performance of LIBs and LMBs under extreme conditions.