EN06.04.20 : Thermal Stability Analysis of Lithium-Sulfur Batteries via Controlled Conditioning Techniques

5:00 PM–7:00 PM Apr 3, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E

Daisy Patino1 Jeffrey Bell1 Rachel Ye1 Cengiz Ozkan1 Mihri Ozkan1

1, University of California, Riverside, Riverside, California, United States

The market for electric vehicles (EVs) has gained significant popularity over recent years. However, in order for that market to continue to expand relative to consumer demands, lithium ion technologies need to be improved to withstand the common stresses encountered in EV applications. An example of such stresses is unanticipated fluctuations in internal and ambient temperatures. Currently, optimal performance of lithium ion batteries is limited to a specific operating temperature, subsequently, batteries that are exposed to temperatures outside of the operating range will exhibit detrimental performance effects such as a loss in capacity, life cycle degradation, and more concerning safety hazards. These effects are attributed to the decomposition of the solid electrolyte interphase (SEI) layer during stressed cycling. The common approach towards improving robustness of SEI is to utilize various electrolyte additives. This approach, however, is prone to adverse effects such as rapid self-discharge and a decrease in energy density. Herein, we propose a noninvasive approach towards developing robust SEI layer in lithium sulfur batteries to improve thermal stability at high temperatures. Robustness of SEI layers is modified via controlled conditioning of lithium sulfur (LiS) batteries within specified voltage regions. This work explores conditioning of LiS batteries at low temperatures within 8 – 17 degrees Celsius in attempt to slow down the kinetics involved in SEI formation and hence, develop robust SEI layers within the first cycles. The batteries are then evaluated for aging at elevated temperatures within 30 - 60 degrees Celsius, and assessed via GCPL, CV, EIS, and GITT.