Faculty Mentor
Bilal El-Zahab
Presentation Type
Presentation
Start Date
10-11-2022 2:10 PM
End Date
10-11-2022 2:22 PM
Abstract
Lithium−Sulfur (Li-S) batteries have attracted attention due to their high-energy density, 2500 Wh/𝑘𝑔𝑐𝑒𝑙𝑙 [1], and theoretical capacity of 1672 mAh/g-S [2]. In addition to that, sulfur abundance makes it a good candidate for rechargeable batteries. However, Li-S system has a few challenges that hinder its commercialization. Such as the insulating nature of the sulfur element, volume expansion, capacity fade due to intermittent polysulfide dissolution in the electrolyte and drop in capacity during the initial discharge cycles [3]. Herein, we have designed a Li-S in-operando optical observation cell, which allowed us to visualize the formation of higher to lower-order polysulfides as well as the polysulfide formation and dissolution at different voltages and under different testing conditions. Subsequently, we investigated and compared the loss in capacity when using a modified cathode structure, which was designed to minimize the loss of active material upon lithiation. The real-time recording of the cell under an optical microscope clearly shows a significant loss of active material upon first discharge. Nevertheless, a substantial increase in initial discharge capacity is observed with the use of the modified cathode structure. To further analyze the loss in the battery capacity, we develop a mathematical model that uses fundamental governing equations to predict the loss of active material over cycles.
In-Operando Optical Observation/Visualization of Lithium-Sulfur Battery Discharge Process
Lithium−Sulfur (Li-S) batteries have attracted attention due to their high-energy density, 2500 Wh/𝑘𝑔𝑐𝑒𝑙𝑙 [1], and theoretical capacity of 1672 mAh/g-S [2]. In addition to that, sulfur abundance makes it a good candidate for rechargeable batteries. However, Li-S system has a few challenges that hinder its commercialization. Such as the insulating nature of the sulfur element, volume expansion, capacity fade due to intermittent polysulfide dissolution in the electrolyte and drop in capacity during the initial discharge cycles [3]. Herein, we have designed a Li-S in-operando optical observation cell, which allowed us to visualize the formation of higher to lower-order polysulfides as well as the polysulfide formation and dissolution at different voltages and under different testing conditions. Subsequently, we investigated and compared the loss in capacity when using a modified cathode structure, which was designed to minimize the loss of active material upon lithiation. The real-time recording of the cell under an optical microscope clearly shows a significant loss of active material upon first discharge. Nevertheless, a substantial increase in initial discharge capacity is observed with the use of the modified cathode structure. To further analyze the loss in the battery capacity, we develop a mathematical model that uses fundamental governing equations to predict the loss of active material over cycles.
Comments
References
[1] Rajkumar, P., Diwakar, K., Subadevi, R., & Sivakumar, M. (2022). Recent advancements in carbon/sulfur electrode nanocomposites for lithium–sulfur batteries. Lithium-Sulfur Batteries, 225–239. https://doi.org/10.1016/b978-0-323-91934-0.00008-9
[2] Cañas, N. A., Fronczek, D. N., Wagner, N., Latz, A., & Friedrich, K. A. (2014). Experimental and theoretical analysis of products and reaction intermediates of lithium–sulfur batteries. The Journal of Physical Chemistry C, 118(23), 12106–12114. https://doi.org/10.1021/jp5013208
[3] He, Q., Freiberg, A. T., Patel, M. U., Qian, S., & Gasteiger, H. A. (2020). Operando identification of liquid intermediates in lithium–sulfur batteries via transmission UV–vis spectroscopy. Journal of The Electrochemical Society, 167(8), 080508. https://doi.org/10.1149/1945-7111/ab8645