Lithium/sulfur (Li/S) cells that offer an ultrahigh theoretical specific energy of 2600 Wh/kg are considered one of the most promising next-generation rechargeable battery systems for the electrification of transportation. However, the commercialization of Li/S cells remains challenging, despite the recent advancements in materials development for sulfur electrodes and electrolytes, due to several critical issues such as the insufficient obtainable specific energy and relatively poor cyclability. This review aims to introduce electrode manufacturing and modeling methodologies and the current issues to be overcome. The obtainable specific energy values of Li/S pouch cells are calculated with respect to various parameters (e.g., sulfur mass loading, sulfur content, sulfur utilization, electrolyte-volume-to-sulfur-weight ratio, and electrode porosity) to demonstrate the design requirements for achieving a high specific energy of >300 Wh/kg. Finally, the prospects for rational modeling and manufacturing strategies are discussed, to establish a new design standard for Li/S batteries.

No abstract

The entropy of reaction is necessary to estimate how much heat could be generated by a battery. Calculating heat generation is critical both for safety reasons and to improve the longevity and performance of the cell. Traditional methods of measuring the entropy of reaction are painstakingly slow and require environmental control machinery. Previously we modified a frequency domain method using a physics-based model and demonstrated that the entropy could be measured at a significantly faster pace. In this paper, we measured the entropy of reaction of a customized pouch cell with two different methods: the modified frequency domain method and the traditional method. Results from the new method were compared against measurements taken on coin cells of the same chemistry using a traditional method. The model validation shows a high degree of accuracy, roughly 50 μV/K, using the new method.