"Quantitative Investigation of Polysulfide Adsorption Capability of Candidate Materials for Li-S Batteries"

David Sichen Wu: Feifei Shi, Guangmin Zhou, Chenxi Zu, Chong Liu, Kai Liu, Yayuan Liu, Jiangyan Wang, Yucan Peng, Yi Cui; Energy Storage Materials, 02/03/18.

Additional Authors: Feifei Shi, Guangmin Zhou, Chenxi Zu, Chong Liu, Kai Liu, Yayuan Liu, Jiangyan Wang, Yucan Peng, Yi Cui

Abstract:

Lithium-sulfur batteries have a high theoretical energy density of 2500 Wh/kg and are promising candidates for meeting future energy storage demands. However, dissolution of the intermediate polysulfide species into the electrolyte remains as a major challenge, causing fast capacity degradation in Li-S batteries. Many recent studies have reported various materials such as metal oxides and sulfides that interact strongly with polysulfide species and can alleviate the dissolution problem, though little work has focused on quantitative comparison of different materials under equivalent conditions. Here, we establish a standard procedure to quantitatively compare the polysulfide adsorption capability of candidate materials. We found that an order of magnitude of difference is evident between poor adsorption materials such as carbon black and strong adsorption materials such as V2O5 and MnO2. We elucidate different adsorption mechanisms may be present and probe possible adsorption species. We expect our work will provide a useful strategy to screen for suitable candidate materials and valuable information for rational design of long cycle life Li-S batteries.