Restricting the Solubility of Polysulfides in Li-S Batteries Via Electrolyte Salt Selection

Journal Article · Tue Mar 29 00:00:00 EDT 2016 · Advanced Energy Materials

DOI:https://doi.org/10.1002/aenm.201600160· OSTI ID:1337218

Chen, Junzheng ^[1]; Han, Kee Sung ^[1]; Henderson, Wesley A. ^[1]; Lau, Kah Chun ^[2]; Vijayakumar, Murugesan ^[1]; Dzwiniel, Trevor ^[2]; Pan, Huilin ^[1]; Curtiss, Larry A. ^[2]; Xiao, Jie ^[1]; Mueller, Karl T. ^[1]; Shao, Yuyan ^[1]; Liu, Jun ^[1]

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1. Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA
2. Joint Center for Energy Storage Research (JCESR), Argonne National Laboratory, Argonne IL 60439 USA

Polysulfide solubility in the electrolyte has a critical role to the Li-S battery but the mechanism study on the solubility needs to be carefully carried out. In this paper we found that lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI) reveals a suppression of the polysulfide solubility in electrolytes (relative to the most widely used electrolyte formulation) and the Li-S cells achieved homogeneous stable capacity retention upon extensive cycling and Li metal deposition on the anode. Combined experimental, simulation and calculation methods suggest the dominate disproportionation product of Li2S8 is Li2S4 in the LiTDI electrolyte due to a different interaction between lithium ion and TDI anion. The Li2S4 would continuesly form a Li4S8 dimer and be fully locallized to precipitate out. The use of the electrolyte with the LiTDI salt (with polysulfide and LiNO3 additives) enabled a cell with a high sulfur (3 mg-S cm-2) loading to deliver a 1.67 mAh cm-2 areal capacity after 300 stable cycles at a high current (2.4 mA cm-2) density.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1337218
• Report Number(s): PNNL-SA-113496; 49164; 48681; KC0208010
• Journal Information: Advanced Energy Materials, Vol. 6, Issue 11; ISSN 1614-6832
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory