Wetting behavior of four polar organic solvents containing one of three lithium salts on a lithium-ion-battery separator

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:529

Article

Sun, Yanjun^1,2  Radke, Clayton J.²  McCloskey, Bryan D.²  Prausnitz, John M.² 

[1] Xi An Jiao Tong Univ, Sch Human Settlements & Civil Engn, Inst Bldg Energy & Sustainabil Technol, Xian 710049, Shaanxi, Peoples R China

[2] Univ Calif Berkeley, Dept Chem & Biomol Engn, Berkeley, CA 94720 USA

关键词: Non-aqueous electrolyte solution;    Lithium salt;    Li-battery separator;    Surface tension;    Advancing contact angle;   

DOI  :  10.1016/j.jcis.2018.06.044

来源: Elsevier

【 摘 要 】

Hypothesis: The wetting behavior of an electrolyte solution on the separator, determined by contact angle measurements, has a significant effect on the internal resistance of the battery and on its cycle life. The solvent, the lithium-salt type and its concentration may affect the wettability. However, few systematic studies address the effect of salt concentration on surface tension and contact angle. Experiments: Surface tensions and advancing contact angles were measured for dimethyl sulfoxide (DMSO), propylene carbonate (PC), dimethyl carbonate (DMC), and a PC/DMC mixture (1:1 mass ratio) with various concentrations of a lithium salt (LiCIO4, LiPF6, and LiTFSI) at 23 degrees C. Measurements were made by a Kriiss Drop Shape Analyzer 100, with a video camera mounted on a microscope to record the drop image. Findings: For DMSO, PC and PC/DMC, surface tensions increase by adding LiClO4 or LiPF6 but decrease upon addition of LiTFSI. For DMC, the lithium salts have little impact on the surface tensions. For each solvent, contact angles and adhesion energies follow the same trend as those for surface tensions. The TFSI- anion reduces the surface tension of the solvent, favoring good wettability of the separator. The optimal surface tension for wettability of Celgard 2500 is at or below 26.1 mN/m. (C) 2018 Elsevier Inc. All rights reserved.

【 授权许可】

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