Solvate Structures and Computational/Spectroscopic Characterization of LiPF6 Electrolytes

Journal Article · Thu Apr 23 04:00:00 EDT 2015 · Journal of Physical Chemistry C, 119(16):8492-85

DOI:https://doi.org/10.1021/acs.jpcc.5b00826· OSTI ID:1221467

Han, Sang D.; Yun, Sung-Hyun; Borodin, Oleg; Seo, D. M.; Sommer, Roger D.; Young, Victor G.; Henderson, Wesley A.

Raman spectroscopy is a powerful method for identifying ion-ion interactions, but only if the vibrational band signature for the anion coordination modes can be accurately deciphered. The present study characterizes the PF6- anion P-F Raman symmetric stretching vibrational band for evaluating the PF6-...Li+ cation interactions within LiPF6 crystalline solvates to create a characterization tool for liquid electrolytes. To facilitate this, the crystal structures for two new solvates—(G3)1:LiPF6 and (DEC)2:LiPF6 with triglyme and diethyl carbonate, respectively—are reported. The information obtained from this analysis provides key guidance about the ionic association information which may be obtained from a Raman spectroscopic evaluation of electrolytes containing the LiPF6 salt and aprotic solvents. Of particular note is the overlap of the Raman bands for both solvent-separated ion pair (SSIP) and contact ion pair (CIP) coordination in which the PF6- anions are uncoordinated or coordinated to a single Li+ cation, respectively.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1221467
• Report Number(s): PNNL-SA-107628
• Journal Information: Journal of Physical Chemistry C, 119(16):8492-85, Journal Name: Journal of Physical Chemistry C, 119(16):8492-85
• Country of Publication: United States
• Language: English

Related Subjects

Raman
crystal structure
electrolyte
ionic association
solvate