Polymer electrolyte based on lithium oxalate

• Published in: Ionics 2015-01, Vol.21 (1), p.89-94
• Main Authors: Heishi, Masaru, Shinmei, Kenichi, Sanjiwa, Dasanarayake Althge Rasika, Uno, Takahiro, Kubo, Masataka, Itoh, Takahito
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Optical and Electronic Materials; Original Paper; Renewable and Green Energy
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-014-1167-3

Polymer electrolytes composed of poly(ethylene oxide) (PEO), lithium oxalate (LiOX), and borontrifluoride diethyl ether (BF 3 ·OEt 2 ) were prepared, and their ionic conductivities, lithium ion transference number, thermal properties, and infrared spectra were investigated. The polymer electrolyte for the PEO/LiOX in the absence of BF 3 ·OEt 2 showed the ionic conductivity of 10 –6  S cm −1 at 130 °C. The addition of BF 3 ·OEt 2 into the polymer electrolyte for the PEO/LiOX system induced an increase of the ionic conductivities by three orders of magnitude. IR spectra showed that in the polymer electrolyte for the PEO/LiOX system in the presence of BF 3 ·OEt 2 , new interactions between LiOX and BF 3 ·OEt 2 and also between LiOX and PEO were observed. The polymer electrolyte for the PEO/LiOX system in the presence of BF 3 ·OEt 2 showed the lithium ion transference number of 0.55, which is higher than that (0.19) of PEO/LiTFSI polymer electrolyte. It was found that usage of the carboxyl discrete lithium salt for the polymer electrolyte is a promising method to improve lithium transference number. Figure ᅟ