title: Stability of Glyme Solvate Ionic Liquid as an Electrolyte for Rechargeable Li-O2Batteries.
abstract: A solvate ionic liquid (SIL) was compared with a conventional organic solvent for the electrolyte of the Li-O2battery. An equimolar mixture of triglyme (G3) and lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA]), and a G3/Li[TFSA] mixture containing excess glyme were chosen as the SIL and the conventional electrolyte, respectively. Charge behavior and accompanying gas evolution of the two electrolytes was investigated by electrochemical mass spectrometry (ECMS). From the linear sweep voltammetry performed on an as-prepared cell, we demonstrate that the SIL has a higher oxidative stability than the conventional electrolyte and, furthermore, offers the advantage of lower volatility, which would benefit an open-type lithium-O2cell design. Moreover, CO2evolution during galvanostatic charge was less in the SIL, which implies less side reaction. However, O2evolution during charge did not reach the theoretical value in either of the two electrolytes. Several mass spectral fragments were generated during the charge process, which provided evidence for side reactions of glyme-based electrolytes. We further relate the difference in observed discharge product morphology for these electrolytes to the solubility of the superoxide intermediate, determined by rotating ring disk electrode (RRDE) measurements.
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Hoi-Min
authors.initials: HM
authors.lastname: Kwon
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Morgan L
authors.initials: ML
authors.lastname: Thomas
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Tatara
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Azusa
authors.initials: A
authors.lastname: Nakanishi
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Ueno
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Kaoru
authors.identifier: http://orcid.org/0000-0002-9622-4345
authors.initials: K
authors.lastname: Dokko
authors.affiliation: Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Masayoshi
authors.identifier: http://orcid.org/0000-0003-4092-6150
authors.initials: M
authors.lastname: Watanabe
keywords: electrochemical mass spectrometry; glyme; lithium−oxygen battery; rotating ring disk electrode voltammetry; solvate ionic liquid