Co-reporter:Noriyoshi Matsumi, Akihito Kagata, Keigo Aoi
Journal of Power Sources 2010 Volume 195(Issue 18) pp:6182-6186
Publication Date(Web):15 September 2010
DOI:10.1016/j.jpowsour.2009.11.050
Novel supramolecular type solid polymer electrolytes were prepared by self-assembly of diborylated ionic liquid in the presence of bifunctional ligands. The polymers obtained were well soluble in methanol, and their structures were supported by 1H and 11B NMR spectra. The ionic conductivity of the polymers was evaluated by ac-impedance method after the samples were dried thoroughly. The ionic conductivity observed was 8.8 × 10−6 to 5.4 × 10−6 S cm−1 at 51 °C in the presence of equimolar amount of LiTFSA to ionic liquid unit. The temperature dependence of ionic conductivity was successfully fitted to VFT (Vogel–Fulcher–Tamman) plots, indicating that ionic conduction is taking place according to typical ion transport model in viscous matrix.
Co-reporter:Noriyoshi Matsumi, Yusuke Nakamura, Keigo Aoi, Takeshi Watanabe, Tomonobu Mizumo and Hiroyuki Ohno
Polymer Journal 2009 41(5) pp:437-441
Publication Date(Web):March 18, 2009
DOI:10.1295/polymj.PJ2008289
Novel ion-gels bearing lithium borate were synthesized via condensation between cellulose and boric acids in IL. Ion-gels obtained showed high ionic conductivity comparable to IL itself. First, ion-gels containing 5 wt % and 7 wt % of cellulose were prepared in 1-allyl-3-ethylimidazolium chloride. Their ionic conductivities were evaluated by ac-impedance method after drying ion-gels thoroughly. The ion-gel including 5 wt % of cellulose exhibited higher conductivity than that including 7 wt % of cellulose. This should be because of lower activating energy under lower composition of cellulose. The effect of concentration of C6F5B(OH)2 on ionic conductivity was also examined with varying the ratio of B(OH)3 and C6F5B(OH)2. It was demonstrated that the ion-gel including greater amount of pentafluorophenylborate showed significantly enhanced ionic conductivity. Preparation of ion-gels including 1-allyl-3-ethylimidazolium formate was also examined at the cellulose concentration of 7wt%. The ion-gels synthesized in 1-allyl-3-ethylimidazolium formate showed higher ionic conductivity (1.98 x 10-3 Scm-1; 30°C) than that synthesized in 1-allyl-3-ethylimidazolium chloride. This should be because of lower viscosity of 1-allyl-3-ethylimidazolium formate.
Co-reporter:Noriyoshi Matsumi, Mari Miyamoto, Keigo Aoi
Journal of Organometallic Chemistry 2009 694(11) pp: 1612-1616
Publication Date(Web):
DOI:10.1016/j.jorganchem.2008.10.056
Co-reporter:Noriyoshi Matsumi, Keita Kawaguchi, Yousuke Hirota, Keigo Aoi
Journal of Organometallic Chemistry 2009 694(11) pp: 1776-1779
Publication Date(Web):
DOI:10.1016/j.jorganchem.2009.01.031