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Thickness dependence of proton conductivity of anodic ZrO2-WO3-SiO2 nanofilms
| Title: | Thickness dependence of proton conductivity of anodic ZrO2-WO3-SiO2 nanofilms |
| Authors: | Ye, Ke Browse this author | | Aoki, Yoshitaka Browse this author →KAKEN DB | | Tsuji, Etsushi Browse this author | | Nagata, Shinji Browse this author | | Habazaki, Hiroki Browse this author →KAKEN DB |
| Keywords: | Amorphous materials | | Anodic oxidation | | Ion conducting materials | | Proton transport | | Nanofilms |
| Issue Date: | 1-May-2012 |
| Publisher: | Elsevier B.V. |
| Journal Title: | Journal of Power Sources |
| Volume: | 205 |
| Start Page: | 194 |
| End Page: | 200 |
| Publisher DOI: | 10.1016/j.jpowsour.2012.01.083 |
| Abstract: | Amorphous ZrO2-WO3-SiO2 nanofilms are simply prepared by anodizing of sputter-deposited Zr37W47Si16 alloy at several formation voltages for 1.8 ks in 0.1 mol dm-3 phosphoric acid electrolyte at 20℃. Efficient proton conductivity was observed after thermal treatment at 250℃ with the conductivity enhanced by reducing the film thickness. The conductivity is enhanced more than one order of magnitude by reducing the thickness from 300 to 140 nm. The anodic oxide films consist of two layers, comprising a thin outer ZrO2 layer free from silicon and tungsten species and an inner main layer containing all zirconium, silicon and tungsten species. The thickness-dependent conductivity of the anodic ZrO2-WO3-SiO2 films is associated with the conductivity of the outer ZrO2 layer, which increases exponentially with reducing the film thickness. The area-specific resistivity of 0.14 Ω cm2, which is below the minimum requirement (0.2 Ω cm2) for a practical electrolyte membrane in commercial fuel cells, is achieved at a temperature at 225 ℃ for 100 nm-thick anodic ZrO2-WO3-SiO2 films. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/49115 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 幅崎 浩樹
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