Electrochemical properties of [V.sub.2][O.sub.5]/carbon composite electrodes in aqueous solutions

• Published in: Journal of materials science 2014-08, Vol.49 (16), p.5579
• Main Authors: Kamei, Kota, Suzuki, Shinya, Miyayama, Masaru
• Format: Article
• Language: English
• Subjects: Chemical properties; Dielectric films; Electrodes; Thin films
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-014-8267-3

The reaction mechanism of [V.sub.2][O.sub.5] xerogel and the electrode properties of [V.sub.2][O.sub.5]/carbon composites in an aqueous electrolyte solution were examined to obtain high-performance electrodes for rechargeable proton batteries. Based on the results of the chemical analysis of the electrode, proton intercalation is suggested to be the dominant reaction mechanism. By using the relationship between the capacity and current density of a thin-film electrode consisting of [V.sub.2][O.sub.5] xerogel, the diffusion coefficient in the [V.sub.2][O.sub.5] xerogel was determined to be 8 ± 1 x [10.sup.-11] [cm.sup.2] [s.sup.-1]. The [V.sub.2][O.sub.5]/ carbon composite electrode was prepared by drying a homogeneous dispersion of carbon particles in the [V.sub.2][O.sub.5] sol. The composite electrodes showed a large capacity of 460 mAh [g.sup.-1] at a current density of 1 A [g.sup.-1] and maintained a relatively large capacity of 160 mAh [g.sup.-1] at 100 A [g.sup.-1]. These properties were attributed to the homogeneous microstructure of the [V.sub.2][O.sub.5]/carbon composites. The [V.sub.2][O.sub.5]/ carbon composite electrodes were thus revealed as high-performance electrodes with large capacities and excellent high-rate capabilities.