Electrochemical and spectroelectrochemical properties of SnO{sub 2} and SnO{sub 2}/Mo transparent electrodes with high ion-storage capacity
- National Inst. of Chemistry, Ljubljana (Slovenia)
- J. Stefan Inst., Ljubljana (Slovenia)
Thin solid SnO{sub 2} and SnO{sub 2}/Mo (10%, 2:1 and 1:1) films with an ion-storage capacity of 20 to 30 mC/cm{sup 2} and weakly expressed cathodic electrochromism were deposited using the dip-coating technique. The films were deposited from peroxo sols prepared by reacting SnCl{sub 2} {center_dot} 2H{sub 2}O and a metallic molybdenum precursor with H{sub 2}O{sub 2}. Thermogravimetric, surface area (BET), x-ray diffraction, and IR spectroscopic measurements of films heat-treated at 500 C revealed a nanocrystalline (grain size {approximately}30 {angstrom}) cassiterite structure with a large surface area ({approximately}60 to 70 m{sup 2}/g). The electrochemical properties of the films were studied in a 1 M LiClO{sub 4}/propylene carbonate electrolyte using cyclic voltammetry (CV) at different scanning rates (0.1 to 200 mV/s). Electrochromic properties, measured in situ with ultraviolet-visible measurements, revealed that the coloring/bleaching changes accompanying insertion/extraction of Li{sup +} ion processes are 10 to 15% for SnO{sub 2}/Mo (1:1) films but decrease to a few percent with decreasing Mo content. Low-scan-rate CV measurements confirmed the presence of two different redox processes: Sn{sup 4+}/Sn{sup 2+} and Mo{sup 6+}/Mo{sup 5+}. This was confirmed from the ex situ IR spectroelectrochemical measurements of films charged/discharged to different extents. IR spectra of films heat-treated at 500 C in a vacuum also showed that SnO{sub 2}/Mo (2:1) films contain Broensted acidic protons. These films, because of their low coloration efficiency (2 to 10 cm{sup 2}/C), are promising counterelectrodes for electrochromic devices with light reflection modulation.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 562202
- Journal Information:
- Journal of the Electrochemical Society, Vol. 144, Issue 10; Other Information: PBD: Oct 1997
- Country of Publication:
- United States
- Language:
- English
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