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Your search keyword '"Chuang, Huey-Jan"' showing total 9 results
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9 results on '"Chuang, Huey-Jan"'

4. New solid polymer electrolytes based on PEO/PAN hybrids

Author

Chuang Huey-Jan, Wu Chiung-Hui, Wu Chun-Guey, and Lu Ming-I

Subjects
Materials science, Polymers and Plastics, technology, industry, and agriculture, Polyacrylonitrile, macromolecular substances, General Chemistry, Electrolyte, Conductivity, Lithium perchlorate, Surfaces, Coatings and Films, chemistry.chemical_compound, Crystallinity, Differential scanning calorimetry, chemistry, Chemical engineering, Polymer chemistry, Materials Chemistry, Ionic conductivity, Polymer blend
Abstract

Hybrid polymer dry electrolytes comprised of poly(ethylene oxide) (PEO), polyacrylonitrile (PAN), and LiClO 4 were investigated. The impedance spectroscopy showed that the effect of PAN on the ion conductivity of PEO-based electrolytes depends on the concentration of lithium salt. When the mole ratio of lithium to oxygen is 0.062 (15%LiClO 4 -PEO), adding PAN will increase the ionic conductivity. Differential scanning calorimetry, NMR, and IR data suggested that the enhanced conductivity was due to both the decreasing of the PEO crystallinity and increasing of the degree of ionization of lithium salt. There was obviously no interaction between PAN and lithium ions, and PAN acts as a reinforcing filler, and hence contributes to the mechanical strength besides reducing the crystallinity of the polymer electrolytes. When the LiClO 4 -PEO-PAN hybrid polymer electrolyte was heated at 200°C under N 2 , PAN crosslinked partially, which further decreased the crystallinity of PEO and increased the ionic conductivity, and at the same time prevented the recrystallization of PEO upon sitting at ambient environment.

Published
2005

9. Preparation and characterization of nanometric-sized LiCoO2 cathode materials for lithium batteries by a novel sol–gel method

Author

Yang, Wein-Duo, Hsieh, Ching-Yuan, Chuang, Huey-Jan, and Chen, Yun-Sheng

Subjects
*NANOSTRUCTURED materials, *LITHIUM, *POLYMERIZATION, *CITRIC acid, *METAL ions, *INFRARED spectroscopy, *RAMAN spectroscopy
Abstract

Abstract: Nanometric-sized LiCoO2 powders were obtained from a novel sol–gel method, in which the gels were synthesized by the polymerization of citric acid and hydroxypropyl cellulose. Molar ratios of citric acid to metal ions were varied, and the resulting effects on the properties of powders were studied using Fourier transfer infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results indicate that with a molar ratio of citric acid/metal ions=1, the resin contains a number of bidentate ligand fractions and higher portion of C–C–O structure, which makes it possible to synthesize the low temperature phase of LiCoO2 at a temperature as low as 300°C. The powder calcined at 600°C exhibits a pure high temperature phase of LiCoO2 (HT-LiCoO2) with a particle size of about 40–60nm and a specific surface area of 25.24m2/g. The electrode prepared at 600°C exhibits a better HT-LiCoO2 structure and demonstrates a higher first run charge/discharge capacities at 186 and 168mAh/g, respectively. [Copyright &y& Elsevier]

Published
2010
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