交聯型固態高分子電解質

• Main Author: 蔡麗娟
• Other Authors: 諸柏仁
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/45559393369527084495

碩士 === 國立中央大學 === 化學研究所 === 89 === Low ion conductivity and mechanical property limits the utility of solid polymer electrolyte in solid sate electrochemical device applications. Current research approach is to modify the solid polymer electrolyte to improve mechanical stability and ion conductivity by cross-liking PEO/phenolic polymer electrolyte with Hexamethylene Tetramine (CH2)6N4). The cross-linking is found to be more affect on mechanical property, dimension stability, ion conductivity, PEO crystallinity and surface morphology. To investigate surface morphology, molecule structure, segmental motion, lithium transport and ion conductivity before and after cross-linking with Hexamine modified SPE were carried by using variety of experimental techniques like IR, DSC, TGA, NMR, SEM, AC-impedance measurements etc. The surface morphology is improved dramatically and thermal stability increased to 420 to 460 oC after cross-linking, which corroborates the improved mechanical property. Compared to pure PEO and PEO/phenolic without cross-linking, PEO crystallinity is reduced due to the constraint micro-domain. Furthermore the PEO chain motion is increased after cross-linking due to the expanded free-volume, as reflected in the reduction of glass temperature. For example, Tg for sample D4y (composition) is —46.9 ℃. However, the ion conductivity is not sacrificed by the improved mechanical property, instead it exhibited more superior room temperature conductivity, reaching the order of 10-3S/cm.. These results, especially the substantial improvement in room temperature conductivity, are significant to the development of solid polymer electrolyte technology. Sample D3y shows the most promising balance of mechanical and electrical properties and should be explored for battery assembly tests.