High Performance Phosphoric Acid Fuel cell with Glass Microfiber and Polytetrafluoroethylene Composite Porous Membrane

• Main Authors: Lu, Chia Lien, 呂佳蓮
• Other Authors: Tseng, Fan Gang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/r5rybz

碩士 === 國立清華大學 === 工程與系統科學系 === 102 === The research proposes a composite membrane using glass microfiber and polytetrafluoroethylene(PTFE) thin film applied in phosphoric acid fuel cell as proton exchange membrane. The glass microfiber is soaked in 86% phosphoric acid to possess proton conductivity, and the PTFE thin film outside the glass microfiber prevents the leakage of phosphoric acid. The glass microfiber and PTFE thin film both have thermal and chemical stability at phosphoric acid fuel cell’s working temperature 150~220℃.Otherwise, the two membrane are also very cheap. From the analysis of micron structure and mercury porosimeter, glass microfiber membrane has many micron pores that is similar to previous phosphoric acid porous membrane SiC’s structure. However, our glass microfiber has higher porosity(93%) than SiC matrix that can let glass microfiber possess more phosphoric acid contents. PTFE thin film has many nano pores. We can let PTFE nano pores fulfilled with phosphoric acid by hydrophilic treatment. The combination of two membranes possesses rich phosphoric acid electrolyte content and prevents leakage of phosphoric acid, and the composite membrane’s proton conductivity achieve 0.71 S/cm at 150℃. When phosphoric acid fuel cell tests, anode and cathode use carbon cloth as diffusion layer. The catalyst layer is Pt/C. After cold pressing, we measure the MEA’s effects and study the phenomenon. A best fuel cell performance using the composite membrane with Pt/C and 35%PTFE binder exhibits a peak power density of 296mW/cm2 at 150℃ with H2 and pure O2.