The research of DMFC gas diffusion layer

• Main Authors: Zheng--xun Song, 宋政勳
• Other Authors: Chung-jen Tseng
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/48903359746141528600

碩士 === 國立中央大學 === 能源工程研究所 === 96 === The purpose of this study is to investigate the effects of microporous layer (MPL) and gas diffusion layer (GDL) on the performance of direct methanol fuel cell (DMFC). Both carbon cloth and carbon paper are used as the GDL. The scrapping method is used to prepare the MPL. The MPL is made hydrophobic using PTFE and hydrophilic using Nafion. The effects of hydrophobic and hydrophilic treatment on cell performance are studied. Unlike in proton exchange membrane fuel cells, the GDL and MPL in DMFCs need to provide the function of carbon dioxide removal as well as uniform fuel distribution. Most previous work shows that using a hydrophilic MPL with hydrophobic carbon cloth at anode and hydrophobic MPL with hydrophobic carbon cloth at cathode results in better DMFC cell performance. Results of this work show that, for the condition used in this study, using 20 wt% PTFE hydrophobic MPL at anode and 60 wt% PTFE hydrophobic MPL at cathode with 10 wt% PTFE hydrophobic carbon cloth as the GDL at both anode and cathode exhibit the best cell performance. The carbon black loading in this case is 1.87 mg/cm2 at anode MPL and 1.12 mg/cm2 at cathode MPL. The current density reaches 274 mA/cm2 and the power density reaches 74.9 mW/cm2 at 0.27 V and 50℃.