Preparation and Performance Study of Anode Self-Humidifying Gas Diffusion Layer

Abstract

Hydrogen is oxidized into H+ and e- on the anode side of fuel cell. H+ are transported from anode to cathode of fuel cell in the form of H3+O. When fuel cell is running under low humidity, the relatively small water content will reduce H+ transmission efficiency and causes an increase in ohmic impedance. In order to solve this problem, this paper prepared self-humidifying gas diffusion layer （GDL） by spraying method. The content of PTFE in the microporous layer (MPL) near carbon paper side is relatively high, and the content of PTFE in MPL near catalyst layer side is relatively low, thus forming MPL with graded hydrophobic structure. Since the MPL near catalyst layer side is relatively hydrophilic, it will condense into liquid water when external humidifying gas passes, thereby generating self-humidifying effect. Through research, self-humidifying GDL with double MPL structure can produce good self-humidification.