关键词: 燃料电池, 氢, 空气自呼吸, 阴极催化层, 气体扩散层, 设计, 免增湿

Abstract: Environment-friendly air-breathing proton exchange membrane fuel cells （PEMFCs） have been prospected as the next generation of portable power sources with a brilliant commercial prospect due to their relatively small volume with simplification of air supply and humidifying system，high energy conversion efficiency，high power density，clean and pollution-free. The related research is becoming one of the hottest topics in fuel cell. In this paper，the research progress of air-breathing proton exchange membrane fuel cell is reviewed with respect to structure，mechanism，components，and performance. Perfecting the porosity and hydrophobicity of cathode catalyst layer of air electrode （cathode） would accelerate oxygen transfer and water removal，and improve air activation ability. The composition，structure and thickness of gas diffusion layer also influence gas permeability and water undock. Applicable structure design and material selection can regulate temperature and reinforce cross-ventilation，and the application of self-humidifying technology can maintain the stability of fuel cell at low humidity.

Key words: fuel cells, hydrogen, air-breathing, cathode catalyst layer, gas diffusion layer, design, self-humidification