Biomimetic integrated gas diffusion layer inspired by alveoli for enhanced air-breathing fuel cell performance and stability

Abstract

Air-breathing proton exchange membrane fuel cells (air-breathing PEMFCs) have the advantages of portability, simple structure, environmental friendliness and no noise. However, due to their open cathode structure and operation environment, including gas diffusion, water and thermal management, PEMFCs are difficult to manage and largely influence the fuel cell performance and durability. In this study, inspired by alveoli, a biomimetic integrated gas diffusion layer (GDL) is designed to effectively improve the operation environment of the air-breathing PEMFC. The fuel cell using the biomimetic integrated GDL shows higher performance and more stability than a traditional fuel cell under various temperatures and wind speeds. The air-breathing PEMFC with biomimetic integrated GDL showed high performance with a peak power density of 148.5 mW cm⁻², which is superior to the traditional air-breathing PEMFC's density of 109.8 mW cm⁻². Additionally, at the cathode wind speed of 4 m s⁻¹, the fuel cell performance using the biomimetic integrated GDL only decreases by 2.38% after discharge at 150 mA cm⁻² for 100 h, while that of the traditional fuel cell declines by 64.5% in 10 minutes. Moreover, the fuel cell stack exhibits 17.5 W at 3.17 V and the performance declines by only 11.8% after discharge for 200 h under 3.5 A. The biomimetic integrated GDL offers a simple and effective approach to achieving high performance and stability for air-breathing PEMFC.