Effect of a polybenzimidazole coating on carbon supports for ionomer content optimization in polymer electrolyte membrane fuel cells

JOURNAL OF POWER SOURCES

卷:496

Article

Jayawickrama, Samindi Madhubha^1,2  Wu, Dan¹  Nakayama, Rei¹  Ishikawa, Shota³  Liu, Xuanchen³  Inoue, Gen³  Fujigaya, Tsuyohiko^1,2,4 

[1] Kyushu Univ, Grad Sch Engn, Dept Appl Chem, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[2] Kyushu Univ, World Premier Int Res Ctr Initiat, Int Inst Carbon Neutral Energy Res, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[3] Kyushu Univ, Grad Sch Engn, Dept Chem Engn, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[4] Kyushu Univ, Ctr Mol Syst, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

关键词: Fuel cell;    Carbon blacks;    Ionomer;    Catalyst layer;    Polybenzimidazole;    Oxygen diffusion;   

DOI  :  10.1016/j.jpowsour.2021.229855

来源: Elsevier

【 摘 要 】

Optimizing the ionomer/carbon (I/C) ratio in the catalyst layer (CL) of polymer electrolyte membrane fuel cells (PEMFCs) is vital for maximizing PEMFC efficiency. In this study, the effect of the I/C ratio for a platinum (Pt) catalyst loaded on a polybenzimidazole (PBI)-coated Vulcan (Vulcan/PBI/Pt) is compared with a conventional Pt catalyst on Vulcan (Vulcan/Pt). Furthermore, this study determines that a CL comprising Vulcan/PBI/Pt with an I/C = 0.2 exhibits the highest maximum power density (750 mW cm-2), while that of a CL having Vulcan/Pt is calculated to be 610 mWcm? 2 at I/C = 0.6. Effective interactions between ionomer and the PBI-coated Vulcan enables stable ionomer coating and high proton conductivity, even at very low I/C ratios. At such low I/C ratios, the O2 diffusion coefficient of Vulcan/PBI/Pt CL is improved by 51% when compared to Vulcan/Pt CL with an I/ C = 0.6. Cross-sectional scanning electron microscopy images further reveal that Vulcan/PBI/Pt CLs possess better pore connectivity than those of Vulcan/Pt. Hence, it concludes that the proposed PBI coating approach is advantageous and significant breakthrough to fabricate highly efficient CLs by improving both proton conduction and O2 diffusion simultaneously with lower ionomer contents.

【 授权许可】

Free