气体扩散层对空气电极寿命的影响

Influence of gas diffusion layer on the life of air electrode

以乙炔黑、60%PTFE乳液为原料,用辊压法制备空气电极的气体扩散层。研究了烧结与未烧结气体扩散层的性能参数及其对空气电极寿命的影响。用压汞分析法和SEM研究了气体扩散层的孔结构及形貌。结果表明:相对未烧结扩散层的空气电极,烧结扩散层的空气电极寿命更长,1 000 h寿命试验中无渗液现象,且性能较好。烧结提高了电极材料的疏水性和孔隙率。烧结后气体扩散层适宜的孔结构为:孔隙率约为70%,平均孔径约为70 nm。

The gas diffusion layer of air electrode was prepared by the rolling method with acetylene black and 60% PTFE emulsion as raw materials. The performance parameters of sintered and non-sintered gas diffusion layer and its effects on the life of air electrode were studied. The pore structure and morphology of gas diffusion layer were studied by mercury intrusion method and SEM. The results showed that the air electrode with sintered gas diffusion layer had longer life compared with the one with nonsintered gas diffusion layer, the 1 000 h life test had no flooded and the electrochemical performance was better. The hydrophobicity and porosity of the electrode material were improved by sintering. The optimal pore structure of the sintered gas diffusion layer was about 70% in porosity and about 70 nm in mean pore diameter.