碱性介质中空气电极性能的研究

STUDY ON PERFORMANCE OF AIR ELECTRODE IN ALKALI MEDIUM

采用极化曲线、XRD和SEM等方法系统地研究了催化剂、催化层中PTFE(聚四氟乙烯)的含量、电解液浓度以及空气电极的结构对空气电极性能的影响。结果表明,5.5%(文中如无特别说明,百分数均为质量分数)Ag/C催化剂的性能较好,而且价格相对便宜,其中Ag颗粒具有立方晶型结构,但粒径分布不是很均匀;Ag/C和PTFE的最佳质量比是4:1;KOH溶液的最佳浓度是6.25mol/L;当空气电极的结构为催化层/炭纸/催化层时,空气电极的电化学性能得到进一步的提高。

The effects of catalysts, PTFE content in catalyst layer, electrolyte concentration and air electrode structure on the air electrode performance were systematically investigated by polarization curves, XRD and SEM. The results showed that, 5.5 % （wt）Ag/C is the catalyst of lower price and better properties; Ag particles had cubic crystal structure and un- even distribution; the optimum ratio of w （Ag/C）： w （FFFE） is 4： 1; the best concentration of KOH solution is 6.25mol/L; and when the structure of air electrode is catalyst layer/carbon paper/catalyst layer, electrochemical properties of air electrode could be greatly increased.