Fe-Mn-Al-Cr合金双极板在模拟PEMFC环境中的电化学性能

采用电化学方法测定一种Fe-Mn-Al-Cr合金在模拟PEMFC环境中的极化曲线以及在PEMFC工作电位下的电流密度随时间变化的曲线.结果表明,Fe-Mn-Al-Cr合金在0.05 mol/L H2SO4＋2 mg/L F-溶液中呈现明显的活化-钝化转变.在恒电位极化过程中,阴极一侧表面能够形成稳定的钝化膜,钝化电流密度低于l6μA.cm-2.而在阳极一侧则产生了大量溶解的金属离子.

Electrochemical Property of Fe-Mn-Al-Cr Alloy Bipolar Plate in Simulated PEMFC Environments

Graphite is considered as a kind of traditional bipolar plate material due to its excellent chemical stability and conductivity,however,high machining cost and brittleness prevent it from using in commercial market.In order to decrease the fabricate cost of proton exchange membrane fuel cell（PEMFC） stacks,selecting metallic materials with low cost,easy machining,high strength and chemical stability has become a concerning point.Polarization curves of Fe-Mn-Al-Cr alloy are measured in the simulated aggressive PEMFC environments by electrochemical method,and the current densities-time curves are also recorded at respective operation potentials.The results show that the Fe-Mn-Al-Cr alloy exhibits obvious activation-passivation transition in 0.05mol/L H2SO4 ＋ 2mg/L F-purged with H2 or air,and the passive current densities are lower than 16μA·cm-2.Stable passive film can formed on the surface of Fe-Mn-Al-Cr alloy at cathodic side during the potentiostatic polarization,while a lot of dissolved metallic cations at anodic side are resulted from serious corrosion.