镀铬不锈钢双极板在PEMFC环境中的性能

Performance of Cr-coated stainless steel bipolar plate in simulated PEMFC environments

为克服不锈钢表面存在的钝化膜非均匀性的缺陷，采用镀铬方法对304不锈钢进行表面改性，研究表面镀铬的304不锈钢在模拟质子交换膜燃料电池（PEMFC）环境中的电化学性能和电性能．结果表明：在不锈钢表面生成了厚7～8μm的均匀完整的镀铬层；镀铬的304不锈钢在模拟PEM—FC阴极和阳极环境中均具有比基体更低的钝化电流密度，更易于钝化；在空气中形成的氧化膜较基体具有更低的界面接触电阻，恒电位极化后表面生成的钝化膜可引起表面接触电阻的增加．

To make up the deficiencies of the nonuniformity of passive film on stainless steel surface, the Cr-coated 304 stainless steel was modified, and its electrochemical properties and electrical properties were studied in the simulated polymer electrolyte membrane fuel cell （ PEMFC ） environments. Results show that the 7- 8 μm coating layer was formed in the 304 stainless steel surface. The Cr-coated 304 stainless steel has lower passive current densities than that of substrate in both the simulated anodic and cathodic environments. Oxide film formed in the air has lower interracial contact resistance than that of the pure 304 stainless steel, and the interfacial contact resistance of passive film increases after potentiostatic polarization.