PEMFC金属双极板金涂层原电池腐蚀机理研究

Research on corrosion mechanism of PEMFC metal bipolar plate goldcoated galvanic battery

为了追求低接触电阻和高耐腐蚀性能,金涂层虽然成本高昂但是仍然在金属双极板涂层中得到广泛应用。通过镀金涂层金属双极板在3000 h电堆实际测试分析了金涂层的电化学腐蚀情况,同时采用电化学加速测试分析了其原电池腐蚀机理。研究结果表明,金属双极板金层在寿命测试过程中首先因为点蚀而出现轻微缺陷,钛层裸露到质子交换膜燃料电池(PEMFC)的酸性环境中而与金层形成原电池腐蚀。本研究将有助于提出缓解金涂层腐蚀失效的方案,为镀金涂层金属双极板在PEMFC上的应用提供理论指导。

In order to pursue low contact resistance and high corrosion resistance,the gold coatings are still widely used in metal bipolar plate coatings despite their high cost.The electrochemical corrosion of the gold coating was analyzed through the actual test of the gold-coated metal bipolar plate in the 3000 h stack,and the corrosion mechanism of the primary battery was analyzed by the electrochemical accelerated test.The research results show that the gold layer of the metal bipolar plate first has slight defects due to the pitting corrosion during the life test,and the titanium layer is exposed to the acidic environment of the PEMFC and forms a galvanic corrosion with the gold layer.The research can help to propose a solution to alleviate the corrosion failure of gold coating,and provide the theoretical guidance for promoting the application of gold-coated metal bipolar plates in PEMFC.