Corrosion resistance and electrical properties of carbon/chromium–titanium–nitride multilayer coatings on stainless steel
Corrosion resistance and electrical properties of carbon/chromium–titanium–nitride multilayer coatings on stainless steel
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DOI：
10.1016/j.jpowsour.2013.10.103
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发表时间：
2014-03
影响因子：
9.2
通讯作者：
K. Feng;Zhuguo Li;F. Lu;Jian Huang;Xun Cai;Yixiong Wu
中科院分区：
文献类型：
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作者：
K. Feng;Zhuguo Li;F. Lu;Jian Huang;Xun Cai;Yixiong Wu
高导电性和耐腐蚀性是金属双极板在聚合物电解质膜燃料电池（PEMFC）中广泛应用的核心。采用物理气相沉积法制备了C/Cr-Ti-N多层涂层，系统研究了Cr：Ti比对涂层耐蚀性和界面接触电阻（ICR）的影响。扫描电子显微镜（SEM）结果表明，碳层致密、均匀.当Cr：Ti比分别为2：4和3：3时，在PEMFC阴极环境中，工作电压下的电流密度为0.127 μA cm-2，压坯力为150 N cm-2时的ICR为2.03 mΩ-cm-2，具有优异的耐腐蚀性能。表面导电性的显著增强可能是因为来自碳纸的电流被两个导电层均匀化并流向具有更大接触面积的钝化膜。极化后，在模拟PEMFC阴极和阳极环境中，ICR分别增加到3.07 mΩ-cm 2和3.02 mΩ-cm 2。然而，拉曼光谱的结果显示，极化前后的顶部碳膜的键合类型显示的差异不大。结果表明，Cr：Ti = 2：4的C/Cr-Ti-N多层涂层成分最佳。
High electrical conductivity and corrosion resistance are central to advances in wider application of metallic bipolar plates in polymer electrolyte membrane fuel cell (PEMFC). In this study, C/Cr–Ti–N multilayer coatings are deposited by physical vapor deposition and the effect of Cr:Ti ratio on the corrosion resistance and interfacial contact resistance (ICR) are systematically investigated. Scanning electron microscopy (SEM) result shows that the carbon layer is compact and uniform. Excellent corrosion resistance of 0.127 μA cm−2current density at operating voltage in PEMFC cathode environment and low ICR of 2.03 mΩ-cm2at compaction force of 150 N cm−2are achieved when Cr:Ti ratio is 2:4 and 3:3, respectively. The significant enhancement in surface conductivity is probably because that the current comes from carbon paper is homogenized by two electrically conductive layers and flows to the passive film with much more contact area. After polarization, ICR increase to 3.07 mΩ-cm2and 3.02 mΩ-cm2in the simulated PEMFC cathode and anode environment, respectively. However, the Raman spectroscopy results disclose that the bonding type of top carbon film before and after polarization shows little difference. The results indicate that C/Cr–Ti–N multilayer coating with Cr:Ti ratio of 2:4 achieves the optimal composition.