Abstract Amorphous carbon (a-C) films exhibit properties that make them attractive for a wide range of applications in automotive components. Proton exchange membrane fuel cells (PEMFCs) assembled by metallic bipolar plates (BPPs) are promising power sources for new energy vehicles. Harsh environments of PEMFCs require preparing coatings on metallic BPPs to achieve high corrosion resistance and electrical conductivity, and a-C based coatings have the great potential. However, their low stability and high internal stress significantly damage their durability. This work aims to develop a fundamental understanding of the effect of doping Ag and Cr on the performance and durability of a-C based coatings. Experimental results revealed that a-C films doped with Ag and Cr (a-C:Ag:Cr) simultaneously achieve ultra-low interfacial contact resistance (ICR), low internal stresses, and higher stabilities. We also developed an atomistic model by molecular dynamics (MD) to understand certain behaviors of a-C:Ag:Cr. The ultra-low ICR was mainly attributed to Ag nanoclusters embedded in a-C phases, low hardness, and a more graphite-like structure. The enhanced stability was attributed to denser structures and lower internal stresses. MD simulations suggested that the effect of doping Ag or Cr on the surface morphology and internal stress of a-C films may have different mechanisms.

中文翻译：

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掺杂银和铬的非晶碳薄膜实现超低界面电阻和长期耐久性在质子交换膜燃料电池中的应用

摘要 无定形碳 (aC) 薄膜所表现出的特性使其在汽车部件中的广泛应用中具有吸引力。由金属双极板 (BPP) 组装的质子交换膜燃料电池 (PEMFC) 是新能源汽车的有前途的电源。PEMFCs 的恶劣环境需要在金属 BPPs 上制备涂层以实现高耐腐蚀性和导电性，而 aC 基涂层具有巨大的潜力。然而，它们的低稳定性和高内应力严重损害了它们的耐用性。这项工作旨在深入了解掺杂 Ag 和 Cr 对 aC 基涂层的性能和耐久性的影响。实验结果表明，掺杂 Ag 和 Cr (aC:Ag:Cr) 的 aC 薄膜同时实现了超低的界面接触电阻 (ICR)，低内应力和更高的稳定性。我们还通过分子动力学 (MD) 开发了一个原子模型，以了解 aC:Ag:Cr 的某些行为。超低 ICR 主要归因于嵌入 aC 相中的 Ag 纳米团簇、低硬度和更像石墨的结构。增强的稳定性归因于更致密的结构和更低的内应力。MD 模拟表明，掺杂 Ag 或 Cr 对 aC 薄膜的表面形貌和内应力的影响可能有不同的机制。增强的稳定性归因于更致密的结构和更低的内应力。MD 模拟表明，掺杂 Ag 或 Cr 对 aC 薄膜的表面形貌和内应力的影响可能有不同的机制。增强的稳定性归因于更致密的结构和更低的内应力。MD 模拟表明，掺杂 Ag 或 Cr 对 aC 薄膜的表面形貌和内应力的影响可能有不同的机制。