钛双极板TaTiN涂层耐腐蚀性与导电性的协同增强

Synergistic Enhancement of Corrosion Resistance and Electrical Conductivity of TaTiN Coating for Ti Bipolar Plates

摘要:

质子交换膜水电解（PEMWE）的大规模应用迫切需要双极板具有强耐腐蚀性和高导电性的涂层。通过磁控溅射制备了高性能TaTiN涂层。结果表明，具有(111)晶面择优取向和晶粒细化的TaTiN涂层表现出更高的耐腐蚀性和更好的导电性。一方面，密排(111)晶面有利于形成致密结构，同时晶粒细化可使表面平整，促进连续致密钝化层的形成，从而提升耐腐蚀性能。另一方面，TaTiN (111)晶面与Ti (0001)基底之间较小的晶格失配增强了界面结合，进而改善了界面导电性，降低界面接触电阻（ICR）。优化后的TaTiN涂层腐蚀电流密度低至6.56×10^-7 A·cm^-2，ICR值仅为9.11 mΩ·cm²，表明TaTiN涂层在保护PEMWE系统中金属双极板方面具有巨大潜力。

Abstract:

Coatings with strong corrosion resistance and high electrical conductivity on bipolar plates are urgently required for large-scale applications of proton exchange membrane water electrolysis (PEMWE). High-performance TaTiN coatings were fabricated via magnetron sputtering. Results show that TaTiN coatings with preferred (111) planes and refined grains show higher corrosion resistance and better electrical conductivity. On the one hand, the closely-packed (111) plane favors a dense texture; moreover, grain refinement can smooth the surface and facilitate the formation of a continuous, compact passive layer, thereby improving corrosion resistance. On the other hand, the small lattice mismatch between TaTiN (111) and Ti (0001) enhances interfacial bonding and thus electrical conductivity across the interface, resulting in lower interfacial contact resistance (ICR). The optimized TaTiN coating shows a low corrosion current density of 6.56×10^-7 A·cm^-2 and an ICR of 9.11 mΩ·cm², indicating the strong potential of TaTiN coatings to protect metallic bipolar plates in PEMWE systems.