靶流对磁控溅射CrN金属双极板耐腐蚀性能的影响

Effect of target current on corrosion resistance of CrN coatings on metal bipolar plates using magnetron sputtering

为改善燃料电池金属双极板的电阻及抗腐蚀性能,采用磁控溅射工艺,在304不锈钢表面沉积CrN薄膜。分析了不同靶电流对膜层表面形貌和相结构的影响,测试其接触电阻及耐腐蚀性能。结果表明,表面改性后的不锈钢双极板导电性良好,在质子交换膜燃料电池电堆的组装力范围内,与Toray碳纸的接触电阻为22.65–24 m?/cm2。双极板的耐腐蚀性能相对于未处理的304不锈钢基体有了显著的增强:在80℃的0.05 mol/LH2SO4+2 mg/L F–的模拟电池环境腐蚀溶液中,改性后双极板的腐蚀电流为0.5×10–6 A/cm2,比304不锈钢小1个数量级。随着电流的增加,双极板耐腐蚀性和导电性能提高。

To improve contact resistance and corrosion resistance of the bipole in proton exchange membrane fuel cells （PEMFC）, chromium nitride films were deposited on 304 stainless steel by magnetron sputtering. Effects of the target current on morphology and phase of the CrxN coatings were investigated. The contact resistance and corrosion resistance of the coatings was tested. The results show that the contact resistance between the modified 304 stainless steel and Toray carbon films is 22.65–24 m？/cm2, within the package force of PEMFC. In the simulative environment of PEMFC （0.05 mol/L H2SO4 ＋ 2 mg/L F– on 80℃）, the corrosion current of modified bipolar plates is 0.5×10^–6 A/cm^2. Increasing the target current can improve the properties of anti-corrosion and conductive on metal bipolar plates.