摘要:燃料电池具有能量转换率高、环境亲和、安全性高、工作噪音低等优点,可 将燃料的化学能转变为电能,是洁净和高效的发电技术。质子交换膜燃料电池是 第五代燃料电池,具有能量转化率高、比功率高和零污染等长处,应用前景非常 广。双极板是质子交换膜燃料电池的重要组成部分之一,一般以金属双极板和石 墨双极板为主。相较于石墨双极板,金属双极板具有更好的导热性、气密性、导 电性和机加工性能,成为质子交换膜燃料电池的最好选择。但金属双极板目前还 存在许多问题亟待解决。
本文采用化学镀方法在 316L 不锈钢表面制备 Ni-P、Ni-P/TiN 镀层。通过扫 描电镜对试样进行微观形貌观察,可以看出制备的涂层微观组织紧密、连续且与 基体表面有很好的结合力。用硬度计对试样涂层硬度分析,可以看出 TiN 颗粒的 加入,使得涂层的硬度明显提高,200℃时长 2.5h 的退火处理并未改变试样涂层 的组织结构,硬度变化很小;但 400℃时长 2.5h 的退火处理使相的组成发生了变 化,硬度明显提高。用电化学阻抗谱、动电位极化和恒电位极化测试方法测试镀 层在模拟质子交换膜燃料电池腐蚀环境中的耐腐蚀性能。电化学测试的数据显示, 纳米 TiN 颗粒的加入,会使涂层的耐蚀性会降低,但试样在经过 200℃时长 2.5h 的退火处理后,涂层的耐蚀性能得到加强;试样经过 400℃时长 2.5h 的退火处 理,试样的耐蚀性明显下降。
关键词:质子交换膜燃料电池;双极板;Ni-P 镀层;TiN 纳米颗粒;316L 不 锈钢
Abstract:The fuel cell has the advantages of high energy conversion rate, environmental affinity, high safety and low working noise. It can convert the chemical energy of fuel into electric energy and is a clean and efficient power generation technology. Proton exchange membrane fuel cell is the fifth generation of fuel cells, with high energy conversion rate, high power and zero pollution and other advantages, the application prospect is very wide. Bipolar plate is one of the important components of proton exchange membrane fuel cell. It is mainly based on metal bipolar plate and graphite bipolar plate. Compared with graphite bipolar plate, metal bipolar plate has better thermal conductivity, air tightness, electrical conductivity and machining performance, a proton exchange membrane fuel cell the best choice. But there are still many problems with metal bipolar plate to be solved.
Ni-P, Ni-P / TiN coatings were prepared on the surface of 316L stainless steel by electroless plating. The microstructures of the prepared microstructures were observed by scanning electron microscopy (SEM), and the microstructures of the prepared films were close and continuous. With the hardness of the sample coating hardness analysis, we can see the TiN particles to join, making the hardness of the coating significantly improved, 200 ℃ 2.5h long annealing process does not change the sample coating structure, hardness change is very small ; But the annealing treatment at 400 ℃ for 2.5h changed the composition of the phase, and the hardness was improved obviously. Electrochemical impedance spectroscopy, potentiodynamic polarization and potentiostatic polarization test were used to test the corrosion resistance of the coating in the simulated environment of proton exchange membrane fuel cell corrosion. The electrochemical test data show that the addition of nano-TiN particles will reduce the corrosion resistance of the coating, but the corrosion resistance of the coating is enhanced after annealing at 200 ℃ for 2.5h. After annealing at 400 ℃ for 2.5h, the corrosion resistance of the samples decreased obviously.
Key words: proton exchange membrane fuel cell; bipolar plate; Ni-P coating; TiN nanoparticles; 316L stainless steel
目录
第一章 绪论 1