High-temperature fuel cell bipolar plate anti-oxidation plating layer

Abstract

The invention provides a high-temperature fuel cell bipolar plate anti-oxidation plating layer, and relates to the technical field of fuel cells. The high-temperature fuel cell bipolar plate anti-oxidation plating layer comprises a composite plating layer, wherein the composite plating layer is composed of a CrN film layer, a silver plating layer and a gold plating layer. The preparation method ofthe anti-oxidation plating layer comprises the steps of 1) selecting a stainless steel plate as a bipolar plate material, and pretreating the stainless steel plate; 2) generating a film and depositing the film on the surface of the stainless steel plate to obtain a CrN film layer; 3) plating a silver plating layer on the CrN film layer; and 4) plating a gold plating layer on the silver plating layer. According to the invention, the contact resistance of the bipolar plate can be reduced, the contact resistance value of the stainless steel plate can be further reduced after silver plating due to good conductivity of silver, and meanwhile, the binding force of the plating layer is very good; and a small amount of thin gold is electroplated or sputtered on the silver layer, so that the problem of infirm combination of a gold-plated plating layer can be well solved, and good conductivity and relatively small contact resistance are obtained.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to an anti-oxidation coating for bipolar plates of high-temperature fuel cells. Background technique [0002] The principle of a fuel cell is an electrochemical device whose composition is the same as that of a general battery. Its single cell is composed of positive and negative electrodes (the negative electrode is the fuel electrode and the positive electrode is the oxidant electrode) and the electrolyte. The difference is that the active material of the general battery is stored inside the battery, thus limiting the battery capacity. The positive and negative electrodes of the fuel cell itself do not contain active materials, but are just catalytic conversion components. Therefore, a fuel cell is a veritable energy conversion machine that converts chemical energy into electrical energy. When the battery is working, fuel and oxidant are supplied from outside to react. In p...

AI Technical Summary

Problems solved by technology

[0003] The bipolar plate is one of the key components of the fuel cell. The bipolar plate plays the role of providing a gas reaction place, collecting current, supporting the membrane electrode, and water management. The bipolar plate material should have good electrical conductivity and strong corrosion resistance. Capability, high mechanical strength and low cost, graphite and graphite-based composite materials have low contact resistance and strong corrosion resistance are applied to fuel cell plates, but due to the poor mechanical strength of graphite materials, it is difficult to mass production Processing limits its wide application. Metal materials have good electrical conductivity, strong vibration resistance, and are suitable for stamping and forming mass production. This is the main development direction of fuel cell metal plates. Corrosion occurs in the battery working environment, corroding metal ions pollutes the catalyst, reduces the conductivity of the proton exchange membrane, and seriously affects the service life of the fuel cell; at the same time, the metal plate is easy to form a protective passivation film in an acidic environment, increasing the contact between the plate and the battery. The contact resistance of the gas diffusion layer reduces the output performance of the fuel cell