Conductive and corrosion-resistant coating for metal bipolar plate of fuel cell

Abstract

The invention relates to a conductive and corrosion-resistant coating for a metal bipolar plate of a fuel cell. The coating comprises a precious metal part, and a conductive and corrosion-resistant non-precious metal part, wherein a precious metal accounts for 10-90wt% of the coating; and a precious metal coating is doped with a corrosion-resistant non-precious metal material through different modes. The precious metal in the coating is used for ensuring high conductivity, corrosion resistance and stability of the metal bipolar plate; under the premise that good coating performance is ensured,the added corrosion-resistant non-precious metal is used for reducing the amount of the precious metal in the coating, so that the coating cost is reduced; compared with the prior art, the coating provided by the invention has the advantages that through the different doping modes, excellent physical and chemical properties of the precious metal can be utilized to ensure better performance of themetal bipolar plate, and the coating preparation cost can be greatly reduced; and therefore, the coating is of great significance in promoting fuel cell industrialization.

Description

technical field [0001] The invention belongs to the technical field of fuel cells and relates to a low-cost doping method for conductive corrosion-resistant coatings of metal bipolar plates of fuel cells. Background technique [0002] Fuel cells use hydrogen as an energy source. They have many advantages such as high efficiency and environmental protection, high specific energy and specific power, and fast start-up. They have broad application prospects in various fields. Among them, the bipolar plate is one of the key components of the fuel cell. It has key functions such as supporting the cell structure, distributing the reaction gas, collecting current, and connecting the cells in series. Therefore, its performance restricts the commercialization process of the fuel cell. [0003] At present, the commonly used materials for bipolar plates are graphite or metal. Among them, graphite bipolar plates have disadvantages such as difficult processing, gas permeation, and poor me...

AI Technical Summary

Problems solved by technology

Commonly used functional films include amorphous carbon films, metal carbide films, metal nitride films, noble metal films, organic films, etc. Among them, noble metal films have good electrical conductivity, corrosion resistance and stability, but their cost is high and difficult Commercial application, although the preparation cost of non-precious metal coatings is lower, but its performance is worse than that of noble metals, and it cannot meet the life requirements of fuel cells at present

Chinese patent CN103484910A discloses a gold coating prepared by electroplating, followed by heat treatment of the gold coating to reduce the porosity of the coating, but the contact resistance of the coating is 15-22mΩ·cm 2 , the battery output voltage will be reduced due to the higher contact resistance value, and the coating preparation cost is higher; Chinese patent CN 101640276A discloses an amorphous carbon coating on a fuel cell bipolar plate, which has good conductivity And corrosion resistance, but the data show that its contact resistance is greater than 10mΩ·cm under the working pressure of the bipolar plate 2 , and the conductivity of the coating is unknown after a long time electrochemical test

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