ELECTROCHEMICAL METHOD OF APPLYING A DOUBLE-LAYERED ELECTRICALLY CONDUCTIVE PROTECTIVE COATING TO AN INTERCONNECT

摘要

The invention relates to techniques for applying an electrically conductive protective coating to interconnects of the chamber of an air electrode of a solid oxide fuel cell (SOFC), and can be used for protecting against high-temperature corrosion of the electrical contacts of SOFC interconnects made of high-chromium steel or nickel-iron alloy. The present method includes applying a first layer of metal by electrodeposition from a nickel plating or cobalt plating electrolyte solution, and applying a second layer to said first layer of coating by deposition from a suspension consisting of particles of the oxide phase СоМn₂О₄ which are dispersed in a solution of an electrolyte containing cations of Co and Mn, wherein a flow of direct current is used and the coated surface is heat treated in a two-step annealing process, in which heat treatment is carried out at 850°С in a vacuum in a first step, and at 1000°С in an atmosphere of air in a second step. The method makes it possible to reduce the porosity, increase the corrosion resistance and improve the adhesion of the resulting interconnect coating. Furthermore, specimens of steel and alloys with corresponding coatings exhibit lower resistance at elevated temperatures.