Fabrication Methode of Metal Bipolar Plate for Direct Methanol Fuel Cell

摘要

PURPOSE: A method for manufacturing a metal bipolar plate for a direct methanol fuel cell is provided to secure high corrosion resistance and high conductivity(low contact resistance) by modifying the surface of the plate and to obtain excellent mechanical strength. CONSTITUTION: A method for manufacturing a metal bipolar plate for a direct methanol fuel cell comprises the following steps: preparing ferrite-based stainless steel; molding the stainless steel in to a bipolar plate; washing the bipolar plate in a sulfuric acid solution; passivating the bipolar plate in a mixed solution of nitric acid and hydrofluoric acid. The ferrite-based stainless steel contains C of 0.02 weight% or less, N of 0.02 weight% or less, Si of 0.4 weight% or less, P 0.04 weight% or less, S 0.02 weight% or less, Cr 15-34 weight% or less, Mo 0.1-5 weight%, Cu 0.1-2 weight%, Ni 0.8 weight% or less, Ti 0.5 weight% or less, Nb 0.5 weight% or less, V 0-1 weight%, W 0-4 weight%, La 0-1 weight%, Zr 0-1 weight%, and B 0-0.1 weight%.