Patent ID: 8778567

Claim:
A method of preparing a stainless steel bipolar plate for a fuel cell, said method comprising: configuring a bipolar plate forming apparatus to progressively form said bipolar plate, said progressively forming comprising: using a first shaping step to pre-form a sheet of stainless steel such that a portion of the material making up said sheet is selectively moved, said pre-formed sheet defining a nominal thickness and a plurality of undulations representative of bipolar plate reactant channel flowpaths therein; and using a second shaping step to change the shape of said pre-formed sheet such that a maximum deviation from said nominal thickness as a result of said first and second shaping steps is substantially reduced relative to formation of a bipolar plate from a single-step forming process; and providing said sheet to said bipolar plate forming apparatus such that upon operation of said bipolar plate forming apparatus on said sheet, the shape of said sheet is substantially converted into that of said bipolar plate.