Patent ID: 8142841
Filing Date: 2012-03-27
Classification: C23G,C25F,H01M,Y02E

Abstract:
1. A method for deoxidizing a surface of a metal strip for use in a bipolar plate comprising: preselecting a potential drop value across a thickness of a metal strip; contacting the surface of the metal strip with a phosphate solution for a first preselected period of time, the phosphate solution having a pH between 10 and 14; and contacting the surface of the metal strip with an acid solution that consists essentially of acid and optionally surfactant and/or a fluoride source, for a second preselected period of time, the acid solution having a pH between 1 and 3, thereby deoxidizing the surface to produce deoxidized metal such that, after contacting the surface of the strip with the solutions, a measured potential drop across a thickness of the strip is less than the preselected potential drop value, wherein the preselected potential drop value is 8.2 mV at a current density of 1 ampere per square centimeter such that the metal strip is suitable for fabrication of bipolar plates.