New Materials and Procedures to Protect Metallic PEM Fuel Cell Bipolar Plates

Abstract

High carbon content polymers have been synthesized and pyrolyzed between 600 and 850°C in inert ambient, during various pyrolysis times, to obtain freestanding carbon films with specific resistivities that can be as low as ∼ 0.01 Ω cm. One of these polymers (M2-48), with a low specific resistivity at low pyrolysis temperature and pyrolysis time, can be easily sprayed on stainless steel 316L, a possible material to be used for bipolar plates in polymer electrolyte membrane (PEM) fuel cells. The layer of M2-48 on SS316L is used as a first layer of a three-layer coating, which is able, after its pyrolysis at 750°C, to protect the stainless steel against corrosion in fuel cell tests. The second and third layers of the 70-100 μm thick protective coating are made of a commercial graphite spray and a top layer of M2-48, respectively. © 2002 The Electrochemical Society. All rights reserved.