Electrical and corrosion properties of stainless steel bipolar plates coated with a conduction polymer composite

Metal bipolar plates fabricated from stainless steel have many advantages, such as low contact resistance, good mechanical properties, easy manufacturing, and low cost. However, they suffer from corrosion due to the acid created in the proton exchange membrane (PEM) fuel cell environment. In this research, a polymer composite of polyamide-imide (PAI) filled with carbon black (CB) was coated onto stainless steel substrates. The effects of the carbon black content on the corrosion resistance and the electrical contact resistance were investigated. The contact resistance of the polymer composite-coated stainless steel was found to increase upon increasing the carbon black content. However, increasing the carbon black content also decreased the corrosion resistance. From the results obtained, the optimum carbon black content was determined.