Nanometers Layered Conductive Carbon Coating on 316L Stainless Steel as Bipolar Plates for More Economical Automotive PEMFC

The major obstacle for the application of stainless steel bipolar plates is its high surface electrical resistance. J&L Tech Co. has developed proprietary processing technologies that have been applied on the commercially available thin stainless steel bipolar plates. Conductive carbon film approximately nano scale in thickness is coated on 316L stainless steel bipolar plates by plasma linear ion gun process. The Atomic Force Microscopy and Raman Spectroscopy results reveal that the nanolayered conductive carbon coating is dense and compact with a few nano size of strong conductive graphitic crystallites and large number of amorphous carbon particles. Interfacial contact resistance (ICR) results show that the surface conductivity of the bare 316L is significantly improved by our proprietary nanolayered conductive carbon coating, with very similar values of the baseline, gold coating on 316L. Also discussed are the microstructural aspects of this newly developed nanometers thick conductive carbon coating.