Study on Condition of Low-Cost Carbon-Based Surface Treatment for Application of Metallic Bipolar Plates in PEMFC

Tuesday, 7 October 2014
Expo Center, 1st Floor, Center and Right Foyers (Moon Palace Resort)
M. H. Kim, Y. Goo (KOREA AUTOMOTIVE TECHNOLOGY INSTITUTE), and S. E. Yoo (Korea Automotive Technology Institute)
Metallic bipolar plates coated with low-cost carbon-based surface treatment were developed for polymer electrolyte membrane fuel cells(PEMFC) and were evaluated by properties(corrosion, contact resistance) and performance(I-V curve). The carbon-based coating by dry surface treatment exhibited a good mechanical strength and corrosion resistance. But these could not be applied as bipolar plates because of a high electrical resistance by non-conductive structure(sp3↑, sp2↓). In this study, we developed the metallic bipolar plates with conductive structure((sp3↓, sp2↑) by change of coating temperature and thickness.

The coating thickness(A type, B type) and temperature(A-1~4, B-1~4) were used as parameters for conductive bipolar plates. The B type sample was more thicker than A type and A-4 sample was treated with heat more higher than A-1. These samples were evaluated by properties and performance of unit cell.

The surface treatment temperature of A-3 sample exhibited low contact resistance and corrosion current density. This trend showed in B type sample. Therefore, the condition of A-3 or B-3 revealed the optimum temperature in this experiment. However, the increase of coating thickness was for nothing in properties. The fuel cell assembled from metallic bipolar plates coated with carbon-based surface treatment exhibited the same performance as compared with graphite.