Effect of electrode fabrication method and substrate material on performance of alkaline fuel cells

Performance of an electrode is influenced by electrode fabrication method and electrode substrate. In this study, different anodes were prepared by either electron beam physical vapor deposition or ink paste method, using Ni foam or carbon paper as electrode substrate. These electrodes were tested in an alkaline fuel cell using borohydride as the fuel. A nanoscale palladium thin film anode prepared by physical vapor deposition delivered power performance close to that of an ink pasted electrode with a much higher catalyst loading. Ni foam as electrode substrate demonstrated a higher power performance and yet a lower efficiency than carbon paper. Ni foam alone was used as anode and achieved a peak power density of 174 m Wcm− 2 at 60 °C. Thus, nickel foam had both positive effect (e.g. electrooxidation of NaBH4) and negative effect (e.g. hydrolysis) on the fuel cell performance.

► Electrode fabrication method and substrate were studied for alkaline borohydride fuel cells.
► A nanoscale palladium thin film anode was prepared by physical vapor deposition.
► Physical vapor deposition is an effective way to reduce catalyst loading.
► Ni foam had higher power density yet lower efficiency than carbon paper as electrode substrate.
► Ni foam alone as anode achieved a peak power density of 174 mWcm− 2 at 60 °C.