An investigation of coated aluminium bipolar plates for PEMFC

The performance of Al-alloy bipolar plates for the PEMFC (proton exchange membrane fuel cell) system is investigated in this paper. The metallic bipolar plates are modified with a Ni–P coating. The performance of the Al-alloy bipolar plates is evaluated by the coating structure, corrosion resistance, contact angle and single cell performance. The results indicate that the coated aluminium bipolar plates demonstrate hydrophobic and anti-corrosive properties. The hydrophobic property increases the contact angle on the surface from 46.08° to 80.51°. Meanwhile, the corrosion rate of the Ni–P coating can be over 1 order of magnitude lower than that of the substrate. Hence, the substrate with the coating maintains superior performance under the long term test. The present study proves that both the hydrophobicity and corrosion resistance significantly affect the metallic bipolar plate.

► Coated aluminium bipolar plates demonstrate the hydrophobic property than the raw material.
► The corrosion behaviour of bipolar plate decreases the PEMFC performance severely.
► These PEMFCs are measured by current–voltage (I–V) curve test.
► The oxide film increases the interfacial contact resistance.