New Interface for PEM Electrolysis by Thermally Sprayed BPP-PTL Coating System

Abstract In order to take climate action for carbon neutrality, green hydrogen should be implemented in all industrial sectors. The proton exchange membrane water electrolyzer (PEMWE) allows sustainable hydrogen production if electrolyzer lifetime can be balanced with the production costs. In terms of electrolyzer effectiveness, ohmic losses from interfacial contact resistances between the cell components have to be reduced. In this study, a new two-step approach in interface modification of cell components is discussed. Firstly, a steel-based bipolar plate (BPP) is coated by cold gas spraying. Secondly, a cold gas-sprayed porous transport layer (PTL) is directly applied onto the coating, reducing construction gaps in the cell design. The interface modification is evaluated by measuring the total resistance of the BPP-PTL coating system. Accordingly, the electrical resistance between BPP and PTL is successfully reduced by approximately 40% through this approach. The reason for this observation is that BPP and PTL are joined in a new way, namely by mechanical interlocking. The newly developed BPP-PTL coating system is a promising approach for interface modification in the context of PEMWE.