Contact Resistance of Tantalum Coatings in Fuel Cells and Electrolyzers Using Acidic Electrolytes at Elevated Temperatures

摘要

Tantalum has so far been found to be the only construction material with sufficient corrosion resistance for high temperature polymer electrolyte membrane electrolyzers using acidic electrolytes above 100cC. In this work the interfacial contact resistances of tantalum plates and tantalum coated stainless steel were found to be far below the US Department of Energy target value of 10 mΩ cm~2 , The good contact resistance of tantalum was demonstrated by simulating high temperature polymer electrolyte membrane electrolysis conditions by anodization performed in 85% phosphoric acid at 130°C, followed by contact resistance measurements. Upon anodization the contact resistances remained unchanged.