Metallic Material Selection and Prospective Surface Treatments for Proton Exchange Membrane Fuel Cell Bipolar Plates—A Review

Abstract

The aim of this review is to summarize the possibilities of replacing graphite bipolar plates in fuel-cells. The review is mostly focused on metallic bipolar plates, which benefit from many properties required for fuel cells, viz. good mechanical properties, thermal and electrical conductivity, availability, and others. The main disadvantage of metals is that their corrosion resistance in the fuel-cell environment originates from the formation of a passive layer, which significantly increases interfacial contact resistance. Suitable coating systems prepared by a proper deposition method are eventually able to compensate for this disadvantage and make the replacement of graphite bipolar plates possible. This review compares coatings, materials, and deposition methods based on electrochemical measurements and contact resistance properties with respect to achieving appropriate parameters established by the DOE as objectives for 2020. An extraordinary number of studies have been performed, but only a minority of them provided promising results. One of these is the nanocrystalline β-Nb2N coating on AISI 430, prepared by the disproportionation reaction of Nb(IV) in molten salt, which satisfied the DOE 2020 objectives in terms of corrosion resistance and interfacial contact resistance. From other studies, TiN, CrN, NbC, TiC, or amorphous carbon-based coatings seem to be promising. This paper is novel in extracting important aspects for future studies and methods for testing the properties of metallic materials and factors affecting monitoring characteristics and parameters.

Influence of Changes in the Shape of the Anode Channel in Polymer Electrolyte Fuel Cell on the Loss of Its Service Life

“…The channels were separated from each other by a polymer membrane (MEA), as presented in Figure 1 . The polymer membrane used for the transport of hydrogen protons consisted of successive layers of an anode gas diffusion layer (electrode) and a symmetrical GDL cathode [ 19 ]. Both layers operated as electrodes discharging the electric charge by means of an external circuit.…”

Ion Implantation Combined with Heat Treatment Enables Excellent Conductivity and Corrosion Resistance of Stainless Steel Bipolar Plates for Hydrogen Fuel Cells

“…The proton exchange membrane fuel cell (PEMFC), owing to its exceptional energy conversion rate, zero emissions, and rapid startup at room temperature, has emerged as one of the primary power sources for electric vehicles [1,2]. The bipolar plate (BP) is the core component in a PEMFC, and accounts for 70% of the weight, almost all of the volume, and 30-50% of the production cost of the entire cell stack [3,4]. Consequently, bipolar plates play a crucial role in PEMFC battery packs by providing support to the membrane electrode assembly, facilitating gas conduction, current collection, and water drainage [5].…”

Comparison of Magnetron-Sputtered and Cathodic Arc-Deposited Ti and Cr Thin Films on Stainless Steel for Bipolar Plates

“…Both PVD methods exhibit advantages and drawbacks that may be advantageous or disadvantageous for coating metallic BPP. As can be ascertained from recent reviews regarding bipolar plate coatings [ 14 , 17 , 23 ], a direct comparison of magnetron sputtering and cathodic arc evaporation in the context of PEMFC, and here BPP-related properties, had not been conducted so far. Thus, the aim of this work was to investigate the potential of both processes with regard to their suitability for coating metallic bipolar plates for PEM fuel cells.…”