Fabrication of Titanium Bipolar Plates by Rubber Forming Process and Evaluation Characteristics of TiN coated Titanium Bipolar Plates

Abstract

In this study, the rubber forming process is used to fabricate a micro-channel titanium plate for a PEM fuel cell. The micro-channel plate is fabricated using a 200 ton hydraulic press, and various parameters (punch speed, press pressure, rubber thickness, rubber hardness) are investigated in order to evaluate the formability. TiN films are deposited by reactive DC magnetron sputtering (DCMS) with an electromagnetic field system (EMFS). For the uncoated titanium and TiN-coated titanium substrates, the hardness, surface roughness, and corrosion resistance are estimated by nano-indentation and electrochemical methods, respectively. The improved corrosion resistance of the TiN films can be attributed to the densification of the film caused by enhancement of nitrification with increasing high reactive nitrogen radicals. The uncoated titanium and TiN-coated titanium bipolar plates are combined with a unit cell for a performance test, and respective current densities of 0.396 and 0.888 A cm -2 at 0.6 V are obtained.

Synergistic Effects of Carbon Fillers of Phenolic Resin Based Composite Bipolar Plates on the Performance of PEM Fuel Cell

“…Both of these materials have some advantages and disadvantages. The graphite-based bipolar plates have good electrical conductivity and excellent corrosion resistance [13,14] in the fuel cell environment but they are difficult to machine because of their brittle nature [15]. Due to brittleness of graphite, the bipolar plates are required to be prepared a few millimeters thick which enlarge the size of fuel cell stack and hence affect the cost of PEM fuel cell directly [8,16].…”

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

“…TiN is well compatible with titanium and corrosion tests have achieved a very low corrosion rate of 0.0086 µA•cm −2 and the contact resistance meets the DOE limits, even after a 8-h potentiostatic test (4 mΩcm 2 at 200 N•cm −2 ); however, the tests were run at room temperature [146]. In another study of a coating prepared using the DC magnetron sputtering method, a contact resistance value of 7.2 mΩcm 2 was achieved at 140 N•cm −2 which is about seven times lower than that of uncoated titanium [147]. Powder immersion reaction assisted coating method (PIRAC) is a potential technique, alongside PVD and plasma methods, to prepare dense, well-adhered and protective layers based on TiN with a minor amount of TiN x O y and TiO 2 .…”

Simulation optimization and experimental research on three-stage stamping of micro-channels with titanium ultra-thin sheet used for PEM fuel cell bipolar plates

“…A 0.1mm thick bipolar plate of SS304 stainless steel is fabricated with high surface quality, dimension precision and low cost [14]. In forming of titanium bipolar plate, experimental results showed that the maximum channel depth was 0.270mm (68% of punch channel depth), and current density for titanium bipolar plate was 396mA cm -2 at a voltage of 0.6V, which was smaller than 1156 mA cm -2 of graphite bipolar plate and 799 mA cm -2 of TiN-coated titanium bipolar plate [15]. Design of experiment was used to nd the key parameters of the rubber forming process and their optimal levels.…”