Sandwich-like functional design of C/(Ti:C)/Ti modified Ti bipolar plates for proton exchange membrane fuel cells

An important challenge for proton exchange membrane (PEM) fuel cells is to achieve design innovation and lifetime enhancement of bipolar plates. The development of surface coatings for metal bipolar plates that combine electrical conductivity and corrosion resistance is essential to enhance durability and reduce costs. In this work, sandwich-like C/(Ti:C)/Ti modified Ti bipolar plates have been proposed based on computational simulations and experimental verification. The functional design is represented by predicted electrical conductivity and H2O adsorption behavior based on theoretical calculations. Experimentally, the C/(Ti:C)/Ti modified Ti bipolar plates achieves lower interfacial contact resistance (ICR) values of 1.51 mΩ cm2 with Ti mesh and 1.66 mΩ cm2 with carbon paper at 1.4 MPa. The corrosion current density significantly decreases to 0.21 μA cm−2 after potentiostatic polarization for 4 h at 0.6 V vs. Ag/AgCl. To meet the durability requirements of variable operating conditions, performance of Ti bipolar plates under high temperature, high acidity and high potential conditions has been discussed to assist in the functional design of surface films. •Electrical conductivity and corrosion resistance of film were predicted.•Sandwich-like C/(Ti:C)/Ti nano-film was designed on Ti bipolar plates.•Interfacial contact resistance and corrosion current density met DOE requirements.•High potential accelerates the failure of films in simulated cathodic conditions.