Influence of sintering temperature on microstructure and electrical properties of titanium porous-transport layers for proton exchange membrane water electrolyzer applications

Porous transport layers (PTL) are used in the proton exchange membrane water electrolyzers to facilitate the gas/water transport and the electric charge transfer. As a result, the PTL is critical in ensuring the efficiency of the electrolyzing process. This work aims to produce titanium PTLs through the spark plasma sintering process. The sintering temperature was varied from 500 to 650°C to investigate the characteristics of the titanium PTL samples while maintaining the sintering pressure and holding time at 10 MPa and 10 min, respectively. The phase structure and morphology of the samples were investigated by X-ray diffraction and scanning electron microscopy analyses. The compressive strength and the corrosion behaviour of the samples were investigated by the compressive testing and the electrochemical corrosion testing, respectively. The experimental results showed that there were no new phases formed when the Ti PTLs were sintered at different temperatures. With an increase in the sintering temperature, the porosity of the samples considerably decreased, while their compressive strength, electrical conductivity and corrosion resistance increased. It is suggested that selecting the optimum sintering temperature for sintered samples can improve the mass transport behaviour in PEM electrolyzers and produce superior PTLs.