Development of novel anode material for intermediate temperature SOFC (IT-SOFC)

Solid oxide fuel cells (SOFC) offer a clean technology to electrochemically generate electricity and heat from hydrogen or hydrocarbon based fuel at high efficiencies. All the active components of the SOFC unit cell comprise of rare-earth or low abundant elements. An increase in the cost of rare-earths is likely to jeopardize the commercialization prospects of SOFC based technologies. Hence, a greater scientific effort should be focused on the development of rare-earth free SOFC materials. The previous research works on electrode-supported intermediate temperature solid oxide fuel cells (IT-SOFCs) indicate that the anode supported concept provides better electro-chemical performance than the cathode supported one. Therefore, the total material cost of anode-supported SOFC is largely governed by the cost of the anode material. The objective of the present investigation was, therefore, the development of a rare-earth free anode material for IT-SOFC. The present work envisages application of titanium oxycarbide as a possible rare-earth free anode material for intermediate temperature solid oxide fuel cells. Titanium oxycarbide samples (TiOxC1-x with x = 0.2-0.8) were prepared by reaction-sintering of TiO and TiC powders under vacuum at 1500 degrees C for 5 h. Basic studies on TiOxC1-x (x = 0.2-0.8) with respect to phase purity and stability under oxidizing and reducing environments were carried out. The compatibility of titanium oxycarbide with intermediate-temperature electrolyte material (Ce0.9Gd0.1O3-delta) was studied. The electrochemical properties of planar cells using Ce0.9Gd0.1O3-delta as electrolyte and employing TiO0.2C0.8 and La0.8Sr0.2Co0.2Fe0.8O3-delta based anode and cathode materials were investigated. The present study indicates that titanium oxycarbide is an alternative anode material for IT-SOFC. This is the first report on the possibility of application of a rare-earth free ceramic in the form of titanium oxycarbide as a potential fuel electrode in IT-SOFC.