High Performance Direct Ammonia Fueled Solid Oxide Fuel Cells Based on Proton Conducting Solid Electrolytes

The high performance anode supported single cells for ammonia fueled SOFCs, comprising of BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-delta)//BCY//NiO-BCY have been fabricated by wet colloidal spray for depositing 10-15 mu m thin film electrolytes. The detailed characterization of BSCF, including electrical conductivities of sintered specimen as a function of temperature has been conducted to investigate the possibility to utilize BSCF as cathode for proton conducting electrolyte based cells. The electrochemical performance of single cells was characterized at the temperature 600-700 degrees C under humid 75% H-2 in N-2 (3% H2O) as well as cracked ammonia as the fuel gas and air as the oxidant gas at a gas flow rate of 10-100 mL min(-1) The open circuit voltages were around 1.05-1.08 V at 600 degrees C indicating little gas leakage through the electrolyte. Maximum power density of 400 mW/cm(2) was obtained at 600 degrees C and 0.7 V under air as the oxidant gas and humid 75% H-2 in N-2 (3% H2O) as the fuel gas at gas flow rates of 100 and 100 mL min(-1), respectively.