Yuqiang Liu

Thermal and electrical properties of new cathode material Ba0.5Sr0.5Co0.8Fe0.2O3-delta for solid oxide fuel cells

A newly developed cathode material, Ba0.5Sr0.5Co0.8Fe0.2O3-delta, was synthesized and characterized. X-ray diffraction results identified it as a cubic perovskite structure. Thermogravimetric results showed that lattice oxygen loss was about 2% in weight between 50 and 1000 degrees C. Thermal expansion coefficient results in air and argon were extraordinarily high, with slope changes occurring at about 382 and 360 degrees C, respectively. Electrical conductivity values were sufficient for cathode application with the maximum of about 28.1 S cm(-1) at 500 degrees C in air and 17.3 S cm(-1) at 900 degrees C in N-2, correspondingly. Both thermal and electrical properties were closely associated with lattice oxygen behaviors and oxygen partial pressure. (c) 2005 The Electrochemical Society.

An anode for solid oxide fuel cells: NiO+(Ce0.9Ca0.1O1.9)0.25(YSZ)0.75 solid solution

A (CCO)(0.25)(YSZ)(0.75) solid solution (YSZ is Y2O3-stabilized ZrO2; CCO is an abbreviation of Ce0.9Ca0.1O1.9) was successfully synthesized by a solid-state method. A composite anode material, NYCx (60 wt% NiO+40 wt% (CCO)(x)(YSZ)(1-x)), for SOFCs (solid oxide fuel cells) was prepared. XRD results suggest that a solid solution reaction occurs between YSZ and CCO after sintering at 1400 degreesC for 10 h. From the impedance results, the conclusion can be drawn that the (CCO)(0.25)(YSZ)(0.75) solid solution is a mixed conductor (ionic and electronic). Its total conductivity is greater than that of YSZ. The NYCx (x>0) anodes exhibited better performance than the commonly used Ni+YSZ anode with regards to overpotential and anode interfacial impedance, with the NYC0.25 anode exhibiting the best performance (C) 2003 Elsevier B.V. All rights reserved.

A Ni/YSZ composite containing Ce0.9Ca0.1O2−δ particles as an anode for SOFCs

A composite material (hereafter referred to as NYC) containing Ni, Y2O3-stabilized ZrO2 (YSZ) and Ce0.9Ca0.1O2-delta (CC10) particles was prepared and used as the anode of solid oxide fuel cells (SOFCs). The performance of NYC was better than that of conventional Ni/YSZ anodes in terms of anodic overpotential and interface impedance. The additional CC10 particles improved the anode properties. XRD results suggest that a solid solution of YSZ and CC10 was produced. From impedance measurements, it is concluded that the solid solution exhibits substantial electronic conduction. Ni/YSZ/15 wt% Ce0.9Ca0.1O2-delta anodes exhibited the best properties over the experimental temperature range. A SOFC with an anode of Ni/YSZ/15 wt% Ce0.9Ca0.1O2-delta provided the maximum power density and current density. Addition of CC10 with an average particle size of 0.3 mum was more advantageous than that with an average size of 3 mum