Development of lanthanum strontium cobalt ferrite composite cathodes for intermediate- to low-temperature solid oxide fuel cells

Solid oxide fuel cells (SOFCs) offer high energy conversion, low noise, low pollutant emission, and low processing cost. Despite many advantages, SOFCs face a major challenge in competing with other types of fuel cells because of their high operating temperature. The necessity to reduce the operational temperature of SOFCs has led to the development of research into the materials and fabrication technology of fuel cells. The use of composite cathodes significantly reduces the cathode polarization resistance and expands the triple phase boundary area available for oxygen reduction. Powder preparation and composite cathode fabrication also affect the overall performance of composite cathodes and fuel cells. Among many types of cathode materials, lanthanum-based materials such as lanthanum strontium cobalt ferrite (La1-xSrxCo1-yFeyO3-δ) have recently been discovered to offer great compatibility with ceria-based electrolytes in performing as composite cathode materials for intermediate- to low-temperature SOFCs (IT-LTSOFCs). This paper reviews various ceria-based composite cathodes for IT-LTSOFCs and focuses on the aspects of progress and challenges in materials technology

An intermediate-temperature solid oxide fuel cell with electrospun nanofiber cathode

Lanthanum strontium cobalt ferrite (LSCF) nanofibers have been fabricated by the electrospinning method and used as the cathode of an intermediate-temperature solid oxide fuel cell (SOFC) with yttria-stabilized zirconia (YSZ) electrolyte. The three-dimensional nanofiber network cathode has several advantages: (i) high porosity; (ii) high percolation; (iii) continuous pathway for charge transport; (iv) good thermal stability at the operating temperature; and (v) excellent scaffold for infiltration. The fuel cell with the monolithic LSCF nanofiber cathode exhibits a power density of 0.90 W cm(-2) at 1.9 A cm(-2) at 750 degrees C. The electrochemical performance of the fuel cell has been further improved by infiltration of 20 wt% of gadolinia-doped ceria (GDC) into the LSCF nanofiber cathode. The fuel cell with the LSCF-20% GDC composite cathode shows a power density of 1.07 W cm(-2) at 1.9 A cm(-2) at 750 degrees C. The results obtained show that one-dimensional nanostructures such as nanofibers hold great promise as electrode materials for intermediate-temperature SOFCs