Preparation and characterization of copper based cermet anodes for use in solid oxide fuel cells at intermediate temperatures

Abstract

Two Cu-based anode cermets suitable for direct hydrocarbon oxidation in Solid Oxide Fuel Cells (SOFC) based on yttria stabilized zirconia (YSZ) electrolyte were tested in the temperature range (500-800°C). The ceramic c o m p o n e n t s w e r e C e O 2 a n d t h e p e r o v s k i t e La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3−d (LSCM). The cermets were made in both the form of pellets and films applied onto the YSZ electrolytes. Pellets exhibited good mechanical strength and resistance to fracture in both oxidized and reduced state. Cu-LSCM cermets exhibited good redox cycling behavior between 700-800°C. Reduction temperature plays a significant role on final morphology with Cu segregation occurring at 800°C. Cu-LSCM films were found to exhibit lower polarization resistances than CuCeO 2 under 5% H 2 . Examination of the data revealed a poorer contact of the Cu-CeO 2 electrode with the YSZ surface than the Cu-LSCM electrode. Reduction temperature should be less than 750°C to ensure suitable microstructure and adhesion of both film electrodes with the electrolyte.

A Review of RedOx Cycling of Solid Oxide Fuel Cells Anode

“…A RedOx stability test at 800 °C was performed on Cu-LSCM (La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3−d ) pellets by four-point electrical conductivity measurement giving promising results [ 227 ].…”

Fabrication and Characterization of Functional Ceramic Films by Solution Spray Pyrolysis: Correlations with the Thermal Decomposition Characteristics of the Constituent Salts

“…The structure and morphology of ceramic or ceramicmetal (cermet) electrodes significantly affect the performance of ceramic fuel and electrolysis cells. Electrode parameters such as thickness, porosity and degree of tortuosity affect significantly the values of gaseous effective diffusivities that eventually determine the extent of concentration polarization losses (1). When these electrodes are in the form of thin films, high concentration polarization losses e.g., in working fuel cells and electrolyzers are avoided (2).…”

“…From the functional materials used, Cu-CeO2 serves as an anode combining the functionalities of copper (an electronic conductor) and a good oxidation catalyst (i.e. CeO2) while LSM is a mixed ionic and electronic conductor (LSM) used as typical cathode in SOFCs (14). CGO10 on the other hand, is a typical solid electrolyte more suitable for intermediate temperature applications (i.e.…”

Cu/CGO cermet based electrodes for Symmetric and Reversible Solid Oxide Fuel Cells

“…A suitable anode for the direct oxidation of methane needs good electronic conductivity and electrocatalytic activity decoupled from the tendency to form carbon. Copper based ceria cermets demonstrated to be advantageous in replacing Ni-cermets for direct hydrocarbons SOFCs [2][3][4][5][6]. In these cermets the electrical conductivity is warranted by copper, whereas ceria is responsible for the catalytic activity in oxidation reactions.…”