Appraisal of Ce1−yGdyO2−y/2 electrolytes for IT-SOFC operation at 500°C

The analysis of various parameters of metal oxides and the search of criteria, which could be used during material selection for solid-state gas sensor applications, were the main objectives of this review. For these purposes the correlation between electro-physical (band gap, electroconductivity, type of conductivity, oxygen diffusion), thermodynamic, surface, electronic, structural properties, catalytic activity and gas-sensing characteristics of metal oxides designed for solid-state sensors was established. It has been discussed the role of metal oxide manufacturability, chemical activity, and parameter's stability in sensing material choice as well.

Metal oxides for solid-state gas sensors: What determines our choice?

http://web.stanford.edu/group/efmh/jacobson/Articles/I/JDEnPolicyPt1.pdf

Providing all global energy with wind, water, and solar power, Part I: Technologies, energy resources, quantities and areas of infrastructure, and materials

Solid oxide fuel cells (SOFCs) have the promise to improve energy efficiency and to provide society with a clean energy producing technology. The high temperature of operation (500−1000 °C) enables the solid oxide fuel cell to operate with existing fossil fuels and to be efficiently coupled with turbines to give very high efficiency conversion of fuels to electricity. Solid oxide fuel cells are complex electrochemical devices that contain three basic components, a porous anode, an electrolyte membrane, and a porous cathode. In this short review, a survey of the types and properties of materials that have been considered for each of these components is presented with an emphasis on the requirements for operation at intermediate temperature (500−800 °C). Some directions for future research are discussed.

Materials for Solid Oxide Fuel Cells

Progress in material selection for solid oxide fuel cell technology: A review

Scandia-zirconia electrolytes for intermediate temperature solid oxide fuel cell operation

Direct coupling of an electrolyser to a solar PV system for generating hydrogen

Solid-state electrochemical cells based on oxygen-ion conduction (pure ionic or mixed ionic/electronic conductors) allow selective transport of oxygen (oxygen-ion conducting materials) in the form of ionic flux at high temperatures. Thus these systems can act as filters for molecular oxygen and can be used for both generation or removal of oxygen selectively. The usage of such devices are numerous, including production of high purity oxygen for medical applications, aqua-culture and combustion processes; control of oxygen partial pressure in industrial environments; production of power and chemicals; and removal of oxygen from enclosures and gas streams. In this paper, a brief overview of the technology has been given and various membrane materials for construction of such devices have been discussed.

Ceramic Membrane Technologies for Oxygen Separation

An investigation of conductivity, microstructure and stability of electrolyte compositions in the system 9 mol% (Sc2O3-Y2O3)-ZrO2(Al2O3)

Oxygen-ion conducting solid electrolyte systems have been reviewed with specific emphasis on their use in solid oxide fuel cells. The relationships between phase assemblage, electrolyte stability and ionic conductivity have been discussed. The role of parameters such as sintering temperature and atmosphere which influence the segregation of impurities, present in the starting ceramic powders, at grain boundaries and at the external surface of the electrolyte compacts has been emphasised. The stability of various electrolyte materials in contact with other fuel cell components and in fuel environments has been discussed in detail. The ageing behaviour at fuel cell operating temperatures has been described. Data on ionic conductivity, mechanical and thermal properties have been presented for a number of electrolyte materials.

Fabio T. Ciacchi

Papers

Scandia-zirconia electrolytes for intermediate temperature solid oxide fuel cell operation

Direct coupling of an electrolyser to a solar PV system for generating hydrogen

Ceramic Membrane Technologies for Oxygen Separation

An investigation of conductivity, microstructure and stability of electrolyte compositions in the system 9 mol% (Sc2O3-Y2O3)-ZrO2(Al2O3)

Oxygen-ion conducting electrolyte materials for solid oxide fuel cells