The solid oxide fuel cell SOFC is one of the most exciting systems for future power generation because of its fuel flexibility and very high potential efficiency. Alternative electrolyte materials, such as Ce 0. The limitations and advantages of LSGM are discussed in detail elsewhere in this volume; however, the most important limitation with respect to anode chemistry is its reactivity with NiO [3, 4], which means that Ni-based anodes are quite difficult to manufacture.
One possible solution is to develop perovskite-based anodes, which leads to the attractive concept of the all-perovskite solid oxide fuel cell [5—7]. Among other types of fuel cells, deployment of solid oxide fuel cells SOFCs into the distributed energy sector of the consumer market is fast becoming a reality, predominantly because technological advancements are making them more reliable and relatively cost competitive.
In addition, there has been a concerted effort in designing and manufacturing novel ceramic materials for high-performance cell components [1—4]. Over the decades, a large collection of materials have been systematically investigated for possible application of SOFC electrolyte and electrodes. In addition, reduced temperature operation of SOFCs has been attracting attention due to numerous advantages offered by this mode of operation. Some of these advantages can be listed as follows: 1 less expensive metallic materials can be used as interconnects, 2 less degradable components imply higher stability and durability, and 3 responses to start-up and shut-down procedures are faster.
Part of the Fuel Cells and Hydrogen Energy book series (FCHY). Download book Oxide Ion Conductivity in Perovskite Oxide for SOFC Electrolyte. Tatsumi. Perovskite Oxide for Solid Oxide Fuel Cells (Fuel Cells and Hydrogen Energy) [ Tatsumi Ishihara] on dynipalo.tk *FREE* shipping on qualifying offers. Fuel cell .
Even internal reforming of hydrocarbonaceous fuels remains possible at intermediate temperatures. Overall, the common denominator impetus is to achieve higher area or volume -specific power densities at lower temperatures. TOTO is the top sanitary ware manufacturer in Japan. The company also has much experience in making both traditional and advanced ceramic products. Solid oxide fuel cells SOFCs are mainly composed of ceramics, and our fabrication technology has been utilized to produce high-performance SOFCs at a low cost.
Proton conduction, resulting from oxide ability to dissolve protons from water vapor or hydrogen, is no exception: Some perovskites contain virtually no protons at all and are thus barriers to protons, hydrogen, and water vapor. Other perovskites are dominated by proton defects to high temperatures and are predominantly proton conductors. Some perovskite-type oxides show protonic conduction and are useful for hydrogen-related electrochemical devices, including application to solid oxide fuel cells SOFCs.
Iwahara et al. Since that time, various perovskite-type proton-conducting oxides have been found. For use of the proton-conducting perovskite oxides, we should understand not only their merits but also their weak points. This chapter concerns the proton-conducting properties of typical cerium- and zirconium-containing perovskite oxides from the points of view of conductivity, stability, electrode affinity, and dopant effect.
Mixed conduction occurring in a special composition of the perovskite oxide is also introduced. The proton is the only ion of chemical significance that has no electron shell on its own. It, therefore, strongly polarizes its environment, which leads to high binding energies. Speaking in terms of transport, this corresponds to a high degree of self-localization and implies a strong coupling of long-range proton motion to the dynamics of the proton environment. This is actually one common feature of all proton conduction mechanisms in quite diverse families of compounds .
Today, most vehicles are driven by internal combustion engines with liquid fuel. A fuel cell is one leading candidate for this alternative power source. Regarding the PEFC, it is well known that several problems remain, such as high cost due to the use of platinum, liquid water management, and the durability of the polymer electrolyte. However, the two major issues of this system lie on the fuel side, hydrogen infrastructure and hydrogen storage.
Although hydrogen itself has very high power density, it is very difficult to store hydrogen with high physical density. Many researchers are working on the search for better hydrogen storage technology, such as a high-pressure tank, hydrogen storage metal, carbon nano-tubes, and liquid hydrogen. However, so far the driving range of fuel cell FC vehicles is much less than that of vehicles with internal combustion engines.
The issue regarding hydrogen infrastructure is more a political and economic one. Lanthanum chromite-based perovskite oxides LaCrO 3 have been widely recognized as promising interconnect materials for solid oxide fuel cells SOFCs. Therefore, interconnects should meet the following requirements.
ChemSusChem 8 , — Further, the materials are subjected to reducing atmosphere from room temperature where oxidized Ag is in the perovskite lattice. The cell under 10 vol. The conductivity of the Ni-cermets anode has been found to depend not only on the Ni content but also on the particle size of YSZ and the mixture ratio between the coarse and the fine YSZ. Anjan Barman.
Print ISBN Electronic ISBN Stoichiometric amount of Ti OC 4 H 9 4 was dissolved into dilute nitric acid solution to make solution B. Solutions A and B were mixed into a uniform mixture. Citric acid in a 1. With the evaporation of water, a viscous gel of metal-citrate complexes was obtained. In the cell fabrication, commercial YSZ disks were used as the electrolyte. In the same way, the slurry was screen-printed on the other side of the YSZ disk as the cathode.
The active area of working electrode was 1 cm 2. The prepared cell was bonded on the end of the Al 2 O 3 tube with high temperature inorganic binder. Ambient air was maintained on the cathode side. After the temperature reaching steady state, the atmosphere of anode chamber was switched to hydrogen for reducing the anode of cell.
It can be seen from Fig.
This difference might be due to the larger particle formation by agglomerated crystallites, resulting in a larger particle size as observed from SEM. This small crystallite size of nanolevel is very important for the improved electrocatalytic activity of SOFC anode. The OCV are 1.
The maximum power density is Such a temperature dependence of maximum power density is obviously due to the increasing overpotential with decreasing temperature. Performances of cell with LSTC10 as anode at different temperatures. In order to investigate the effect of the dopant content of chromium on the cell performance, the La 0. The preparation and characterization of LSTC20 material can be found in literature [ 20 ]. The maximum power density of cell is Performances of cell with LSTC20 as anode at different temperatures.
As can be seen from the above test results, the power density of cell is low, which may be due to the following two reasons.
First, the ohmic resistance of cell increases significantly with increasing the thickness of electrolyte layer [ 21 ]. Second, the doped titanates show low electrocatalytic activities for oxidation of hydrogen and hydrocarbon fuels [ 22 ]. Accordingly, for the sake of improving the output performance of cell, it is necessary to prepare an anode-supported cell with YSZ thin film as electrolyte and incorporate some catalytic materials into LSTC so as to optimize the catalytic properties of the anode.
The expected structure with a dense YSZ layer, porous anode and cathode layers can be clearly seen from Fig. It can also be seen from the surface and cross section of anode Figs. The network structure is also in favor of the electronic transmission.
However, from Fig. This may also be one of the reasons for the low power density of cell. So the composition and preparation of anode slurry should be further optimized to improve the anode microstructure. SEM pictures of cell after performance testing: a surface of anode; b cross section of anode; c cross section of cell; and d interface between anode and electrolyte.
As seen in Fig. Figures 5 c and 5 d show good contact and good adhesion of the interfaces between the anode or cathode and the YSZ electrolyte. This indicates that the preparation process of electrodes in this study is feasible, which lays the foundation for our subsequent studies and provides a reference for similar studies. LSTC10 was proved to be a potential anode material for SOFC, with which as an anode and dry hydrogen as fuel, the maximum power density of cell is The rather thick electrolyte layer, low electrocatalytic activity and nonuniform pore distribution of anode are probably the main reasons for the low power density of cell.
Therefore, the configuration of cell must be changed and the catalytic properties and microstructure of anode need to be further improved. S and National Center for Biotechnology Information , U. J Fuel Cell Sci Technol.