Solid oxide electrolyzer cells

Computational Fluid Dynamics (CFD) analyses of individual flow channels in a solid oxide electrolyzer cell are being used to model temperature, current density, and local hydrogen production. In 2004, the integrated performance of an HTE plant and the thermal optimisation of the plant through various component arrangements were modeled. In addition, solid oxide electrolyser cell electrode materials with improved durability in the variable environment of the electrolyser cell are currently being developed. 

Ni M, Leung M K H and Leung D Y C (2008), Technological development of hydrogen production by solid oxide electrolyzer cell (SOEC) , Int J Hydrogen Energy,33,2331-2354. 

Solid oxide electrolyzer cells (SOEC) have a solid oxide ion conductor as electrolyte, often yttria-stabilized zirconia (YSZ). The cathode (CO evolution, negative) is often a Ni-YSZ composite called a cermet. The anode (O2 evolution, positive) most often consists of a composite of YSZ electrolyte and an electron-conducting perovskite-structured oxide, e.g., (Lao.75Sro.25)o.95Mn03 [1]. 

Physically, a solid oxide electrolyzer cells (SOEC) may be exactly the same cell as solid oxide fuel cell (SOEC) Solid Oxide Fuel Cells, Introduction as this cell type is fully reversible [1]. It can be used for CO2 electrolysis only but will most often be intended for electrolysis of a mixture CO2 and steam, H2O. This is called co-electrolysis of steam and CO2. The principle of both SOEC and SOEC is illustrated in Fig. 2. 

In the literature, the acronyms SOEC (Solid Oxide Electrolyzer Cell) or SOE also occur fairly regularly. The term high-temperature electrolysis (HTE) is fairly common, referring to the operating temperature of the component (typically 800°C) rather than to the nature of its electrolyte. 

Figure 8.1 Principle of Solid Oxide Fuel Cell (SOFC) and Solid Oxide Electrolyzer Cell (SOEC).

The reflected infrared radiation is gathered by a fiber-optics light pipe and conducted to the high-temperature solid-oxide electrolysis cell. The electrical output of the solar cells also powers the electrolysis cells. About 120 megajoules are needed—whether in electrical or thermal form, or both—to electrolyze water and generate 1 kg of hydrogen. The result is that more of the solar energy is used for... 

Evaluate the economic impact of the reversible solid oxide fuel cell /solid oxide electrolyzer system and consider applications where a competitive advantage may be achieved. 

Exchange ideas for the development and design of solid oxide fuel cells (SOFC) and proton exchange membrane (PEM) fuel cells for electricity and heat generation, vehicles, reversible fuel cell electrolyzes, and fuel cell microturbine hybrids, for example. 

Further, the first electrochemical devices based on oxide ion-conducting solid electrolytes, i.e., solid oxide fuel cells, water vapor electrolyzers, and oxygen concentrators, were also developed in the Institute of High-Temperature Electrochemistry. In 1978 the Laboratory of Physical and Chemical Properties of Solid Electrolytes has been renamed to the Solid Electrolytes Laboratory. Different cation-conductive solid electrolytes were investigated in the laboratory. Oxide semiconductor materials with fast ion and electron transport have been studied for different electrode applications in high-temperature electrochemical devices and MHD generators. 

Neuymin s research interests were extremely wide. At the early stage he synthesized new solid oxide electrolytes and measured their conductivity and transfer numbers and studied electrode kinetics in the solids. But his main interest was the development of various electrochemical devices based on solid oxide electrolytes, e.g., solid oxide fuel cells (SOFCs), electrolyzers, oxygen pumps, and sensors. From the morning till late in the evening, he was at the institute, and actually he led the laboratory. 

Iwahara, H., High temperature proton conducting oxides and their applications to solid electrolyte fuel cells and steam electrolyzer for hydrogen production. Solid State Ionics, 28/30, 573, 1988. 

The Technology Management, Inc. (TMI) reversible (fuel cell - electrolyzer) system employs a high temperature solid-oxide based electrochemical process to produce either electricity from common hydrocarbon fuels (e.g., natural gas, propane, and... 

Mahapatra, M.K. and Lu, K. (2010) Glass-based seals for solid oxide fuel and electrolyzer cells - a review. Mater. Sci. Eng. R, 67, 65-85. 

AI2O3 - B2O3 - Si02-based glass sealant for solid oxide fuel/electrolyzer cells. J. Power Sources, 179, 106-112. 

Three main water electrolyzer technologies can be distinguished alkaline technology, proton exchange membrane (PEM) technology and solid oxide (SO) technology. Note that these three technologies present numerous similarities respectively with the fuel cells (AFC, PEMFC and SOFC) discussed in... 

A planar-design SO electrolyzer is fairly similar, in stractural terms, to a PEM electrolyzer. Figure 2.12 shows the diagram of a typical layout of such a device. We see a sandwich-type structure, in which the solid electrolyte (a solid oxide which is a ceramic) is bordered on both sides by two porous electrodes (a ceramic is used for the anode and a ceramic/metal alloy (cermet) for the cathode). The interconnectors which serialize the cells are based on metallic materials. Depending on the design of the stack, channels are scored into the intercormectors or are replaced by flow-fields (pre-electrodes, so to speak), which are usually nickel-based. 

Electrolysis of water has been used for over a century to produce hydrogen and oxygen. The concept of a reversible fuel cell for space applications is based on a combined electrolytic-galvanic fuel cell. Like fuel cells, several different types of electrolyzers and catalysts have been developed, including atmospheric and high-pressure acid-based polymer electrolyzers, alkaline solution systems, and solid oxide-based systems. 

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