A ceramic fuel cell in an all solid-state energy conversion device that produces electricity by electrochemically combining fuel and oxidant gases across an ionic conducting oxide. Current ceramic fuel cells use an oxygen-ion conductor or a proton conductor as the electrolyte and operate at high temperatures (>600°C). Ceramic fuel cells, commonly referred to as solid-oxide fuel cells (SOFCs), are presently under development for a variety of power generation applications. This paper reviews the science and technology of ceramic fuel cells and discusses the critical issues posed by the development of this type of fuel cell. The emphasis is given to the discussion of component materials (especially, ZrO2 electrolyte, nickel/ZrO2 cermet anode, LaMnO3 cathode, and LaCrO3 interconnect), gas reactions at the electrodes, stack designs, and processing techniques used in the fabrication of required ceramic structures.

Ceramic Fuel Cells

In recent years, Carbon Capture and Storage (Sequestration) (CCS) has been proposed as a potential method to allow the continued use of fossil-fuelled power stations whilst preventing emissions of CO2 from reaching the atmosphere. Gas, coal (and biomass)-fired power stations can respond to changes in demand more readily than many other sources of electricity production, hence the importance of retaining them as an option in the energy mix. Here, we review the leading CO2 capture technologies, available in the short and long term, and their technological maturity, before discussing CO2 transport and storage. Current pilot plants and demonstrations are highlighted, as is the importance of optimising the CCS system as a whole. Other topics briefly discussed include the viability of both the capture of CO2 from the air and CO2 reutilisation as climate change mitigation strategies. Finally, we discuss the economic and legal aspects of CCS.

Carbon capture and storage update

Electrolytes for solid oxide fuel cells

One of the challenges in improving the performance and cost-effectiveness of solid oxide fuel cells (SOFCs) is the development of suitable interconnect materials. The interconnect material is in contact with both the anode and the cathode, and thus must be stable with both electrode materials and in oxidizing and reducing environments. The interconnect material must also maintain a low electrical resistance during cell operation to avoid decreased efficiency due to ohmic losses. The common feature of the two approaches (metallic and ceramic) to the development of interconnect materials is the presence of chromium. The most promising ceramic materials are chromites, while the most promising metallic materials are chromia-forming alloys. The focus of this paper is comparison of metallic alloys for use as interconnects in solid oxide fuel cells, in terms of properties including oxidation resistance, volatility, electrical resistance and thermal expansion.

Metallic interconnects for solid oxide fuel cells

Fuel cells generate electricity and heat during electrochemical reaction which happens between the oxygen and hydrogen to form the water. Fuel cell technology is a promising way to provide energy for rural areas where there is no access to the public grid or where there is a huge cost of wiring and transferring electricity. In addition, applications with essential secure electrical energy requirement such as uninterruptible power supplies (UPS), power generation stations and distributed systems can employ fuel cells as their source of energy. The current paper includes a comparative study of basic design, working principle, applications, advantages and disadvantages of various technologies available for fuel cells. In addition, techno-economic features of hydrogen fuel cell vehicles (FCV) and internal combustion engine vehicles (ICEV) are compared. The results indicate that fuel cell systems have simple design, high reliability, noiseless operation, high efficiency and less environmental impact. The aim of this paper is to serve as a convenient reference for fuel cell power generation reviews.

Comparative study of different fuel cell technologies

Solid Oxide Fuel Cells: Technology Status

The oxidation of ferritic stainless steels has been studied under solid oxide fuel cell (SOFC) interconnect “dual” exposure conditions, i.e. simultaneous exposure to air on one side of the sample, and moist hydrogen on the other side. This paper focuses on the oxidation behavior of ferritic stainless steels during the isothermal oxidation in the dual environments. It was found that scales grown on the air side under these dual exposure conditions can be significantly different from scales grown on samples exposed to air on both sides. In contrast, no substantial difference was observed between the scales grown on the fuel side of the dual atmosphere samples and scales grown on samples exposed to moist hydrogen on both sides. AISI430, with 17% Cr, suffered localized attack via formation of Fe2O3 hematite-rich nodules on the air side of dual exposure samples, while the spinel top layer of the air side scale of Crofer22 APU (23% Cr) was enriched in iron. For E-brite, with the highest Cr content (27%), no unusual phases were found in the scale on the air side, but it was noticed the air side scale was less dense and appeared to be more prone to defects than the scalemore » grown in air only. The anomalous oxidation behavior of ferritic stainless steels on the air side of dual exposure specimens is related to the transport of hydrogen through the steel and its subsequent presence in the air side scale.« less

https://iopscience.iop.org/article/10.1149/1.1810393/pdf

Oxidation Behavior of Ferritic Stainless Steels under SOFC Interconnect Exposure Conditions

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations.

/pdf/self-sustainable-protonic-ceramic-electrochemical-cells-o158apg8a5.pdf

Prabhakar Singh

Papers

Solid Oxide Fuel Cells: Technology Status

Oxidation Behavior of Ferritic Stainless Steels under SOFC Interconnect Exposure Conditions

Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production.

A finite element analysis modeling tool for solid oxide fuel cell development: coupled electrochemistry, thermal and flow analysis in MARC®

LSM–YSZ interactions and anode delamination in solid oxide electrolysis cells