Intermediate Temperature Solid Oxide Fuel Cells: Electrolytes, Electrodes and Interconnects introduces the fundamental principles of intermediate solid oxide fuel cells technology. It provides the reader with a broad understanding and practical knowledge of the electrodes, pyrochlore/perovskite/oxide electrolytes and interconnects which form the backbone of the Solid Oxide Fuel Cell (SOFC) unit. Opening with an introduction to the thermodynamics, physiochemical and electrochemical behavior of Solid Oxide Fuel Cells (SOFC), the book also discusses specific materials, including low temperature brownmillerites and aurivillius electrolytes, as well as pyrochlore interconnects. This book analyzes the basic concepts, providing cutting-edge information for both researchers and students. It is a complete reference for Intermediate Solid Oxide Fuel Cells technology that will be a vital resource for those working in materials science, fuel cells and solid state chemistry. - Provides a single source of information on glass, electrolytes, interconnects, vanadates, pyrochlores and perovskite SOFC - Includes illustrations that provide a clear visual explanation of concepts being discussed - Progresses from a discussion of basic concepts that will enable readers to easily comprehend the subject matter

This book discusses recent advances in intermediate-temperature solid oxide fuel cells (IT-SOFCs), focusing on material development and design, mechanism study, reaction kinetics and practical applications. It consists of five chapters presenting different types of reactions and materials employed in electrolytes, cathodes, anodes, interconnects and sealants for IT-SOFCs. It also includes two chapters highlighting new aspects of these solid oxide fuel cells and exploring their practical applications. This insightful and useful book appeals to a wide readership in various fields, including solid oxide fuel cells, electrochemistry, membranes and ceramics. Zongping Shao is a Professor at the State Key Laboratory of Materials-Oriented Chemical Engineering and the College of Energy, Nanjing University of Technology, China. Moses O. Tade is a Professor at the Department of Chemical Engineering, Curtin University, Australia.

Abstract: Fuel cells are one of the most promising clean energy technologies under development. But a constraining factor in their further development is related to operating temperature ranges of current fuel cell systems, which is either low or high temperature. The intermediate temperature (200°C to 600°C) would be the most desirable temperature range for a fuel cell for most applications, but there is no existing mature fuel cell technology in this range, mainly because of an absence of appropriate electrolytes. An effort to develop an intermediate-temperature molten-salt electrolyte fuel cell (IT-MSFC) was undertaken in this study. As a start, molten KOH was used as an electrolyte around 200°C supported on a porous matrix. Tests used Pt loaded carbon cloth to be the electrode-catalyst layer, hydrogen and oxygen as fuel. The major challenge for this fuel cell was to hold electrolyte within a suitable porous support layer, without crossover of fuel gas during operation. Performance was short-lived, thus several ceramic materials were investigated in this research, including Zirconia felt, Zirconia disk, and porous NiO. To evaluate the properties of KOH molten salts working for IT-MSFCs, the performances were compared to fuel cell tests with KOH saturated solution and phosphoric acid with the same electrolyte support. KOH molten salt has large potential to work as electrolyte, with an open circuit voltage (OCV) of 1.0 V, and had linear performance curve between 1.0 V and 0.6 V, which is characteristic of fuel cells with low kinetic overpotentials. The highest performance was got by using porous NiO support in certain porosity range. Longevity of the fuel cell was a little better than the former, but still far from practical application. The result suggested that the capillarity, permeability and compatibility of support material are essential for performance of this type of fuel cell. Besides the problem of electrolyte II retention by the support matrix, unsuitable water management, degradation of the gas diffusion layer and catalyst may also reduce the fuel cell performance. Although this work is at a preliminary stage, it has demonstrated the immense potential of IT-MSFC, and a great deal of additional work will be required to produce a practical fuel cell.

The Solid Oxide Fuel Cell (SOFC) defined by its ceramic and oxide electrolyte, is an electrochemical energy conversion device that produces electricity directly from the chemical reaction of fuel. Nowadays, apatite type rare earths silicates and germaniums attract many interests as the solid electrolyte due to the superior transport properties with high ionic conductivity and low activation energy. They can operate stably at intermediate temperature over a wide oxygen partial pressure range and maintain excellent performances, being considered as a candidate for IT-SOFC electrolytes. Among this series of conductors, the La-Si-O type has a higher conductivity and the performance would be modified by different doping elements.The objective of this thesis is to study the effects of element substitution/doping and synthesis methods on the structural and conductivity properties of apatite type lanthanum silicates. In this study, we use a double approach: a simulation approach and an experimental approach to optimize the electrolyte materials purity and performance.Using simulation approach, a first principle calculation based on DFT (Density Functional Theory) was carried out to investigate the effect on doping positions: Sr dopant at La position and Ge dopant at Si position. The calculation results give a connection to the ionic conductivity obtained by experiments.With experimental approach, we present the synthesis and characterization of Sr-doped La10Si6O27 (LSO) prepared through an optimized water-based sol-gel process. The results show that the ionic conductivity is thermally activated and values lies between 4.5×10-2 and 1×10-6 Scm-1 at 873 K as a function of the composition and powder preparation conditions.

One of the major trends of development of solid oxide fuel cells is to reduce the operating temperature from the high temperature range (>950ʻC) and intermediate temperature range (750-850ʻC) to the low temperature range (450-650ʻC). Development of low temperature oxygen ion conducting electrolytes is focused on single-phase materials including Bi2O3 and CeO2-based oxides. These materials have high ion conductivity at the low temperature range, but they are unstable in reducing environments and they are also electronic conductors. In the present research, three types of multiphase materials, Ce0.887Y0.113O1.9435 (CYO)-ZrO2, CYO- yttria-stabilized zirconia (YSZ), and CuO-CYO were investigated. We found that the conductivity of multiphase electrolyte CuO-CYO with a mass ratio of 1:3 is at least 4 times greater than that of CYO and 10 times greater than that of YSZ, the most commonly used material, obtained in the present experiments at 600ʻC. The enhancement of conductivity in multiphase materials correlates with the level of mismatch between the two phases. Large mismatches in terms of valance and structure result in high vacancy density and hence high oxygen ion conductivity at grain boundaries. This study demonstrates that synthesis of multiphase ceramic materials is a feasible new avenue for development of oxygen ion electrolyte material for low temperature SOFCs.

Hydrogen, Batteries and Fuel Cells provides the science necessary to understand these important areas, considering theory and practice, practical problem-solving, descriptions of bottlenecks, and future energy system applications. The title covers hydrogen as an energy carrier, including its production and storage; the application and analysis of electrochemical devices, such as batteries, fuel cells and electrolyzers; and the modeling and thermal management of momentum, heat, mass and charge transport phenomena. This book offers fundamental and integrated coverage on these topics that is critical to the development of future energy systems. - Combines coverage of hydrogen, batteries and fuel cells in the context of future energy systems - Provides the fundamental science needed to understand future energy systems in theory and practice - Gives examples of problems and solutions in the use of hydrogen, batteries and fuel cells - Considers basic issues in understanding hydrogen and electrochemical devices - Describes methods for modeling and thermal management in future energy systems

Advances in Energy Equipment Science and Engineering contains selected papers from the 2015 International Conference on Energy Equipment Science and Engineering (ICEESE 2015, Guangzhou, China, 30-31 May 2015). The topics covered include:- Advanced design technology- Energy and chemical engineering- Energy and environmental engineering- Energy scien

The world's ever-growing demand for power has created an urgent need for new efficient and sustainable sources of energy and electricity. Today's consumers of portable electronics also demand devices that not only deliver more power but are also environmentally friendly. Fuel cells are an important alternative energy source, with promise in military, commercial and industrial applications, for example power vehicles and portable devices. A fuel cell is an electrochemical device that directly converts the chemical energy of a fuel into electrical energy. Fuel cells represent the most efficient energy conversion technologies to-date and are an integral part in the new and renewable energy chain (e.g., solar, wind and hydropower). Fuel cells can be classified as either high-temperature or lowtemperature, depending on their operating temperature, and have different materials requirements. This book is dedicated to the study of high temperature fuel cells. In hightemperature fuel cells, the electrolyte materials are ceramic or molten carbonate, while the electrode materials are ceramic or metal (but not precious metal). High operation temperature fuel cells allow internal reforming, promote rapid kinetics with non-precious materials and offer high flexibilities in fuel choice, and are potential and viable candidate to moderate the fast increase in power requirements and to minimize the impact of the increased power consumption on the environment. 'Materials for High Temperature Fuel Cells' is part of the series on Materials for Sustainable Energy and Development edited by Prof. Max Q. Lu. The series covers advances in materials science and innovation for renewable energy, clean use of fossil energy, and greenhouse gas mitigation and associated environmental technologies.