During the last decade, fuel cells have received enormous attention from research institutions and companies as novel electrical energy conversion systems. In the near future, they will see application in automotive propulsion, distributed power generation, and in low power portable devices (battery replacement). This review gives an introduction into the fundamentals and applications of fuel cells: Firstly, the environmental and social factors promoting fuel cell development are discussed, with an emphasis on the advantages of fuel cells compared to the conventional techniques. Then, the main reactions, which are responsible for the conversion of chemical into electrical energy in fuel cells, are given and the thermodynamic and kinetic fundamentals are stated. The theoretical and real efficiencies of fuel cells are also compared to that of internal combustion engines. Next, the different types of fuel cells and their main components are explained and the related material issues are presented. A section is devoted to fuel generation and storage, which is of paramount importance for the practical aspects of fuel cell use. Finally, attention is given to the integration of the fuel cells into complete systems.

Fuel Cells: Principles, Types, Fuels, and Applications

High temperature solid oxide fuel cell (SOFC) has prospect and potential to generate electricity from fossil fuels with high efficiency and very low greenhouse gas emissions as compared to traditional thermal power plants. In the last 10 years, there has been significant progress in the materials development and stack technologies in SOFC. The objective of this paper is to review the development of anode materials in SOFC from the viewpoint of materials microstructure and performance associated with the fabrication and optimization processes. Latest development and achievement in the Ni/Y2O3-ZrO2 (Ni/YSZ) cermet anodes, alternative and conducting oxide anodes and anode-supported substrate materials are presented. Challenges and research trends based on the fundamental understanding of the materials science and engineering for the anode development for the commercially viable SOFC technologies are discussed.

A review of anode materials development in solid oxide fuel cells

Alternative anode materials for solid oxide fuel cells

SOFC system and technology

A solid oxide fuel cell (10) comprises a solid electrolyte layer (30), a barrier layer (40), and a cathode (50) The cathode (50) includes a cathode current collecting layer (51) and a cathode active layer (52) The cathode active layer (52) includes a plurality of micro-cracks (SL) in an interface region (52a) within a predetermined distance (Da) from the interface (P2) between the cathode current collecting layer (51) and the cathode active layer (52)

Solid-oxide fuel cell

Oxidation mechanism and effective anode thickness of SOFC for dry methane fuel

Power‐generation experiments of solid‐oxide fuel cells with Ni/yttria‐stabilized zirconia cermet anodes were carried out by changing the water‐to‐methane ratio in the fuel. To separate the electrochemical reactions occuring on the three‐phase boundary of the anode from the steam‐reforming reactions, premixed gases corresponding to the composition at thermal equilibrium were used as the fuel. The reactions on the anode were quantitatively clarified at different steam‐to‐methane ratios by making a mass balance of the elements and electrons and by determining the anode exit gas composition. For dry (i.e., no water) methane fuel, the carbon deposited on the three‐phase boundary from the methane mainly reacted with oxide ions . With increasing steam‐carbon (S/C) ratio from S/C = 0.5 to 1, hydrogen became the dominant reactant. The anode potential vs. current density for S/C = 1 agreed with that for hydrogen diluted with argon. At S/C ratios higher than 1.5, CO in the inlet gas reacted with oxide ions. © 1999 The Electrochemical Society. All rights reserved.

Effect of the Steam‐Methane Ratio on Reactions Occurring on Ni/Yttria‐Stabilized Zirconia Cermet Anodes Used in Solid‐Oxide Fuel Cells

Reactions of dry methane on nickel/yittria stabilized zirconia (YSZ)cermet anode in a temperature range from 800°C to 1000°C were investigated for solid oxide fuel cells during power generation. Dry methane decomposed into carbon and hydrogen in the cell. The carbon deposited on/near the boundary of the nickel and YSZ particles reacted with oxide ions to give carbon monoxide under a low current density. On the other hand, when the fresh boundary of the nickel and YSZ was kept under a high current density, methane was converted to carbon dioxide and water without carbon deposition on the boundary. The deterioration of the anode by carbon deposition was not observed for 12 h operation at a current density of 0.13 Acm−2.

Abulet Abudula

Papers

Oxidation mechanism and effective anode thickness of SOFC for dry methane fuel

Effect of the Steam‐Methane Ratio on Reactions Occurring on Ni/Yttria‐Stabilized Zirconia Cermet Anodes Used in Solid‐Oxide Fuel Cells

Direct oxidation of methane on anode of solid oxide fuel cell

Anodic Reaction Mechanism of Solid Oxide Fuel Cell with Water-methane Fuel