Fuel cells: Principles, types, fuels, and applications

During the last decade, fuel cells have received enormous attention from re search institutions and companies as novel electrical energy conversion sys tems. In the near future, they will see application in automotive propulsio n, 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 p romoting fuel cell development are discussed, with an emphasis on the advan tages of fuel cells compared to the conventional techniques. Then, the main reactions, which are responsible for the conversion of chemical into elect rical energy in fuel cells, are given and the thermodynamic and kinetic fun damentals are stated. The theoretical and real efficiencies of fuel cells a re also compared to that of internal combustion engines. Next, the differen t types of fuel cells and their main components are explained and the relat ed material issues are presented. A section is devoted to fuel generation a nd storage, which is of paramount importance for the practical aspects of f uel cell use. Finally, attention is given to the integration of the fuel ce lls into complete systems.