Introduction

Abstract

Since the beginning of research into fuel cells the key focus was on achieving efficient conversion of chemical energy into electricity. Progress was made both in the cell structure itself and in selection of appropriate materials for electrolytes. The first device allowing the direct conversion of chemical energy into electricity was called a voltaic gas battery, and its electrolyte was composed of an aqueous acid solution. There were also attempts to use coal as a fuel for fuel cells, and it was tested in different types of cells: alkaline, carbonate and oxide. Fuel cells are ideal devices, directly converting a delivered fuel into electricity through electrochemical processes. From the many types of fuel cells, two—Solid Oxide Fuel Cells (SOFCs) and Molten Carbonate Fuel Cells (MCFC) are high temperature types and allow the use of hydrocarbon fuels instead of hydrogen. SOFCs are the most efficient devices invented to date for converting chemical energy directly into electricity. Significant progress is still being made in both theory and experimental practice, even though it is now over 100 years since the original ideas and materials were proposed by Nernst and his colleagues. It seems unbelievable that this process has not yet been commercialized to replace the inefficient and polluting internal combustion heat engines which currently dominate our civilization.