Book excerpt: Electrochemistry is the branch of chemistry that deals with the chemical action of electricity and the production of electricity by chemical reactions. In a world short of energy sources yet long on energy use, electrochemistry is a critical component of the mix necessary to keep the world economies growing. Electrochemistry is involved with such important applications as batteries, fuel cells, corrosion studies, hydrogen energy conversion, bioelectricity. Research on electrolytes, cells, and electrodes is within the scope of this old but extremely dynamic field.