electrochemistry

thumb|English chemist John Frederic Daniell|John Daniell (left) and physicist [[Michael Faraday (right), both credited as founders of electrochemistry]] Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change. These reactions involve electrons moving via an electronically conducting phase (typically an external electric circuit, but not necessarily, as in electroless plating) between electrodes separated by an ionically conducting and electronically insulating electrolyte (or ionic species in a solution).

When a chemical reaction is driven by an electrical potential difference, as in electrolysis, or if a potential difference results from a chemical reaction as in an electric battery or fuel cell, it is called an electrochemical reaction. In electrochemical reactions, unlike in other chemical reactions, electrons are not transferred directly between atoms, ions, or molecules, but via the aforementioned electric circuit. This phenomenon is what distinguishes an electrochemical reaction from a conventional chemical reaction.