ABSTRACT
Electrochemistry deals with chemical reactions taking place at the interface of an electrode and the electrolyte, and studies conversions between the electrical energy and chemical changes [1-4]. Electrons involved in these chemical reactions move between the interface and the electrodes. The basic element of each battery is the electrochemical cell, which consists of a positive electrode, a negative electrode, and an electrolyte. The electrode reactions occur at both electrodes, releasing or taking electrons. The electrode half-reactions can be written as follows:
Negative electrode: Sred → Sox + ne− (1.1)
Positive electrode: Sox + ne− → Sred (1.2)
where Sred and Sox indicate the reduced and oxidized states of the chemical reactants and n is the number of electrons involved in the process. The electrons involved in the reaction are collected as a current flow.
