An electrochemical cell is a device that can produce an electrical current from a chemical reaction and/or use electrical energy to produce a chemical reaction. When an electrochemical cell produces electricity, it is referred to as a voltaic or galvanic cell. When an electromechanical cell produces a chemical reaction, it is referred to as an electrolytic cell.
Electrochemical cells consist of two main types in consumer devices: primary and secondary cells. In a primary cell, current is produced by way of a one way chemical reaction where one metal is oxidized through an acidic or alkaline reaction. Primary cells are used in single-use alkaline batteries. In secondary cells, the chemical reaction is reversible by applying an electrical current. The practical effect of this reversal is a rechargeable cell. Secondary cells are commonly seen in devices that use rechargeable batteries and include lithium ion, nickel metal hydride and nickel cadmium batteries.
Electrochemical cells may be joined in series to provide extra battery life or in parallel in order to provide more electrical current. Electrochemical cell-based batteries generally use harsh chemicals that require hazardous waste disposal. Therefore, it is important to consider batteries when disposing of consumer electronics.