Anode

In an electrochemical system, Electrochemical System the anode is the electrode Electrode at which oxidation Oxidation is occurring.

 

The terms anode and cathode Cathode are most frequently used in two-electrode systems, Two-Electrode System such as fuel cells Fuel Cell and batteries. Battery They are less commonly used in typical three-electrode systems. Three-Electrode System

 

In the context of fuel cells and batteries, the anode is also sometimes called the negative electrode, and may be denoted with a minus sign.  In the context of secondary (rechargeable) batteries where both the anode and cathode may alternatively undergo both oxidation and reduction Reduction (depending on whether the battery is being charged or discharged), the anode is defined as the electrode experiencing oxidation during discharge.