An electrode is a conductor that passes an electrical current from one medium to another, usually from a power source to a device or material. It can take a number of different forms, including a wire, a plate, or a rod, and is most commonly made of metal, such as copper, silver, lead, or zinc, but can also be made of a non-metallic substance that conducts electricity, such as graphite. Electrodes are used in welding, electroplating, batteries, medicine, and in industry for processes involving electrolysis.In the case of a direct (DC) current, electrodes come in pairs, and are known as anodes and cathodes. For a battery, or other DC source, the cathode is defined as the electrode from which the current leaves, and the anode as the point where it returns. |