Electrode: definition in chemistry
Electrode: A conductor through which electric current enters or leaves an electrolyte, as in a battery or an electrolysis cell.
Every cell has two electrodes: oxidation happens at the anode and reduction at the cathode. In a battery the anode is the negative electrode, while in electrolysis the anode is positive, but oxidation still happens there. Electrodes are often made of metals or graphite, and inert electrodes such as platinum carry current without reacting themselves.
Examples
- Zinc and copper electrodes in a Daniell cell
- The carbon rod in a zinc–carbon battery
- A lithium cobalt oxide cathode in a lithium-ion battery
- Platinum electrodes used to split water into hydrogen and oxygen
On the periodic table
Lithium, at the top of group 1, is ideal for battery electrodes because it is the lightest metal and gives up electrons very easily.