Electrode
A conductor through which electric current enters or leaves an electrolyte.
Unit
Dimensionless
In depth
Electrodes may be active, taking part in the reaction as zinc does in a Daniell cell, or inert, merely providing a surface for electron transfer as platinum and graphite do. Their surface area and catalytic properties strongly affect the current a cell can deliver.
Examples in the real world
A zinc rod in a battery; graphite rods in an aluminium smelting pot; a platinum wire in a hydrogen electrode.