An electrode conducts electricity in an electric circuit. It can come in the form of a plate, rod or wire and is made of metals like copper, lead, zinc or silver. Some electrodes, though are made of non-metallic substances like carbon.
Electrodes used in electrochemical cells are either anodes or cathodes, depending on the electrical charge. The anode is the positive electrode, and it is through this that the electrical current passes out of the cell and triggers oxidation. The cathode is the negative electrode, and it is the point where electrical current passes into the cell and triggers reduction.
In electric batteries, though, the reverse happens: the anode carries the negative charge and the cathode carries the positive charge. The amount of voltage can also change the nature of the electrode from anode to cathode. There are also electrodes that act as both; these are called bipolar electrodes.
Care must be taken when handling or charging electrodes, as a mistake can cause the battery to explode. Note if the electrode allows for reactions or flows to be reversed: primary cells can’t be charged, secondary cells can. This is because anode electrodes have a negative charge when a cell is being discharged. Consult the user’s manual of an electrical gadget, or if in doubt,
There are also some electrical devices that use alternating currents. In this situation, electrodes still perform the function of conducting electrity, but the distinction between positive and negative charges are dropped. Instead, the current flows are often switched or reversed.