Britannica Sources used in this answer

How do anodes and cathodes work inside a battery?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Cross-section diagram of an alkaline-manganese dioxide battery showing labeled internal components, including the steel-plated covers, cathode, anode gel, current collector, separator, steel can, and brass rivet. — battery Cutaway view of an alkaline–manganese dioxide power cell.

Inside a battery, the anode and cathode act as the two electrodes that facilitate the conversion of chemical energy into electrical energy through electrochemical reactions.12

The Anode

The anode is the negative terminal of a battery. It is typically composed of a metal that undergoes an oxidation process, meaning it gives up electrons. When the battery is in use, these electrons travel from the anode through an external circuit to power a device.31

The Cathode

The cathode is the positive terminal of a battery. It generally consists of a metal oxide or sulfide that accepts electrons returning from the external circuit. This process is known as reduction.41

Internal Operation

To maintain the flow of electricity, the interior of the battery contains an electrolyte. While electrons move through the external circuit, ions move through the electrolyte inside the cell to balance the charge.12

Discharge: When the battery powers a device, electrons flow from the anode to the cathode, and chemical potential energy is converted into electricity.2
Recharge: In rechargeable batteries, this process is reversed; electrons move from the cathode to the anode, restoring the battery's chemical potential energy.2