Alkaline batteries are used as power sources in most of our everyday devices. In these batteries, electric current is created by electrochemical reactions.
The two main components of a battery are the anode and the cathode. Electrons are released by the anode; they enter the circuit and migrate to the cathode. Meanwhile, they power whatever device is connected to the circuit. The anode contains powdered zinc and potassium hydroxide. Zinc atoms and hydroxide ions form zinc oxide, while water and electrons are released. These are transferred to the negative pole by an electrical conductor. The electrons pass through the circuit and enter the cathode through the positive pole. In the cathode, the electrons, manganese dioxide and water form manganese(III) oxide and hydroxide ions. The reaction is repeated continuously as long as the circuit is closed or until the battery is empty.