How does a battery work? Easily explained

A battery stores chemical energy and releases electrical energy. But how exactly does it work? We will explain it to you in our practical tip.

Building a battery

For a better understanding of how a battery works, its structure is briefly explained here. The most common type is the so-called alkaline-manganese battery, the structure and function of which we explain to you in this article as an example.

• A battery consists of one or more galvanic cells, i.e. cells that store chemical energy and can release electrical energy.
• The battery is enclosed in a metal shell that functions as a positive pole. At the bottom, the case is open for now.
• At the edge of the battery is manganese, which is the positive electrode, also called the cathode.
• The negative electrode, the anode, is separated from the cathode by a separator, for example made of a paper-like substance. It is made of zinc.
• Both areas, cathode and anode, are soaked in potassium hydroxide solution. It forms an electrolyte that improves the conductivity of the materials.
• There is a metal pin in the zinc mass in the middle of the battery, which makes contact with a metal plate on the underside.
• The metal plate on the underside forms the negative pole and closes off the battery. It is separated from the positive pole and the cathode by an insulator.

Function of a battery

A circuit is created when the battery is inserted into a device. For example, if a light bulb is connected, electrons flow from the negative pole through the filament to the positive pole. But why is this happening?

• Zinc is a metal that the chemist calls base. It tends to donate electrons.
• Manganese, on the other hand, is a noble metal, it takes up electrons.
• If both areas, cathode and anode, are now connected to one another, the zinc soaked in potassium hydroxide releases electrons to the manganese via the conductor.
• The electrons in the zinc mass result from a reaction of the zinc with the potassium hydroxide solution to zinc hydroxide and two electrons.
• The zinc hydroxide then continues to oxidize to zinc oxide and water.
• The battery is empty when all the zinc is oxidized to zinc oxide and water with the potassium hydroxide solution and has released all free electrons.