Question

How is battery formed? What is the difference between a cell and a battery?

Answer 1

A battery is a device that is able to store electrical energy in the form of chemical energy and convert that energy into electricity. There are three main components of a battery: two terminals made of different chemicals (typically metals), the anode and the cathode; and the electrolyte, which separates these terminals. The electrolyte is a chemical medium that allows the flow of electrical charge between the cathode and anode. When a device is connected to a battery — a light bulb or an electric circuit — chemical reactions occur on the electrodes that create a flow of electrical energy to the device. During a discharge of electricity, the chemical on the anode releases electrons to the negative terminal and ions in the electrolyte through an oxidation reaction. Meanwhile, at the positive terminal, the cathode accepts electrons, completing the circuit for the flow of electrons. The electrolyte is there to put the different chemicals of the anode and cathode into contact with one another, in a way that the chemical potential can equilibrate from one terminal to the other, converting stored chemical energy into useful electrical energy. The ions transport current through the electrolyte while the electrons flow in the external circuit, and that’s what generates an electric current.


A cell is a single electrolyte and anode/cathode chemical reaction cell. It has a characteristic voltage which is set by the chemistry. A battery is generally a stack of series-connected cells, although typically a single-celled battery is also called a battery.