How a battery works?

A battery has two terminals (a positive (+) terminal and a negative (-) terminal).
Inside a battery is a solution called electrolyte.

An electrolyte is a solution that conducts electricity. It is a solution that contains free ions.
Because of that, sometimes an electrolyte is also called an ionic solution.
Examples of electrolyte are acids, bases and salts in solution.

See below to understand how a battery works

See Figure 1:


Chemical formula for salt is NaCl. When salt dissolves in water, it produces free ions.
Positive ions are Na+ and negative ions are Cl-.

Negative ions (Cl-) are attracted to positive electrode called anode and positive ions (Na+) are attracted to negative electrode called cathode.

At the positive electrode, negative ions give up electrons that flow through the bulb and light it up and then return to the negative electrode.

At the negative electrode, positive ions take electrons.
This results in a continuous flow of electrons in the circuit and a continuous flow of ions in the electrolyte solution.
The continuous flow of electrons and ions produces electricity and electricity only occurs when there is a complete circuit or path.

The same process happens inside a battery in Figure 2.

At the positive electrode, negative ions give up electrons that flow through the bulb and light it up and then return to the positive terminal of battery.

At the negative electrode, positive ions take electrons.
This results in a continuous flow of electrons in the circuit and a continuous flow of ions in the electrolyte solution.

Electrons come out of the negative terminal (-) of a battery and flow around the circuit and re-enter the positive terminal (+) of a battery.

The continuous flow of electrons and ions produces electricity and electricity only occurs when there is a complete circuit or path.