Batteries store a large amount of energy in small packages. They come in a variety of sizes and help us generate electricity when needed, especially in power outages. Batteries are useful in our everyday lives and power a variety of things most people feel they could not do without, including computers, watches, flashlights, toys, electronics and cars. Some even help save lives by powering pacemakers inside people's chests. But how does a battery work? What components does it have that allow it to generate electricity to power so many different things? Here is a look at the different parts of a battery and how they work together to create electricity.
All batteries contain at least one cell, which is the working chemical unit. There are three main parts of a cell: a positive electrode, a negative electrode and an electrolyte that separates the two. The electrolyte usually consists of a dry powder, although it can also be in liquid form. The battery's positive terminal connects to a positive electrode, called a cathode. The bottom of the battery includes the negative terminal, or negative electrode, also called the anode.
Connecting the battery to a circuit causes several simultaneous chemical reactions, or buildups of electrons (negative electrical charges), in the electrolyte. These buildups are unstable and cause electrons to repel each other. Electrons try to go to the cathode, but the electrolyte prevents this from happening. The only way electrons can get to the cathode is if the circuit is closed (a wire connects the anode and cathode). When electrons go through the wire, this movement creates electricity. However, these processes eventually change the chemicals in the battery parts, causing a decrease in electrons and battery power. Recharging a battery changes the flow of electrons. The processes run in reverse and supply the battery with full power again.