We know that rechargeable batteries will not last indefinitely, but they are definitely better options than disposable batteries and they do help in saving our planet as well. Let us find out how these rechargeable batteries work...
Everyday Chemistry - How do rechargeable batteries work?
A rechargeable battery is a battery that can be recharged and used many times. It is also known as a 'storage battery' as it has the ability to accumulate and store energy. A rechargeable battery is also known as a 'secondary cell'. Gone are the days when we had to buy new batteries every time it stopped working. Any photographer will agree that rechargeable batteries are definitely a better and cheaper option than disposable batteries. Not to mention how they help save our planet!
Let's find out how rechargeable batteries work.
The function of rechargeable batteries
Batteries have two electrodes; an anode, which is the negative end and a cathode, which is the positive end. Together, the anode and the cathode are called the electrodes.
Every battery is made of chemicals and metals such as nickel, mercury and lead acid. In between the battery's two electrodes, an electrical current runs which is primarily caused from a voltage difference between the anode and cathode. The voltage runs through a chemical known as 'electrolyte', which is in either liquid or solid state. A battery with two electrodes is called a voltaic cell.
Today, batteries are made up of plates with the help of reactive chemicals that are separated by barriers. These barriers are polarized so that all the electrons gather on one side. The side where they gather becomes negatively charged and the other side becomes positively charged. When we connect a device, it creates a current and the electrons flow through the device to the positive side. At the same time, an electrochemical reaction takes place inside the batteries, which cause the electrons to replenish. The result is a chemical process that creates electrical energy.
In a non-rechargeable battery, these changes are irreversible. A rechargeable battery, however, can efficiently reverse the chemical changes that occur during the discharge process. In this manner, it is restored to full charge and is fit for use repeatedly.
The ability for reverse reaction, however, is not the sole characteristic of a rechargeable battery. It must also be able to undergo the reverse reaction both efficiently and safely multiple times. Some batteries can be recharged but because the chemical reactions are not completely reversed, they are only able to undergo the recharging process a few times and their performance is less efficient each time. Additionally, dangerous gases may build up and can lead to explosions or ignition either during or after recharging.
Earlier, it was difficult to find rechargeable batteries of various sizes. But that is not the case anymore. Battery capacities are also increasing, self-discharge rates are getting longer, recharging times are getting shorter, and prices coming down. All of this contributes towards making our lives easier and protects our planet from harmful chemicals and metals found in batteries.