The Li-Ion batteries have become very popular and today not only our phones but our cars and many other gadgets run on these Li-Ion batteries. Our life is busy indirectly revolving around these batteries and the equipments dependent on it but has this question ever stuck you that how does this battery retain a charge and is rechargeable as well as so efficient? Let’s have a look at the basic functionality and composition of a Li-Ion battery.
The basic model of a lithium battery consists of many small batteries known as cell. Each cell then consists of a cathode and an anode where by the movement of the electron electricity is produced which can then be converted into mechanical energy in the case of a car for instance.
Digging deep into the working of the Li-Ion battery let’s start off with the composition of the battery. The conductive element used is Aluminum on one side and copper on the other side. Like any other battery Li-Ion battery also has a cathode and an anode. Let’s have a look at the composition of both the electrodes. Cathode which is the positive part is made up of pure lithium oxide. The more pure the lithium is the more efficient the battery will be in holding the charge. Negative part that is the anode is made up of graphite which is a form of carbon with layered structure. For the electron to flow freely it also need a transport medium known as the electrolyte and it should be very pure and free of water as much as possible. The next thing to come into picture is the separator which is there to prevent any kind of short circuit, it is permeable for Li and this property is known as microporocity.
When a battery is charged the positively charged lithium ion passes from the cathode through the separator into layered graphite structure and thus the battery is charged. When discharged the Lithium ion moves from the anode through the permeable separator back to the cathode.
This cycle of charging and discharging keeps going on depending on the usage of the battery. By this movement the anode forms a Solid Electrolyte Interface on itself and a similar interface is also formed on the cathode. The restrictive layer formed on the cathode is known as the electrolyte oxidation. The more the battery gets older i.e the more cycles of charging it does the thicker is the coats formed on the cathode and the anode and eventually resulting in no conducting effect and now the Lithium cannot interact with the graphite present on the anode and hence the battery dies out.
Don’t forget to check out our related blog written on – How to make your Li-Ion battery last longer. So that you can take care of the battery you have and procrastinate buying a new one for some time!!!