We talk about battery health , tips & tricks to improve battery health and all kinds of stuff over the internet but we don’t really talk about the technology behind lithium ion batteries and how do they work.
It’s worth wondering that in a solid compact device like a smart phone there is a volcano of chemical reactions happening continuously well hidden inside your smartphone. These chemical reactions actually provide the juice for your smart phone to run & execute task. Once this juice stops flowing your phone is basically a dead piece of antique which we all have experienced with our phones.
How does your battery power your smartphone ?
Let’s start with what we know….
All batteries have a positive terminal & a negative terminal and supply power or electricity to our portable devices. Electricity is essentially a flow of electrons through our smart phones and depending on their charge they flow either from negative terminal or from the positive terminal. The negatively charged electrons flow from negative terminal and run things like the speakers and the display and end up in the negative terminal.
Where does this flow of electrons come from ?
As the name suggests the electrons come from the element lithium. At the negative terminal which is technically called the Anode, lithium is stored in layers of carbon graphite similar to the graphite in your pencils.Graphite has a crystal structure of layered planes that allows the lithium to be stored between each of the layers. This process is called intercalation.
The lithium element has this property of giving up the farthest electron from its nucleus. So when there is an available path form the negative terminal to the positive terminal this electron separates from the lithium and starts heading to the other side. At this time when the lithium leaves the graphite it becomes positively charged and is now called lithium ion. When a lot of lithium ion leaves the graphite at the same time a flow of electrons gets built up.
Now the positive terminal which is technically called the cathode has cobalt which has lost some electron to oxygen thus making the cobalt positive, as a result it wants to gain back an electron. So when we connect the negative and positive terminals to a smartphone the electrons flow from the lithium which wants to give up an electron through the circuits and components of a smartphone to cobalt which wants to gain an electron. Thus this way at the end of the day almost all of the lithium has left the graphite layer and to join the cobalt to become lithium cobalt oxide and your battery is now basically empty.
What does a smartphone charger do ?
A charger for a phone reverses this whole process thereby forcing the lithium to move back into the layers of graphite. This is why lithium ion batteries are rechargeable.
Why does your battery final capacity reduce over time ?
- One of the reason is when lithium and the incoming electron react with the electrolyte and organic solvent to form compounds that are called solid electrolyte interphase or SEI.
- SEI irreversibly consume the lithium into the electrolyte thus reducing the over all quantity of lithium and thereby reducing the max capacity of your battery.
- Another reason is that when you fully discharge your battery it can result in too much lithium on the cobalt side, which causes the irreversible generation of lithium oxide and cobalt 2 oxide . These compounds are stuck in that stage which thereby reduces the amount of lithium and cobalt for free for use.
Guide to proper usage for maximum battery health
1st of all do not let your battery go below 30%. It’s advisable to recharge your battery well before complete drainage.
Explanation : A lithium ion battery is most unstable at 0-10% charge and 90-100% charge as the electrons are not evenly distributed between the cathode and the anode. A 50-60% charge mark is an ideal state of a lithium ion battery as the charge is balanced and provide least degradation. That’s why you must have seen newly purchased phones have a battery around 50% mark so as to reduce battery degradation during the time the smartphone is kept in store shelf till it is purchased by anyone.
Caution: Fast Chargers these days are presented a major USPs for a smartphone and companies around the world promote fast charging as their major selling point. Of course fast charging helps in saving time by reducing charging cycle significantly but what’s the catch in it ??
- Fast charging basically speedup the electron transfer process from between the terminals significantly but due to the speed at which electrons have to flow through the terminal the whole system becomes unstable and it needs a wider and more bulky divider to prevent electron leak.
- Due to quick electron transfer the whole systems generate a lot of heat in the system making it an undesirable condition for any smartphone battery. With time the storage capacity of the battery reduces quickly leading to quick battery drains. This is one of the major reason why wireless charging is not so good for your smartphones as it dissipates more heat.
Don’t make these mistakes while charging your smartphone
- One of the accessories we use with a phone are the smartphone covers. These smartphone covers inhibit heat dissipation from a smartphone resulting in quick heating of the smartphone. Covers are not necessarily bad but the least we can do is remove covers while we are charging our smartphones.
- While charging our smartphone we can use any charger which is compatible for our smartphone but compatibility is an important factor as it determines the voltage and amperes that the charger allows. This helps the battery to charge ideally and in a healthy manner.
- Diminishing return: The smartphone charging goes in a way that when you charge a smartphone from 0-50% it will be faster than from 50-100%. So next time when you charge your phone try charging it to 50-60% and then again charging it again to 50-60% after it discharges. It will be quicker and keeps your battery in better shape.
Lots of tech influencers provide tricks to maintain battery health but there is no such trick to regain the diminished battery capacity but there are few things we can do to create a good desirable environment for our batteries which will enable smartphones to efficiently use battery capacity without unnecessary drain.