Lithium-ion batteries are basically what power the world right now. Everything that has a battery right now, you can bet your bottom dollar it’s got lithium in it. Peel away the stickers and the first two words that’ll greet you are Li-ion. So, with millions upon millions of them in circulation, there are bound to be some problems,

like we saw with the Samsung Galaxy Note 7 battery fiasco (there were memes about terrorists substituting their usual arsenal of TNT with the mobile device). With all that banter, today we’ll look into it: why do lithium-ion batteries swell? And is a lithium battery dangerous? Let’s get right into it.

How Does a Lithium-ion Batteries Work?

Lithium-ion, or Li-ion batteries are rechargeable batteries which utilize the free electrons (from the reaction of positive charge lithium towards a negative charge). This makes it one of the most energy efficient rechargeable batteries on the planet, much more efficient than their lithium-based cousins.

However, along with the efficiency quotient, there is also the risk of them catching on fire, smoking out, or swelling, which does not present an immediate danger, but needs to be disposed of or rectified immediately. We’ll discuss why do lithium-ion batteries swell, and whether Li-ion batteries are dangerous when in said condition.

Sets Lithium Batteries Apart?

But first, lets take a look at how batteries usually function. Every battery in the world (with wide usage) uses two metal plates dipped in an electrolyte. These two plates act as electrodes, and the flow of electrons between these two is what provides the battery with the power it provides for various applications. Lithium-ion batteries function in a similar way;

except that it uses Lithium as electrodes and the flow of electrons from the positive cations (cathodes) to the negatively charged anodes (anions) is what makes the battery rechargeable, all the while able to hold its charge for extended periods. This is what sets Li-ion batteries apart from the normal batteries (lead-acid) that are used for vehicular and power generation applications.

Is a Lithium-ion Battery Dangerous?

Under normal use circumstances, lithium-ion batteries are usually pretty safe. There is a degree of certain danger when handling power generation equipment; obviously, it is basically a small bomb (technically, yes, it is). If we look at the recent battery debacle of the notorious Galaxy Note 7, it was the Li-ion battery that made it a potential threat, getting banned from being carried on flights worldwide.

And all of this while the device was either being charged, or had just gotten off the charger, with Samsung blaming the manufacturing process of the batteries, which in turn were sourced from a third-party. Like we said before, Li-ion batteries are usually pretty safe in normal operational conditions, but there is always a degree of danger when using a manufactured product that generates power.

Also Read: Is Alcohol a Solution? Or is Alcohol a Compound?

So Why Do Li-ion Batteries Swell?

A quick search reveals the most common cause; as it is a chemical reaction that powers the battery, it is the same chemical reaction that causes it to swell. We know that Li-ion batteries use the chemical reactions to generate electrons, whose flow from one electrode to another is what essentially powers up your device.

The battery is designed so that the chemical reaction can be sustained for a substantial amount of time; sometimes exceeding five or six years. But eventually, as depreciation goes, the battery gets to the point where the chemical reaction cannot be performed properly, which results in gaseous discharges emanating from the reaction. This gas gets trapped within the battery, giving the impression that the battery has swollen. 

Common Causes of Battery Swelling

But this is just one of the few reasons that a Li-ion battery might swell up. Gaseous expulsion is just one of the most common ones; and is usually only seen in batteries well past their expectancy. However, manufacturing defects (as seen in the Note 7’s case) could case this swelling to go off prematurely, and so, a word of caution for anybody who finds their phone’s battery like this. 

Furthermore, many other factors play in this process. For instance, exposing Li-ion batteries to high temperatures can result in them either discharging in an instant, or some might overheat to the point of their efficacy getting seriously affected. Similarly, if you overcharge your phone constantly, this will also result in an accelerated wear and tear of the battery, and if it has been improperly manufactured, it could short-circuit or smoke out,

which is actually worse than it swelling up. And lastly, physical damage could also affect the electrodes; they could either be forced together, causing it to rapidly overheat and in extreme cases, could explode on impact. So, while there is a myriad of reasons as to why it would happen, it ends the same almost every time; you end up discarding the battery, which is the right thing to do in these scenarios. 

Can a Swollen Li-ion Battery Explode?

It is uncommon for a swollen battery to explode, because after a swollen battery has been disposed of, it is usually handled with care and dismantled before it can cause any damage. In case of faulty batteries swelling up, they either usually start smoking or catch on fire; explosions as in a violent release of energy with a sudden bang are uncommon but not impossible.  Again, the battery in case would be the faulty unit supplied for the ill-fated Note 7.

Initially, while it was just overheating, later reports came in about phones or batteries getting alight after overcharging; one or two battery explosions were also reported, but never confirmed. Which is why we cannot say with confidence that a swollen Li-ion battery will never explode, but it is probably better for everyone that a battery that is obviously disfigured and cannot be salvaged must be disposed of immediately, in a safe manner compliant with local disposal rules and regulations of such hazardous personal use materials. 

Points to Keep in Mind W.R.T a Swollen Battery

Batteries are basically mini-power generates and even if you have robots and advanced chemical engineering and materials engineering degrees at hand, you cannot repair a battery. Even manufacturers don’t mess around with damaged or faulty batteries; again, look at what happened with Note 7. Samsung could’ve easily revised or replaced the battery, but they decided to forego the entire model along with the battery supplier rather than try to fix it. A Li-ion battery, once swollen, cannot be fixed and must be disposed of in compliance with local regulations on e-waste.

A swollen lithium-ion battery is never good news and it must be treated as such. As soon as you feel something wrong with the battery, try to inspect the device. For removable batteries, you can simply check the battery physically; if it feels bloated, you need to take it out, place it in a fireproof bag and dispose of it off. For non-removable batteries, considering the large majority of phones that use them now, inspect the device or phone.

To Conclude,

If the hardware feels loose, buttons are tight and seams not joined anymore, this could be a sign of a battery swell. Turn off your phone, place it in a fireproof bag and take it to your nearest phone repair expert. Many retailers have a refund policy in force, so all might not be lost.


Here are the answers to some of the most frequently asked questions related to Lithium-ion Batteries

  1. Can You Fix a Swollen Lithium-ion Battery?

    Many people seek to fix a swollen battery. The first rule with batteries is; if its broke, don’t fix it.

  2. Is it Safe to Use a Swollen Lithium Battery?

     It is not fine, in any situation, to keep on using a device with a swollen battery; even if it does not explode, the gases and smoke it emanates are toxic and hazardous and must not be inhaled. Many people try to keep the battery or phone running or in use even when there are visible signs of the battery swelling up. Mind you, with non-removable batteries, while you might not be able to remove the battery, you can still place the phone in a fire-resistant packaging and let the battery drain out, as it reduces the risk of the battery catching fire.

  3. What Do I Do if My Lithium Battery is Puffed Up?

    Whenever you notice a swollen battery, you should immediately shut off your phone or computer. Turn it off and don't charge it. In any case, connecting it to the power might be dangerous. Taking your device to a professional would be best.