Smartphone batteries(Li-ion) explosion:Causes & tips to prevent it

Recently when the Samsung Galaxy Note 7 caught fire in mid- air of Jet airways,Samsung officially recalled all of its Note 7 model world wide.This was not the end of Samsung woes as another model of Samsung called Grand duos caught fire in a man's shirt pocket causing hazard to his life.But this is not the case with Samsung only as may other smartphones from global manufacturers have also caught fire in the past and well this might not be the end too.On verification of these incidents it has been found that the major of these cellphone explosion was due to Li-ion.

Image:Texas man received third degree burns when his mobile battery exploded

In this post we will talk about the Li-ion batteries explosion and the ways of preventing it.

What is a Li-ion battery?

A Li-ion battery is a rechargeable battery which is used in most of the gadgets such as laptops, smartphones,toys etc where the cathode of battery is made of a Li-compound like lithium cobalt oxide etc and the anode is made of graphite or carbon.The electrolyte used in the battery is also made from an alkaline lithium salt. In this lithium ions move from negative electrode to positive electrode during discharge and positive to negative during charge. The batteries are not made up of a solid block as one but as continuous strips put firmly one over another. Each of the strip is insulated from one another by a thin insulating sheet. After connecting all the terminals they are packed as one which we get commercially.

Image:Structure of Li-ion battery

Why only a Li-ion battery?

From the earlier days since the cell was developed,it has gone through major technology changes.Earlier we had those heavy lead sulfate acid batteries which was quite heavy and most dangerous.So it was not useful for devices which were portable and small. This led to the development of Li-ion batteries. The advantages of these batteries were:

High energy density:Li-ion batteries can store more electrical energy per inch of its surface as compared to other batteries.It can store up to six times more charge than Ni-Cd battery.

Self discharge: Li-ion batteries have a very less self discharge when battery is kept idle or not put to work.So no need of periodic discharge and charge.

Variety of shapes: Li-ion batteries can be put to different shapes and sizes without affecting its energy density.

Portable and light weight:Li-ion batteries have less weight and hence portable.

Why do Li-ion batteries explode?

Lithium having advantages has some disadvantage too. Lithium is a highly reactive alkali metal and can cause an exothermic reaction in case of short circuit between electrodes or when exposed to more heat.The main reason for the battery explosion is due to the fact of thermal runaway. Thermal runaway is due to the fact of lithium cobalt cathodes reacting with the combustible lithium electrolyte releases oxygen which when reacting with the carbon anodes releases carbon dioxide which are effervescent and this reaction is exothermic(leading to a lot of heat release). It has also been found out that battery explosion causes release of hydrogen releasing a temperature as high as 800 degree Celsius. (You can check this by puncturing your cellphone battery with any sharp edged tool).

Image:Explosion of a Vivo V5 model smartphone.

Cause of thermal runaway:

major cause of thermal runaway includes;

1)Overcharging of the battery

2)Overheating

3)physical damage

4)manufacturing defects leading to electrical short.

Steps to avoid an exploding cellphone battery:

1)Don't overcharge your battery: don't keep your battery on charging for long as it may help the battery to accumulate more heat leading to a thermal runaway.

2)Try to keep your cellphone and its charger compatible. if your battery or your charger dies then replace it with a compatible one. Going for a cheap battery or charger may risk your battery to explosion.

3)Prevent your phone from getting any physical shocks such as dropping.

4)Avoiding manufacturing defect can be done by purchasing your cellphone from a reputed and trusted brand which has good credibility and follows all the safety standards.

5)Don't use your cellphone while charging.

Li-ion may be a very efficient solution when it come to charge storage but the battery manufactures has to go a long way to find out a way that this efficient source of charge storage doesn't becomes hazardous to people's life.One better solution can be a smart battery which would be talked about in a later post

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