We all use them, they are in your phone, tablet or laptop Lithium-ion
batteries are the most common power source for them all.However there is a potential deadly risk in
expensive and more energy dense than other battery technologies the lithium-ion has become the rechargeable
battery of today. It powers everything from mobile phones and laptops to cars
and commercial jets. But there is one little problem—these batteries don't just
short circuit, they explode into flames. Here's what goes on inside a lithium
cell before it goes boom.
battery's explosive tendencies are the result of a process known as thermal
runaway. It's essentially an energetic positive feedback loop whereby
increasing temperature causes the system to get hotter, which increases the
temperature, which causes the system to get even hotter, and so on. Thermal
runaway is surprisingly common and can be found in a wide array of physical and
chemical processes, from curing concrete (which releases heat) to exploding
stars (supernovae are the result of TR on a cosmic scale).
batteries can suffer thermal runaway for a variety of reasons. Much like
bridging a 9V battery's terminals with a coin, short circuits caused by a tear
in the membrane that separates the negative and positive poles of a Li-ion
battery will often cause a thermal meltdown. Ambient temperatures exceeding 60
degrees C, repeated overcharging, or unauthorized modifications to the case
have all also been reported as the source of battery fires.
the reason, when conditions are right, it's the battery's cobalt oxide
chemistry that actually undergoes the reaction. "When you heat this
material up it can reach an onset temperature that begins to self-heat and
progresses into fire and explosion. It may also burn openly if exposed to high
temperatures or a spark.
uncontrollable reaction doesn't happen particularly often, the sheer number of
Li-ion cells in the world today amplifies the perceived effect. In 2006, for
example, high-profile recalls came from virtually every major laptop
manufacturer—Apple, HP, Toshiba, Lenovo, Dell, and others—after a small number
of batteries overheated. Apple alone yanked 1.8 million iBook and PowerBook
battery packs from market after just nine reports of overheating according to
There is no
need to fear your laptop as a ticking time bomb, however. With a bit of regular
maintenance, Li-ion batteries will perform safely and reliably throughout their
operational service lives. Li-ions are powerful but short lived, lasting two to
three years at most (whether or not you use it or leave it on a shelf). As
such, all Li-ion packs should be replaced every 36 months or so to avoid
pushing a worn cell too hard. Also, these batteries should be recharged once
their capacity hits 50 percent. Li-ions don't suffer from memory effects but
are severely damaged if the voltage drops too low.