With the popularity of lithium-ion batteries, they're so common and some of the most energetic rechargeable batteries available.
If you have been reading news lately, you will notice that these batteries have the ability to burst into flames occasionally. It's not very common -- just two or three battery packs per million have that type of problem -- but when it happens, it's extreme. In some situations, the failure rate can rise, and it ends up with a worldwide product recall that can cost millions of dollars.
So, what makes lithium-ion batteries so popular? How do they burst into flame? And is there any solution to prevent the problem?
Lithium-ion batteries are popular because they have an important number of advantages:
· Lithium-ion batteries are lighter and their electrodes are made of lightweight lithium and carbon. With their capability of energy storage, it also comes with a very high energy density. For example, a typical lithium-ion battery can store 150 watt-hours of electricity in 1 kilogram of battery. A NiMH (nickel-metal hydride) battery pack can store perhaps 100 watt-hours per kilogram, although 60 to 70 watt-hours might be more typical. A lead-acid battery can store only 25 watt-hours per kilogram. Using lead-acid technology, it takes 6 kilograms to store the same amount of energy that a 1 kilogram lithium-ion battery can handle. That's a huge difference
· A lithium-ion battery pack loses only about 5 percent of its charge per month
· They have no memory effect, which means that you do not have to completely discharge them before recharging, as with some other battery chemistries.
· Lithium-ion batteries can handle hundreds of charge/discharge cycles.
That is not to say that lithium-ion batteries are flawless. They have a few disadvantages as well:
· They are extremely sensitive to high temperatures. Heat causes lithium-ion battery packs to degrade much faster than they normally would.
· A lithium-ion battery pack must have an on-board computer to manage the battery.
· There is a small chance that, if a lithium-ion battery pack fails, it will burst into flame.
Many of these characteristics can be understood by looking at the chemistry inside a lithium-ion cell.