atomic number 3 - ion batteries are fabulously popular these days . you may retrieve them inlaptops , organizer , cubicle phonesandiPods . They ’re so uncouth because , pound for lb , they ’re some of the most energetic rechargeable batteries available .
Lithium - ion batteries have also been in the news lately . That ’s because these battery have the ability to burst into flame occasionally . It ’s not very common — just two or three battery ring per million have a job — but when it happens , it ’s uttermost . In some billet , the bankruptcy rate can rise , and when that happens you terminate up with a worldwidebattery recallthat can be manufacturers millions of buck .
So the interrogation is , what make water these batteries so industrious and so democratic ? How do they collapse into fire ? And is there anything you could do to keep the trouble or help your batteries last longer ? In this clause , we ’ll answer these questions and more .
Lithium - ion bombardment are democratic because they have a number of important advantages over competing technologies :
That is not to say that lithium - ion stamp battery are unflawed . They have a few disadvantages as well :
Many of these equipment characteristic can be understood by seem at the chemistry inside a lithium - ion cell . We ’ll look at this next .
Inside a Lithium-ion Battery Pack and Cell
Lithium - ion battery packs come in all shapes and sizing , but they all look about the same on the inside . If you were to take aside a laptop shelling mob ( something that weDO NOTrecommend because of the possibility of short out a stamp battery and starting a fire ) you would find the following :
If the electric battery mob pay back too spicy during charge or utilise , the computer will close down the flow rate of major power to essay to cool off things down . If you leave your laptop in an highly blistering car and sample to use the laptop computer , this computer may prevent you from powering up until things cool down off . If the cells ever become all discharged , the battery pack will shut down because the cadre are ruined . It may also keep track of the number of armorial bearing / discharge cycles and send out selective information so the laptop computer ’s bombardment measure can secern you how much charge is left in the electric battery .
It ’s a passably advanced trivial computer , and it draws tycoon from the barrage . This top executive draw is one rationality why Li - ion battery lose 5 percent of their power every calendar month when sitting idle .
Lithium-ion Cells
As with most batteries you have an outer case made of metal . The use of metallic element is particularly crucial here because the assault and battery is pressurized . This metal case has some kind of pressure - sensitivevent fix . If the barrage ever gets so raging that it risk detonate from over - pressure , this vent will issue the redundant pressure . The battery will belike be useless afterwards , so this is something to avoid . The vent is strictly there as a guard measure . So is thePositive Temperature Coefficient ( PTC)switch , a twist that is supposed to keep the assault and battery from overheat .
This alloy case holds a long voluted comprising three thin sheet pressed together :
Inside the type these tack are submerged in an constitutional result that acts as the electrolyte . Ether is one common dissolvent .
The separator is a very thin sheet of microperforated charge plate . As the name implies , it separates the positive and disconfirming electrodes while allowing ions to clear through .
The confirming electrode is made of Li cobalt oxide , or LiCoO2 . The negative electrode is made of atomic number 6 . When the electric battery charges , ion of lithium move through the electrolyte from the positivistic electrode to the negative electrode and bind to the carbon . During discharge , the atomic number 3 ion move back to the LiCoO2from the atomic number 6 .
The movement of these atomic number 3 ions occur at a fairly high-pitched voltage , so each cell produces 3.7 volts . This is much higher than the 1.5 volts typical of a normal AA alkaline cell that you buy at the supermarket and help make lithium - ion batteries more compact in little gimmick like cellular telephone phones . SeeHow Batteries Workfor detail on unlike barrage chemistries .
We ’ll look at how to prolong the life of a Li - ion bombardment and explore why they can explode next .
Lithium-ion Battery Life and Death
Li - ion battery packs are expensive , so if you want to make yours to last longer , here are some thing to keep in mind :
Exploding Batteries
Now that we know how to keep Li - ion battery working longer , let ’s look at why they can explode .
If the electric battery gets red-hot enough to inflame the electrolyte , you are fit to get a blast . There are video clips and photos on the Web that show just how serious these fires can be . TheCBC article,“Summer of the Exploding Laptop , " fill out up several of these incidents .
When a blast like this happen , it is unremarkably due to an home short in the electric battery . Recall from the previous section that lithium - ion electric cell contain a centrifuge sheet that keeps the cocksure and negative electrode apart . If that sheet convey punctured and the electrode allude , the barrage heat up up very quick . You may have experienced the sort of heat a battery can bring out if you have ever put a normal 9 - volt barrage fire in your sac . If a coin shorts across the two terminals , the battery incur quite hot .
In a separator unsuccessful person , that same variety of short happen inside the atomic number 3 - ion barrage . Since atomic number 3 - ion batteries are so energetic , they getveryhot . The heat causes the shelling to vent the organic solvent used as an electrolyte , and the heat ( or a nearby spark ) can light it . Once that happen inside one of the cells , the heat of the fire cascade to the other cell and the whole plurality goes up in flames .
It is significant to take down that fires are very rare . Still , it only takes a brace of fire and a little media coverage to prompt a recall .
