Or any other rechargeable item.
On a hot Sunday afternoon in August, Destiny Williams and her daughter went into their home after a morning at Church. Soon after, Destiny started smelling smoke. After searching her house, she looked out the window and saw that her car's interior was on fire.
After a neighbor helped put out the flames with a garden hose, Destiny called the fire department, which discovered that the lithium button battery in her daughter's book, resting on the back seat, had ignited.
What is a Lithium Battery
A lithium-ion battery is a rechargeable battery that stores energy by reversibly intercalating Li+ ions into electronically conducting solids. Compared with other commercial rechargeable batteries, Lithium-Ion batteries are characterized by higher energy density and efficiency, a longer cycle life, and a longer calendar life.
Generally, the negative electrode of a conventional lithium-ion cell is graphite made from carbon. The positive electrode is typically a metal oxide or phosphate. The electrolyte is a lithium salt in an organic solvent. A separator prevents the negative and positive electrodes from shorting. The electrodes are connected to the powered circuit through two pieces of metal called current collectors. The negative and positive electrodes swap their electrochemical roles (anode and cathode) when the cell is charged.
All types of batteries can pose a safety risk and be hazardous. The difference with lithium-ion batteries available on the market today is that they typically contain a liquid electrolyte solution with lithium salts dissolved into a solvent, like ethylene carbonate, to create lithium ions.
It is the presence of these lithium ions that yields superior battery performance and allows the battery to store a large amount of energy in a relatively small area.
However, the liquid electrolyte containing these lithium ions is highly volatile and flammable, creating a serious risk of fire or explosion, particularly when exposed to high temperatures.
In addition to this, the way a lithium-ion battery produces power also generates heat as a by-product.
In an uncontrolled failure of the battery, all that energy and heat increases the hazard risks in terms of fuelling a potential fire. The heat from lithium-ion battery failures can reach up to 400 degrees Celsius in just a matter of seconds, with peak fire temperatures being higher than this.
Why Lithium Batteries Catch Fire
There are several reasons a lithium battery ignites, but the main one is heat. Typically, excessive heat damages the battery cell causing it to fail.
The outdoor temperature the day Destiny's car burned (August 29th) was 98° F. The inside temperature of a car sitting in the sun with the windows closed would have been close to 150° F after 30 minutes. Lithium batteries will heat up to higher temperatures as they retain heat inside their shells. Excessive heat can lead to an uncontrolled release of energy called a thermal runaway, causing fire or explosion.
The flammable electrolytes in Lithium-ion battery cells store significant stored energy. In addition to heat, other fire causes include internal short circuits due to manufacturing defects, "lithium plating" (the formation of metallic lithium on an anode surface within a battery cell), mechanical damage like piercing or dropping, or overcharging/over-discharging.
Battery explosions occur when a range of flammable and toxic gases from battery casings are ejected and immediately ignite, or they spread out unignited until an external ignition source is encountered and an explosion occurs.
Lithium-ion battery fires generate their own oxygen and can be very difficult to extinguish. Specialist Aqueous Vermiculite Dispersion (AVD) fire extinguishers can help put out small nascent fires, but lithium-ion fires are very often controlled and extinguished only when the fire departments can deliver copious amounts of water to the burning materials.
What Items You Shouldn't Keep In Your Car On Warm Days
Lithium batteries are used in more than just cell phones and children's books. They are also in children's toys, smartwatches, laptops, tablets, camping lanterns, flashlights, battery rechargers, and even your car key.
The old adage, "Better safe than sorry," is the best advice when considering what to leave in your car on a warm day. If in doubt, take any battery-operated item with you to avoid a fire.
Sources: AP, Slashgear, techxplore
it's good lesson to learn for any family.