mini fire extinguishers inside lithium batteries may stop blazes - lithium ion polymer battery
How do you stop your smartphone from exploding?
Implant a miniature fire extinguisher inside the battery. Lithium-
Ion batteries are used on mobile phones, laptops and other portable devices because they are light in weight and efficient.
However, they also have fire risk due to their flammable liquid composition.
When the lithium battery is short-circuited, the heat accumulates and the liquid evaporates and catches fire.
Recent reports of a smartphone fire, such as the report that led to the global recall of the Samsung Galaxy Note 7 in 2016, have accelerated efforts for lithium battery safety.
One strategy is to add a flame-retardant chemical, called electrolyte, to the battery liquid.
But this reduces the conductivity of the electrolyte and hinders the performance.
To solve this problem, Yi Cui and his team at Stanford University in California closed the flame retardant in a thin polymer capsule and separated it from the electrolyte.
The idea is that the flame retardant releases into the electrolyte only when the battery overheat and melts the polymer housing-like a fire extinguisher, it automatically goes out when it overheat.
When capsules are tested in a burning battery liquid, they quickly melt and release the flame retardant and extinguish the flame in less than half a second.
In addition, the performance of conventional batteries does not decrease when polymer capsules are commercially tested
Lithium battery.
If the capsule is shown to prevent battery fire
Cui Tiankai said that they can make lithium batteries more feasible in electric vehicles and aircraft worldwide.
Neeraj Sharma of the University of New South Wales in Australia says the durability of the capsule will be a determinant.
"If electric cars are going to use them, you will want a life of 10 or 20 years," he said . ".
Cui and his team found that when the lithium battery was charged and discharged 360 times, a small amount of flame retardant substance spread into the electrolyte through a polymer capsule.
Over time, this gradual leakage may eventually damage the conductivity of the electrolyte.
"Further testing is needed," Cui said . "
Reference Magazine: Progress in science1126/sciadv.