Remember those Samsung Galaxy Note 7 phones that caught fire a couple years back? A new and startlingly simple solution involving children’s slime toys could have possibly prevented those fires entirely—and the billions that the problem cost Samsung.
Skeptical about a fix involving children’s slime toys? Fires occur in lithium-ion (Li-ion) batteries when the electrodes come into direct contact with each other, usually due to some damage in the battery that causes it to get bent or warped in some way. When the electrodes touch, the current runs between them directly, causing the liquid component of the battery (called the electrolyte) to combust. If this liquid electrolyte could be solidified upon impact, then the electrodes could be prevented from touching each other by the hardened liquid. This is what Gabriel Veith was pondering as he watched his children playing with a cornstarch and water mixture that possessed some interesting properties.
“If you put the mixture on a cookie tray, it flows like a liquid until you start poking it, and then it becomes a solid,” explained Veith, who is based at Oak Ridge National Laboratory and is the project’s principal investigator. “After the pressure is removed, the substance liquefies again.” Veith realized that he could exploit this reversible “shear thickening” behavior to make batteries safer.
Veith and his team will present their results at the 256th National Meeting & Exposition of the American Chemical Society (ACS).
The now-infamous Galaxy Note 7 incidents caused some injuries to their owners, but it could have been far worse. Burns, house fires, and at least one plane crash have all been attributed to Li-ion batteries.
Currently, the Li-ion battery is preparing to take center stage as the future energy-storage solution of choice, but the transition is generating some controversy for more than a few reasons.
Engineers all over the world are seeking solutions to the environmental and ethical dilemmas associated with cobalt and lithium production. Safety is another feature of the Li-ion that requires additional work, particularly as it is being used in an increasing number of our cars and devices.
To address these issues, most engineers have set their sights on what is called the “holy grail” of electricity storage: the solid-state Li-ion battery. Although progress has been made on achieving a solid-state battery—most recently by the inventor of the Li-ion himself—we have yet to see these new Li-ion prototypes make their way out of the lab and into our smartphones.
It’s possible that an altogether different solution will solve this Li-ion problem. Materials like recycled glass and even diamonds have been used in efforts to try and stabilize the electrodes in the batteries and prevent fires.
It remains to be seen, however, when or whether these solutions will ever reach OEM stage.