Nowadays, many of us are glued to our phone screens, looking at them for hours on end. None of us expect that such a small electronic device could possibly be so dangerous.
However, in 2016, there were dozens of reports showing that Samsung's newly released Galaxy Note 7 gave off excessive amounts of heat, causing several phones to overheat and one even to explode—it was found that the lithium-ion batteries were to blame.
This prompted scientists to look for ways to make these batteries safer. Since previous lithium-ion batteries are made with highly flammable and moisture-sensitive materials, alternatives are now being explored to deliver both better performance and increased safety.
Last 2017, a team of researchers from John Hopkins University, University of Maryland, and the Army Research Laboratory unveiled a breakthrough new lithium-ion battery. Their study was published in Advanced Materials.
Made from embedding a novel "water-in-salt" electrolyte inside a polyvinyl alcohol polymer, the result is what's called a gel polymer electrolyte which shows vastly superior energy and power densities compared to other similar materials used in lithium-ion batteries.
What's especially astounding about it is how it reacts to stress, and it can take a lot of it—exposed to conditions that would ordinarily cause most lithium-ion batteries to fail, like twisting, bending, cutting, immersing in seawater, and being exposed to ballistic impact from an air cannon; the material kept on going with minimal loss of performance. Features like these could potentially expand lithium-ion batteries used to several more applications than we thought possible.
But that wasn't enough.
Now, the members of the John Hopkins University Applied Physics Laboratory (JHU APL) have produced the next generation of their innovative battery, this time making them incombustible and self-extinguishing. This new dimension of safety is particularly important, especially with the recorded cases of lithium-ion battery combustions and explosions.
Konstantin Gerasopoulos, Senior Research Scientist at the JHU APL and lead author of the study, remarks in a press release video:
"Our team has taken a two-pronged approach to solving this problem. First, we're replacing the liquid with a polymer electrolyte, and second, we're replacing the hazardous organic solvents with non-flammable equivalents."
By exploring water-in-bisalt electrolytes and polymerization using UV light in their new study, published in the latest issue of Chemical Communications, they were able to produce a material that still proceeds to work even after burning, even self-extinguishing the flame. Compared to the first generation, this new material is also much more mechanically stable.
Improvements for the material are proceeding at a rapid pace, Konstantin Gerasopoulos explains:
"Our latest work shows that we can make water-based polymer lithium-ion batteries that are not only safe and practical but also damage tolerant. And we've only begun to scratch the surface of our polymer technology."
While still in early development and prototyping stages, and quite a long way off from commercialization and widespread adoption, the material looks promising to power the next generation of batteries and energy storage devices that are not only durable and flexible, but safer as well.
