Remember those reports of exploding hoverboards a few years ago? The culprit behind those spontaneous electrical combustions were low-quality Li-ion batteries, which contain highly flammable, toxic, and moisture-sensitive electrolytes.
A team of scientists at the Johns Hopkins Applied Physics Laboratory has partnered with researchers from the University of Maryland and the Army Research Laboratory to develop a new type of flexible lithium-ion battery that is not hazardous and can operate under extreme conditions including cutting, submersion, and ballistic impact.
In their paper, "Flexible Aqueous Li-ion Battery with High Energy and Power Densities," which was published online last month in Advanced Materials, the scientists describe their work, which builds upon a novel, highly-concentrated water-based electrolyte called "water-in-salt" that can address the instability of traditional Li-ion batteries.
In their demonstration, the battery powered a significant motor load without any safety concerns. To demonstrate the full safety potential, the team performed a series of tests while the battery was in operation, including cutting it, immersing it in sea water, and subjecting it to ballistic testing at an APL facility. None of these tests would be possible with traditional Li-ion batteries.
Impressively, not only did these abuse tests cause no catastrophic failure, but the battery maintained its performance and continued to power the load even when damaged and completely exposed to air and water.