Hoverboards won't stop exploding lately, perhaps due to overheating batteries. But what if the battery could shut off before it got all hot and flamey? That's the idea behind recent research at Stanford, and the benefits go far beyond gimmicky gadgets looking to avoid recalls. Today, Stanford researchers say they have made the first lithium-ion battery that shuts off when temperatures get too hot and then switches back on once things cool down. The study was published today in the journal Nature Energy. Practical applications for the new technology include upgrading batteries in computers, navigation systems and other electronics at risk of catching fire.
Here's how it works. Researchers made a thermally responsive polymer: A flimsy but powerful material that could encase a battery. That polymer's filled with spike-shaped nickel particles that conduct electricity. When those spikes are close to each other, electricity flows, powering the device. But if temps get cranked up, the polymer expands, sending those spiked particles drifting apart and halting the electric flow. The device shuts off. But once things cool down, the nickel particles find their way back to each other and the electric flow restarts, allowing the gizmo to run normally again.
The team tested the new material by hooking it up to a simple LED light, and then blasting it with a hot-air gun. Sure enough, the light switched off immediately when the heat was applied, and blinked right back on once the heat source was removed.
This is all still in the laboratory stage, so it will be a good while before we see this in any crotch-searing laptops. But it's a big step in making gadgets better performing and, more importantly, safer.
Image via Stanford University Precourt Institute for Energy YouTube