The Federal Aviation Administration recently warned passengers against packing lithium batteries in their checked bags, as they present a risk of igniting and fueling fires in the cargo hold.

Lithium batteries are the main reason "hoverboards" aren't allowed on most planes (or college campuses, New York subways and basically anywhere you don't want a sudden fire). As these batteries decay, they expand, breaking through their own internal components and sometimes bursting into flames.

New research attempts to solve this overheating issue, including a method from Standford that automatically shuts down the batteries if they overheat. Sony -- the company that developed the first commercial lithium-ion battery -- is working on safer, more efficient alternatives like magnesium-sulfur batteries, though those won't be ready until 2020, at least.