Lithium-ion batteries have become popular options in institutional and commercial buildings in recent years for a range of applications, from electric vehicles (EV) to handheld power tools and grounds equipment. But as their popularity grows, so do concerns about the potential fire risk that the batteries pose, as evidenced by reports of explosions and fires linked to the batteries. Now, research has uncovered clues to these incidents.
Researchers have long known that high electric currents can lead to thermal runaway, which is a chain reaction that can cause a battery to overheat, catch fire and explode. But without a reliable method to measure currents inside a resting battery, it has not been clear why some batteries go into thermal runaway, even when an EV is parked.
Using an advanced imaging technique, scientists at Lawrence Berkeley National Laboratory have shown that the presence of large local currents inside batteries at rest after fast charging could be one of the causes behind thermal runaway.
Their work shows for the first time that it is possible to directly measure current inside a resting battery even when the external current measurement is zero, but they say much more work is needed before the findings can be used to develop improved safety protocols.
Dan Hounsell is senior editor for the facilities market. He has more than 30 years of experience writing about facilities maintenance, engineering and management.
