The potential for accidental combustion is a persistent problem for lithium-ion batteries; it’s one which a number of research teams across the world are attempting to address at the moment. Now scientists at Stanford University in the US have announced a new development which could help to make this a thing of the past, according to CNET.
They have come up with a grapheme and nickel-infused polyethylene film which can be applied to batteries and automatically shut down the charging process if excessive heat levels are detected.
This is achieved because if the film gets too hot, it ceases to be able to conduct electricity. Then once the temperatures have returned to lower levels, charging can resume automatically, according to project spokesperson Zheng Chen.
This is achievable because the nickel particles have to be making contact with one another in order for electricity to be conducted. As the heat increases, the plastic film expands and the particles are no longer touching one another, thus preventing conduction outright.
“A Type of Nanotechnology”
Since it uses grapheme, this system is being described as a type of nanotechnology. Although it could equally be seen as a heat-sensitive circuit breaker which can automatically reset itself without the need for human interaction.
Perhaps most impressive of all is the fact that the temperature at which the film becomes non-conductive can actually be altered by researchers, so different products could be endowed with different cut-off limits depending on the safety requirements of a battery pack manufacturer.
Chen explained that the team had already proven that the film could stop charging at as little as 50 degrees Celsius or as much as 100 degrees Celsius. And the research, which first appeared in Nature Energy this month, has been accompanied by videos in which practical demonstrations of its safety capabilities in operation are provided in full.
In the final weeks of 2015 there was much controversy caused by the combustion incidents involving so-called hoverboards powered by cheap lithium-ion cells. And experts believe that the introduction of this technology could help to make such hazards a thing of the past.
Since the commercial availability of this technology is still a long way down the road, in the interim it is likely that businesses and consumers will be better off using products which are powered by high-quality lithium-ion cells from a respected battery pack manufacturer. These have a far smaller chance of combustion than their cheaper, less reputable counterparts.