In recent months there have been accidental fires of electric cars, to the point that GM officials asked owners to park away from other vehicles. Experts point out that they are as safe as a gasoline car, but there is a factor that you cannot fight today and that we will tell you about.
Electric cars will flood our streets in just under a decade, becoming the usual ones compared to combustion cars that will gradually disappear. However, in recent months the fire of some new electric vehicles has drawn power, affecting practically all brands with zero-emission models.
Although there is no great evidence that this type of propulsion is more conducive to fires, the alarms immediately go off to be the great novelty. But an electric has the same chances of suffering a loss of this type as a gasoline car, whose stats are really low. So, you wonder what factors can cause a fire, ranging from failures in the control software to a deficiency in the insulation of the battery box, passing through the ambient temperature.
Dendrites, the great enemy of lithium batteries
But there are also other additions that go unnoticed, and it is an overheating in the charging process, and from what we told you a few weeks ago with some tips to avoid problems and maintain the longest possible life. Despite these factors, there is one that cannot be fought today and that is the dendrites, which originate from lithium-ion batteries and typically are already in the cells fitted at the factory.
Fires are the consequence of a short circuit caused by dendrites, tiny lithium crystals that are created on the negative electrode and they are attracting the positive ions, so that when the dendrites reach the positive electrode the short circuit and the fire take place. Wolfgang Schmickler and Elizabeth Santos, technicians from the University of Ulm, explain that “With metals such as copper or silver, the surface is positively charged during deposition. If there is a small bump on the surface, a positive charge will accumulate, it repels the positively charged metal ions, the cluster cannot grow further and forms dendrites. ‘
Be careful, it is not usual in the battery industry, but it is one of the challenges facing car brands and their suppliers to end the fires. In fact, the solution exists but it is more expensive: they are called high-performance batteries that do not contain lithium or cobalt.