Electric vehicles offer a path to better air quality, lower fuel costs, and form a growing new category for automakers. But with the transition to electric vehicles comes a new challenge: Vehicles using lithium ion batteries can be especially dangerous when they catch fire.
The good news is that tram fires don’t happen very often.
EV FireSafe project manager in Melbourne, Australia, Emma Sutcliffe, said researchers needed more data to determine exact fire rates, but preliminary studies show fires are rare. in all-electric cars.
Research by another company, AutoinsuranceEZ, says battery electric vehicles have only a 0.03% chance of catching fire, compared with a 1.5% chance for an internal combustion engine vehicle. According to their research, hybrid electricity, which includes both a high-voltage battery and an internal combustion engine, has a 3.4 percent chance of burning a vehicle.
When a fire does occur, however, electric vehicles with lithium ion batteries will burn hotter, faster, and require more water to reach their final extinguishing capacity, says Sutcliffe. And batteries can flare up again hours or even days after the blaze is initially brought under control, putting rescue yards, repair shops and other places at risk.
Chas McGarvey, Fire Chief for Pennsylvania’s Lower Merion Fire Department, told CNBC that a Tesla Model S Plaid fire his department handles in 2021 burned so hot that it melted the roadway inside. under it.
Sutcliffe told CNBC, “A lot of the time firefighters and fire agencies just expect to find it.” With so many new models hitting the market, said McGarvey, the Pennsylvania fire chief, “We’re still trying to keep up with all of this. But it changes almost every day!”
The director of the Energy Institute of Maryland, Eric Wachsman, says that the qualities that make lithium ion battery cells powerful enough to move a passenger vehicle can also make them susceptible to fire – especially if the cells The battery cells inside them are damaged or defective.
Lithium ion battery cells have electrodes placed close together, which increases the chance of a short, and they are filled with flammable liquid electrolytes, he said.
“This flammable liquid can get into so-called heat runaway situations where it starts to boil and lead to a fire,” he said.
Electric vehicles include battery management systems to maintain the proper operating temperature for the high-voltage batteries inside, and these systems control the charging and discharging rates of the batteries. Improvements to them as well as the battery cells themselves promise to make electric vehicles safer.
Tesla recently announced that it will be switching from lithium ion batteries to lithium iron phosphate (LFP) batteries. Other major automakers including Ford and VW are also replacing LFPs with nickel or cobalt formulations used in some of their electric vehicles.
“These are generally thought to be a lot safer,” said Paul Christensen, professor of electrochemistry at Newcastle University, whose research has focused on the fires and safety of lithium ion batteries.
Ultimately, he believes, all-electric vehicles have a better chance of being safer than the petrol or diesel vehicles they replace.
“We’ve come a long way to fully understand the risks and dangers associated with petrol and diesel cars. We’ll have to learn faster how to deal with the challenges with electric vehicles. But We’ll make it.”
