August 12, 2021: One in three electric vehicles fires has occurred with ‘no obvious cause’ while the car was parked, according to the latest report by research consultancy IdTechEx.
The startling figures show that 17% of EV fires occur in regular driving and a quarter occur when charging.
More predictably, 20% of fires occur in a crash situation or 4% when immersed in water when the reactive lithium is exposed to the air or water.
IdTechEx’s report —Thermal Management for Electric Vehicles 2021-2031 — also points out that the cost of recalls to solve problems continues to be hugely expensive and sometimes intractable to solve.
GM’s first recall of the Bolt in 2020, for example, entailed a call back of 69,000 cars produced between 2017-2019 for potential battery fires.
“The ‘solution’ was a software update limiting the battery capacity to 90% and an inspection of the battery,” says the report. “In 2021, two more Bolts have caught fire, both of which had the recall.
“Continued investigation between GM and LG Chem has determined the cause is the ‘presence of two rare manufacturing defects in the same cell’. This has prompted another recall by GM to replace the battery modules.
“This recall is said to have cost GM around $11,000 per vehicle, totalling nearly $800 million.”
Other carmakers have faced similar bills. Hyundai, for example, recalled 82,000 EVs due to battery fire risk at an estimated $900 million. Much of this was paid for by LG Chem, the report says.
“Ford’s Kuga plug-in hybrid also faced issues with cells supplied by Samsung, resulting in a recall of 33,000 cars costing Ford approximately $400 million,” it says.
The effects of EV fires tend to be far more severe than fires in conventional ICE vehicles.
One Hyundai Kona fire in 2020, for example, blew the roof off the garage in which it was stored. And, as with the recent lithium explosions and blazes in Chicago in the US and in late July in Victoria, Australia, these fires are a lot harder to contain and put out.
A Tesla Model S fire in April required nearly 30,000 gallons of water to extinguish it because “it kept reigniting, burning continuously for over four hours,” says one media report. By comparison, a typical car fire involving a ICE can be extinguished with about 300 gallons.
One effect of these high-profile fires and their severity is their press coverage, which runs contrary to the desire of governments and OEMs that have recently been setting out bold decarbonization targets based on energy storage for fossil-free renewables.
But with every cloud there comes a silver lining.
The reports concludes: “We expect EVs to continually improve in safety, there will always be the risk of a battery fire due to many potential causes. This presents an opportunity for those material suppliers making thermal interface materials, flame-retardant materials, or fire protection materials. These materials can help with the thermal management of EV batteries making it less likely they will overheat.
“Fire-retardant construction materials and fire protection materials are beneficial to enclose a fire or prolong the time between a thermal runaway event and the fire exiting the battery pack.”
Regulations are also evolving in the UK. China implemented new EV fire safety regulations at the start of the year, which include a five-minute warning between a thermal event and fire or smoke exiting the battery pack.
The EU also has various draft regulations with a similar focus. IDTechEx expects regulations in this field to become more stringent, presenting greater opportunities for material suppliers.