Final month, a Mercedes Benz EQE 350 electrical car caught fire in a South Korean condo constructing’s underground parking storage. Reportedly, 23 folks had been despatched to the hospital and roughly 900 vehicles had been broken. The hearth reached temperatures of greater than 2,700 levels Fahrenheit (1,500 levels Celsius), and took firefighters nearly eight hours to extinguish.
The incident led to a collection of swift policy changes within the nation, together with the acceleration of a deliberate EV battery certification program and new guidelines in Seoul that ought to forestall house owners from “overcharging” their automobiles in underground parking garages. It has additionally pushed automakers to do one thing they wouldn’t usually: reveal who makes the batteries inside their electrical vehicles. (In early September, the South Korean authorities mentioned it could require automakers to reveal this typically secret data.)
Information from the Nationwide Transportation Security Board, the US’s impartial federal investigation company, exhibits that the dangers of electrical car battery fires are low. In reality, very low. An evaluation of that knowledge by one insurance company urged that greater than 1,500 gasoline vehicles catch on fireplace per 100,000 gross sales, in comparison with simply 25 electrical automobiles.
On some degree, fireplace is a danger of any type of battery expertise. Professionals speak in regards to the “fireplace triangle”—the three-ingredient recipe for ignition. Hearth wants oxygen, a spark, and gasoline. As a result of the purpose of a lithium-ion electrical car is to retailer power, the gasoline is at all times there. EV batteries are supposed to be tightly packed and remoted from different components of the automotive, however an incident like a catastrophic crash may rapidly introduce oxygen and warmth to the brew.
Constructing a Hearth-Proof(ish) Battery
Some battery makers have taken steps to cut back the danger of their batteries catching fireplace. The primary is to create stringent manufacturing processes and requirements. That is vital as a result of any type of flaw in a battery may result in an inferno, says Venkat Srinivasan, who research batteries and directs the Argonne Collaborative Middle for Vitality Storage Science on the US’s Argonne Nationwide Laboratory.
To grasp why battery manufacturing issues to fireside danger, it’s important to perceive the basics of lithium-ion batteries. The battery’s anode and cathode retailer lithium, and they’re related by an electrolyte, a liquid chemical that passes lithium ions between the 2 to retailer or launch power. If, say, a tiny particle of metallic will get into that electrolyte by way of an unclean manufacturing course of, and it retains getting electrified because the battery costs up and down, it may create a spark, open the battery cell, and permit oxygen to come back dashing in and presumably expose the whole battery pack to fireside.
These kinds of battery-making screw-ups do occur. In August, Jaguar told some 3,000 house owners of its 2019 I-Tempo SUV to park their automobiles exterior due to fireplace danger, which was linked to a few fires. The producer behind these automobiles’ packs, the South Korean agency LG Vitality Resolution, has been topic to a US road safety probe since 2022. BMW, General Motors, Hyundai, Stellantis, and Volkswagen have all recalled automobiles over battery dangers (a few of them in hybrid moderately than all-electric automobiles). However these conditions are uncommon. By means of stable manufacturing processes, “one can by no means make the danger of fireside completely zero, however good firms have minimized the danger,” says Srinivasan.
Much less Hearth-y Chemistries
The excellent news is that less-fire-prone batteries are already rolling round in vehicles, because of particular battery chemistries which are more durable to ignite. Because the first Tesla hit the street in 2008, the usual electrical car battery has been made primarily from nickel and cobalt. Batteries with this make-up cost rapidly and maintain a number of power, which is nice for EV use as a result of drivers of automobiles that use them take pleasure in longer ranges and quicker top-ups. They’re additionally extra more likely to enter “thermal runaway” at decrease temperatures, within the 400- to 300-degrees Fahrenheit (210 to 150 levels Celsius) vary.
Thermal runaway is a state through which lithium-ion batteries enter a type of fireplace doom loop: A broken battery cell produces warmth and flammable gases, which in flip produces extra warmth and flammable gases, which begins to warmth close by battery cells, which launch extra warmth and gasoline. The hearth then turns into self-sustaining and arduous to place out.
