By ROB HULL
Battery experts have sounded the alarm on a rise in the number of electric car fires, predicting there could be 25,000 instances per year by 2030.
While evidence shows they are currently far less frequent than infernos involving internal combustion engine (ICE) cars, they pose major safety concerns as EV fires are far more dangerous.
They are more likely to take place when a vehicle is parked or during charging and EV blazes are also incredibly difficult to extinguish.
According to the International Energy Agency, there are 40 million EVs on the world's roads today. However, this is forecast to reach 250 million by 2030.
'Even at a conservative rate of one fire per 10,000 EVs, thermal incidents could reach 25,000 per year worldwide by the end of the decade,' experts at 24M Technologies said on Thursday.
This predicted rise in cases will significantly increase risk to public safety, as well as car manufacturer profitability, unless major upgrades are made to battery cell design to reduce the risk of fires, it warned.
The UK fire service last year reported a 33 per cent year-on-year increase in electric car blazes in Britain.
Pictured: an electric Peugeot which 'exploded' at an address in Worcester earlier this year while the owner was asleep in their home
24M Technologies, which specialises in battery cell design, says the industry's current safety challenges 'stem from decades-old battery principles' that are unchanged for the last 30 years.
The battery maker, which formed in 2010 in a spin-off from MIT, attributes the increasing risk of EV fires to a combination of the rising number of electric cars on the road and battery cell energy densities growing dramatically to provide longer ranges between charges.
The latter requires 'energy richer materials and smaller cell component safety margins', the company said, as it suggested manufacturers' best efforts to prevent blazes with existing battery technology is falling short.
'These issues, as well as the growth in ever faster charging capabilities, increases the threat of internal short circuits, which cannot be stopped externally,' it claimed.
As well as posing a greater threat to public safety, 24M Technologies says there are also huge financial ramifications at play for automakers.
This is because recalls related to EV fires carry an estimated price tag of $1billion (£750million) per vehicle model line.
As such, it says cell design must be 'reimagined to be fundamentally safer'.
The aftermath of an EV in Northamptonshire on October 31 2024. A family's Mercedes EQA electric SUV exploded in a fireball while sitting on their driveway, causing fire damage to their property
Naoki Ota, President and CEO at 24M Technologies said: 'The industry's current safety challenges stem from decades-old battery design principles.
'While we've achieved remarkable progress in cost reduction and energy density, we're still building upon architectures that have not fundamentally changed in more than 30 years.
'Process improvements alone cannot address these design limitations and multiple OEMs [Original Equipment Manufacturers] have faced costly recalls as a result.'
Ota adds: 'Rather than address these issues through add-on system features, safety must be incorporated as a foundational element at the core of the battery cell.'
An investigation by international insurer QBE last year revealed that EV blazes attended by UK fire services grew from 89 cases in 2022 to 118 instances the following year
Batteries that power electric vehicles such e-bikes, e-scooters and electric cars were involved in almost three fires a day in 2023, compared to under two fires a day in 2022, it was revealed last year.
An investigation by international insurer QBE revealed that electric car blazes attended by UK fire services grew from 89 cases in 2022 to 118 instances the following year.
Fires in lithium batteries typically used for today's EVs often occur because of 'dendrite' growth in cells.
These are tree-like structures of lithium metal that grow inside the battery, especially during charging, and can trigger a short circuit, resulting in a blaze. They also impact battery performance and lifespan.
Dendrites are inevitable over a battery's lifecycle as it ages and undergoes thousands of charge and discharge cycles and can also occur as a result of overcharging, charging at very low temperatures or frequent fast charging.
A short circuit - which is called a 'thermal runaway' in EVs - will cause a battery cell to overheat, releasing flammable gases which then ignite. It only takes one cell to overheat, which can happen in milliseconds.
When a thermal runaway event begins, it impossible to stop without intervention.
And once one cell is impacted, it can quickly spread to others before engulfing the entire battery and ultimately the vehicle.
When ablaze, lithium batteries require more effort to be extinguished because the batteries can generate enough heat to reignite after the initial fire has been put out.
These 'dormant phases' can last for hours before they relight, experts warn.
And such high temperatures can cause gassing of the battery and blazes so hot that they become extremely difficult to put out.
When a battery thermal runaway event begins, it impossible to stop without intervention. And because this can spread to other cells in a battery and they typically burn fast and extremely hot, it can be dangerous to attempt to put out an EV blaze
A statement from the National Fire Chiefs Council (NFCC) explains: 'The reignition of batteries is possible after prolonged periods, after mechanical shock, heating or battery faults.
'They may require extended periods of cooling and monitoring after a fire or collision.
'Damaged batteries can be too sensitive to move, and personnel may have to consider cordoning off a vehicle and handing it over to a responsible person.'
Because of this, traditional firefighting methods often prove ineffective when trying to extinguish EV blazes.
As such, the NFCC has a bespoke set of guidelines for fire service crew to deal with fires with electrified cars.
Various fire services across Europe and around the globe have invested in transportable plunge pools for EVs to submerge them in water to reduce the battery temperature and kill the flames quicker.
In 2021, the Leuven fire department in Belgium released these images showing how it tackles battery vehicle fires...
A crane lowers the blazing EV into a container full of water. The vehicle is submerged to reduce the temperature of the battery cells to extinguish the fire faster than traditional methods
Mr Ota, a recognised global expert in lithium-ion batteries, says the only solution to prevent EV battery fires is to incorporate in-cell fire prevention technology.
24M has developed a system - called Impervio - which it claims is 'uniquely capable of suppressing dendrites and neutralising thermal runaway' before it can start.
He explained: 'Unlike other technologies, it not only monitors individual cells but prevents thermal incidents.
'The industry must shift from reactive measures to try to contain fires to proactive designs preventing failures before they occur.
'Without this step change approach, the safety and financial challenges will only intensify as EV adoption accelerates.'
The battery designer has already conducted side-by-side test of battery cells with Impervio (bottom) and one without (top). Both were charged to 100%, then to 100% overcapacity to dramatically increase the risk of dendrite growth, as displayed in these graphics
It claims the non-Impervio cells (pictured bottom) began to shorts after 15 minutes, with the cell catching fire and exploding after 38 minutes. Whereas its tech (top) did not set ablaze after an hour over 100% overcharging
The US battery designer says it has already conducted side-by-side test of battery cells with Impervio and one without.
These were charged to 100 per cent, then to 100 per cent overcapacity to dramatically increase the risk of dendrite growth.
It claims the non-Impervio cells began to shorts after 15 minutes, with the cell catching fire and exploding after 38 minutes.
However, cells with the company's tech saw 'negligible temperature increase, did not short and did not catch fire – even after an entire hour of overcharging,' it reports.
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