When a lithium ion battery fails and catches fire then we have a chemical fire and things are very different from normal. Read what exactly is happening and what to do.
Lithium-ion batteries, whether they're small and found in a cell phone or large and power an electric car, have the potential to fail and catch fire. In such cases, especially for cars, firefighters are called upon to extinguish a strange, chemical fire which is not an easy task.
As electric vehicles (EVs) become more common on our roads, with the potential to reach 50 percent of new car sales by 2030, firefighters face the challenge of putting out battery fires.
Despite the increasing number of electric vehicles on the road, firefighters still struggle to receive proper training on how to quickly and effectively put out electric vehicle fires.
Unlike traditional gasoline or diesel cars, electric vehicles require a different approach to firefighting.
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How electric vehicle fires happen
The most common case is an electric car crash that destroys the EV's battery and starts a fire by a process called thermal runaway.
But also a manufacturing error can cause a local, small short circuit that will lead to a chain internal fire. Especially in low-budget and quality vehicles without a reliable manufacturing brand, such as scooters, skates, gadgets, etc.
Lithium-ion batteries are not a solid brick. Instead, think of these batteries as a collection of many smaller batteries, called cells, pressed together.
A single cell of a car battery may look like case ή cylinder and is filled with the chemical components that allow the battery to store energy: an anode, a cathode, and a liquid electrolyte.
The cells are assembled into a battery pack that is encased in an extremely strong material such as titanium, and this battery is usually bolted to the underside of the vehicle. The idea is to make the battery nearly impossible to access and ideally protect it even in the worst crashes.
When the temperature of one or more cells exceeds a certain threshold as it is not sufficiently cooled, the tiny membranes that separate the cathode and anode they melt, exposing the highly flammable electrolyte to high temperature.
Thus begins a chemical reaction in the first cell which will ignite an initial fire. The heat soon spreads to each neighboring cell until the entire battery burns out and this phenomenon is called “thermal runaway”.
The same can happen to your cell phone or laptop battery. When the temperature limits are exceeded then a chemical reaction can occur.
If you have ever opened a cell phone battery you will see that it is a thin sandwich wrapped in several layers, so that it creates the shape of the battery. During the "unwrapping" process and because some parts of the battery will be short-circuited, you will feel the sandwich practically burning in your hands.
The first moments of a lithium-ion battery fire may seem relatively calm, with only smoke rising from the battery or underneath the car.
But as the heat escape runs, they project bright orange flames that can quickly engulf an entire car. And because EV batteries are packed with an incredible amount of stored energy, one of these fires can even reach 2.500 degrees Celsius.
And how to put out a battery fire
Conventional suppression methods that smother the fire with foam or a fire blanket are ineffective because the lithium-ion batteries that power EVs are capable of releasing their own oxygen, effectively making the fire self-sustaining.
The most common solution (for now) to effectively extinguish an electric car fire is to use a lot of water to cool the battery material and reduce the oxygen by suffocating it from the ambient air.
When we say "a lot of water", there were reports from the fire services that it is not unusual for an electric vehicle fire to require 25.000 to 50.000 liters of water to put out. To put that into perspective, a petrol or diesel car fire only needs between 2.000 and 4.000 liters of water to put out. We are talking about more than ten times the amount.
This presents a new challenge for firefighters, especially in situations where hydrants may be far away or if local fire services have limited resources. Of course, a single fire engine will not be able to extinguish a burning electric car, as it has a water tank with a maximum of 5.000 liters, an amount not sufficient for this type of fire.
Some countries use a technique in which the burning electric vehicle is collected by a crane and thrown into large containers of water. However, if the fire is already raging out of control, getting close enough to use this method is a problem.
Rekindling dead batteries
The dangers posed by electric vehicle fires do not stop when the flames are extinguished, as there have been cases of electric vehicle fires rekindling even days after being extinguished.
Both firefighters and secondary crews such as vehicle recycling or towing companies must also be aware of the potential for latent energy that may remain in the undamaged parts of the battery. Doing so may present risks of electric shock or vehicle fire.
And for your home, take this phenomenon into account. If a cell phone battery catches fire, handle it properly as soon as it goes out. Don't leave it half-burnt on your desk because it may well come back to life.
How to react in case of a chemical fire
According to the National Fire Protection Association (NFPA), if your electric car ever catches fire while behind the wheel, immediately find a safe way to pull the car over or off the main road.
Then turn off the engine and make sure everyone leaves right away the vehicle. Don't linger getting your stuff or personal items, just get out. Stay more than 30 meters away from the burning car and call 112 or the fire department for help.
Also, you should not try to put out the flame yourself. This is a chemical fire, so a few buckets of water will not adequately smother the flames. Even firefighters can sometimes make up their own minds to let the battery burn itself out, instead of pouring water on her.
While it may be tempting to get back into the car and grab your wallet or other important items if the flame dims or goes out for a second, resist the urge.
Wait until the local fire department arrives to assess the overall situation and give you the go-ahead. Staying away from the car also helps minimize the chance of inhaling unhealthy fumes from the battery fire.
We are still designing today's future
And while internal combustion vehicles have been around for over a century, electric vehicles are still relatively new, which means they could become even safer, as we are still discovering bugs and we spend money on research to avoid them.
The problem is that electric car technology has been on the rise. Even fire departments are starting to use electric vehicles.
General Motors is studying how a battery separator could help improve battery safety. The US Department of Energy is working on technology that could incorporate flame retardants directly into battery design.
Engineers are also researching new battery chemistries, such as with less flammable electrolytes. Although the research is still early, solid-state batteries, which would replace a liquid electrolyte with a solid that is much less likely to catch fire, also show promise.
Not to mention the fuel cells that use hydrogen to produce electricity and will be the next step in electrification.
Meanwhile, fire services around the world are also working to adapt to this new technology. In May 2023, the Los Angeles Fire Department debuted the first electric fire truck which hit the road in the US. The Austin Fire Department has created a new fire hydrant to specifically address electric vehicle fires.
In short, everyone so far is improvising on how to eliminate or even deal with these fires.
