Jeet Jhaveri
31st March 2022
The Importance of battery safety
Lithium-ion batteries were developed in the 1970s and first commercialized by Sony in 1991 for the company’s handheld video recorder. Today everything you see is powered by batteries from smartphones to electric cars to even the International Space Station,which makes increased battery safety all the more crucial.
In 2008, Tesla unveiled the Roadster making it the first car company to commercialize a battery-powered electric vehicle. By 2025, the global lithium-ion (Li-ion) battery market is expected to reach USD 100.4 billion, over 50% of which will be used for the automotive market.
Why such a craze for lithium-ion?
Lithium-ion batteries are popular because of how much power they can put out at a given size and weight. A typical lithium-ion battery stores 150 watt-hours of electricity in 1 kilogram of battery, compared to NiMH Battery pack (100 watt-hours per kg) or Lead Acid Battery (25 watt-hours per kg). It takes 6 kilograms to store the same amount of energy in a lead-acid battery that a 1-kilogram lithium-ion battery can handle.
However, lithium-ion batteries are extremely sensitive to high temperatures and inherently flammable. These battery packs tend to degrade much faster than they normally would, due to heat. If a lithium-ion battery pack fails, it will burst into flames and can cause widespread damage. This calls for immediate measures and guidelines for battery safety.
Recently, there have been a few incidents of fires caused by Lithium-Ion batteries. On January 8, 2019, spontaneous combustion of a lithium-ion battery caused the fire to break out on the COSCO Pacific, a vessel in the Arabian Sea, caused by the. In April last year, a 2MW battery at an APS facility in Arizona exploded, injuring four firefighters.
Hans-Otto Schjerven, head of the Vestfold Fire Department, said that rechargeable lithium batteries can cause “fires that are difficult to extinguish and the batteries emit fire that quickly spreads.” As the adoption of electric vehicles grows, these incidents are set to increase.
Before analyzing why lithium-ion batteries catch fire, let’s understand how they work.
A lithium-ion battery pack consists of lithium-ion cells stacked together in modules, temperature sensors, voltage tap and an onboard computer (Battery Management System) to manage the individual cells. Like any other cell, the lithium-ion cell has a positive electrode (cathode), a negative electrode (anode) and a chemical called an electrolyte in between them. While the anode is generally made from graphite (carbon), different lithium materials are used for the cathode – Lithium Cobalt Oxide (LCO), Lithium Nickel Manganese Cobalt (or NMC), etc.
When a charging current is provided to the cell, lithium ions move from the cathode to the anode through the electrolyte. Electrons also flow but take the longer path outside the circuit. The opposite movement takes place during discharge with the result that the electrons power up the application that the cell has been connected to.
When all the ions have moved back to the cathode, the cell has been completely discharged and will need charging.
The lithium-ion cells have been designed with battery safety measures like:
A. Pressure-sensitive vent holes
Batteries are pressurized and so they need an outer wall made of metal, which has a pressure-sensitive vent hole. If there’s a risk of the battery becoming very hot and exploding from over-pressure (pressure buildup at 3,000 kPa), this vent will release the extra pressure and prevent other cells in the battery pack from catching fire.
B. Separator serves as a fuse
Most lithium-ion cells use a separator made of a material known as polyolefin, which boasts of good chemical stability, excellent mechanical properties and is affordable. It serves as a fuse when the cell heats up. On excessive heat, when the core reaches 130°C (266°F), the separator melts which stops the transport of ions. This action immediately shuts down the cell.
Had this provision not been provided, there would have been a possibility of the heat in the failing cell to give rise to the thermal runaway threshold and vent with flame.
C. Positive Temperature Coefficient (PTC)
This a switch that prevents the battery from overheating by protecting it against current surges
Lithium-ion cells like all chemistries undergo self-discharge. Self-discharge means the batteries lose their stored charge without connecting the electrodes or the external circuit. This takes place due to chemical reactions inside the cell. Self-discharge of cells increases with age, cycling, and elevated temperature.
Elevated self-discharge can cause temperatures to rise which if uncontrolled can lead to a Thermal Runaway also known as ‘venting with flame’. A mild short won’t cause thermal runway because the discharging energy is very low and little heat is generated.
If however due to some damage to the cell, impurities penetrate into the cell, a major electrical short can develop and a sizable current will flow between the positive and negative plates. There is a sudden rise in temperature and the energy stored in the battery is released within milliseconds. Battery packs consist of thousands of cells packed together.
During a thermal runaway, the heat generated by a failed cell can move to the next cell, causing it to become thermally unstable as well. This chain reaction can cause the entire pack to be destroyed within a few short seconds.
Now that we know why lithium-ion batteries catch fire, let’s look at the some of the ways this can happen:
A. Manufacturing Defects
Flaws in production can cause metallic particles (impurities) to seep into the lithium-ion cell during the manufacturing process. Battery manufacturers need to ensure stringently controlled cleanrooms for manufacturing batteries.
Another defect could be the thinning of separators which could prove detrimental in actual use. Cells should undergo strict quality-control tests and validation before being sold.
B. Design Flaws
Car companies want to design their cars as sleek and slim while giving the maximum range and performance. These requirements push battery pack manufacturers to come up with compact designs by packing high-capacity cells into a smaller body, messing with an otherwise well-built battery.
Compromising on the design can cause damage to the electrodes or the separator. Either of which could result in a short circuit. Further, the absence of a proper cooling system or vent can cause battery temperatures to rise as the flammable electrolyte heats up.
If uncontrolled, it could result in a chain reaction of cell failures, causing the battery to heat up even more and spiral out of control.
C. Abnormal or Improper Usage
External factors like keeping the battery very close to a heat source or near a fire can cause it to explode. Penetrating the battery pack either deliberately or through an accident is bound to cause a short circuit and the battery to catch fire. That’s why unauthorized disassembly of the battery pack in electric vehicles leads to the lapse of warranty.
Users are advised to only get the batteries checked and repaired from the car maker’s authorized service centers. Even high-voltage charging or excessive discharging of the battery could damage it.
D. Charger Issues
Using poorly insulated chargers can damage the battery. If the charger shorts or generates heat near the battery, it can do enough damage to cause failure.
While lithium-ion batteries have built-in protections to stop them from overcharging, using unofficial chargers can damage the battery in the long term.
E. Low-quality components
In addition to manufacturing defects, using low-quality components is one of the highest causes of battery failures. Increasing competition is driving the prices of batteries down, causing battery manufacturers to cut corners where they shouldn’t. By skimping on poor quality electronics like the battery management system, the risk of battery failure increases.
The battery management system is critical to battery safety and performance. It protects the battery pack from operating outside of its safe operating area. As batteries form a high-value component of an electric vehicle or energy storage system, it’s essential to invest in a smart battery management system that can detect cell failures immediately and prevent the battery from exploding.
What to do when a battery catches fire?
If you notice the lithium-ion battery overheat, try moving the device away from flammable materials and cutting of the current supply. If you’re in an electric vehicle, you should immediately evacuate and never attempt to extinguish lithium battery fires yourself. Your health and safety are far more important, call the emergency services instead.
In case of fire, a standard ABC or BC dry chemical fire extinguisher must be used since these are considered Class B fire. A common misconception is that lithium-ion batteries contain any actual lithium metal. They don’t and that’s why you shouldn’t use a Class D Fire Extinguisher.
There are new and improved methods to douse lithium fires as well. The Aqueous Vermiculite Dispersion (AVD) is a fire extinguishing agent that disperses chemically exfoliated vermiculite in the form of a mist. However, larger lithium-ion fires as that of EVs or ESS may need to burn out. Using water with copper material is effective but is costly.
Battery Safety experts advise against using water even for large lithium-ion fires. Fires like these may burn for days and it’s important to isolate them from flammable materials and prevent them from expanding.
Ensuring Battery Safety
Battery pack makers should adopt a no-compromise approach to battery safety. Lithium-Ion batteries can be made safer by making them ‘smart’. By building a layer of intelligence into the batteries, we can not just diagnose but also predict abnormal usage or performance of the battery. This will help us take timely action, prevent damage to the system and ensure battery safety.
To know more about lithium-ion battery safety, write to us on hello@ionenergy.co
Electric 2 & 3 wheelers such as scooters and rickshaws have complex use-cases that require smarter management of their batteries.ION Energy’sautomotive-grade battery management systems have been designed to meet the requirements of next-generation electric two and three-wheelers.
Learn how ION Energy can help you build a high-performing e-scooter/rickshaw battery pack with long-lasting battery life.
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ION Energy is an advanced battery management and intelligence platform. We’re focused on building technologies that improve the life and performance of lithium-ion batteries that power electric vehicles and energy storage systems.
Our customers typically choose ION Energy because of its reliability, transparency, commitment towards customer success, and innovative business models. OEMs and battery pack manufacturers across the globe choose ION’s integrated battery management solutions to continuously improve the life and performance of the battery.
Also read:Maxwell gets accredited with ISO 9001:2015 Certification
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FAQs
What causes lithium-ion batteries to catch fire? ›
The electrodes are submerged in a liquid called an electrolyte, which allows for the movement of ions and consists of lithium salt and organic solvents. It is these organic solvents which are the leading fire hazard in Li-ion batteries.
What is the main safety concern with lithium-ion batteries? ›Lithium-ion batteries can overheat, catch fire or explode if they are not charged in a safe manner.
How common is lithium-ion battery fire? ›One out of every 10 million lithium-ion batteries fails, a condition that almost always leads to a fire, Ms. Hutchison said. While that is a relatively low rate, the batteries are being used in more devices, including cheaper, uncertified batteries with greater risk, she said.
What are the safety precautions for lithium batteries? ›NEVER overcharge or leave battery charging overnight. NEVER charge a battery or device under your pillow, on your bed, or near a couch. NEVER leave e-bikes or e-scooters unattended while charging. NEVER block your primary way in or out of a room/space • NEVER place batteries in Trash or Recycling bin.
How do you prevent fire from a lithium-ion battery? ›Don't Store Fully-Charged Batteries For Long Periods
Ensure any lithium-ion batteries in storage for longer periods are charged at levels below 30% charge capacity, to minimize the risk of thermal runaway from damage, manufacturing defects, or internal failures.
The central risk with lithium-ion batteries is fire. The batteries are unlikely to catch fire – but they can, through faults inside the battery, or from external damage. And when they do catch fire, the consequences can be serious.
What are 3 negative features of lithium-ion batteries? ›Drawbacks or disadvantages of Lithium Ion Battery
➨It lasts only two to three years after manufacturer. ➨It is sensitive to high temperatures. ➨If the battery is completely discharged, it can no longer be recharged again. ➨It is relatively expensive.
Lithium Batteries and Transportation Regulations
Lithium batteries present both chemical and electrical hazards. Lithium batteries pose hazards during transport including: Short circuits, which can lead to fires; and/or. Leaks of corrosive liquid or other material that can injure people or harm the environment.
Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Built into each pack, the protection circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge.
How do batteries cause fires? ›Once one battery cell goes into thermal runaway, it produces enough heat to cause adjacent battery cells to also go into thermal runaway. This produces a fire that repeatedly flares up as each battery cell in turn ruptures and releases its contents.
What is the biggest safety risk when dealing with batteries? ›
Flammable gases: Batteries emit hydrogen gas, which is flammable. It ignites easily and can cause a fire or explosion if allowed to accumulate in a small area.
What are signs of a lithium-ion battery fire? ›In rare cases, they can cause a fire or explosion. Stop using the battery if you notice these problems: odor, change in color, too much heat, change in shape, leaking, odd noises. If it is safe to do so, move the device away from anything that can catch fire. Call 9-1-1.
What is the leading cause of lithium-ion battery failure? ›While lithium-ion batteries have built-in protections to stop them from overcharging, using unofficial chargers can damage the battery in the long term. In addition to manufacturing defects, using low-quality components is one of the highest causes of battery failures.
What is the difference between lithium and lithium-ion? ›The difference between lithium and lithium-ion batteries is that one is not rechargeable (primary cell) and the other can be recharged (secondary cell). In addition to this, Lithium batteries have a shelf life up to four times longer than lithium-ion batteries and are also much cheaper and easier to make.
What is the difference between lithium battery and lithium-ion battery? ›The main difference between lithium batteries and lithium-ion batteries is that lithium batteries are primary cells and lithium-ion batteries are secondary cells. The term "primary cell" refers to cells that are not rechargeable. on the other hand, lithium-Ion batteries feature secondary cell construction.
What makes lithium batteries hazardous? ›Unlike standard alkaline batteries, most lithium batteries manufactured today contain a flammable electrolyte and have an incredibly high energy density. They can overheat and ignite under certain conditions, such as a short circuit, physical damage, improper design, or assembly.
What makes lithium batteries toxic? ›Lithium-ion batteries contain metals such as cobalt, nickel, and manganese, which are toxic and can contaminate water supplies and ecosystems if they leach out of landfills. Additionally, fires in landfills or battery-recycling facilities have been attributed to inappropriate disposal of lithium-ion batteries.
What are the hazards of lithium? ›► Exposure to Lithium can cause loss of appetite, nausea, vomiting, diarrhea and abdominal pain. ► Lithium can cause headache, muscle weakness, twitching, blurred vision, loss of coordination, tremors, confusion, seizures and coma.
What battery is better than lithium-ion? ›Sodium-ion batteries are an emerging technology with promising cost, safety, sustainability and performance advantages over commercialised lithium-ion batteries.
What are the pros and cons of lithium-ion batteries? ›They provide high levels of charge than other battery technologies, and they have a higher voltage, and can often cost more than some of other types. This makes them more applicable to some electronic circuit designs than other types of battery technology, or in other cases it may make them less suiable.
Which battery is more powerful than lithium-ion? ›
Fluoride batteries have the potential to last eight times longer than lithium batteries, but that's easier said than done. That's because fluoride is an anion, or a negatively charged ion, which is the magic behind its high energy density but is also the reason it's reactive and hard to stabilize.
What are the four main hazards associated with batteries? ›The hazards associated with the types of batteries listed above include chemical, fire or explosion, electrical shock, and ergonomic. These hazards are described further below.
What are battery safety hazards? ›Recharging, moving, or shaking a lead-acid battery can produce an explosive mixture of hydrogen and oxygen gases that escape through the battery's vents. These fumes, if allowed to accumulate in a small area, ignite easily and can cause a fire or explosion.
What are safety concerns with batteries? ›- Avoid bringing metal into contact with batteries. ...
- Never allow both terminals to make contact with an item (particularly yourself) simultaneously. ...
- Do not hand-guide batteries during lifting/moving process. ...
- Practice safe and appropriate lifting procedures.
But when those batteries fail or overheat, they release flammable, toxic gasses that can spark a fast-spreading fire that is extremely difficult to extinguish.
Do lithium batteries give off gas when charging? ›The gases are potentially fatal, they can cause strong irritations to the skin, eyes and nasal passages, and harm the wider environment. These toxic gases can be emitted when a Li-ion battery is overheated during charging.
What is this hazard of lithium batteries? ›Lithium batteries pose a fire hazard, even when they are no longer useful in consumer equipment/products. Damaged, defective, or recalled batteries have greater potential than undamaged lithium batteries to short circuit, to release heat, or even to cause a fire.
Why are batteries a fire hazard? ›Are batteries dangerous? When used properly, no. But batteries can present a fire risk when over-charged, short-circuited, submerged in water or if they are damaged. It's really important to charge them safely too.
What characteristics make lithium a fire concern? ›Finely divided Lithium particles, powder or dust may IGNITE SPONTANEOUSLY in AIR. Lithium reacts violently with MOISTURE, WATER or STEAM to produce heat and flammable and explosive Hydrogen gas and toxic Lithium Hydroxide.
What happens if you leave a lithium battery plugged in? ›This isn't a safety issue: Lithium-ion batteries have built-in safeguards designed to stop them from exploding if they're left charging while at maximum capacity. But in the long term, electronics will age faster if they're constantly plugged in while already charged to 100 percent.
What gases do lithium batteries give off? ›
Li-ion batteries release a various number of toxic substances14,15,16 as well as e.g. CO (an asphyxiant gas) and CO2 (induces anoxia) during heating and fire.
How long can you leave a lithium battery without charging? ›A lithium-ion battery can last anywhere from 8 hours to a few days on a full charge, depending on several factors, including battery type and chemistry, battery size and capacity, usage environment or temperature, and charging practice.