Lithium Batteries Present Unique Fire Risks

March 6, 2020 garry.mcgauran

In this article Emerging Tech Safety addresses the major role lithium batteries are playing in the digital age. We explore the factors that are driving demand for this technology, and highlight the risk-related areas that require attention from employers and organisations.

Technology: Lithium batteries

Technology category: Energy storage

Battery types: Rechargeable. Disposable.

Work applications: Portable devices. Electric transport. Mass storage systems.

Risks: Fire. Explosion. Toxic fumes. Asset and business loss.

Those at risk: Product designers. Product researchers. Product manufacturers. Product consumers. Companies and organisations utilising electronic devices.

we highlight the risk-related areas that require attention from employers and organisations

Lithium mining and extraction

Lithium is mined from lithium-rich salt flats in the Andes

Lithium is a relatively light metal capable of storing an abundance of energy via batteries. It is mainly mined from lithium-rich salt flats in the higher regions of Chile, Bolivia and Argentina. This process of extraction involves the pumping of salt water from underground chambers and allowing the brine to evaporate in artificially created settling ponds. This method is cheap to produce because it uses the suns energy to evaporate the brine. Lithium is also mined from rock in Mexico, the US, China, and Western Australia.

It is worth noting that lithium is now considered an industrial mineral, and lithium mining comes with environmental costs such as water and soil pollution. Lithium is a finite resource and many of the technologies developed in the digital age depend on lithium batteries.

Lithium battery types and applications

Lithium batteries are everywhere in the modern developed world. They provide extremely high energy relevant to their weight, size and cost. There are currently two types of lithium batteries in use:

1. Disposable lithium batteries

Sometimes known as Lithium metal batteries these are light single-use cells. They mostly contain metallic lithium and cannot be recharged. Due to their chemistry and voltage disposable lithium batteries pose a much lower safety risk than the rechargeable variety. Single-use lithium batteries come in the form of button cell batteries, Lithium 9 volt, AA and AAA. Common applications include consumer electronics, such as watches, toys, clocks, laser pointers, hearing aids, and TV controls.

There are also newer disposable lithium batteries on the market which are more suited to industrial applications, including Lithium thionyl chloride and Lithium iron disulfide. Of particular interest is Lithium thionyl chloride batteries which have a particularly high voltage, an excellent shelf-life, and a high tolerance to extreme temperatures. These qualities make them an attractive option for applications in remote sensing devices (IOT), in medical devices and in fracking technology. In addition to their high energy content and ruggedness, they contain liquid thionyl chloride, which is toxic by inhalation and corrosive to the skin, eyes, and mucous membranes. Continuous exposure to fumes may cause lung damage. LTC batteries are not used on consumer devices and because of their chemistry should only be utilised by trained technicians. They should also be treated with the same caution as rechargeable lithium batteries.

2. Rechargeable lithium batteries

Since their introduction lithium batteries have become the standard for rechargeable devices. These are commonly used in laptops, phones, scooters, hospital equipment, cameras, IOT devices, and anything that requires regular use.

With rechargeable lithium batteries there are four basic cell designs which include prismatic, cylindrical, polymer/pouch and button varieties. Polymer/pouch designs are typically found in research devices, tablets and laptops. Most portable electrical devices require numerous connected cells in packs to achieve the required voltage and storage capacity.

Many multi-cell batteries have built-in circuitry which control the charging and discharging functions. This means it will control charge and discharge when the required voltage, max temperature or capacity exceeds the preset values. These are sometimes known as “smart batteries”.

Lithium-ion batteries use liquid lithium ion as electrolyte, and have a particularly high energy density. They tend to lose power capacity when ageing, charge slower, and are particularly sensitive to temperature. Because of their higher tolerance to impacts and vibration lithium-ion batteries are commonly utilised in newer laptops, cell phones, power tools, e-bikes, e-scooters and newer electric cars. Lithium ion is also recognised as the future of mass energy storage systems.

Lithium polymer (LiPo) batteries use a solid or gelatinous polymer as the electrolyte. They can retain a charge while ageing slowly. In general LiPo batteries cost more but are considered the safer of the two rechargeable types with less chance of explosion. Because of their lighter weight they are the preferred power source for radio controlled helicopters, drones, and electric aircraft. LiPo batteries are subject to the ‘memory effect” and must be charged fully on the very first charge to access the full battery capacity thereafter. They also require special care required when storing and discharging unused voltage.

What is driving demand for lithium batteries?

Electric vehicles are creating a surge in lithium demand

Lithium as a mineral has been referred to as “white gold” due to its role in the development of 21st century technologies. The two main drivers for lithium batteries are mobile applications, and mass energy storage applications.

Mobile applications

As highlighted there are a multitude of mobile applications that utilise lithium batteries such as telecommunications, IT, and sensor devices. However the main economic demand comes from the move towards electric vehicles, and away from the combustion engine. The Netherlands for example want to be fully electric by 2030. And China is aiming for 3 million e-cars on the road by 2025 in order to lower its carbon footprint.

As the price of LiPo batteries comes down and efficiencies improve, lithium-ion batteries will continue to take over from traditional power supplies used in data centres and other mass storage applications

Mass energy storage applications

Lithium-ion batteries are fast becoming the preferred mass energy storage method for data centres over traditional valve-regulated lead-acid (VLRA batteries). The data-centre industry is particularly conservative and cautious, and any lithium-ion batteries utilised by data centres have already been used and improved on by the e-vehicle sector. As the price of lithium batteries comes down and efficiencies improve, lithium-ion batteries will continue to take over from traditional power supplies used in data centres and other mass storage applications.

Lithium battery risks

Overheating of lithium-ion batteries is a significant fire risk

High energy densities along with flammable organic electrolyte make rechargeable lithium batteries a significant fire hazard. Since their introduction in the early 1990’s there has been a spate of high profile fire and explosion incidents associated with both lithium ion and lithium polymer batteries which have highlighted the need for awareness, control, and changed behaviours:

In 2007 Toshiba recalled 10,000 lithium-ion batteries used in HP laptops due to reports of overheating
In 2016 Samsung recalled the Galaxy Note 7 phone due to overheating during charging. The model was eventually discontinued.
In 2018 and 2019 a spate of exploding e-cigarette devices made international news
In 2018 Amazon ceased sales of low grade hoverboard brands due to recorded fire and explosion risks
Several airplane fires and emergency landings have been recorded due to exploding and smoking batteries mid-flight

Thermal runaway hazard

The failure and rapid overheating of lithium batteries results in a process known as “thermal runaway”. This is a chain reaction event where the temperature of the batteries rises quicker than it can be dissipated. The resulting overheating causes the adjacent battery cell to go into thermal runaway causing a chain reaction. A thermal runaway is a unique fire event whereby the fire repeatedly flares-up as each cell reacts to the heat. The following activities can result in fire and explosion in lithium battery cells:

Short circuit or cell failure due to manufacturing deficiencies
Puncture or rupture due to impact or fall
Overcharging, or extreme external temperature

Battery fires

The potential for loss of life, serious property damage, and threats to business continuity are very real where lithium battery fires are concerned. Lithium fire hazards produce rather strange reactions and the fires can range form black smoke, to fireballs, right up to explosions. In all instances these fires will produce flammable gases, toxic gases and flying debris. Dangerous concentrations of combustion by-products can affect the human respiratory system. The severity of fire and explosion associated with these batteries depends on the electrolyte, voltage, capacity, amount of charge, and the cell construction.

Comment

Lithium batteries do present unique fire and explosive risks however these can be mitigated with the right management practices

Lithium batteries have become an integral part of the modern workplace and their use is set to rise dramatically. They are a key component in technologies that will transform the modern workplace. Lithium batteries do present unique fire and explosive risks that should not be taken lightly, however these can be mitigated with the right management practices. Organisations should consider the following actions to ensure lithium batteries do not impact health and business continuity:

Actionable information

Risk assess the procurement, storage, transport, charging, use and disposal of lithium-ion batteries for your organisation.

Develop standard procedures for purchasing, storage, transport, charging, use and disposal of lithium-ion batteries at your organisation

Educate and communicate procedures and safe practices (see below) to battery purchasers and users, and to those involved in disposal of damaged batteries.

Provide necessary safety resources to users i.e. storage and charging space, certified electrical goods, original charging parts, and fire safety equipment.

Lithium Battery Safe Practices

Procurement

Procure batteries and electrical devices from reputable providers and outlets.
Give attention to selection of the correct size and type of battery for the application.
Only purchase batteries and devices with the correct mark and certification of conformance for that particular jurisdiction e.g. CE, FCC, CSA, ACMA.

Shipping

Before shipping lithium batteries, contact the relevant transport authority regarding their requirements.

Flights

Before flying with batteries check each airlines lithium battery rules.
Carry each battery in a good quality fire storage bag. We recommend the ROSENICE Fire Proof Bag and the larger ENGPO Battery Fire Bag for their construction and value.
Tape across the battery contacts to isolate the terminals.
Never check-in spare batteries with flight luggage.
Smart luggage with inbuilt Lithium batteries should be identified at check-in.
Tape devices in the “OFF” position to avoid accidental activation during flights.

Charging

Create a designated charging zone at your premises i.e. on a concrete or ceramic base
Ensure the charging zone has a 60 min fire break wall separating it from production, office, and retail areas
Never charge batteries in the vicinity of other combustibles, chemicals or battery chemistries.
Only use the manufacturers charger, cord, and power adaptor
Never overload a single wall socket and utilise a good quality multi-port socket when charging multiple devices. These are equipped with long leads, allow all devices to be charged in a the designated area, and allow a short circuiting battery to be isolated without handling the device. They are also fireproof, and protected against surges and overheating.
It is advised to never leave charging batteries unattended or charging overnight.
Ensure fire detection systems are utilised in the charging area and the storage area. The Nest Protect Fire Alarm allows building owners to be alerted to smoking batteries via their phone. This is particularly important in catching smoking batteries and preventing large-scale fire and damage.
Keep an ABC dry powder extinguisher outside the charging and storage area i.e. it should be accessible from the room entrance.
Do not allow staff, students or guests to charge large lithium batteries e.g. drones, scooters, e-bikes, on the premises without following internal protocols.
Never charge a warm or recently used lithium batteries. Allow them to cool first.
Following a period of charging, batteries should be allowed to cool down for a period before use.

Storage

Prolonged storage of batteries causes them to age. Note the shelf life of each battery being stored, and rotate it as required.
Develop a battery inspection schedule and safely dispose of underperforming, overheating, leaking, damaged, or bulging batteries.
Remove redundant batteries from premises and only store what is required for active business.
Store batteries in their own preparatory fire bag, or in a good quality fire chest.
Ensure battery storage areas have a 60 minute fire break wall separating it from production, storage, and retail areas.
Avoid storing batteries in damp areas and away from extreme temperatures (-40°C or above 50°C).

Diposal

Redundant batteries should be recycled and not sent to landfill.
When recycling, tape over the battery contacts before placing them in the correct disposal bins.
Lithium battery recycling and disposal bins should be non-combustible and non-metallic receptacles with a high melting point.
Identify lithium battery waste when utilising a licensed waste provider.

Note: Lithium battery safety and workplace safety is your responsibility. Always follow the battery manufacturers directions. You should use the above information as general guidance.

Emerging Tech Safety