Where are lithium-ion batteries found? What are their risks?
Based on our experience as a manufacturer and our know-how on fire resistant safety cabinets in accordance with the European standard EN14470.1, 90 minutes version, and given the risks related to Lithium batteries explained below, we have created a range of safety cabinets, allowing to :
Store your lithium batteries
Store and charge your batteries
Trigger a special Lithium fire extinguishing system
Alert the emergency services in the event of a problem (smoke detection, fire, etc.)
We have pushed the safety requirement further by creating cabinets that resist beyond 90 minutes up to 105 minutes, thus positioning us as the only ones on the market to offer such fire resistance.
What is a lithium-ion battery?
A Li-ion battery, or Li-ion accumulator, consists of two electrodes (cathode and anode) and an electrolyte that provides the ion exchange of the system.
During the discharge (use) of the battery, ions move from the anode to the cathode. During charging, the reverse occurs. These two electrodes are insulated by a separator which prevents a short circuit.
Advantage: very long life
Disadvantage: flammability, thermal runaway
What are the dangers of these batteries?
Of the 50 potential accidental scenarios identified by INERIS (Institut National de l’Environnement Industriel et des Risques) during the various stages of the battery life cycle, 12 were considered critical. They concern in particular the storage, recharging and use stages. The most problematic outcome of these risks concerns battery fire (or metal fire). This is a significant risk because the fire caused by lithium-ion batteries cannot be extinguished in a conventional way, as the battery itself generates the oxygen molecules and heat needed for combustion. It can only be extinguished with the help of special powders, all in a confined environment (with the risk of the powder losing its effectiveness).
How do these battery fires arise?
By thermal runaway due to overcharging or exposure to excessive temperatures
A battery usually delivers the chemically stored energy on discharge as electrical energy. However, not all of the energy may be delivered as electrical energy, but may cause overheating that can be as much as 7 to 11 times the electrically stored energy. Given the structure of the battery, the reaction itself becomes stronger and causes critical overheating. The battery materials also release bound oxygen, which further fuels the fire.
By full discharge
Full discharge due to not using the battery for too long periods can damage the battery. If the battery is then exposed to temperatures that are too cold, this can cause a change in the physical-chemical properties of the electrolyte liquid and lead to the formation of flammable gas. The absence of the liquid breaks down the protection of the battery, leading to a short circuit or fire.
By mechanical damage
Shocks or misuse can damage the internal structure of the battery and lead to deterioration of the battery separator, leading to a short circuit or fire.
How to store them safely?
Storage recommendations depend on the size and power of the battery:
Low power lithium batteries (less than 100 Wh per battery)
These are the small batteries contained in telephones or computers, for example.
No special safety requirements apply here, as long as all the manufacturer’s instructions and safety locations are followed.
For larger quantities stored (volume over 7 m3) the guidelines for medium capacity lithium batteries apply.
Medium capacity lithium batteries (approx. 100 Wh per battery and 12 kg gross per battery)
Batteries in this category are used in electric bicycles, electric scooters or similar small vehicles. They should be stored in separate fire-resistant enclosures (e.g. a fire room or safety cabinet).
For larger quantities stored (60 m2 occupied area) the guidelines for high capacity lithium batteries apply.
High capacity lithium batteries (more than 100 Wh per battery and 12 kg gross per battery)
Batteries in this category are mainly used in electric cars and large stand-alone appliances. The recommendations for the storage of medium power batteries should form the basis for consideration. However, safeguards should be put in place on a case-by-case basis after consideration. If the storage space is large, fire protection must be adapted. If the use of sprinklers is allowed, it should be as localised as possible and it is recommended that the batteries are separated and stored in a confined environment to prevent a fire outbreak.
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