Lithium-ion Battery Fires in the Waste Management Industry
Lithium-ion Batteries pose a significant risk to the Waste Management Industry – a risk that’s increasing with the proliferation of battery usage in so many applications, which finds its way into the waste stream.
What is a Lithium-ion Battery?
The below diagram is schematic of a how a lithium-ion battery is constructed.
As can be seen, there are 4 main elements in the power-producing part of the battery – the Anode, the Cathode, a semi-permeable Separator and the electrolyte solution.
If the separator is breached due to physical damage, warping, manufacturing defects or simply old age, the electrons are able to pass from the anode to the cathode and vice versa through the electrolyte solution. This means that the volume and rapidity of transfer can no longer be controlled.
This quickly results in heat generation, compounding the damage to the separator and making things worse. This process is called Battery Disassembly (better known as ‘Thermal Runaway’). Finally, heat and pressures within the battery rise to such levels, that the battery finally bursts into flames and/or explodes.
Why are Lithium-Ion Batteries such a threat to the industry?
In the normal course of things, despite their qualities as the most powerful battery type in circulation, lithium-ion batteries are very reliable. However, as discussed above, if they get damaged, the uncontrolled reaction causes a surge in heat levels leading to combustion.
Due to the nature of the Waste Sector, high-energy processes are used from the moment the material is collected or received into HRWCs. Many of the common process line machinery has potential to damage the fragile components.
In addition, the size of a lithium-ion battery (ranging from button batteries to smartphones to cordless tools) make them extremely hard to identify, yet even a very small one is enough to cause a fire. This means that they could very easily be caught up in any waste stream, only being discovered when the flames start to appear!
Fire Protection Systems
Due to the threat they pose to the industry, having an effective fire protection solution to combat the fires they cause is critical.
Process Line Detection
Detection is the most important part of a fire safety solution. The reason is simple – If a threat is not detected, it cannot be suppressed.
There are two main types of detection process line detection systems that Blazequel recommend, namely Flame Detection and Ember Detection.
Flame Detection relies on optical sight to detect flashes of visual light characteristic of flame. These are mainly used on outfeed conveyors and infeed bunkers where high-energy processes could spark a fire.
Whilst these may not necessarily detect the hot battery itself if it is not actually burning at that point, if material surrounding it catches fire (which is where the greatest risk lies) this will be detected.
Ember Detection works in much the same way as a thermal imaging camera, but is much more sensitive. This system ‘reads’ Infra-Red radiation emitted by a hot object.
In the case of Lithium-ion Batteries, this is probably the most effective system. These are used only on conveyors due to a limited effective range, but are very effective in this application.
Blazequel Case Study
Blazequel installed a system involving ember detection at a DMR recycling facility. The device successfully identified an 18v Lithium-ion battery on a shredder outfeed conveyor in the early stages of thermal runaway – It’s not just theory!
Process Line Suppression
As discussed at the start of this post, a Lithium-ion battery fire works due to the uncontrollable transfer of atoms and electrons. For this reason, extinguishing the fire isn’t just a matter of cooling it down with water. In addition, if the battery is a lithium-metal battery (which is rather different an uses a solid Lithium cathode), the lithium will react violently with water and make the situation worse.
Thankfully Lithium-metal batteries aren’t too common due to their significant limitations and heafty price-tag. For this reason, we still suggest the use of a water-based fire suppression system, primarily Water Mist Suppression.
Water Deluge Suppression Systems
Water Deluge Systems work in a similar manner to sprinkler systems, but suppression is triggered by a third-part detection system (e.g. a Flame Detector or Ember Detector).
They are designed to deliver substantial volumes of water to an area in which a threat has been detected.
In the event of the detection system identifying a threat, a ‘process stop’ can be introduced to prevent the threat being carried further into the plant. This also ensures that the risk stays in the area covered by suppression, and maximises the suppression systems effectiveness.
Many industries praise the power and effectiveness of Lithium-ion Batteries. However, the Waste Sector views the rising consumer demand for these products as a significant threat to plant, property and the industry as a whole.
I hope that you have found this brief document useful in understanding the construction of Lithium-ion Batteries, why they are so combustible and some systems available that are suitable to dealing with the threat. We may need to look at your application in more detail to ensure the system would be suitable and in the correct positions for maximum effect, but please contact our team on the below details and we’d be happy to help.
If you would like to discuss our fire protection systems in more detail and discover how effective systems can be applied to your application, please don’t hesitate to contact us on 01234 357357 or email email@example.com.
Image – Lithium-Ion Battery Construction – https://batteryuniversity.com/learn/article/lithium_based_batteries