In any sort of ‘combat’, it’s a good idea to know the enemy.
The ‘Taming of Fire’ sets man – Homo sapiens – apart from all other creatures on earth. The fire that early man tamed, probably started from burning grass ignited by lightning, and later the chance discovery that some stones and minerals made sparks together.
Whatever and whenever the origin, for millennia thereafter, fire was no more than the burning of carbon-based plant material, natural waxes and oils. Fire was simple – fairly easy to start, and easy to extinguish ‒ if not too big.
This all changed with the Scientific Revolution in the early 17th Century when man’s understanding of Chemistry and Physics created Fire which could be much more powerful and less easy to manage. Even so, most of the Fire that humans dealt with was still hydrocarbon burning in air – easy to start and fairly easy to extinguish with water.
Lithium-ion Batteries change all that. It’s a new chapter and that’s what this post is about. To keep you safe, you need to see how and why Li-ion fires are so different….
We want you to understand what is happening and what happens next if a battery ‘goes off’.
It will be easier to understand if we look at the way the batteries are arranged, and then look at the way that they can fail.
Do you remember the Filo Pastry ‘Battery’! post of June 10 “We need to Manage the Risk”
……. we described the battery as being ‘..packed with very reactive chemicals… which contain a huge amount of energy’. We make use of this chemical energy to make lots of electrical power…. but if the chemicals get mixed up they can release all that energy very quickly, and that is the Hazard of Li-ion batteries. If the battery is fully charged then that stored electrical energy also is released, maybe instantly, making everything much more dramatic.
The chemicals are layered in thin envelopes with Cathode, Anode, Electrolyte and Separators – the thin plastic semi-permeable films which allow the ions (the charges) to pass, but must NOT allow the chemicals to mix. These are visible in the image – the tissue-thin film. If they are ruptured the battery suffers what Elon Musk picturesquely calls “rapid unscheduled disassembly”, because the chemicals mix, making a violent reaction, producing smoke and gases, and usually a lot of heat. The smoke and gases are everything you don’t want! They are poisonous, and very flammable, and they react with each other.
*** Note: You will find many videos of people cutting Li-ion batteries open and saying that they can repair them. PLEASE do not try this at home. The consequences of making a mistake could be death, burning your house down, or at least a broken finger-nail. Remember, every bit of the battery is hypersensitive – that’s why they burn so easily and so hot
Where you will find Lithium-ion batteries –
The batteries are either rolled and put in a small metal ‘Can’, like an oversize AA battery, or for phones and computers they usually are made in pouches so that they lie flat.
Small appliances like Phones and Vape batteries usually are one battery cell only.
Computers usually have 4 pouch cells, Scooters may have 20 ‘Can’ cells or more….and Electric Vehicles – cars, may have 3000 to 8000 ‘Can’ type cells.
In earlier Posts we have talked about the way that Li-ion batteries can fail … let’s check one more time.
Ageing, including the growth of crystals of Lithium – Impact – Piercing – Water….
Any one of these can cause the Battery to fail – to overload some cells – to overload or overheat part of the battery – to cause an internal short circuit…….
…. and then there will be internal overheating, outgassing, ignition and explosion, and fire. Do you get any warning that a Li-ion battery is about to ‘go off’?
If you have experienced a li-ion vape or phone explosion, please tell us in the Comments about any warning you had, so the Author and his Readers can be informed about your personal experiences.
– treating the battery well. Don’t overcharge it …. always use the ‘right charger’…… don’t drop it or hit it or let it get wet, and most importantly don’t let it get overheated. We have talked about not using a laptop in bed – it stops the fan’s cooling airflow. Don’t leave your phone on the dash of your car, in the sun….. and so on. Just think…..
Remember that they have the potential to be lethal.
This post is going to tell you the different ways an explosion or flame in a Lithium-ion Battery can hurt you.
We can simplify the stages of a Li-ion Battery ‘Event’ to about three or four stages.
They will be in this order, but they may happen so fast that you will not notice them happening, or they may happen all at the same time –
- Hissing and popping noises
Overheating, by any internal or external cause will create heat and more internal breakdowns. Because of the electrolyte’s nature, a 20% increase in battery temperature causes chemical reactions to occur much faster, which release more excessive heat. This excess heat increases the battery temperature, which makes the reactions more violent. The increased battery temperature increases the reaction rate, creating a process called Thermal Runaway.
At this point the ‘Event’ cannot be stopped.
Hissing and popping are the sounds of cells venting. Venting because they have electrolyte mixing cause by overheating, separation membrane failure, external damage, old age, over charging, internal short circuit, and the rest. With the hissing and popping the battery will start outgassing, although outgassing may also be the first sign of the battery overheating. - Outgassing
The batteries may vent ‘white’ gases or ‘black’ gases – looking like smoke, or both, or a mixture. Some gases are lighter than air and rise to the ceiling and fill the space downwards.
Some gases are heavier than air and roll along the floor filling upwards when they come to an obstruction.
The gasses themselves are extremely dangerous …… a mixture of more than a dozen – both poisonous and flammable gasses, (but some in low concentration) ….
They are either, Poisonous – Organo-Phosphoron-Fluoridates (precursers to Sarin Nerve gas), Carbon Monoxide, and others, or Flammable/Explosive – Hydrogen gas – and Organic Solvent Vapours - Ignition
When the gasses meet they probably will have a chemical reaction. A short circuit at the battery will ignite them, so there probably will be a flash flame at ignition and then the gases will burn with a ‘jet flame’ as they expand out of the battery cells under pressure – like a gas welding or cutting torch. When this happens, the temperature in a battery can rise from 212°F (100°C) to 1,800°F (1,000°C) in just ONE second.
VERY IMPORTANT NOTE:
IGNITION IS NOT NECESSARILY A SINGLE EVENT.
Remember we showed that larger Li-ion batteries are made up of many cells. As one lights up and burns, the next ones are ‘cooking’. When a laptop blows out a battery, you might think it is ‘over’ if the computer doesn’t continue to burn with flames. You might be tempted to pick it up and take it outside, but BEWARE the second cell of the four-cell battery may go off while in your hands, followed by the third and fourth.
The same with a scooter battery…. You might get a series of maybe ten or more separate small explosions, each one with a jet flame…. or more likely they might all go up at once which will probably burn down your house.
Tests have been run on lithium-ion Scooter batteries in which it took only 15 seconds from the first sign of smoke, to the windows of a house being blown out.
In a traditional fire, it typically takes about three minutes for a room to be engulfed.
4. Aggressive Chemicals
As if the fire itself is not enough, there is a real danger of being hurt by the chemicals that are involved. The Battery produces a lot of chemical ‘smoke’ and gases when it bursts. We have listed some of the poisonous gases that are produced. Don’t stand around breathing them. Hydrogen Fluoride in particular is very poisonous and also affects the eyes, and many others are poisonous.
But there is another hazard, and that is the chemicals themselves that are in the Batteries, and the chemicals that they make when they interact.
We have seen in our Blog Post “Vape Russian Roulette – the 21st Century game of ‘Chicken’” that a common injury from Vapes or their Batteries exploding in pockets are quite severe CHEMICAL burns, together with the thermal burns from the fire.
We seem to forget about the chemicals, but they are there even if the vape bursts but does not catch fire. The chemicals and gasses can hurt you badly.
And there is another unseen consequence. After a Li-ion battery fire, the water that is left behind after extinguishing the fire is contaminated with rather nasty chemicals, which need to be dealt with. Usually we flush them down the drain or the gutter, into the ….. er ….. wherever.
Just remember – the fire is not the only hazard.
Blog Post #10 which follows very soon, will help give you an Answer MAYBE…
in Association with 
