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So firefighters are lacking in technology to deal with this problem. I wonder how hard it would be to engulf a vehicle with something like a fire retardant exp

So firefighters are lacking in technology to deal with this problem. I wonder how hard it would be to engulf a vehicle with something like a fire retardant expanding foam to contain it? I guess we could practice on our dead mobile phones for a scaled mock up of the problem? At least that would also help deal with the e-waste problem and is something any individual could do in their own garden shed!

RosanaAnaDana 3y ago
There are special chemical fire extinguishers to deal specifically with this. I'd bet dollars to donuts this came out of an insurance exercise where it wasn't necessarily the scale of the risk, but rather the uncertainty around the risk (because of its novelty). Insurance companies are very cautious about uncertainty, even if the risk seems low.
- projektfu 3y ago
  They don't necessarily stop the reactions that started the fires though. If intense heat starts the fire, you likely need to cool it down and continue cooling to prevent reignition, while allowing the reaction to run its course. It's basically a hypergolic fuel once the cells are ruptured.
thatguy0900 3y ago
Look into groundwater poisoning around us air force bases due to firefighting foam practice. Swamping a car with it every time a car battery is punctured would be really bad.
mrguyorama 3y ago
This isn't a technology problem but a physics one: How do you sink a lot of heat energy from a chunk of material that responds to water by reacting and generating a lot of heat? Gasoline carries much more energy than a lithium battery, but spraying it with regular water (I don't know if this is actually common) could disperse the fuel and sap the heat easily, killing two parts of the fire triangle. You just can't do that with a lithium battery. Other fluids which can soak up massive amounts of energy have other problems, like being very toxic. You can't disperse the fuel either, because lithium will react with water anywhere it finds it. There's not that much lithium in a battery, but it's enough to keep re-igniting the rest of the battery.
- darkclouds 3y ago
  CO2 or a carbonate seems to be key. Lithium ion batteries are like semtex or rocket fuel, their weakness is they cant be dispersed easily due to their solid compact nature unlike petrol or diesel or gas vapours which can all be dispersed easily, typically with water, and to transfer heat. A hose that produces a fine mist of water has water droplets with greater surface area with less volume of water which then enables the heat to be absorbed by the water. So the problem seems to be dispersing or containing the reaction to limit damage.

RosanaAnaDana 3y ago

There are special chemical fire extinguishers to deal specifically with this. I'd bet dollars to donuts this came out of an insurance exercise where it wasn't necessarily the scale of the risk, but rather the uncertainty around the risk (because of its novelty). Insurance companies are very cautious about uncertainty, even if the risk seems low.

projektfu 3y ago
They don't necessarily stop the reactions that started the fires though. If intense heat starts the fire, you likely need to cool it down and continue cooling to prevent reignition, while allowing the reaction to run its course. It's basically a hypergolic fuel once the cells are ruptured.

thatguy0900 3y ago

Look into groundwater poisoning around us air force bases due to firefighting foam practice. Swamping a car with it every time a car battery is punctured would be really bad.

mrguyorama 3y ago

This isn't a technology problem but a physics one: How do you sink a lot of heat energy from a chunk of material that responds to water by reacting and generating a lot of heat? Gasoline carries much more energy than a lithium battery, but spraying it with regular water (I don't know if this is actually common) could disperse the fuel and sap the heat easily, killing two parts of the fire triangle. You just can't do that with a lithium battery. Other fluids which can soak up massive amounts of energy have other problems, like being very toxic. You can't disperse the fuel either, because lithium will react with water anywhere it finds it. There's not that much lithium in a battery, but it's enough to keep re-igniting the rest of the battery.

darkclouds 3y ago
CO2 or a carbonate seems to be key. Lithium ion batteries are like semtex or rocket fuel, their weakness is they cant be dispersed easily due to their solid compact nature unlike petrol or diesel or gas vapours which can all be dispersed easily, typically with water, and to transfer heat. A hose that produces a fine mist of water has water droplets with greater surface area with less volume of water which then enables the heat to be absorbed by the water. So the problem seems to be dispersing or containing the reaction to limit damage.