I've worked with a lot of robots/machines with large lipo and LiFePO4 batteries and as far as I'm aware your best bet is to let it burn and try to prevent the surroundings from catching fire. Using water can make it burn longer.
Water does work to suppress Li-ion fires. Its important that we spread this news because many people online confuse Li-element with Li+ ions. They work very differently in practice.
It just takes a LOT more water than you probably expect. But high quantities of water is effective. As Li-ion batteries become more common in our devices (and even vehicles), knowing that water is a usable solution is helpful. We obviously need to develop better tactics than dumping 36,000+ gallons per car fire however.
Listed is many EV manufacturer's official recommendations for how to fight an EV fire. I'm choosing a large, well respected EV manufacturer. Lets choose Rivian for sake of this argument.
Oh look at that? They say to use thousands of gallons of water (2000 to 3000 gallons for the initial fire), and then work to keep the Li-ion cells below 100C for at least the next 24-hours (which is obviously easiest in what I've discussed elsewhere in this thread: a full submerged container). I've seen other fire-department manuals recommending 7-days (a full week) of submerged cells just to be sure.
In practice, fire-departments do not have the equipment for that long-term sustained cooling. So they end up baby-sitting the car for like 8+ hours and keep spraying it with a hose every few minutes, wasting tens-of-thousands of gallons of water. Its not the best solution and its a high cost both in water and fire-department's time, but it does work when a container (or other device) is unavailable.
Sure, you win. That was the first result that came up for me on google. If I have a class B fire extinguisher around then I'll use that before using water.
The problem is that a fire extinguisher only works on the initial flames. If the battery pack remains overheated (as is the case in a large vehicle fire), it will spontaneously combust a few minutes later. This problem is well documented in all the fire-department manuals / discussion on EVs.
So you're literally spreading misinformation on how to properly fight an EV Fire. I mean, not on purpose or whatever, what you're saying is a common misconception. But IMO, its in our best interest to spread the proper firefighting tactics across our society so that everyone's on the same page on the dangers here.
Well, I don't have an EV and I'm not a firefighter, so EV battery fires aren't on my radar. If I had an EV and it caught fire I'm not going to try and put it out. The biggest batteries in my life these days are less than 2kWh, so I'm going to use the class B fire extinguishers I bought after I've already called the fire department.