Astronuc said:
Best to cover it with a metal pot. Don't use water on large batteries, which might react chemically to produce hydrogen gas, which would be worse.
I have to do some research. Apparently 'small' Li-ion batteries can be dropped into a pot/bucket water.
Large Li-ion batteries, such as those used in vehicles apparently require a foam or dry extinguisher, e.g., ABC, D, CO2, or other powder.
The good news is that lithium cell fires will burn themselves out reasonably quickly at high temperature. The bad news is that nearby materials are exposed to high temperature, quickly reach ignition temperature expanding the hazard . In addition, adjacent cells in a battery pack will rise in temperature and can self ignite, again expanding the hazard.
Covering the cell will help to smother the fire, and enclose the flames, but not cool the cell. A hot cell can re-ignite if exposed again to the oxygen in the air. Adjacent cells in a battery pack can still self ignite due to internal chemical reactions at high temperature. For a small cell, or pack, covering with a pot, sand, earth, dry chemical may be still considered an option for fire control.
Production of hydrogen gas is the least of concerns at the onset of the flames, as enclosed space oxygen, especially in a small room, and dependent upon cell size, is rapidly consumed as the fire progresses, along with other noxious fumes produced from the fire, and from combustion of nearby flammable material. Limiting the spread of the fire to other combustibles in some way is preferred so that a 'small' fire does not become all consuming.
Dunking the cell/battery in water is a wise choice, but then who has a pot of water available at hand, or the tongs necessary to pick up the flaming item, or the time to think rationally under extreme circumstances. A metal sink, bathtub( shower curtain hazard ), swimming pool, hot tub are also choices for control, if possible.
Water is used, not as a means to extinguish the fire, but to cool the cell, and adjacent cells in a battery pack from reaching self ignition temperature - in other words to limit the fire situation to not spread out of control. Tons and tons of water are needed well above that required for a non-electric battery powered vehicle fire. Dry chemical, CO2, and other non-water solutions can temporarily smother the fire from oxygen from the air, but does not cool the item. For example, the fire can restart when the CO2 dissipates.
There is no quick and easy way to extinguish a lithium fire
Usually water is recommended as a control of the fire situation.
AFAIK, airline cabin crew suppress a lithium battery fire with a halon fire extinguisher, and dump the item in the toilet area.
https://www.aviationhunt.com/aircraft-fire-extinguisher/
Safe Use of Halocarbon Extinguishers
Here are some general guidelines for crew members for the safe use of halocarbon extinguishers according to
FAA AC 20-42D.
- Turn off air recirculation: Immediately turn off all air recirculation systems if permitted by your aircraft flight manual (AFM) or flight crew operations manual (FCOM). Halocarbon agents are much heavier than air and typically stratify at lower levels over time. Turning off the recirculation redirects the agent from low-level air returns to the air outflow valves, expelling it from the aircraft more rapidly. Some aircraft have up to 50% recirculation, so it is important to turn off the air recirculation quickly.
- Use Portable Protective Breathing Equipment (PBE): Flight crewmembers should use portable PBE if available and/or as directed by FCOM procedures or AFM. Unprotected personnel should not enter a protected space during or after agent discharge until ventilated. Crew members should follow firefighting procedures when using portable PBE.
- Extinguish the Fire and Ventilate the Cabin: Ensure the fire is completely extinguished. To rid the cabin and flight deck of hazardous gases and smoke, ventilate all unpressurized aircraft compartments overboard at the highest possible rate permitted by established crew procedures for your specific aircraft. However, if the fire is not entirely extinguished or if a smoldering fire persists, be cautious when increasing airflow as it may potentially promote fire growth.
- Descend to Lower Altitudes: Immediately initiate a descent at the maximum safe rate to 8,000 ft. or to an altitude that is as low as practicable. Descending serves to dilute agent concentration, reduce exposure to both agent and combustion gases, and elevate oxygen concentration. Aircraft with a maximum flying altitude of 12,500 ft. can mitigate hypoxia risk without supplemental oxygen by promptly descending as outlined above.
http://sds.staples.com/msds/744903.pdf
MSDS Lithium ion
SECTION III - FIRE AND EXPLOSION HAZARD DATA If fire or explosion occurs when batteries are on charge, shut off power to charger. In case of fire where lithium ion batteries are present, flood the area with water. If any batteries are burning, water may not extinguish them, but will cool the adjacent batteries and control the spread of fire. CO2, dry chemical, and foam extinguishers are preferred for small fires, but also may not extinguish burning lithium ion batteries. Burning batteries will burn themselves out. Virtually all fires involving lithium ion batteries can be controlled with water. When water is used, however, hydrogen gas may be evolved which can form an explosive mixture with air. LITH-X (powdered graphite) or copper powder fire extinguishers, sand, dry ground dolomite or soda ash may also be used. These materials act as smothering agents.
Fire fighters should wear self-contained breathing apparatus. Burning lithium ion batteries can produce toxic fumes including HF, oxides of carbon, aluminum, lithium, copper, and cobalt. Volatile phosphorus pentafluoride may form at a temperature above 230° F.
https://www.renata.com/en-us/downloadfile/asds-lithium-metal/?fileid=a8e84ae2dacd1cf69874af5dd3
MSDS Metal ion
5.1 Suitable extinguishing media In case of fire in an adjacent area, use water. Use CO2 or dry chemical extinguishers if cells are packed in their original containers since the fuel of the fire is basically paper products. For bulk quantities of unpackaged cells use for example LITH-X (Graphite Base). In this case, do not use water. In a small room, remember that the supply of oxygen is quickly consumed in feeding a lithium fire.
5.2 Specific hazards arising from the chemicals When exposed to heat, the battery may rupture and release hazardous substances. Burning lithium manganese dioxide batteries produce toxic and corrosive lithium hydroxide fumes. Lithium metal reacts with water and forms flammable hydrogen gas.
5.3 Special protective actions for fire-fighters Wear self-contained breathing apparatus to avoid inhalation of hazardous decomposition products. Wear protective clothing and equipment.
