There is no metallic Lithium in a Rechargeable Lithium ion Polymer cell. It is possible to plate-out metallic Lithium but it takes some doing. In a pit side accident what you need to be most worried about is the highly flammable electrolyte. The fire fighting measures (from MSDS) for LiCo2 Panasonic Lithium Ion cells is as follows (it will be the same or similar for the Chinese polymer cells at they use the same chemical system):
FIRE-FIGHTING MEASURE ・Suitable extinguishing media: Plenty of water, carbon dioxide gas, nitrogen gas, chemical powder fire extinguishing medium and fire foam.
Specific hazards: Corrosive gas may be emitted during fire.
Specific methods of fire-fighting: When the battery burns with other combustibles simultaneously, take fire extinguishing method which correspond to the combustibles. Extinguish a fire from the windward as much
as possible.
Special protective equipment for firefighters: Respiratory protection: Respiratory equipment of a gas cylinder style or protection-against-dust mask Hand protection: Protective gloves Eye protection: Goggle or protective glasses designed to protect against liquid splashes Skin and body protection: Protective cloth.
In my view, the use of a LiPo sack is a good move forward as it will help to contain any fire and shield the user or surrounding materials. As I understand it, the LiPo Sack rule is one that must be adopted by the regions. We have added it to the rules section of our website
www.brca-midwest.co.uk