Li-ion battery having improved safety against combustion

1. A process for forming a Li-ion battery having a region of electrochemical activity and an enclosure therefor, said process comprising:

forming a first chamber within said enclosure separate from said region of electrochemical activity;

providing a vent in said enclosure;

positioning said first chamber between said vent and said region of electrochemical activity; and

positioning a composition comprising at least one combustion abatement agent within said first chamber, wherein said at least one combustion abatement agent comprises liquid fluoropolyether, whereby said composition is not in contact with said region of electrochemical activity;

said first chamber being pressure and/or heat sensitive, whereby when said region of electrochemical activity overheats, said first chamber is breached, allowing said at least one combustion abatement agent to contact said region of electrochemical activity to abate combustion of said region of electrochemical activity, and said vent releases pressure upon said overheating.

2. The process of claim 1 further comprising positioning a first membrane between said first chamber and said region of electrochemical activity.

3. The process of claim 2 , wherein said first membrane is breachable by said overheating to thereby release said combustion abatement agent into said region of electrochemical activity to abate combustion therewithin.

4. The process of claim 3 , wherein said first membrane is breachable by rupture by said overheating.

5. The process of claim 3 , wherein said first membrane is breachable by melting by said overheating.

6. The process of claim 2 , wherein said first membrane comprises a thermally-destabilizable fluoropolymer.

7. The process of claim 6 , wherein said thermally-destabilizable fluoropolymer is selected from the group consisting of a tetrafluoroethylene/hexafluoropropylene copolymer and a tetrafluoroethylene/hexafluoropropylene/perfluoro(alkyl vinyl ether) copolymer.

8. The process of claim 6 , wherein said thermally-destabilizable fluoropolymer has at least 300 unstable end groups per 10 6 carbon atoms, said end groups being selected from the group consisting of —COOH, —COF, and —CONH 2 .

9. The process of claim 1 , wherein said enclosure comprises metal foil.

10. The process of claim 1 , wherein said enclosure is a can.

11. The process of claim 1 , wherein said composition further comprises decomposition catalyst and solid material.

12. The process of claim 11 , wherein said at least one combustion abatement agent further comprises said solid material.

13. The process of claim 11 , wherein said decomposition catalyst comprises a Lewis acid.

14. The process of claim 11 , wherein said composition is in a semi-solid state.

15. The process of claim 1 , wherein said liquid fluoropolyether is a perfluoropolyether.

16. The process of claim 1 further comprising providing a closure on said vent such that said closure opens said vent and releases said pressure through said vent, the opening of said vent accompanying the rupture of said first membrane.

17. A process for forming a Li-ion battery having a region of electrochemical activity and an enclosure therefor, said process comprising:

forming a first chamber within said enclosure separate from said region of electrochemical activity and forming a second chamber remote from said first chamber within said enclosure, wherein said second chamber comprises a second membrane breachable by overheating;

positioning a composition comprising at least one combustion abatement agent within said first chamber, wherein said at least one combustion abatement agent comprises liquid fluoropolyether, whereby said composition is not in contact with said region of electrochemical activity, said first chamber being pressure and/or heat sensitive, whereby when said region of electrochemical activity overheats, said first chamber is breached, allowing said at least one combustion abatement agent to contact said region of electrochemical activity to abate combustion of said region of electrochemical activity; and

positioning a vent at an end of said enclosure and positioning said second chamber between said vent and said region of electrochemical activity, whereby said combustion abatement agent from each of said first chamber and said second chamber is released into said region of electrochemical activity upon said overheating to thereby abate combustion within said region of electrochemical activity.

18. The process of claim 17 , wherein said second membrane is breachable by rupture by said overheating.

19. The process of claim 17 , wherein said second membrane is breachable by melting by said overheating.

20. The process of claim 17 , wherein said second membrane comprises a thermally-destabilizable fluoropolymer.

21. The process of claim 20 , wherein said thermally-destabilizable fluoropolymer is selected from the group consisting of a tetrafluoroethylene/hexafluoropropylene copolymer and a tetrafluoroethylene/hexafluoropropylene/perfluoro(alkyl vinyl ether) copolymer.

22. The process of claim 20 , wherein said thermally-destabilizable fluoropolymer has at least 300 unstable end groups per 10 6 carbon atoms, said end groups being selected from the group consisting of —COOH, —COF, and —CONH 2 .

23. The process of claim 17 further comprising positioning a first membrane between said first chamber and said region of electrochemical activity, wherein said first membrane is breachable by said overheating to thereby release said combustion abatement agent into said region of electrochemical activity to abate combustion therewithin.

24. The process of claim 23 , wherein said first membrane comprises a thermally-destabilizable fluoropolymer.

25. The process of claim 17 , wherein said enclosure comprises metal foil.

26. The process of claim 17 , wherein said enclosure is a can.