Li-ion battery having improved safety against combustion
A Li-ion battery is provided in combination with fluorinated material positioned effective to abate combustion by said battery, the fluorinated material being normally non-gaseous and non-liquid and being itself effective to provide the combustion abatement by said battery, such fluorinated material being is such forms as the material of construction of the battery case containing the battery, film wrapped around said battery, and/or semi-solid material at least proximate to the battery, such as by forming a coating on said battery or said film on said battery.
1. A coated lithium-ion battery comprising:
a lithium-ion battery;
a first fluorinated material comprising fluoropolyether positioned as a coating on said lithium-ion battery, said first fluorinated material being a semi-solid and non-gaseous and non-liquid at ambient temperature and under a pressure of one atmosphere; and
a second fluorinated material comprising fluoropolymer film in contact with said lithium-ion battery;
wherein said fluoropolymer of said second fluorinated material fluoropolymer film comprises a melt processible tetrafluoroethylene copolymer; and
wherein said first and second fluorinated materials are effective to abate combustion of said lithium-ion battery.
2. The coated lithium-ion battery of claim 1 , wherein said melt processible tetrafluoroethylene copolymer is selected from the group consisting of tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene/hexafluoropropylene/perfluoro(alkyl vinyl ether) copolymer and tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer, wherein said perfluoroalkyl group is a linear or branched having from 1 to 5 carbon atoms.
3. The coated lithium-ion battery of claim 1 , wherein said first fluorinated material further comprises solid fluoropolymer.
4. The coated lithium-ion battery of claim 3 , wherein said solid fluoropolymer is a thermally destabilizable fluoropolymer having at least 300 unstable end groups per 10 6 carbon atoms, said unstable end groups being selected from the group consisting of —COON, —COF, and —CONH 2 .
5. The coated lithium-ion battery of claim 3 wherein said fluoropolyether is a liquid under conditions of ambient temperature and a pressure of one atmosphere, but is present as a non-liquid mixture with said solid fluoropolymer under conditions of ambient temperature and a pressure of one atmosphere.
6. The coated lithium-ion battery of claim 1 wherein said fluoropolyether is a perfluoropolyether.
7. The coated lithium-ion battery of claim 6 wherein oxygen atoms in the backbone of said perfluoropolyether are separated by saturated perfluorocarbon groups having 1 to 3 carbon atoms.
8. The coated lithium-ion battery of claim 7 wherein said saturated perfluorocarbon groups are at least one selected from the group consisting of: —CFCF 3 —CF 2 —O—, —CF 2 CF 2 CF 2 —O—, —CF 2 CF 2 —O— and —CF 2 O—.
9. The coated lithium-ion battery of claim 1 wherein said first fluorinated material forms a coating on said second fluorinated material fluoropolymer film.
10. The coated lithium-ion battery of claim 1 , additionally including a case within which said battery is contained, wherein at least the interior surface of said case comprises a melt processible tetrafluoroethylene copolymer.
11. The coated lithium-ion battery of claim 10 , wherein said melt processible tetrafluoroethylene copolymer is selected from the group consisting of tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene/hexafluoropropylene/perfluoro(alkyl vinyl ether) copolymer and tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer, wherein said perfluoroalkyl group is a linear or branched alkyl group having from 1 to 5 carbon atoms.