The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 20, 2000

Filed:

Aug. 14, 1997
Applicant:
Inventors:

Porter H Mitchell, Las Vegas, NV (US);

Jeremy Barker, Henderson, NV (US);

Tracy E Kelley, Henderson, NV (US);

Assignee:

Valence Technology, Inc., Henderson, NV (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01M / ;
U.S. Cl.
CPC ...
429217 ; 429212 ;
Abstract

The methods and compositions of the invention provide two solutions to reduce the reactivity of VDF-based copolymers to lithiated graphite. The two approaches can be used separately or combined. In one embodiment, the relative proportion of the VdF and the other fluorinated monomer (OFM, i.e. HFP) in the copolymer is significantly reduced below conventional formulations in order to reduce the reactivity of the copolymer. In a second approach, the reactivity of the copolymer, over a broad range of monomer VdF:OFM molar ratios, is reduced by deactivating the reactive sites on the copolymer, thereby blocking the ability to undergo undesired reaction during cell operation. These methods and compositions have heretofore not been proposed and are of primary importance in preventing large exothermic reaction which can lead to thermal runaway when conventional polymer formulations are utilized in batteries in the presence of reactive components such as lithiated graphite.


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