Liquid crystal polymer battery enclosure material

Abstract

The present invention features a pouch comprising a single layer of polymer material having a first surface and a second surface, wherein the second surface is disposed to define an interior space surrounded by the second surface of the pouch, and wherein the first surface is disposed to define the exterior of the pouch, wherein the single layer has a uniform thickness between the first surface and second surface, wherein the polymer material comprises a liquid crystal polymer, and wherein the pouch has a water vapor transmission rate of less than 0.1 g/m2/day between the interior space and the first surface of the pouch.

What is claimed is: 
     
         1 . A battery system comprising:
 an electrochemical cell comprising one or more electrodes and at least two electrically conductive tabs extending from the one or more electrodes, wherein the electrochemical cell is a lithium battery or a lithium ion battery; and   a polymer enclosure surrounding the electrochemical cell, wherein the at least two electrically conductive tabs extend from within the polymer enclosure to an exterior of the polymer enclosure, and wherein the polymer enclosure comprises one or more liquid crystalline polymers.   
     
     
         2 . The battery system of  claim 1 , wherein the one or more liquid crystalline polymers have a crystalline melting point of from 250° C. to 375° C. 
     
     
         3 . The battery system of  claim 2 , wherein the one or more liquid crystalline polymers have a crystalline melting point of from 270° C. to 355° C. 
     
     
         4 . The battery system of  claim 1 , wherein the one or more liquid crystalline polymers are selected from the group consisting of: polyesters comprising monomer units derived from 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; a polyester comprising monomer units derived from 6-hydroxy-2-naphthoic acid, terephthalic acid; and a polyester comprising monomer units derived from 4-hydroxybenzoic acid, terephthalic acid and 4,4′-bisphenol. 
     
     
         5 . The battery system of  claim 1 , wherein the polymer enclosure is formed of a single layer of polymer material having a first surface and a second surface, wherein the second surface is disposed to define an interior space of the polymer enclosure and the first surface is disposed to define an exterior of the polymer enclosure. 
     
     
         6 . The battery system of  claim 5 , wherein the single layer has a thickness of between 40-200 microns. 
     
     
         7 . The battery system of  claim 6 , wherein the single layer has a thickness of between 75-150 microns. 
     
     
         8 . The battery system of  claim 5 , wherein the polymer enclosure has a water vapor transmission rate of less than 0.1 g/m 2 /day between the interior space and the first surface. 
     
     
         9 . The battery system of  claim 5 , further comprising a pre-sealed sealing layer adhered to the one or more electrically conductive tabs, wherein a first portion of the second surface of the polymer enclosure is adhered to the sealing layer via an oversized heat seal band, wherein the oversized heat seal band prevents heat conduction in one direction by fostering adhesion between the polymer material and the one or more electrically conductive tabs on one side of the sealing layer to create an airtight seal. 
     
     
         10 . The battery system of  claim 1 , wherein the one or more liquid crystalline polymers are compounded with fillers and/or blend resins in a range of 5-40 wt. % to form the polymer enclosure. 
     
     
         11 . The battery system of  claim 1 , wherein the polymer enclosure includes between 5-80 wt. % inorganic filler. 
     
     
         12 . The battery system of  claim 1 , wherein the at least two electrically conductive tabs are the form of one or more current collector tabs. 
     
     
         13 . The battery system of  claim 1 , wherein the at least two electrically conductive tabs are planar-shaped. 
     
     
         14 . The battery system of  claim 1 , wherein the at least two electrically conductive tabs are formed of copper or aluminum. 
     
     
         15 . The battery system of  claim 1 , wherein the electrochemical cell comprises LiBF4 and/or LiPF6. 
     
     
         16 . The battery system of  claim 1 , wherein the polymer enclosure is produced by thermoforming or injection molding.