Electrochemical Cells Employing Expandable Separators

Abstract

An electrochemical cell is provided comprising a first electrode and a second electrode. A separator, which includes an expansion joint, surrounds and seals the first electrode. The separator may comprise a first major surface and a second major surface substantially opposite the first major surface, and the expansion joint may be coupled between the first major surface and the second major surface.

1 . A separator assembly for enveloping an electrode of an electrochemical cell, the separator assembly comprising:
 a first sheet;   a second sheet substantially opposite said first sheet, the electrode between said first sheet and said second sheet; and   an expansion joint disposed around said electrode between said first sheet and said second sheet, said expansion joint having at least one fold therein and configured to expand to allow divergence between said first sheet and said second sheet.   
     
     
         2 . A separator assembly according to  claim 1  wherein said expansion joint is sealed to said first sheet proximate the electrode. 
     
     
         3 . A separator assembly according to  claim 2  wherein the electrode comprises an upper portion having a first circumference, and wherein said expansion joint is sealed to said first sheet around said first circumference. 
     
     
         4 . A separator assembly according to  claim 2  wherein said expansion joint is sealed to said second sheet proximate the electrode. 
     
     
         5 . A separator assembly according to  claim 1  wherein first sheet is sealed to said second sheet. 
     
     
         6 . A separator assembly according to  claim 5  wherein said first sheet and said second sheet cooperate to form said expansion joint. 
     
     
         7 . A separator assembly according to  claim 1  wherein said at least one fold is substantially curved. 
     
     
         8 . A separator assembly according to  claim 1  wherein said at least one fold is substantially V-shaped.