Solid gel membrane

Abstract

A highly conductive polymer based solid gel membrane is disclosed. The membrane is especially well suited for use in such electrochemical devices as, for example, aluminum/air, zinc/air, Zn/MnO 2 , Ni/Cd and hydrogen fuel cells, as well as in electrochromic devices such as smart windows and flat panel displays. In accordance with the principles of the invention, anion- and cation-conducting membranes are formed. The gel composition of the membrane contains the ionic species within its solution phase such that the species behaves as in a liquid electrolyte, while at the same time, the solid gel composition prevents the solution phase from diffusing into the device. Methods of forming polymer based solid gel membranes of the present invention are also disclosed.

We claim:  
     
         1 . A polymer based solid gel membrane for use in an electrochemical cell, said membrane having an ionic species contained within a solution phase of said polymer based gel.  
     
     
         2 . A polymer based solid gel membrane according to  claim 1  wherein the polymer based gel comprises the polymerization product of a polymerization initiator and: 
 (a) methylenebisacrylamide, acrylamide, methacrylic acid, poly(sodium 4-styrenesulfonate);  
 (b) methylenebisacrylamide, acrylamide, methacrylic acid, and polysulfone (anionic);  
 (c) methylenebisacrylamide, poly(sodium 4-styrenesulfonate), acrylic acid, 1-vinyl-2-pyrrolidione and a reducing agent; or  
 (d) methylenebisacrylamide, acrylic acid and a reducing agent.  
 
     
     
         3 . A polymer based solid gel membrane according to  claim 2  wherein the polymer based gel is formed on a matrix of a woven or non-woven fabric.  
     
     
         4 . An electrochemical cell comprising first and second electrodes and one or more polymer based solid gel membranes according to  claim 1  disposed there between.  
     
     
         5 . An electrochemical cell according to  claim 4  wherein the first electrode is a zinc anode and the second electrode is an air cathode.  
     
     
         6 . The electrochemical cell of  claim 5  wherein a first protective polymer based solid gel membrane is disposed on the zinc anode and a second hydroxide conducting polymer based solid gel membrane is disposed between said first membrane and said cathode.  
     
     
         7 . The electrochemical cell of  claim 5  wherein a first protective polymer based solid gel membrane is disposed on said anode and a second protective polymer based solid gel membrane is disposed on said cathode, and said electrochemical cell further comprises an aqueous electrolyte disposed between said first and second membranes.  
     
     
         8 . The electrochemical cell of  claim 4  wherein the first electrode is an aluminum anode and the second electrode is an air cathode and a hydroxide conducting polymer based solid gel membrane is disposed there between.  
     
     
         9 . The electrochemical cell of  claim 4  wherein the first electrode is a hydrogen anode and the second electrode is an air cathode and a proton conductive polymer based solid gel membrane is disposed there between.  
     
     
         10 . The electrochemical cell of  claim 4  wherein the first electrode is a hydrogen anode and the second electrode is an air cathode and a hydroxide conductive polymer based solid gel membrane is disposed there between.  
     
     
         11 . An electrochromic device wherein electrochromic materials are contained within a solution phase of a polymer based solid gel membrane.  
     
     
         12 . An electrochromic device according to  claim 11 , comprising first and second electrode substrates and first and second polymer based solid gel membranes disposed there between, each of said membranes having an electrochromic material contained within a solution phase thereof.  
     
     
         13 . The electrochromic device according to  claim 12 , further comprising an electrolyte active species disposed between said first and second polymer based solid gel membranes.  
     
     
         14 . An electrochromic device according to  claim 12  wherein said first and second electrode substrates are comprised of platinum, gold, or a conductive glass.  
     
     
         15 . An electrochromic device according to  claim 14  wherein the conductive glass is indium-tin oxide glass.  
     
     
         16 . A method of inhibiting corrosion of a metal anode in a metal/air fuel cell system comprised of a metal anode and an air cathode, said method comprising disposing one or more polymer based solid gel membranes having an ionic species contained within a solution phase thereof, between said anode and said cathode.  
     
     
         17 . A method according to  claim 16  wherein said metal/air fuel cell system is one of an aluminum/air or a zinc/air fuel cell system.