Copolymer compound and electrochemical cell therewith

Abstract

The present invention relates to a copolymer compound prepared by copolymerizing two or more monomers selected from indole and indole derivatives. The copolymer compound can be used as an electrode active material to provide an electrochemical cell with an increased capacity and improved cycle properties.

1 . A copolymer compound comprising copolymerized units of two or more monomers selected from indole and indole derivatives represented by formula (1):  
       
         
           
           
               
               
           
         
       
       wherein Rs each independently represent hydrogen atom, nitro group, carboxyl group, carboxylate group, cyano group, acetyl group, aldehyde group, or halogen atom.  
     
     
         2 . The copolymer compound as claimed in  claim 1 , wherein the units comprise a unit represented by formula (1A) and a unit represented by formula (1B) or (1C):  
       
         
           
           
               
               
           
         
       
       wherein Rs each independently represent hydrogen atom, nitro group, carboxyl group, carboxylate group, cyano group, acetyl group, aldehyde group, or halogen atom.  
     
     
         3 . The copolymer compound as claimed in  claim 1 , having a structure of formula (2):  
       
         
           
           
               
               
           
         
       
       wherein Rs each independently represent hydrogen atom, nitro group, carboxyl group, carboxylate group, cyano group, acetyl group, aldehyde group or halogen atom; and n represents a natural number.  
     
     
         4 . The copolymer compound as claimed in  claim 3 , wherein the monomer comprises an indole derivative having a substituent other than hydrogen at least at 3-position.  
     
     
         5 . The copolymer compound as claimed in  claim 1 , having a structure of formula (3):  
       
         
           
           
               
               
           
         
       
       wherein Rs each independently represent hydrogen atom, nitro group, carboxyl group, carboxylate group, cyano group, acetyl group, aldehyde group, or halogen atom; and n represents a natural number.  
     
     
         6 . The copolymer compound as claimed in  claim 5 , wherein the monomer comprises an indole derivative having a substituent other than hydrogen at least at 2-position.  
     
     
         7 . The copolymer compound as claimed in  claim 1 , which is a proton-conducting compound capable of initiating an electrochemical redox reaction in a solution containing a proton source.  
     
     
         8 . An electrochemical cell comprising at least one selected from the copolymer compounds as claimed in  claim 1  as an electrode active material.  
     
     
         9 . An electrochemical cell comprising at least copolymer compounds as claimed in  claim 1  as an electrode active material accounting for 10 to 100-% by weight of the total amount of electrode active materials in a relevant electrode.  
     
     
         10 . An electrochemical cell comprising at least the copolymer compounds as claimed in  claim 1  as an electrode active material in a cathode.  
     
     
         11 . An electrochemical cell comprising, as an electrode active material in a cathode, at least the copolymer compounds as claimed in  claim 1  accounting for 10 to 100-% by weight of the total amount of electrode active materials in the cathode.  
     
     
         12 . The electrochemical cell as claimed in  claim 8  comprising an electrolyte containing a proton source, wherein protons act as a charge carrier in a redox reaction in association with charge/discharge.