High capacity polymer cathode and high energy density rechargeable cell comprising the cathode

Abstract

The invention features a rechargeable cathode and a battery comprising the cathode. The cathode includes a solid, ionically conducting polymer material and electroactive sulfur. The battery contains a lithium anode; the cathode; and an electrolyte; wherein at least one of anode, the cathode and the electrolyte, include the solid, ionically conducting polymer material.

What is claimed is: 
     
         1 . A cathode electrode comprising sulfur as the active material, and an ionically conductive polymer. 
     
     
         2 . The cathode of  claim 1  where the polymer has an ionic conductivity of greater than 1×10 −4  S/cm at room temperature. 
     
     
         3 . The cathode of  claim 1  wherein the polymer is electrically insulative. 
     
     
         4 . The cathode of  claim 1  wherein the polymer has Lithium cation diffusivity greater than 1×10 −11  meters squared per second at room temperature. 
     
     
         5 . The cathode of  claim 1  further comprising electrically conductive fillers are used to add electrical conductivity. 
     
     
         6 . The cathode of  claim 1  wherein the solid, ionically conductive polymer material encapsulates at least one particle of the active material 
     
     
         7 . The cathode of  claim 1  wherein the solid, ionically conducting polymer material is formed from a reactant product of a base polymer, an electron acceptor, and a compound including a source of ions. 
     
     
         8 . The cathode of  claim 1  wherein the solid, ionically conducting polymer material contains a base polymer which is oxidatively doped in the presence of Li+ groups. 
     
     
         9 . The cathode of  claim 7  where the compound including an ion source is either LiOH, L 2 O or a mixture of the two. 
     
     
         10 . The cathode of claim of  claim 8  where the base polymer is one that can be “oxidized”, and wherein the base polymer is a conjugated polymer. 
     
     
         11 . The cathode of  claim 7  where the base polymer is selected from a group comprising polyphenylene sulfide, liquid crystal polymer, a polyether ether ketone (PEEK) or a semicrystalline polymer with a crystallinity index of greater than 30%, and combinations thereof. 
     
     
         12 . The cathode of  claim 7  where the electron acceptor is selected from a group comprising Dichloro Dicyano Quinone (C 8 Cl 2 N 2 O 2 ), TCNE (C 6 N 6 ), Sulfur Trioxide (SO 3 ) or chloranil and combinations thereof. 
     
     
         13 . An electrochemical cell comprising, an anode, and a cathode, said cathode comprising sulfur as the active material, and an ionically conductive polymer. 
     
     
         14 . The electrochemical cell of  claim 13 , wherein the cathode specific capacity is greater than 500 mAh/g. 
     
     
         15 . The electrochemical cell of  claim 13 , wherein the cathode specific capacity is greater than 1000 mAh/g. 
     
     
         16 . The electrochemical cell of  claim 13 , wherein the cathode specific capacity is greater than 1500 mAh/g. 
     
     
         17 . The electrochemical cell of  claim 13 , wherein the voltage of cell is greater than 1.0 volts. 
     
     
         18 . The electrochemical cell of  claim 13 , wherein the anode is selected from a group comprising Lithium, Tin, Silicon, graphite, or any alloy or mixture thereof. 
     
     
         19 . The electrochemical cell of  claim 13 , wherein the cell is a secondary cell. 
     
     
         20 . The electrochemical cell of  claim 19 , wherein the cathode specific capacity is greater than 1000 mAh/g.