Electrochemical cell

Abstract

An electrochemical cell that converts chemical energy to electrical energy includes a cathode with an active material of fluorinated carbon on a perforated metal cathode current collector, a lithium anode on a perforated metal anode current collector, a stepped header, a stable electrolyte, and a separator. In various embodiments, an anode current collector design, a cathode current collector design, a stepped header design, a cathode formulation, an electrolyte formulation, a separator, and a battery incorporating the electrochemical cell are provided.

1 . An electrolyte for an electrochemical cell, comprising:
 a lithium salt;   a first solvent; and   a second solvent,   wherein the first solvent is 1,2-dimethoxyethane, and   wherein the second solvent is γ-butyrolactone.   
     
     
         2 . The electrolyte of  claim 1 , wherein a weight ratio of the first solvent to the second solvent is 0.5 to 1.3. 
     
     
         3 . The electrolyte of  claim 1 , wherein a weight ratio of the first solvent to the second solvent is 1:1. 
     
     
         4 . The electrolyte of  claim 1 , wherein a concentration of the lithium salt is 0.8 moles per liter to 1.1 moles per liter, based on a total volume of the first solvent and the second solvent. 
     
     
         5 . The electrolyte of  claim 1 , wherein the lithium salt comprises LiBF 4 , LiAsF 6 , LiSbF 6 , or LiClO 4 , or a combination thereof. 
     
     
         6 . The electrolyte of  claim 1 , wherein the lithium salt is LiBF 4 , the concentration of the LiBF 4  in the electrolyte is 1 mole per liter, based on a total volume of the first solvent and the second solvent, the first solvent is 1,2-dimethoxyethane, and the second solvent is γ-butyrolactone. 
     
     
         7 . An electrochemical cell comprising:
 a cathode comprising a cathode composition disposed on a cathode current collector, wherein the cathode composition comprises a cathode active material, a conductive carbon filler, and a binder;   an anode; and   an electrolyte, wherein the electrolyte comprises comprising a lithium salt; a first solvent; and a second solvent,   wherein the cathode active material is fluorinated carbon, the conductive carbon filler is carbon black, the binder is a fluorinated polymer, and a weight ratio of the cathode active material to the conductive carbon filler to the binder is 90:6:4,   wherein a weight ratio of an amount of the electrolyte to an amount of the cathode active material is 0.7 to 1.1, and   wherein the electrochemical cell has a swelling percentage of less than or equal to 2 percent.   
     
     
         8 . The electrochemical cell of  claim 7 , wherein the weight ratio of the amount of the electrolyte to the amount of the cathode active material is 0.93. 
     
     
         9 . The electrochemical cell of  claim 7 , wherein a concentration of the lithium salt in the electrolyte is 0.8 moles per liter to 1.1 moles per liter, based on a total volume of the first solvent and the second solvent. 
     
     
         10 . The electrochemical cell of  claim 7 , wherein the first solvent comprises 1,2-dimethoxyethane, 1,2-diethoxyethane, 1-ethoxy,2-methoxyethane, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, diethyl carbonate, or a combination thereof, and the second solvent comprises propylene carbonate, ethylene carbonate, γ-butyrolactone, N-methyl-pyrrolidinone, or a combination thereof. 
     
     
         11 . The electrochemical cell of  claim 7 , wherein the first solvent is 1,2-dimethoxyethane and the second solvent is γ-butyrolactone. 
     
     
         12 . The electrochemical cell of  claim 7 , wherein a weight ratio of the first solvent to the second solvent is 0.5 to 1.3. 
     
     
         13 . The electrochemical cell of  claim 7 , wherein a weight ratio of the first solvent to the second solvent is 1:1. 
     
     
         14 . The electrochemical cell of  claim 7 , wherein the lithium salt comprises LiBF 4 , LiAsF 6 , LiSbF 6 , or LiClO 4 , or a combination thereof. 
     
     
         15 . The electrochemical cell of  claim 7 , wherein the lithium salt is LiBF 4 , the concentration of the LiBF 4  in the electrolyte is 1 mole per liter, based on a total volume of the first solvent and the second solvent, the first solvent is 1,2-dimethoxyethane, and the second solvent is γ-butyrolactone. 
     
     
         16 . The electrochemical cell of  claim 15 , wherein the anode comprises a lithium metal foil. 
     
     
         17 . An implantable device comprising
 the electrochemical cell of  claim 1 .   
     
     
         18 . A method of manufacturing the electrochemical cell of  claim 12 , the method comprising:
 providing the cathode;   providing the anode, wherein the anode comprises a lithium metal foil; and   disposing the electrolyte between the anode and the cathode.   
     
     
         19 . The method of  claim 18 , wherein the ratio of the amount of the electrolyte to the amount of the cathode active material is 0.93. 
     
     
         20 . The method of  claim 18 , wherein the lithium salt is LiBF 4 , the concentration of the LiBF 4  in the electrolyte is 1 mole per liter based on a total volume of the first solvent and the second solvent, the first solvent is 1,2-dimethoxyethane, and the second solvent is γ-butyrolactone.