Electrolytic salts for lithium batteries

Abstract

Orthoborate salts suitable for use as electrolytes in lithium batteries and methods for making the electrolyte salts are provided. The electrolytic salts have one of the formulae (I). In this formula anionic orthoborate groups are capped with two bidentate chelating groups, Y 1 and Y 2 . Certain preferred chelating groups are dibasic acid residues, most preferably oxalyl, malonyl and succinyl, disulfonic acid residues, sulfoacetic acid residues and halo-substituted alkylenes. The salts are soluble in non-aqueous solvents and polymeric gels and are useful components of lithium batteries in electrochemical devices.

1 . A method of making a compound having the formula 
       
         
           
           
               
               
           
         
       
       wherein:
 B is boron; 
 O is oxygen; 
 Y 1  and Y 2  are each bound to a pair of said oxygens and are selected from the group comprising XC—(CR 2 ) a CX wherein a is 0 to 4 and X is ═O, —C═N, CR′ 3  or R′ 3  wherein R′ is halo, R is hydrogen, alkyl, cyano, or halo provided that when a is 0 and X is CF 3  or ═O, Y 1 , is not Y 2 , and O 2 S(CR 2 ) b SO 2  and OC(CR 2 ) b SO 2  wherein b is 1 to 4 and R is hydrogen, alkyl, or halo, wherein Y 1  and Y 2  are the same or different in each occurrence; and 
 M +  is a metal ion selected from the Group I or Group II elements, the method comprising: 
 providing a fluoro-substituted diol or dibasic acid form of said Y 1  and Y 2 ; and 
 combining said fluoro-substituted diol or dibasic acid form with M hydroxide and boric acid under conditions whereby Y 1  and Y 2  bind pairwise to oxygens in said anion to form the compound. 
 
     
     
         2 . The method of  claim 1 , wherein M +  is Li + . 
     
     
         3 . The method of  claim 1 , wherein the compound is lithium bis(oxalato)borate. 
     
     
         4 . The method of  claim 1 , wherein the compound is lithium bis(malonato)borate. 
     
     
         5 . The method of  claim 1 , wherein the compound is lithium bis(succinato)borate. 
     
     
         6 . The method of  claim 1 , wherein the compound is lithium (malonato oxalate)borate. 
     
     
         7 . The method of  claim 1 , wherein the compound is lithium bis(methylenedisulfonato) borate. 
     
     
         8 . The method of  claim 1 , wherein the compound is lithium bis(sulfoacetato)borate. 
     
     
         9 . A method of making an electrolyte sail having the formula 
       
         
           
           
               
               
           
         
       
       wherein:
 B is boron; 
 o is oxygen;
 Y 1  and Y 2  are each bound to a pair of said oxygens and are selected from the group comprising XC—(CR 2 ) a CX wherein a is 0 to 4 and X is ═O, —C═N, CR′ 3  or R′ 3  wherein R′ is halo, R is hydrogen, alkyl, cyano, or halo provided that when a is 0 and X is CF 3  or ═O, Y 1 , is not Y 2 , and O 2 S(CR 2 ) b SO 2  and OC(CR 2 ) b SO 2  wherein b is 1 to 4 and R is hydrogen, alkyl, or halo, wherein Y 1  and Y 2  are the same or different in each occurrence; and 
 M +  is a metal ion selected from the Group I or Group II elements, the method comprising: 
 
 providing di(methylsilyl)Y 1  and di(methylsilyl)Y 2  and alkoxy orthoborate salt; and 
 combining said di(methylsilyl)Y 1 , said di(methylsilyl)Y 2 , said alkoxy orthoborate salt under conditions whereby said electrolyte salt is formed. 
 
     
     
         10 . The method of  claim 9 , wherein said alkoxy orthoborate salt is lithium tetramethanolatoborate. 
     
     
         11 . The method of  claim 9 , wherein said di(methylsilyl)Y 1  is di(trimethylsilyl) oxalate. 
     
     
         12 . The method of  claim 9 , wherein said di(methylsilyl)Y 1  is di(trimethylsilyl)malonate. 
     
     
         13 . The method of  claim 9 , wherein said di(methylsilyl)Y 1  is di(trimethylsilyl) succinate. 
     
     
         14 . The method of  claim 9 , wherein said di(methylsilyl)Y 1  is di(trimethylsilyl)methylenedisulfonate. 
     
     
         15 . The method of  claim 9 , further comprising dissolving the electrolyte salt in a non-aqueous solvent. 
     
     
         16 . The method of  claim 9 , further comprising dissolving the electrolyte salt in a polymeric gel. 
     
     
         17 . A conductive polymeric gel comprising an electrolyte salt having the formula 
       
         
           
           
               
               
           
         
       
       wherein:
 B is boron; 
 O is oxygen; 
 Y 1  and Y 2  are each bound to a pair of said oxygens and are selected from the group comprising XC—(CR 2 ) a CX wherein a is 0 to 4 and X is ═O, —C═N, CR′ 3  or R′ 3  wherein R′ is halo, R is hydrogen, alkyl, cyano, or halo provided that when a is 0 and X is CF 3  or ═O, Y 1 , is not Y 2 , and O 2 S(CR 2 ) b SO 2  and OC(CR 2 ) b SO 2  wherein b is 1 to 4 and R is hydrogen, alkyl, or halo, wherein Y 1  and Y 2  are the same or different in each occurrence; and 
 M +  is a metal ion selected from the Group I or Group II elements. 
 
     
     
         18 . The conductive polymeric gel of  claim 17 , wherein M +  is Li + . 
     
     
         19 . The conductive polymeric gel of  claim 17 , wherein the electrolyte salt is lithium bis (oxalato)borate. 
     
     
         20 . A conductive polymeric gel of  claim 17  in a lithium battery.