Electrolyte for rechargeable lithium battery and rechargeable lithium battery including the same

Abstract

An additive, an electrolyte for a rechargeable lithium battery, and a rechargeable lithium battery, the additive being represented by Chemical Formula 1:

What is claimed is: 
     
         1 . An electrolyte for a rechargeable lithium battery, the electrolyte comprising:
 a non-aqueous organic solvent,   a lithium salt, and   an additive represented by Chemical Formula 1:   
       
         
           
           
               
               
           
         
         wherein, in Chemical Formula 1, 
         X 1  and X 2  are each independently O, S, CR a R b , or NR c , at least one of X 1  and X 2  being Oor S, 
         R 1  and R 2  are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C3 to C10 cycloalkenyl group, or a substituted or unsubstituted C6 to C20 aryl group, 
         R a , R b , R c , and R 3  to R 6  are each independently hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, or a combination thereof, and 
         n is an integer of 1 to 3. 
       
     
     
         2 . The electrolyte as claimed in  claim 1 , wherein:
 the additive represented by Chemical Formula 1 is represented by Chemical Formula 1A:   
       
         
           
           
               
               
           
         
         in Chemical Formula 1A, 
         X 1  and X 2  are each independently O, S, CR a R b , or NR c , at least one of X 1  and X 2  being O or S, 
         R 1  and R 2  are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C3 to C10 cycloalkenyl group, or a substituted or unsubstituted C6 to C20 aryl group, and 
         R a , R b , R c , and R 3  to R 6  are each independently hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, or a combination thereof. 
       
     
     
         3 . The electrolyte as claimed in  claim 1 , wherein:
 the additive represented by Chemical Formula 1 is represented by one of Chemical Formula 1-1 to Chemical Formula 1-3:   
       
         
           
           
               
               
           
         
         in Chemical Formula 1-1 to Chemical Formula 1-3, 
         R 1  and R 2  are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C3 to C10 cycloalkenyl group, or a substituted or unsubstituted C6 to C20 aryl group, 
         R 3  to R 6  are each independently hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, or a combination thereof, and 
         n is an integer of 1 to 3. 
       
     
     
         4 . The electrolyte as claimed in  claim 1 , wherein R 1  and R 2  of Chemical Formula 1 are each independently a substituted or unsubstituted C1 to C10 alkyl group or a substituted or unsubstituted C2 to C5 alkenyl group. 
     
     
         5 . The electrolyte as claimed in  claim 1 , wherein the additive is included in the electrolyte in an amount of about 0.1 wt % to about 10 wt %, based on a total weight of the electrolyte. 
     
     
         6 . The electrolyte as claimed in  claim 1 , wherein the additive is included in the electrolyte in an amount of about 0.1 wt % to about 3.0 wt %, based on a total weight of the electrolyte. 
     
     
         7 . A rechargeable lithium battery, comprising:
 a positive electrode including a positive active material;   a negative electrode including a negative active material; and   the electrolyte as claimed in  claim 1 .   
     
     
         8 . The rechargeable lithium battery as claimed in  claim 7 , wherein the positive active material includes:
 lithium, and   a composite oxide including cobalt, manganese, nickel, or a combination thereof.   
     
     
         9 . The rechargeable lithium battery as claimed in  claim 7 , wherein:
 the positive active material is represented by Chemical Formula 2:
   Li a M 1   1-y1-z1 M 2   y1 M 3   z1 O 2    [Chemical Formula 2]
 
   in Chemical Formula 2,   0.9≤a≤1.8, 0≤y1<1, 0≤z1<1, 0≤y1+z1<1, and   M 1 , M 2 , and M 3  are each independently Ni, Co, Mn, Al, Sr, Mg, La, or a combination thereof.