Lithium ion secondary battery

Abstract

It is an object of this exemplary embodiment to provide a lithium ion secondary battery using a positive electrode active material having an operating potential of 4.5 V or more, the lithium ion secondary battery having excellent high temperature cycle characteristics. This exemplary embodiment is a lithium ion secondary battery comprising a positive electrode and a negative electrode capable of intercalating and deintercalating lithium, a separator between the positive electrode and the negative electrode, and an electrolytic solution containing a nonaqueous electrolytic solvent, wherein the positive electrode comprises a positive electrode active material operating at a potential of 4.5 V or more versus lithium, the separator comprises cellulose, a cellulose derivative, or a glass fiber, and the nonaqueous electrolytic solvent comprises a fluorinated solvent.

1 - 14 . (canceled) 
     
     
         15 . A lithium ion secondary battery comprising a positive electrode and a negative electrode which are capable of intercalating and deintercalating lithium, a separator between the positive electrode and the negative electrode, and an electrolytic solution containing a nonaqueous electrolytic solvent, wherein
 the positive electrode comprises a positive electrode active material operating at a potential of 4.5 V or more versus lithium,   the separator comprises cellulose, a cellulose derivative, or a glass fiber,   the nonaqueous electrolytic solvent comprises a fluorinated solvent, and   the positive electrode active material comprises a lithium manganese complex oxide represented by the following formula (C),
   Li x [Li a M b Mn 1-a-b ]O 2   (C).
 
   wherein 0≦x≦1, 0.05≦a≦0.3, and 0.1<b<0.4, and M is at least one selected from Ni, Co, Fe, and Cr.   
     
     
         16 . The lithium ion secondary battery according to  claim 15 , wherein the fluorinated solvent is a fluorinated ether represented by the following formula (1-1);
   R 101 —O—R 101   (1-1)
   wherein R 101  and R 102  each independently represent an alkyl group or a fluorine-substituted alkyl group, and at least one of R 101  and R 102  is a fluorine-substituted alkyl group.   
     
     
         17 . The lithium ion secondary battery according to  claim 15 , wherein the fluorinated solvent is a fluorinated phosphate represented by the following formula (2-1); 
       
         
           
           
               
               
           
         
         wherein R 201 , R 202 , and R 203  each independently represent an alkyl group or a fluorine-substituted alkyl group, and at least one of R 201 , R 202 , and R 203  is a fluorine-substituted alkyl group. 
       
     
     
         18 . The lithium ion secondary battery according to  claim 15 , wherein the fluorinated solvent is a fluorinated carboxylate represented by the following formula (3-1); 
       
         
           
           
               
               
           
         
         wherein R 301  and R 302  each independently represent an alkyl group or a fluorine-substituted alkyl group, and at least one of R 301  and R 302  is a fluorine-substituted alkyl group. 
       
     
     
         19 . The lithium ion secondary battery according to  claim 15 , wherein the fluorinated solvent is a fluorinated carbonate represented by the following formula (4-1); 
       
         
           
           
               
               
           
         
         wherein R 401  and R 402  each independently represent an alkyl group or a fluorine-substituted alkyl group, and at least one of R 401  and R 402  is a fluorine-substituted alkyl group. 
       
     
     
         20 . The lithium ion secondary battery according to  claim 15 , wherein the separator is a cellulose-containing separator. 
     
     
         21 . The lithium ion secondary battery according to  claim 15 , wherein the separator is a cellulose derivative-containing separator. 
     
     
         22 . The lithium ion secondary battery according to  claim 15 , wherein the separator is a glass fiber-containing separator. 
     
     
         23 . The lithium ion secondary battery according to  claim 15 , wherein a porosity of the separator is 50% or more and 95% or less. 
     
     
         24 . The lithium ion secondary battery according to  claim 15 , wherein a content of the fluorinated solvent in the nonaqueous electrolytic solvent is 30 to 90% by volume. 
     
     
         25 . The lithium ion secondary battery according to  claim 15 , wherein the nonaqueous electrolytic solvent further comprises a carbonate compound. 
     
     
         26 . The lithium ion secondary battery according to  claim 15 , wherein the nonaqueous electrolytic solvent further comprises a sulfone compound represented by the following formula (A); 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each independently represent a substituted or unsubstituted alkyl group; and a carbon atom of R 1  and a carbon atom of R 2  may be bonded via a single bond or a double bond to form a cyclic structure. 
       
     
     
         27 . The lithium ion secondary battery according to  claim 15 , wherein the nonaqueous electrolytic solvent further comprises a carbonate compound,
 a content of the fluorinated solvent in the nonaqueous electrolytic solvent is 10 to 50% by volume, and   a content of the carbonate compound in the nonaqueous electrolytic solvent is 50 to 90% by volume.   
     
     
         28 . The lithium ion secondary battery according to  claim 16 , wherein the nonaqueous electrolytic solvent further comprises a sulfone compound represented by the following formula (A),
 a content of the fluorinated ether in the nonaqueous electrolytic solvent is 10 to 80% by volume, and   a content of the sulfone compound in the nonaqueous electrolytic solvent is 5 to 75% by volume.   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each independently represent a substituted or unsubstituted alkyl group; and a carbon atom of R 1  and a carbon atom of R 2  may be bonded via a single bond or a double bond to form a cyclic structure. 
       
     
     
         29 . The lithium ion secondary battery according to  claim 28 , wherein the content of the fluorinated ether in the nonaqueous electrolytic solvent is 20 to 70% by volume, and the content of the sulfone compound in the nonaqueous electrolytic solvent is 10 to 50% by volume. 
     
     
         30 . The lithium ion secondary battery according to  claim 28 , wherein the nonaqueous electrolytic solvent further comprises a carbonate compound,
 a content of the carbonate compound in the nonaqueous electrolytic solvent is 10 to 80% by volume.   
     
     
         31 . The lithium ion secondary battery according to  claim 29 , wherein the nonaqueous electrolytic solvent further comprises a carbonate compound,
 a content of the carbonate compound in the nonaqueous electrolytic solvent is 10 to 70% by volume.   
     
     
         32 . The lithium ion secondary battery according to  claim 17 , wherein the nonaqueous electrolytic solvent further comprises a sulfone compound represented by the following formula (A),
 a content of the fluorinated phosphate in the nonaqueous electrolytic solvent is 5 to 80% by volume, and   a content of the sulfone compound in the nonaqueous electrolytic solvent is 5 to 75% by volume.   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each independently represent a substituted or unsubstituted alkyl group; and a carbon atom of R 1  and a carbon atom of R 2  may be bonded via a single bond or a double bond to form a cyclic structure. 
       
     
     
         33 . The lithium ion secondary battery according to  claim 18 , wherein the nonaqueous electrolytic solvent further comprises a sulfone compound represented by the following formula (A),
 a content of the fluorinated carboxylate in the nonaqueous electrolytic solvent is 1 to 60% by volume, and   a content of the sulfone compound in the nonaqueous electrolytic solvent is 5 to 75% by volume.   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each independently represent a substituted or unsubstituted alkyl group; and a carbon atom of R 1  and a carbon atom of R 2  may be bonded via a single bond or a double bond to form a cyclic structure. 
       
     
     
         34 . The lithium ion secondary battery according to  claim 19 , wherein the nonaqueous electrolytic solvent further comprises a sulfone compound represented by the following formula (A),
 a content of the fluorinated carbonate in the nonaqueous electrolytic solvent is 1 to 50% by volume, and   a content of the sulfone compound in the nonaqueous electrolytic solvent is 5 to 75% by volume.   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  each independently represent a substituted or unsubstituted alkyl group; and a carbon atom of R 1  and a carbon atom of R 2  may be bonded via a single bond or a double bond to form a cyclic structure.