Lithium secondary battery

Abstract

The object of the present invention is to provide a lithium secondary battery of high output. According to the present invention, there is provided a lithium secondary battery having a positive electrode and a negative electrode which reversibly intercalate and deintercalate lithium and an electrolyte containing an ion conductive material and an electrolytic salt, where said electrolyte contains an electrolytic salt and a boron-containing compound represented by the following formula (1) or a polymer thereof, or a copolymer of the compounds of the following formulas (2) and (3).

What is claimed is:  
     
         1 . A lithium secondary battery having a positive electrode and a negative electrode which reversibly intercalate and deintercalate lithium and an electrolyte containing an ion conductive material and an electrolytic salt, where said ion conductive material contains a boron-containing compound represented by the following formula (1):  
       
         
           
           
               
               
           
         
       
       wherein B represents a boron atom; Z 1 , Z 2  and Z 3  each represent an organic group having an acryloyl group or a methacryloyl group or a hydrocarbon group of 1-10 carbon atoms, with the proviso that one or two of Z 1 , Z 2  and Z 3  are the organic groups having an acryloyl group or a methacryloyl group; AO represents an oxyalkylene group of 1-6 carbon atoms and comprises one or two or more of the oxyalkylene groups; and l, m and n each represent an average degree of polymerization of the oxyalkylene group and is more than 0 and less than 4.  
     
     
         2 . A lithium secondary battery according to  claim 1 , wherein the electrolyte contains a polymer obtained by polymerizing the boron-containing compound represented by the formula (1).  
     
     
         3 . A lithium secondary battery having a positive electrode and a negative electrode which reversibly intercalate and deintercalate lithium and an electrolyte containing an ion conductive material and an electrolytic salt, where the ion conductive material comprises a polymerizable composition which contains a boron-containing compound represented by the following formula (2) and a boron-containing compound represented by the following formula (3) and which has a molar ratio of the compound of the formula (2) and the compound of the formula (3) [(molar number of the compound of the formula (3))/(molar number of the compound of the formula (2))] of 0.1-4:  
       
         
           
           
               
               
           
         
       
       wherein B represents a boron atom; Z 4 , Z 5  and Z 6  each represent an organic group having an acryloyl group or a methacryloyl group or a hydrocarbon group of 1-10 carbon atoms, with the proviso that at least one of Z 4 , Z 5  and Z 6  is said organic group having an acryloyl group or a methacryloyl group; R 1 , R 2  and R 3  each represent a hydrocarbon group of 1-10 carbon atoms; AO represents an oxyalkylene group of 1-6 carbon atoms and comprises one or two or more of the oxyalkylene groups; and p, q, r, α, β and γ each represent an average degree of polymerization of the oxyalkylene group and is more than 0 and less than 4.  
     
     
         4 . A lithium secondary battery according to  claim 3 , wherein the electrolyte contains a polymer obtained by polymerizing the polymerizable composition.  
     
     
         5 . A lithium secondary battery according to  claim 1 , wherein the electrolytic salt is at least one of LiPF6, LiN(CF 3 SO 2 ) 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiI, LiBr, LiSCN, Li 2 B 10 Cl 10  and LiCF 3 CO 2 .  
     
     
         6 . A lithium secondary battery according to  claim 2 , wherein the electrolytic salt is at least one of LiPF 6 , LiN(CF 3 SO 2 ) 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiI, LiBr, LiSCN, Li 2 B 10 Cl 10  and LiCF 3 CO 2 .  
     
     
         7 . A lithium secondary battery according to  claim 3 , wherein the electrolytic salt is at least one of LiPF 6 , LiN(CF 3 SO 2 ) 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiI, LiBr, LiSCN, Li 2 B 10 Cl 10  and LiCF 3 CO 2 .