Non-aqueous electrolytic solution and lithium battery

Abstract

A non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, which further contains a combination of a nitrile compound and an S═O group-containing compound (or a dinitrile compound) in an amount of 0.001 to 10 wt. % imparts improved cycle performance and storage property to a lithium battery, particularly a lithium secondary battery.

1 . (canceled) 
     
     
         2 . A non-aqueous electrolytic solution comprising a non-aqueous solvent comprising at least a cyclic carbonate and an electrolyte, which contains a dinitrile compound in an amount of 0.01 to 3 wt. %. 
     
     
         3 . The non-aqueous electrolytic solution of  claim 2 , in which the dinitrile compound is selected from the group consisting of succinimide, glutaronitrile, adiponitrile, 1,5-dicyanopentane, 1,6-dicyanohexane, 1,7-dicyanoheptane, 1,8-dicyanooctane, 1,9-dicyanononane, 1,10-dicyanodecane, 1,12-dicyanododecane, tetramethylsuccinonitrile, 2-dicyanopentane, 2,5-dimethyl-2,5-hexanedicarbonitrile, 2,6-dicyanoheptane, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-dicyanobenzene, 1,3-dicyanobenzend and 1,4-dicyanobenzene. 
     
     
         4 . The non-aqueous electrolytic solution of  claim 2 , in which the dinitrile compound comprises glutaronitrile or adiponitrile. 
     
     
         5 . The non-aqueous electrolytic solution of  claim 2 , in which the cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate. 
     
     
         6 . The non-aqueous electrolytic solution of  claim 2 , in which the non-aqueous solvent further comprises a linear carbonate selected from the group consisting of dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate. 
     
     
         7 . The non-aqueous electrolytic solution of  claim 6 , in which the cyclic carbonate and linear carbonate are contained in a volume ratio of 1:9 to 9:1. 
     
     
         8 . The non-aqueous electrolytic solution of  claim 2 , in which the electrolyte comprises LiPF6. 
     
     
         9 . The non-aqueous electrolytic solution of  claim 2 , which further contains an S═O group-containing compound in an amount of 0.2 to 3 wt. %. 
     
     
         10 . The non-aqueous electrolytic solution of  claim 9 , in which the S═O group-containing compound is selected from the group consisting of dimethylsulfite, diethylsulfite, ethylenesulfite, propylenesulfite, vinylenesulfite, dimethylsulfone, diethylsulfone, methylethylsulfone, divinylsulfone, sulforane, sulforene, methyl methanesulfonate, ethyl methanesulfonate, propargyl methanesulfonate, methyl benzenesulfonate, 1,3-propanesultone, 1,4-butanesultone, dimethyl sulfate, diethylsulfate, ethyleneglycol sulfate, and 1,2-propanediol sulfate. 
     
     
         11 . A lithium secondary battery comprising a positive electrode, a negative electrode comprising a carbonaceous material of graphite crystal structure having a lattice distance of lattice surface (002) of 0.34 nanomether or less, and a non-aqueous electrolytic solution of  claim 2 .