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 . A lithium battery comprising a positive electrode, a negative electrode and a non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte which contains 0.01 to 5 wt. % of a nitrile compound and 0.2 to 3 wt. % of an S═O group-containing compound.  
     
     
         2 . The lithium battery of  claim 1  in which the negative electrode comprises a carbonaceous material of graphite crystal structure having a lattice distance of lattice surface (002) of 0.34 nanometer or less.  
     
     
         3 . The lithium battery of  claim 1 , in which the non-aqueous solvent comprises a cyclic carbonate and a linear carbonate in a volume ratio of 1:9 to 9:1.  
     
     
         4 . The lithium battery of  claim 1 , in which the non-aqueous solvent comprises a cyclic carbonate and an ether in a volume ratio of 1:9 to 9:1.  
     
     
         5 . The lithium battery of  claim 1 , in which the non-aqueous solvent comprises a cyclic carbonate and a cyclic ester in a volume ratio of 1:99 to 99:1.  
     
     
         6 . The lithium battery of  claim 1  wherein the nitrile compound is a mononitrile compound.  
     
     
         7 . The lithium battery of  claim 6 , wherein the mononitrile compound is selected from the group consisting of acetonitrile, propionitrile, butylonitrile, valeronitrile, hexanenitrile, octanenitrile, undecanenitrile, decanenitrile, cyclohexanecarbonitrile, benzonitrile, and phenylacetonitrile.  
     
     
         8 . The lithium battery of  claim 1 , wherein the nitrile compound is a dinitrile compound.  
     
     
         9 . The lithium battery of  claim 1 , wherein the dinitrile compound is selected from the group consisting of succinonitrile, 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-methylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,4,4-tetramethylglutaronitrile, 1,4-dicyanopentane, 2,5-dimethyl-2,5-hexanedicarbonitrile, 2,6-dicyanoheptane, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-dicyanobenzene, 1,3-dicyanobenzene, and 1,4-dicyanobenzene.  
     
     
         10 . The lithium battery of  claim 9 , wherein the dinitrile compound is glutaronitrile or adiponitrile.  
     
     
         11 . The lithium battery of  claim 1 , wherein 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, ethylmethanesulfonate, propargyl methanesulfonate, methyl benzenesulfonate, 1,3-propanesultone, 1,4-butanesultone, dimethyl sulfate, diethyl sulfate, ethyleneglycol sulfate, and 1,2-propanediol sulfate.