Electrolytic solution for secondary battery and lithium secondary battery including the same
The present disclosure relates to an electrolytic solution for a secondary battery and a lithium secondary battery employing the same. The electrolytic solution for a secondary battery of the present disclosure contains a sulfonyl compound, such that a lithium secondary battery employing a high content of nickel for a cathode has significantly improved quick charge characteristics, room temperature lifespan characteristics, and low-temperature characteristics.
1 . An electrolytic solution for a secondary battery, comprising:
a lithium salt;
a non-aqueous organic solvent;
a sulfonyl compound represented by the following Chemical Formula 1;
a sultone compound represented by the following Chemical Formula 3; and
a fluorine-substituted carbonate-based compound:
wherein
in the Chemical Formula 1,
A is C1-C5 alkylene or C2-C5 alkenylene;
R 1 is C1-C10 alkyl, C2-C10 alkenyl, C6-C12 aryl, or C6-C12 aryl C1-C10 alkyl;
R 2 is halogen, C1-C5 alkyl, or halo C1-C5 alkyl; and
n is an integer of 0 to 3,
in the Chemical Formula 3,
represents a single bond or a double bond;
R m to R 0 are each independently hydrogen, halogen, C1-C10 alkyl, C2-C10 alkenyl, halo C1-C10 alkyl, halo C2-C10 alkenyl, or C6-C12 aryl; and
n is an integer of 0 to 3.
2 . The electrolytic solution of claim 1 , wherein
in Chemical Formula 1, A is C1-C5 alkylene; R 1 is C1-C10 alkyl, C6-C12 aryl, or C6-C12 aryl C1-C10 alkyl; R 2 is fluoro, C1-C5 alkyl, or fluoro C1-C5 alkyl; and n is an integer of 0 or 1.
3 . The electrolytic solution of claim 1 , wherein
Chemical Formula 1 is represented by the following Chemical Formula 2:
wherein
A is C1-C5 alkylene;
R 11 is C1-C10 alkyl or C6-C12 aryl C1-C10 alkyl;
R 12 is halogen, C1-C5 alkyl, or halo C1-C5 alkyl; and
m is an integer of 0 to 3.
4 . The electrolytic solution of claim 3 , wherein
in Chemical Formula 2, A is C1-C3 alkylene; R 11 is C1-C6 alkyl or C6-C12 aryl C1-C6 alkyl; R 12 is fluoro, C1-C5 alkyl, or fluoro C1-C5 alkyl; and m is an integer of 0 or 1.
5 . The electrolytic solution of claim 1 , wherein
the sulfonyl compound represented by Chemical Formula 1 is selected from the following compounds:
wherein n is an integer of 1 to 5.
6 . The electrolytic solution of claim 1 , wherein
the sulfonyl compound is contained in an amount of 0.1 to 5 wt % with respect to a total weight of the electrolytic solution.
7 . The electrolytic solution of claim 1 , wherein
the sultone compound is one or more selected from 1,3-propane sultone, 1,4-butane sultone, ethene sultone, 1,3-propene sultone, 3-fluoro-1,3-propane sultone, and 1,4-butene sultone, and
the fluorine-substituted carbonate-based compound is one or more selected from fluoroethylene carbonate, difluoroethylene carbonate, fluorodimethyl carbonate, and fluoroethylmethyl carbonate.
8 . The electrolytic solution of claim 1 , wherein
the sultone compound and fluorine-substituted carbonate-based compound are contained in an amount of 0.1 to 5 wt % with respect to a total weight of the electrolytic solution.
9 . The electrolytic solution of claim 1 , further comprising
one or two or more additives selected from the group consisting of an oxalatoborate-based compound, an oxalatophosphate-based compound, and a vinylidene carbonate-based compound.
10 . The electrolytic solution of claim 1 , wherein
the lithium salt is one or two or more selected from the group consisting of LiPF 6 , LiBF 4 , LiClO 4 , LiSbF 6 , LiAsF 6 , LiN(SO 3 C 2 F 5 ) 2 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiC 6 H 5 SO 3 , LiSCN, LiAlO 2 , LiAlCl 4 , LIN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 ), LiCl, LiI, and LiB(C 2 O 4 ) 2 ,
where x and y are natural numbers.
11 . The electrolytic solution of claim 1 , wherein
the non-aqueous organic solvent is a mixed solvent of cyclic carbonate and linear carbonate.
12 . A lithium secondary battery comprising:
a cathode comprising a nickel-cobalt-manganese-based cathode active material containing the following Chemical Formula 11, the following Chemical Formula 12, or a mixture thereof;
an anode;
a separator interposed between the cathode and the anode; and
the electrolytic solution for a secondary battery of claim 1 :
Li x (Ni a Co b Mn c )O 2 Chemical Formula 11
wherein 0.5<x<1.3, 0.8≤a<1, 0<b<1, 0<c<1, and a+b+c=1,
Li x (Ni a Co b Mn c )O 4 Chemical Formula 12
wherein 0.5<x<1.3, 0.8<a<2, 0<b<2, 0<c<2, and a+b+c=2.
13 . The lithium secondary battery of claim 12 , wherein
the cathode active material is Li x (Ni a CO b Mn c )O 2 in which 0.95≤x≤1.10, 0.8≤a<0.9, and a+b+c=1.