US-20260128372-A1 - NON-AQUEOUS ELECTROLYTE FOR LITHIUM SECONDARY BATTERY, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

US20260128372A1US 20260128372 A1US20260128372 A1US 20260128372A1US-20260128372-A1

Abstract

The present invention relates to a non-aqueous electrolyte for a lithium secondary battery, which includes a first additive including a chromone-based compound, and a lithium secondary battery including the same.

Inventors

Sung Ho Shin
Hang Seok Choi
Se Young Chung
Jae Yoon Kim
Mi Yeon Oh
Won Kyun Lee
Jeong Ae Yoon
Kyoung Hoon Kim
Jung Keun Kim
Ki Cheol Kim
Chan Woo Noh

Assignees

LG CHEM, LTD.

Dates

Publication Date: 20260507
Application Date: 20231120
Priority Date: 20221118

Claims (10)

1 . A non-aqueous electrolyte for a lithium secondary battery, comprising a first additive including a compound represented by the following Chemical Formula 1: in Chemical Formula 1: R 1 and R 3 to R 6 are the same or different and each independently represent hydrogen, a halogen, *-L 1 -C≡N, *-L 2 -C(═O)R 7 , *-L 3 -NR 8 R 9 , *-L 4 -OR 10 , a C 1 to C 20 alkyl group, a C 2 to C 20 alkynyl group or a C 6 to C 20 aryl group, R 2 represents hydrogen, a halogen, *-L 5 -C≡N, *-L 6 -C(═O)R 11 , *-L 7 -NR 12 R 13 , *-L 8 -OR 14 , a C 1 to C 20 alkyl group or a C 2 to C 20 alkynyl group, R 7 to R 14 are the same or different and each independently represent hydrogen, *-L 9 -OR 15 , a C 1 to C 20 alkyl group, a C 2 to C 20 alkynyl group or a C 6 to C 20 aryl group, R 15 represents hydrogen, a C 1 to C 20 alkyl group, a C 2 to C 20 alkynyl group or a C 6 to C 20 aryl group, and L 1 to L 9 are the same or different and each independently represent a direct bond or a C 1 to C 10 alkylene group, provided that R 1 to R 6 are not hydrogen at the same time; or one or more of R 1 to R 6 are halogens, and the remainder of R 1 to R 6 are not hydrogen at the same time.
2 . The non-aqueous electrolyte for a lithium secondary battery according to claim 1 , wherein the compound represented by Chemical Formula 1 includes one or more of compounds represented by the following Chemical Formulas 1-1 to 1-22: in Chemical Formulas 1-1 to 1-22, R 1 ′ and R 3 ′ to R 6 ′ are the same or different and each independently represent a halogen, *-L 1 ′-C≡N, *-L 2 ′-C(═O)R 7 ′, *-L 3 ′-NR 8 ′R 9 ′, *-L 4 ′-OR 10 ′, a C 1 to C 20 alkyl group, a C 2 to C 20 alkynyl group or a C 6 to C 20 aryl group, R 2 ′ represents a halogen, *-L 5 ′-C≡N, *-L 6 ′-C(═O)R 11 ′, *-L 7 ′-NR 12 ′R 13 ′, *-L 8 ′-OR 14 ′, a C 1 to C 20 alkyl group or a C 2 to C 20 alkynyl group, R 7 ′ to R 14 ′ are the same or different and each independently represent hydrogen, *-L 9 ′-OR 15 ′, a C 1 to C 20 alkyl group, a C 2 to C 20 alkynyl group or a C 6 to C 20 aryl group, R 15 ′ represents hydrogen, a C 1 to C 20 alkyl group, a C 2 to C 20 alkynyl group or a C 6 to C 20 aryl group, and L 1 ′ to L 9 ′ are the same or different and each independently represent a direct bond or a C 1 to C 10 alkylene group.
3 . The non-aqueous electrolyte for a lithium secondary battery according to claim 1 , wherein the compound represented by Chemical Formula 1 includes one or more of compounds represented by the following chemical formulas:
4 . The non-aqueous electrolyte for a lithium secondary battery according to claim 1 , wherein the compound represented by Chemical Formula 1 is included in an amount of 0.01 to 10.00 parts by weight with respect to 100 parts by weight of the non-aqueous electrolyte for a lithium secondary battery.
5 . The non-aqueous electrolyte for a lithium secondary battery according to claim 1 , comprising a second additive including one or more of compounds represented by the following Chemical Formulas 2 to 4: in Chemical Formula 2: X 21 represents *—S(═O)—* or *—S(═O) 2 —*, and X 22 and X 23 are the same or different and each independently represent a direct bond, *—O—* or a C 1 to C 10 alkylene group, in Chemical Formula 3: Y 31 and L 33 are the same or different and each independently represent *—S(═O)—* or *—S(═O) 2 —*, Y 32 , Y 33 , L 31 , L 32 , L 34 and L 35 are the same or different and each independently represent a direct bond, *—O—* or a C 1 to C 10 alkylene group, and R 31 represents hydrogen, a C 1 to C 10 alkyl group, a C 2 to C 10 alkenylene group or a C 2 to C 10 alkynylene group, in Chemical Formula 4: Z 42 , Z 45 and L 43 are the same or different and each independently represent *—S(═O)—* or *—S(═O) 2 —*, and Z 41 , Z 43 , Z 44 , Z 46 , L 41 , L 42 , L 44 and L 45 are the same or different and each independently represent a direct bond, *—O—* or a C 1 to C 10 alkylene group.
6 . The non-aqueous electrolyte for a lithium secondary battery according to claim 5 , wherein the compound represented by Chemical Formula 2 includes one or more of compounds represented by the following Chemical Formulas 2-1 to 2-4, the compound represented by Chemical Formula 3 includes one or more of compounds represented by the following Chemical Formulas 3-1 to 3-3, and the compound represented by Chemical Formula 4 includes one or more of compounds represented by the following Chemical Formulas 4-1 to 4-3:
7 . The non-aqueous electrolyte for a lithium secondary battery according to claim 5 , wherein the second additive is included in an amount of 0.01 to 5.00 parts by weight with respect to 100 parts by weight of the non-aqueous electrolyte for a lithium secondary battery.
8 . The non-aqueous electrolyte for a lithium secondary battery according to claim 1 , wherein the non-aqueous electrolyte for a lithium secondary battery includes one or more of a lithium salt and an organic solvent.
9 . A lithium secondary battery comprising: the non-aqueous electrolyte for a lithium secondary battery according to claim 1 ; a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and a separator interposed between the positive electrode and the negative electrode.
10 . The lithium secondary battery of claim 9 , wherein the positive electrode active material includes one or more of an over-lithiated layered oxide represented by the following Chemical Formula 5 and an NCM-based lithium composite transition metal oxide represented by Chemical Formula 6: in Chemical Formula 5, 0<x<1, 0≤a1≤2, 0≤b1≤1, 0≤c1≤1, 0≤d1≤1, 0≤e1≤1 and a1+b1+c1+d1+e1=2 are satisfied, and M 1 includes one or more of Na, K, Mg, Al, Fe, Cr, Y, Sn, Ti, B, P, Zr, Ru, Nb, W, Ba, Sr, La, Ga, Gd, Sm, Ca, Ce, Ta, Mo, Sc, V, Zn, Cu, In, S, Bi, Rh, Pd, Ag, Cd and Tc, in Chemical Formula 6, 0.9≤a2≤1.1, 0.7≤b2<1, 0≤c2<1, 0<d2<1, 0≤e2<1 and b2+c2+d2+e2=1 are satisfied, and M 2 includes one or more of Na, K, Mg, Al, Fe, Cr, Y, Sn, Ti, B, P, Zr, Ru, Nb, W, Ba, Sr, La, Ga, Gd, Sm, Ca, Ce, Ta, Mo, Sc, V, Zn, Cu, In, S, Bi, Rh, Pd, Ag, Cd and Tc.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0155698, No. 10-2022-0155700, and No. 10-2022-0155701, filed on Nov. 18, 2022, and Korean Patent Application No. 10-2023-0033302, filed on Mar. 14, 2023, the disclosures of which are incorporated herein by reference in their entireties. TECHNICAL FIELD Technical Field The present invention relates to a non-aqueous electrolyte for a lithium secondary battery and a lithium secondary battery including the same. Background Art Recently, the application area of lithium secondary batteries has rapidly expanded to not only the supply of power to electrical devices, communication devices and electronic devices such as computers but also the storage and supply of power to large-scale devices such as automobiles and power storage devices. Accordingly, there is an increasing demand for secondary batteries with high capacity, high output and high stability. Also, the importance of high capacity, high output and long-term lifespan characteristics is increased in lithium secondary batteries for automotive use. Meanwhile, when lithium secondary batteries are exposed to repeated charging and discharging and a high temperature environment, electrolyte decomposition worsens, and thus gas is generated within the cell. Recently, high-voltage positive electrodes used in lithium secondary batteries have caused decomposition of specific solvents, and thus gas generation becomes more severe. In addition, in the case of high-capacity positive electrodes, the lattice oxygen stability of a positive electrode active material is low under high-pressure operating conditions, and thus the generation of oxygen gas from the positive electrode active material and chain decomposition occur. Accordingly, research is being conducted on an improvement in the performance, lifespan and stability of lithium secondary batteries by solving this gas problem. RELATED-ART DOCUMENTS Patent Documents (Patent Document 1) KR2006-0037592A DISCLOSURE Technical Problem The present invention is directed to providing a non-aqueous electrolyte for a lithium secondary battery, which is capable of minimizing problems resulting from oxygen gas by capturing oxygen gas generated from a positive electrode active material, and improving the lifespan and stability of a lithium secondary battery by suppressing the decomposition of a non-aqueous electrolyte for a lithium secondary battery, and a lithium secondary battery including the same. Technical Solution 1) The present invention provides a non-aqueous electrolyte for a lithium secondary battery, which includes a first additive including a compound represented by the following Chemical Formula 1: in Chemical Formula 1,R1 and R3 to R6 are the same or different and each independently represent hydrogen, a halogen, *-L1-C≡N, *-L2-C(═O)R7, *-L3-NR8R9, *-L4-OR10, a C1 to C20 alkyl group, a C2 to C20 alkynyl group or a C6 to C20 aryl group,R2 represents hydrogen, a halogen, *-L5-C≡N, *-L6-C(═O)R1, *-L7-NR12R13, *-L8-OR14, a C1 to C20 alkyl group or a C2 to C20 alkynyl group,R7 to R14 are the same or different and each independently represent hydrogen, oxygen, *-L9-OR15, a C1 to C20 alkyl group, a C2 to C20 alkynyl group or a C6 to C20 aryl group,R15 represents hydrogen, a C1 to C20 alkyl group, a C2 to C20 alkynyl group or a C6 to C20 aryl group, andL1 to L9 are the same or different and each independently represent a direct bond or a C1 to C10 alkylene group,provided that R1 to R6 are not hydrogen at the same time; or one or more of R1 to R6 are halogens, and the remainder of R1 to R6 are not hydrogen at the same time. 2) According to 1), the present invention may provide the non-aqueous electrolyte for a lithium secondary battery, in which the compound represented by Chemical Formula 1 includes one or more of compounds represented by the following Chemical Formulas 1-1 to 1-22: in Chemical Formulas 1-1 to 1-22,R1′ and R3′ to R6′ are the same or different and each independently represent a halogen, *-L1′-C≡N, *-L2′-C(═O)R7′, *-L3′-NR8′R9′, *-L4′-OR10′, a C1 to C20 alkyl group, a C2 to C20 alkynyl group or a C6 to C20 aryl group,R2′ represents a halogen, *-L5′-C≡N, *-L6′-C(═O)R11′, *-L7′-NR12′R13′, *-L8′-OR14′, a C1 to C20 alkyl group or a C2 to C20 alkynyl group,R7′ to R14′ are the same or different and each independently represent hydrogen, oxygen, *-L9′-OR15′, a C1 to C20 alkyl group, a C2 to C20 alkynyl group or a C6 to C20 aryl group,R15′ represents hydrogen, a C1 to C20 alkyl group, a C2 to C20 alkynyl group or a C6 to C20 aryl group, andL1′ to L9′ are the same or different and each independently represent a direct bond or a C1 to C10 alkylene group. 3) According to 1), the present invention may provide the non-aqueous electrolyte for a lithium secondary battery, in which the compound represented by Chemical Formula 1 includes one or more of compounds represented by the following chemical