Non-aqueous electrolyte additive, and non-aqueous electrolyte for lithium secondary battery comprising the same and lithium secondary battery
View Patent ↗The present invention relates to a non-aqueous electrolyte additive, and a non-aqueous electrolyte for a lithium secondary battery including the same and a lithium secondary battery, and particularly, to a non-aqueous electrolyte additive having a nitrile group and a propargyl group, and a non-aqueous electrolyte for a lithium secondary battery and a lithium secondary battery, which include the non-aqueous electrolyte additive so that capacity and cycle lifespan characteristics at high temperature can be improved.
1. A non-aqueous electrolyte additive comprising at least one compound selected from the group consisting of compounds represented by Formula I and Formula II below:
wherein R 1 is a C 1 to C 5 linear or nonlinear alkylene group substituted or unsubstituted with at least one nitrile group, or a C 6 to C 8 aromatic group substituted or unsubstituted with at least one nitrile group,
R 2 is a C 1 to C 5 linear or nonlinear alkylene group substituted or unsubstituted with at least one nitrile group, a C 6 to C 8 aromatic group substituted or unsubstituted with at least one nitrile group, a C 6 to C 8 heteroaromatic group substituted or unsubstituted with at least one nitrile group, a C 2 to C 5 linear or nonlinear alkenyl group, or —C(O)—R 9 —, wherein R 9 is a C 1 to C 3 linear or nonlinear alkylene group substituted with at least one nitrile group,
R 3 is hydrogen or a C 1 to C 5 linear or nonlinear unsubstituted alkyl group when m is 0, and a C 1 to C 5 linear or nonlinear alkylene group when m is 1,
R 4 is a C 1 to C 3 alkylene group or —R 10 —C(O)—, wherein R 10 is a C 1 to C 3 alkylene group, and n and m each independently are an integer of 0 or 1,
wherein R 5 is hydrogen or a C 1 to C 5 linear or nonlinear alkyl group substituted or unsubstituted with at least one nitrile group,
wherein R 6 is a C 1 to C 5 linear or nonlinear alkylene group, and
wherein R 7 to R 8 each independently are a C 1 , C 3 , C 4 , or C 5 linear or nonlinear alkylene group.
2. The non-aqueous electrolyte additive of claim 1 , wherein the non-aqueous electrolyte additive comprises at least one compound selected from the group consisting of compounds represented by Formulae I-1 to I-9 and I-11 to I-23, and I-25 to I-39 below:
3. The non-aqueous electrolyte additive of claim 1 , wherein the non-aqueous electrolyte additive comprises at least one compound selected from the group consisting of compounds represented by Formula II-1 to Formula II 3 below:
4. A non-aqueous electrolyte for a lithium secondary battery comprising:
an ionizable lithium salt;
an organic solvent; and
a non-aqueous electrolyte additive,
wherein the non-aqueous electrolyte additive includes at least one compound selected from the group consisting of compounds represented by Formula I and Formula II below:
wherein R 1 is a C 1 to C 5 linear or nonlinear alkylene group substituted or unsubstituted with at least one nitrile group, or a C 6 to C 8 aromatic group substituted or unsubstituted with at least one nitrile group,
R 2 is a C 1 to C 5 linear or nonlinear alkylene group substituted or unsubstituted with at least one nitrile group, a C 6 to C 8 aromatic group substituted or unsubstituted with at least one nitrile group, a C 6 to C 8 heteroaromatic group substituted or unsubstituted with at least one nitrile group, a C 2 to C 5 linear or nonlinear alkenyl group, or —C(O)—R 9 —, wherein R 9 is a C 1 to C3 linear or nonlinear alkylene group substituted with at least one nitrile group,
R 3 is hydrogen or a C 1 to C 5 linear or nonlinear unsubstituted alkyl group when m is 0, and a C 1 to C 5 linear or nonlinear alkylene group when m is 1,
R 4 is a C 1 to C 3 alkylene group or —R 10 —C(O)—, wherein R 10 is a C 1 to C 3 alkylene group, and
n and m each independently are an integer of 0 or 1,
wherein R 5 is hydrogen or a C 1 to C 5 linear or nonlinear alkyl group substituted or unsubstituted with at least one nitrile group,
wherein R 6 is a C 1 to C 5 linear or nonlinear alkylene group, and
wherein R 7 to R 8 each independently are a C 1 , C 3, C 4, or C 5 linear or nonlinear alkylene group.
5. The non-aqueous electrolyte of claim 4 , wherein the non-aqueous electrolyte additive is included at 0.5 wt % to 5 wt % based on a total content of the non-aqueous electrolyte.
6. The non-aqueous electrolyte of claim 5 , wherein the non-aqueous electrolyte additive is included at 1 wt % to 5 wt % based on a total content of the non-aqueous electrolyte.
7. The non-aqueous electrolyte of claim 4 , wherein the lithium salt includes Li + as a cation and any one selected from the group consisting of F - , Cl - , Br - , I - , NO 3 - , N(CN) 2 - , BF 4 - ,ClO 4 - , AlO 4 - , AlCl 4 - , PF 6 - , SbF 6 - , AsF 6 - , BF 2 C 2 O 4 - , BC 4 O 8 - , (CF 3 ) 2 PF 4 - , (CF 3 ) 3 PF 3 - , (CF 3 ) 4 PF 2 - , (CF 3 ) 5 PF - , (CF 3 ) 6 P - , CF 3 SO 3 - , C 4 F 9 SO 3 - , CF 3 CF 2 SO 3 - , (CF 3 SO 2 ) 2 N - , (F 2 SO 2 ) 2 N - , CF 3 CF 2 (CF 3 ) 2 CO - , (CF 3 SO 2 ) 2 CH - , CF 3 (CF 2 ) 7 SO 3 - , CF 3 CO 2 - , CH 3 CO 2 - , SCN - , and (CF 3 CF 2 SO 2 ) 2 N - as an anion.
8. The non-aqueous electrolyte of claim 4 , wherein the organic solvent includes a mixture of at least one selected from the group consisting of an ether, an ester, an amide, a linear carbonate, and a cyclic carbonate.
9. A lithium secondary battery comprising a negative electrode, a positive electrode, a separator interposed between the negative electrode and the positive electrode, and a non-aqueous electrolyte,
wherein the non-aqueous electrolyte is the non-aqueous electrolyte for a lithium secondary battery according to claim 4 .