Non-aqueous electrolyte lithium secondary battery
View Patent ↗A non-aqueous electrolyte includes (i) an inhibitor against a reaction between an anode and a linear ester; (ii) a mixed organic solvent containing cyclic carbonate and the linear ester; and (iii) an electrolyte salt, wherein the inhibitor is any one compound or a mixture of at least two compounds selected from the group consisting of cyclic carbonate with a vinyl group, fluorinated ethylene carbonate, vinylene carbonate, cyclic acid anhydride, a compound having a cyclic S═O group and an acrylate-based compound. Also, an electrochemical device includes a cathode, an anode and the above non-aqueous electrolyte.
1. A lithium secondary battery comprising:
an anode, a cathode, a separator between the anode and the cathode, a binding agent comprising a water-based binder for the anode, and a non-aqueous electrolyte,
wherein the anode has a specific surface area of at least about 1.5 m 2 /g, and
wherein the non-aqueous electrolyte comprises a lithium salt; a non-linear carbonate-based mixed organic solvent consisting of (a) a cyclic carbonate comprising ethylene carbonate and (b) a propionate-based ester having the following chemical formula are mixed at a volume ratio (a:b) in the range from about 20:80 to about 60:40; and an inhibitor against a reaction between the anode and the propionate-based ester:
where R 1 is a CH 3 CH 2 group and R 2 is ethyl,
wherein the inhibitor is one or more selected from the group consisting of cyclic carbonate with a vinyl group, fluorinated ethylene carbonate and a compound having a cyclic S═O group, and
a linear carbonate is excluded from the lithium secondary battery.
2. The lithium secondary battery according to claim 1 , wherein the content of the inhibitor against the reaction between the anode and the propionate-based ester is 1 to 10 weight % based on the total weight of the non-aqueous electrolyte.
3. The lithium secondary battery according to claim 1 , wherein the lithium salt is any one compound or a mixture of at least two compounds selected from the group consisting of LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , CF 3 SO 3 Li and LiC(CF 3 SO 2 ) 3 .
4. The lithium secondary battery according to claim 1 , wherein the anode is made of carbon material capable of occluding or emitting a lithium ion.
5. The lithium secondary battery according to claim 1 , wherein the cathode is made of lithium-containing oxide.
6. The lithium secondary battery according to claim 1 , wherein the water-based binder for the anode having the specific surface area range from about 1.5 m 2 /g to about 4.5 m 2 /g.
7. The lithium secondary battery according to claim 1 , wherein the water-based binder includes a styrene-butadiene rubber (SBR).
8. A lithium secondary battery comprising:
an anode, a cathode, a separator between the anode and the cathode, a binding agent comprising a water-based binder for the anode, and a non-aqueous electrolyte,
wherein the anode has a specific surface area of at least about 1.5 m 2 /g, and
wherein the non-aqueous electrolyte comprises a lithium salt; a non-linear carbonate-based mixed organic solvent consisting of (a) a cyclic carbonate comprising ethylene carbonate and (b) a propionate-based ester having the following chemical formula are mixed at a volume ratio (a:b) in the range from about 20:80 to about 60:40; and an inhibitor against a reaction between the anode and the propionate-based ester:
where R 1 is a CH 3 CH 2 group and R 2 is ethyl, and
wherein the inhibitor is one or more selected from the group consisting of cyclic carbonate with a vinyl group, fluorinated ethylene carbonate and a compound having a cyclic S═O group.
9. The lithium secondary battery according to claim 1 , wherein the inhibitor comprises a cyclic carbonate with a vinyl group.
10. The lithium secondary battery according to claim 9 , wherein the cyclic carbonate with a vinyl group is one or more selected from the group consisting of 4-vinyl-4-methyl-1,3-dioxolane-2-one, 4-vinyl-4-ethyl-1,3-dioxolane-2-one, 4-vinyl-4-n-propyl-1,3-dioxolane-2-one, 4-vinyl-5-methyl-1,3-dioxolane-2-one, 4-vinyl-5-ethyl-1,3-dioxolane-2-one, and 4-vinyl-5-n-propyl-1,3-dioxolane-2-one.
11. The lithium secondary battery according to claim 1 , wherein the inhibitor comprises a fluorinated ethylene carbonate.
12. The lithium secondary battery according to claim 1 , wherein the inhibitor comprises a compound having a cyclic S═O group.
13. The lithium secondary battery according to claim 12 , wherein the compound having a cyclic S═O group is one or more selected from the group consisting of ethyl ethylene sulfite, 4,5-dimethyl ethylene sulfite, 4,5-diethyl ethylene sulfite, propylene sulfite, 4,5-dimethyl propylene sulfite, 4,5-diethyl propylene sulfite, 4,6-dimethyl propylene sulfite, 4,6-diethyl propylene sulfite, and 1,3-butylene glycol sulfite, 1,4-butane sultone, ethene sultone, 1,4-butene sultone, and 1-methyl-1,3-propene sultone, dimethyl sulfone, diethyl sulfone, methyl ethyl sulfone, and methyl vinyl sulfone.
14. The lithium secondary battery according to claim 8 , wherein the inhibitor comprises a cyclic carbonate with a vinyl group.
15. The lithium secondary battery according to claim 14 , wherein the cyclic carbonate with a vinyl group is one or more selected from the group consisting of 4-vinyl-4-methyl-1,3-dioxolane-2-one, 4-vinyl-4-ethyl-1,3-dioxolane-2-one, 4-vinyl-4-n-propyl-1,3-dioxolane-2-one, 4-vinyl-5-methyl-1,3-dioxolane-2-one, 4-vinyl-5-ethyl-1,3-dioxolane-2-one, and 4-vinyl-5-n-propyl-1,3-dioxolane-2-one.
16. The lithium secondary battery according to claim 8 , wherein the inhibitor comprises a fluorinated ethylene carbonate.
17. The lithium secondary battery according to claim 8 , wherein the inhibitor comprises a compound having a cyclic S═O group.
18. The lithium secondary battery according to claim 17 , wherein the compound having a cyclic S═O group is one or more selected from the group consisting of ethyl ethylene sulfite, 4,5-dimethyl ethylene sulfite, 4,5-diethyl ethylene sulfite, propylene sulfite, 4,5-dimethyl propylene sulfite, 4,5-diethyl propylene sulfite, 4,6-dimethyl propylene sulfite, 4,6-diethyl propylene sulfite, and 1,3-butylene glycol sulfite, 1,4-butane sultone, ethene sultone, 1,4-butene sultone, and 1-methyl-1,3-propene sultone, dimethyl sulfone, diethyl sulfone, methyl ethyl sulfone, and methyl vinyl sulfone.