Lithium secondary battery with anode containing aqueous binder
View Patent ↗Provided is a lithium secondary battery comprising an anode, a cathode and a non-aqueous electrolyte, wherein the anode includes an aqueous binder, and the non-aqueous electrolyte contains (a) a cyclic anhydride or a derivative thereof; and (b) any one anion receptor selected from the group consisting of a borane compound, a borate compound and mixtures thereof. According to the present invention, a stable SEI film is formed on the anode, and the life characteristics of the battery are improved by controlling the LiF content in the SEI film.
1. A lithium secondary battery comprising an anode, a cathode and a non-aqueous electrolyte,
wherein the anode includes an aqueous binder, wherein the aqueous binder is styrene-butadiene rubber (SBR), and
wherein the non-aqueous electrolyte comprises:
(a) a cyclic anhydride; and
(b) any one anion receptor selected from the group consisting of a borane compound, a borate compound, and mixtures thereof.
2. The lithium secondary battery according to claim 1 ,
wherein the cyclic anhydride is any one selected from the group consisting of compounds represented by the following formulae 1 to 4, and mixtures thereof:
where each of R 1 to R 11 is independently halogen, or an alkyl group, an alkenyl group or an alkoxy group having 1 to 10 carbon atoms, substituted or non-substituted with halogen.
3. The lithium secondary battery according to claim 1 ,
wherein the borane compound is a compound represented by the following formula 5:
where each of R 12 to R 14 is independently hydrogen or halogen, or an alkyl group or a silyl group having 1 to 6 carbon atoms.
4. The lithium secondary battery according to claim 1 ,
wherein the borate compound is a compound represented by the following formula 6:
where each of R 15 to R 17 is independently hydrogen or halogen, or an alkyl group or a silyl group having 1 to 6 carbon atoms.
5. The lithium secondary battery according to claim 1 ,
wherein the content of each of the (a) and (b) components is between 0.05 and 10 weight % per the total weight of the non-aqueous electrolyte.
6. The lithium secondary battery according to claim 1 ,
wherein the non-aqueous electrolyte contains a lithium salt and a carbonate organic solvent.
7. The lithium secondary battery according to claim 6 ,
wherein the lithium salt is any one 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, LiC(CF 3 SO 2 ) 3 , LiC 4 BO 8 , and mixtures thereof.
8. The lithium secondary battery according to claim 6 ,
wherein the carbonate organic solvent is a cyclic carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate and fluoroethylene carbonate, a linear carbonate selected from the group consisting of diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, methyl propyl carbonate, and mixtures thereof.