Non-aqueous electrolytic solution
View Patent ↗The use of lithium bis(oxalate)borate (LiBOB) as an additive in a lithium secondary battery provides improved battery performance such as long life and high capacity retention after high temperature storage.
1. A secondary battery comprising an anode, a cathode, and an electrolytic solution, wherein the electrolytic solution comprises a non-aqueous solvent, a solute, and a salt additive, the salt additive comprising lithium bis(oxalato)borate provided that the concentration of lithium bis(oxalato)borate in the solution does not exceed 0.15 M, wherein
the anode comprises
a first material selected from the group consisting of crystalline carbon, lithium metal, LiMnO 2 , LiAl, LiZn, Li 3 Bi, Li 3 Cd, Li 3 Sb, Li 4 Si, Li 4.4 Pb, Li 4.4 Sn, LiC 6 , Li 3 FeN 2 , Li 2.6 Co 0.4 N, Li 2.6 Cu 0.4 N, Li 4 Ti 5 O 12 , and combinations thereof, and
a second material selected from the group consisting of SnO, SnO 2 , GeO, GeO 2 , In 2 O, In 2 O 3 , PbO, PbO 2 , Pb 2 O 3 , Pb 3 O 4 , Ag 2 O, AgO, Ag 2 O 3 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 , SiO, ZnO, CoO, NiO, FeO, and combinations thereof.
2. The secondary battery of claim 1 , wherein the anode further comprises a binder selected from the group consisting of polyvinylidene fluoride, styrene-butadiene rubber, polyamide, melamine, and combinations thereof.
3. The secondary battery of claim 1 , wherein the solute is selected from the group consisting of LiPF 6 , LiBF 4 , and combinations thereof.
4. The secondary battery of claim 1 , wherein the non-aqueous solvent is selected from the group consisting of ethylene carbonate, propylene carbonate and diethyl carbonate and combinations thereof.
5. The secondary battery of claim 1 , wherein the salt additive comprises 0.01 M to 0.12 M lithium bis(oxalato)borate.
6. The secondary battery of claim 1 wherein the salt additive further comprises cations selected from the group consisting of alkali metal ions, alkaline earth metal ions, transition metal ions and oniums.
7. The secondary battery of claim 1 further comprising a second salt additive selected from the group consisting of lithium bis(malonato) borate, lithium bis(difluoromalonato) borate, lithium (malonato oxalato) borate, lithium (difluoromalonato oxalato) borate, lithium tris(oxalato)phosphate, and lithium tris(difluoromalonato)phosphate, and combinations thereof, provided that the total concentration of orthoborate and orthophosphate salts does not exceed 0.15 M.
8. The secondary battery of claim 7 wherein the salt additive comprises 0.01 M to 0.12 M lithium bis(oxalato)borate.
9. The secondary battery of claim 1 wherein the solute is selected from the group consisting of LiPF 6 , LiBF 4 , LiCIO 4 , LiAsF 6 , LiTaF 6 , LiAlCl 4 , Li 2 B 10 Cl 10 , LiCF 3 SO 3 ; LiE(C n F 2n+1 SO 2 ) m , wherein m=2 or 3, wherein E=N when m=2, wherein E=C when m=3, and n=1-10; LiPF x (R F ) 6-x and LiBF y (R F) 4-y , wherein R F represents perfluorinated C 1 -C 20 alkyl groups or perfluorinated aromatic groups, x=0-5, and y=0-3, and combinations thereof.
10. The secondary battery of claim 9 wherein the solute is present in a concentration of about 0.1 to about 2.5 M.
11. The secondary battery of claim 1 wherein the non-aqueous solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, tetrahydrofuran, 2-methyl tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, acetonitrile, dimethylformamide, methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, γ-butyrolactone, 2-methyl-γ-butyrolactone, 3-methyl-γ-butyrolactone, 4-methyl-γ-butyrolactone, β-propiolactone, δ-valerolactone, trimethyl phosphate, triethyl phosphate, tris(2-chloroethyl) phosphate, tris(2,2,2-trifluoroethyl) phosphate, tripropyl phosphate, triisopropyl phosphate, tributyl phosphate, trihexyl phosphate, triphenyl phosphate, tritolyl phosphate, and combinations thereof.
12. The secondary battery of claim 1 wherein the cathode comprises a lithium mixed metal oxide selected from the group consisting of LiMnO 2 , LiMn 2 O 4 , LiCoO 2 , Li 2 Cr 2 O 7 , Li 2 CrO 4 , LiNiO 2 , LiFeO 2 , LiNi x Co 1−x O 2 (0<x<1), LiFePO 4 , LiMno 0.5 Ni 0.5 O 2 , LiMn 1/3 Co 1/3 Ni 1/3 O 2 , and LiMc 0.5 Mn 1.5 O 4 wherein Mc is a divalent metal, and mixtures thereof.
13. The secondary battery of claim 1 wherein the cathode further comprises a binder selected from the group consisting of polyvinylidene fluoride, styrene-butadiene rubber, polyamide, melamine, and combinations thereof.
14. A secondary battery comprising an electrolytic solution, wherein the electrolytic solution comprises a non-aqueous solvent, a solute, and a salt additive, the salt additive comprising lithium bis(oxalato)borate provided that the concentration of lithium bis(oxalato)borate in the solution does not exceed about 0.10 M, wherein the non-aqueous solvent comprises about 1-50 wt % ethylene carbonate, about 1-50 wt % propylene carbonate and about 1-80 wt % diethyl carbonate.
15. The secondary battery of claim 14 wherein the salt additive further comprises cations selected from the group consisting of alkali metal ions, alkaline earth metal ions, transition metal ions and oniums.
16. The secondary battery of claim 14 further comprising a second salt additive selected from the group consisting of lithium bis(malonato) borate, lithium bis(difluoromalonato) borate, lithium (malonato oxalato) borate, lithium (difluoromalonato oxalato) borate, lithium tris(oxalato)phosphate, and lithium tris(difluoromalonato)phosphate, and combinations thereof, provided that the total concentration of orthoborate and orthophosphate salts does not exceed 0.1 5 M.
17. The secondary battery of claim 14 wherein the solute is present in a concentration of about 0.1 to about 2.5 M and is selected from the group consisting of LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiTaF 6 , LiAlCl 4 , Li 2 B 10 Cl 10 , LiCF 3 SO 3 ; LiE(C n F 2n+1 SO 2 ) m , wherein m=2 or 3, wherein E=N when m=2, and wherein E=C when m=3, and n=1-10; LiPF x (R F ) 6-x and LiBF y (R F ) 4-y , wherein R F represents perfluorinated C 1 -C 20 alkyl groups or perfluorinated aromatic groups, x=0-5, and y=0-3, and combinations thereof.
18. The secondary battery of claim 14 wherein the non-aqueous solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, tetrahydrofuran, 2-methyl tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, acetonitrile, dimethylformamide, methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, γ-butyrolactone, 2-methyl-γ-butyrolactone, 3-methyl-γ-butyrolactone, 4-methyl-γ-butyrolactone, β-propiolactone, δ-valerolactone, trimethyl phosphate, triethyl phosphate, tris(2-chloroethyl) phosphate, tris(2,2,2-trifluoroethyl) phosphate, tripropyl phosphate, triisopropyl phosphate, tributyl phosphate, trihexyl phosphate, triphenyl phosphate, tritolyl phosphate, and combinations thereof.
19. A non-aqueous electrolytic solution for use in a secondary battery comprising a first salt, lithium bis(oxalato)borate, provided that lithium bis(oxalato)borate is present at a concentration not exceeding 0.15 M, and a solvent comprising about 1-50 wt % ethylene carbonate, about 1-50 wt % propylene carbonate and about 1-80 wt % diethyl carbonate.
20. The non-aqueous electrolytic solution of claim 19 wherein the first salt is selected from the group consisting of LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiTaF 6 , LiAlCl 4 , Li 2 B 10 Cl 10 , LiCF 3 SO 3 ; LiE(C n F 2+1 SO 2 ) m , wherein m=2 or 3, wherein E=N when m=2, and wherein E=C when m=3, and n=1-10; LiPF x (R F ) 6-x and LiBF y (R F ) 4-y , wherein R F represents perfluorinated C 1 -C 20 alkyl groups or perfluorinated aromatic groups, x=0-5, and y=0-3, and combinations thereof.