Electrolyte for rechargeable lithium battery and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2025323318-A1
Application number	US-202519066391-A
Country	US
Kind code	A1
Filing date	Feb 28, 2025
Priority date	Apr 16, 2024
Publication date	Oct 16, 2025
Grant date	—

Abstract

An electrolyte and a rechargeable lithium battery includes the electrolyte are provided. The electrolyte includes a non-aqueous organic solvent; a lithium salt; lithium bis(oxalato)borate (LiBOB); a first compound represented by Chemical Formula 1; and a second compound represented by Chemical Formula 2.

First claim

What is claimed is:

1 . An electrolyte, comprising:
a non-aqueous organic solvent; a lithium salt; lithium bis(oxalato)borate; a first compound represented by Chemical Formula 1; and a second compound represented by Chemical Formula 2,

wherein, in Chemical Formula 1,
R 1a to R 8a are each independently hydrogen, a halogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group, and
k is 0 or 1,

wherein, in Chemical Formula 2,
A 1 is O or C(R 1b )(R 2b ),
A 2 is O or C(R 3b )(R 4b ),
B 1 is C(R 5b )(R 6b ) or a carbonyl group,
B 2 is C(R 7b )(R 8b ) or a carbonyl group,
B 3 is C(R 9b )(R 10b ) or a carbonyl group,
B 4 is C(R 11b )(R 12b ) or a carbonyl group,
R 1b to R 12b are each independently hydrogen, a halogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group,
n1, n2, m1, and m2 are each independently an integer of 0 or 1, and
n1+m1≥1 and n2+m2≥1, and

wherein the electrolyte is for a rechargeable lithium battery.

2 . The electrolyte as claimed in claim 1 , wherein the lithium bis(oxalato)borate is in an amount of about 0.01 wt % to about 2 wt % relative to a total weight of 100 wt % of the electrolyte.

3 . The electrolyte as claimed in claim 1 , wherein the first compound is in an amount of about 0.01 wt % to about 5 wt % relative to a total weight of 100 wt % of the electrolyte.

4 . The electrolyte as claimed in claim 1 , wherein the first compound comprises at least one selected from among a compound represented by Chemical Formula 1-1 and a compound represented by Chemical Formula 1-2,

in Chemical Formulae 1-1 and 1-2, R 1a to R 8a each being independently the same as defined in Chemical Formula 1.

5 . The electrolyte as claimed in claim 1 , wherein the first compound comprises at least one selected from among a compound represented by Chemical Formula 1-1-1 and a compound represented by Chemical Formula 1-2-1,

6 . The electrolyte as claimed in claim 1 , wherein the second compound is in an amount of about 0.01 wt % to about 5 wt % relative to a total weight of 100 wt % of the electrolyte.

7 . The electrolyte as claimed in claim 1 , wherein the second compound comprises at least one selected from among compounds represented by Chemical Formulae 2-1, 2-2, 2-3, and 2-4,

in Chemical Formulae 2-1 to 2-4, B 1 to B 4 and R 1b to R 4b each being independently the same as defined in Chemical Formula 2.

8 . The electrolyte as claimed in claim 1 , wherein the second compound comprises at least one selected from among compounds represented by Chemical Formulae 2-1-1, 2-2-1, 2-3-1, and 2-4-1,

in Chemical Formulae 2-1-1 to 2-4-1, R 1b to R 12b each being independently the same as defined in Chemical Formula 2.

9 . The electrolyte as claimed in claim 1 , wherein the second compound comprises at least one selected from among compounds listed in Group 1,

10 . The electrolyte as claimed in claim 1 , wherein the lithium bis(oxalato)borate and the second compound are in a weight ratio of about 1:2 to about 1:20.

11 . The electrolyte as claimed in claim 1 , wherein the lithium bis(oxalato)borate and the second compound are in a weight ratio of about 1:2 to about 1:20.

12 . The electrolyte as claimed in claim 1 , wherein the first compound and the second compound are in a weight ratio of about 1:0.2 to about 1:5.

13 . The electrolyte as claimed in claim 1 , wherein the non-aqueous organic solvent comprises a carbonate-based solvent.

14 . The electrolyte as claimed in claim 13 , wherein the carbonate-based solvent comprises dimethyl carbonate, methylethyl carbonate, and ethylene carbonate.

15 . The electrolyte as claimed in claim 1 , wherein a concentration of the lithium salt is in a range of about 0.1 M to about 2.0 M.

16 . A rechargeable lithium battery, comprising:
a positive electrode comprising a positive electrode active material; a negative electrode comprising a negative electrode active material; and the electrolyte as claimed in claim 1 .

17 . The rechargeable lithium battery as claimed in claim 16 , wherein the positive electrode active material comprises a compound represented by Chemical Formula 3,

in Chemical Formula 3,
0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2,
X comprising at least one selected from among Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, and a rare-earth element, and
D comprising at least one selected from among O, F, S, and P.

18 . The rechargeable lithium battery as claimed in claim 16 , wherein
the positive electrode further comprises a current collector, and the current collector comprises Al.

19 . The rechargeable lithium battery as claimed in claim 16 , wherein the negative electrode active material comprises a carbon-based negative electrode active material and/or a Si-based negative electrode active material.

20 . The rechargeable lithium battery as claimed in claim 16 , wherein the rechargeable lithium battery is configured to operate even at a high voltage of equal to or greater than about 4.2 V.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lim Jin-Hyeok
• Kim Sanghoon
• Koh Sujeong
• Cho Erang
• Kwon Bomee
• Jeong Euisoo
• KIM Sundae
• Seo Jinah

Classifications

• H01M10/52

  Removing gases inside the secondary cell, e.g. by absorption (vent plugs or other mechanical arrangements for facilitating escape of gases H01M50/30) · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2300/0028

  characterised by the solvent · CPC title