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EP-4557402-B1 - ELECTROLYTE SOLUTION FOR RECHARGEABLE LITHIUM BATTERY AND RECHARGEABLE LITHIUM BATTERY INCLUDING THE SAME

EP4557402B1EP 4557402 B1EP4557402 B1EP 4557402B1EP-4557402-B1

Inventors

  • LEE, TAE JIN
  • KIM, MINSEO
  • KIM, Dahyun
  • WOO, MYUNGHEUI

Dates

Publication Date
20260513
Application Date
20241120

Claims (9)

  1. An electrolyte solution for a rechargeable lithium battery (100) comprising: a non-aqueous organic solvent; a lithium salt; and an additive, wherein the additive comprises a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2: wherein, in Chemical Formula 1, R 1 and R 2 are each independently a substituted or unsubstituted C1 to C20 alkyl group or a substituted or unsubstituted C6 to C30 aryl group, provided that at least one of R 1 and R 2 is a substituted or unsubstituted C6 to C30 aryl group, in Chemical Formula 2, M is boron (B) or phosphorus (P), R 3 and R 4 are each independently hydrogen, a halogen, or a substituted or unsubstituted C1 to C10 alkyl group, R 5 is a substituted or unsubstituted methylene group, n is an integer of 1 to 3, m is 0 or 1, m1 and m2 are each independently an integer from 0 to 2, and wherein the term "substituted" refers to replacement of at least one hydrogen by deuterium, a halogen, a hydroxyl group, an amino group, a C1 to C30 amine group, a nitro group, a C1 to C40 silyl group, a C1 to C30 alkyl group, a C1 to C10 alkylsilyl group, a C6 to C30 arylsilyl group, a C3 to C30 cycloalkyl group, a C3 to C30 heterocycloalkyl group, a C6 to C30 aryl group, a C2 to C30 heteroaryl group, a C1 to C20 alkoxy group, a C1 to C10 fluoroalkyl group, and a cyano group.
  2. The electrolyte solution as claimed in claim 1, wherein the first compound represented by Chemical Formula 1 is represented by Chemical Formula 1-1 or Chemical Formula 1-2: in Chemical Formula 1-1, R 1a being a substituted or unsubstituted C1 to C20 alkyl group, and H a to H e being each independently hydrogen, a halogen, a hydroxyl group, a cyano group, a nitro group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy 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 C6 to C20 aryl group, or a substituted or unsubstituted C2 to C20 heteroaryl group; and in Chemical Formula 1-2, H a to H j being each independently hydrogen, a halogen, a hydroxyl group, a cyano group, a nitro group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy 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 C6 to C20 aryl group, or a substituted or unsubstituted C2 to C20 heteroaryl group, wherein the term "substituted" refers to replacement of at least one hydrogen by deuterium, a halogen, a hydroxyl group, an amino group, a C1 to C30 amine group, a nitro group, a C1 to C40 silyl group, a C1 to C30 alkyl group, a C1 to C10 alkylsilyl group, a C6 to C30 arylsilyl group, a C3 to C30 cycloalkyl group, a C3 to C30 heterocycloalkyl group, a C6 to C30 aryl group, a C2 to C30 heteroaryl group, a C1 to C20 alkoxy group, a C1 to C10 fluoroalkyl group, and a cyano group.
  3. The electrolyte solution as claimed in claim 1, wherein the first compound is one or more compounds selected from among compounds in Group 1:
  4. The electrolyte solution as claimed in any one of the preceding claims, wherein the second compound represented by Chemical Formula 2 comprises one or more selected from among compounds represented by Chemical Formula 2-1 to Chemical Formula 2-8:
  5. The electrolyte solution as claimed in any one of the preceding claims, wherein the lithium salt comprises LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiAlO 2 , LiAlCl 4 , LiPO 2 F 2 , LiCl, Lil, LiN(SO 3 C 2 F 5 ) 2 , Li(FSO 2 ) 2 N (lithium bis(fluorosulfonyl)imide, LiFSI), LiC 4 F 9 SO 3 , LiN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 ), and x and y are each independently an integer selected from 1 to 20, lithium trifluoromethane sulfonate, lithium tetrafluoroethane sulfonate, or a combination thereof.
  6. The electrolyte solution as claimed in any one of the preceding claims, wherein the first compound is greater than 0.05 wt% and less than 10 wt% in amount based on a total weight of the electrolyte solution.
  7. The electrolyte solution as claimed in any one of the preceding claims, wherein the second compound is greater than 0.05 wt% and less than 5 wt% in amount based on a total weight of the electrolyte solution.
  8. The electrolyte solution as claimed in any one of the preceding claims, wherein the first compound and the second compound are in a weight ratio of 0.05 : 1 to 50 : 1.
  9. A rechargeable lithium battery (100) comprising: a positive electrode (10) comprising a positive electrode active material; a negative electrode (20) comprising a negative electrode active material; a separator between the positive electrode (10) and the negative electrode (20); and the electrolyte solution as claimed in claim 1.

Description

BACKGROUND 1. Field This disclosure relates to an electrolyte solution for a rechargeable lithium battery and a rechargeable lithium battery including the same. 2. Description of the Related Art Recently, with the rapid spread of electronic devices that use batteries, such as mobile phones, laptop computers, and/or electric vehicles, the demand or desire for rechargeable batteries with relatively high energy density and high capacity is rapidly increasing. Accordingly, research and development to improve the performance of rechargeable lithium batteries is actively underway or being pursued. Rechargeable lithium batteries include a positive electrode and a negative electrode, each including an active material capable of intercalating and deintercalating lithium ions, and an electrolyte solution, and generate electrical energy through oxidation and reduction reactions if lithium ions are intercalated and deintercalated to/from the positive electrode and the negative electrode. For examle US2020/251780A1 discloses an electrolyte solution for a rechargeable lithium battery comprising diphenyl sulfone. Recently, active research has been conducted on rechargeable lithium batteries with high capacity, high energy density, and high safety for use as a driving power source for hybrid vehicles and/or electric vehicles, or as a power storage power source (e.g., for power storage stations and/or power walls). In rechargeable lithium batteries, the electrolyte plays a role in transferring lithium ions, and can exhibit significantly higher ionic conductivity by including organic solvents and lithium salts. These electrolyte solutions play a role in determining the safety and performance of rechargeable lithium batteries. When a rechargeable lithium battery is in an overcharged state, the battery generates heat rapidly and gas is also generated, raising issues with the safety of the battery due to cell explosion, and/or the like. Additionally, if a rechargeable lithium battery is subject to rapid charging, there is a problem where lithium is electrodeposited on the negative electrode and the resistance inside the battery increases. Accordingly, there is a need or desire for the development of an electrolyte solution to implement a battery with excellent or suitable safety even under overcharging and rapid charging conditions. SUMMARY The invention is defined by the appended claims. The description that follows is subjected to this limitation. Any disclosure lying outside the scope of said claims is only intended for illustrative as well as comparative purposes. Aspects according to some embodiments are directed toward an electrolyte solution for a rechargeable lithium battery that has excellent or suitable safety under overcharging and rapid charging conditions and excellent or suitable room-temperature cycle-life characteristics. Aspects according to some embodiments are directed toward a rechargeable lithium battery including the electrolyte solution. Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure. In one or more embodiments, an electrolyte solution for a rechargeable lithium battery includes a non-aqueous organic solvent; a lithium salt; and an additive, wherein the additive includes a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2. In Chemical Formula 1, R1 and R2 are each independently a substituted or unsubstituted C1 to C20 alkyl group or a substituted or unsubstituted C6 to C30 aryl group, provided that at least one of R1 and R2 is a substituted or unsubstituted C6 to C30 aryl group,in Chemical Formula 2,M is boron (B) or phosphorus (P),R3 and R4 are each independently hydrogen, a halogen (F, Cl, Br, or I), or a substituted or unsubstituted C1 to C10 alkyl group,R5 is a substituted or unsubstituted methylene group,n is an integer of 1 to 3, andm is 0 or 1,m1 and m2 are each independently an integer from 0 to 2. In one or more embodiments, a rechargeable lithium battery includes a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; a separator between the positive electrode and the negative electrode; and the aforementioned electrolyte solution. The electrolyte solution for a rechargeable lithium battery according to one or more embodiments has excellent or suitable safety under overcharging and rapid charging conditions, and can implement a rechargeable lithium battery with excellent or suitable room-temperature cycle-life characteristics. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present disclosure and, together wi