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KR-102963307-B1 - ADDITIVE FOR RECHARGEABLE LITHIUM BATTERY, ELECTROLYTE INCLUDING SAME AND RECHARGEABLE LITHIUM BATTERY

KR102963307B1KR 102963307 B1KR102963307 B1KR 102963307B1KR-102963307-B1

Abstract

The present invention provides an additive for a lithium secondary battery comprising a core and a shell surrounding the core, wherein the core comprises a flame retardant, a fire extinguishing agent, a non-combustible material, or a combination thereof, and the shell comprises a polymer having a melting point of 90°C to 120°C, an electrolyte for a lithium secondary battery comprising the same, and a lithium secondary battery.

Inventors

  • 유보경
  • 우명희
  • 김상훈

Assignees

  • 삼성에스디아이 주식회사

Dates

Publication Date
20260508
Application Date
20221018

Claims (14)

  1. It includes a core and a shell surrounding the core, The above core comprises a flame retardant, a fire extinguishing agent, a non-combustible material, or a combination thereof, and The above shell comprises a polymer having a melting point of 90°C to 120°C, and The ratio of the thickness of the core to the thickness of the shell is 1:1 to 4:1, and The above polymer is an additive for a lithium secondary battery electrolyte comprising poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP), polyacrylic acid, polyethylene, poly(methyl methacrylate), polyalkylene oxide, polyalkylene succinate, or a combination thereof.
  2. delete
  3. In paragraph 1, An additive for a lithium secondary battery electrolyte, wherein the core has a thickness of 0.1 μm to 2.0 μm and the shell has a thickness of 0.025 μm to 0.5 μm.
  4. In paragraph 1, The above flame retardant is an additive for lithium secondary battery electrolytes that is a phosphate ester compound, a phosphazene compound, or a combination thereof.
  5. In Paragraph 4, The above phosphate ester compound is an additive for lithium secondary battery electrolytes represented by the following chemical formula 1. [Chemical Formula 1] In the above chemical formula 1, R1 to R3 are each independently substituted or unsubstituted C1 to C10 alkyl groups, and a to c are each independently integers from 0 to 5.
  6. In Paragraph 4, The above phosphazene compound is an additive for a lithium secondary battery electrolyte represented by the following chemical formula 2. [Chemical Formula 2] In the above chemical formula 2, n is 3 or 4, and R 4 and R 5 are the same or different and are -F, -NR x R y , or substituted or unsubstituted C1 to C5 alkoxy groups, and R x and R y are the same or different and are substituted or unsubstituted C1 to C30 alkyl groups, substituted or unsubstituted C3 to C30 cycloalkyl groups, substituted or unsubstituted C2 to C30 alkenyl groups, or C6 to C30 substituted or unsubstituted aryl groups.
  7. In Paragraph 4, The above phosphazene compound is an additive for a lithium secondary battery electrolyte represented by the following chemical formula 2-1 or the following chemical formula 2-2. [Chemical Formula 2-1] [Chemical Formula 2-2] In the above chemical formula 2-1 and the above chemical formula 2-2, R6 to R8 are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a C1 to C10 fluoroalkyl group, or a combination thereof.
  8. delete
  9. In Paragraph 1, The above additive is an additive for lithium secondary battery electrolyte in the form of fibers formed using electrospinning.
  10. Non-aqueous organic solvents, lithium salts, and Additive for a lithium secondary battery electrolyte according to any one of paragraphs 1, 3 through 7, and 9 Electrolyte for a lithium secondary battery containing
  11. In Paragraph 10, The above-mentioned additive for a lithium secondary battery electrolyte is included in an amount of 0.1% to 20% by weight based on the total weight of the lithium secondary battery electrolyte.
  12. In Paragraph 10, The above-mentioned additive for a lithium secondary battery electrolyte is included in an amount of 0.1% to 15% by weight based on the total weight of the lithium secondary battery electrolyte.
  13. In Paragraph 10, The above-mentioned additive for a lithium secondary battery electrolyte is included in an amount of 0.1% to 10% by weight relative to the total weight of the lithium secondary battery electrolyte.
  14. Anode containing a positive active material; A cathode comprising a cathode active material; and Electrolyte of Clause 10; A lithium secondary battery including

Description

Additive for rechargeable lithium battery, electrolyte for rechargeable lithium battery including the same, and rechargeable lithium battery The present invention relates to an additive for a lithium secondary battery, an electrolyte for a lithium secondary battery containing the same, and a lithium secondary battery. Lithium secondary batteries are rechargeable and have an energy density more than three times higher per unit weight than conventional lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries, and can be fast-charged. As a result, they are being commercialized for laptops, mobile phones, power tools, and electric bicycles, and research and development to further improve energy density is actively underway. These lithium secondary batteries are used by injecting an electrolyte into a battery cell comprising a positive electrode containing a positive electrode active material capable of intercalating and deintercalating lithium, and a negative electrode containing a negative electrode active material capable of intercalating and deintercalating lithium. In particular, the electrolyte uses an organic solvent in which lithium salts are dissolved, and this electrolyte is important in determining the stability and performance of the lithium secondary battery. LiPF6 , which is the most widely used lithium salt in electrolytes, has the problem of reacting with the organic solvent in the electrolyte to accelerate solvent depletion and generate a large amount of gas. When LiPF6 decomposes, it produces LiF and PF5 , which causes electrolyte depletion in the battery and results in high-temperature performance degradation and vulnerability to safety issues. Accordingly, there is a demand for an electrolyte with improved safety without performance degradation even under high-temperature conditions. FIG. 1 is a cross-sectional view of an additive according to one embodiment. FIG. 2 is a schematic diagram illustrating a lithium secondary battery according to one embodiment. The following embodiments are described in detail so that those skilled in the art can easily implement them. However, the structure actually applied may be implemented in various different forms and is not limited to the embodiments described herein. The thickness was enlarged in the drawing to clearly represent various layers and regions. When a part such as a layer, membrane, region, or plate is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. In this specification, “at least one of A, B, or C”, “one of A, B, C, or a combination thereof”, and “one of A, B, C, and a combination thereof” mean each component and all combinations thereof (e.g., A; B; A and B; A and C; B and C; or A, B, and C). In the following, "combination" includes two or more mixtures, mutual substitutions, and two or more stacked structures. Unless otherwise specifically defined in this specification, “substituted” means that a hydrogen atom in a compound is deuterium, a halogen atom (F, Br, Cl, or I), a hydroxyl group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or its salt, a sulfonic acid group or its salt, a phosphoric acid or its salt, a C1 to C30 alkyl group, a C2 to C30 alkenyl group, a C2 to C30 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, or a C6 to C15 It means substituted with a cycloalkynyl group, a C2 to C30 heterocyclic group, and a substituent selected from combinations thereof. In addition, two adjacent substituents among the substituted halogen atom (F, Br, Cl, or I), hydroxyl group, nitro group, cyano group, amino group, azido group, amido group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or its salt, sulfonic acid group or its salt, phosphate group or its salt, C1 to C30 alkyl group, C2 to C30 alkenyl group, C2 to C30 alkynyl group, C6 to C30 aryl group, C7 to C30 arylalkyl group, C1 to C30 alkoxy group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, C6 to C15 cycloalkynyl group, or C2 to C30 heterocyclic group They may also fuse to form a ring. For example, the substituted C6 to C30 aryl group may fuse with an adjacent substituted C6 to C30 aryl group to form a substituted or unsubstituted fluorene ring. An additive for a lithium secondary battery according to one embodiment is described below with reference to FIG. 1. FI