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US-20260128370-A1 - SOLID ELECTROLYTE COMPOSITION, SOLID ELECTROLYTE FORMED FROM THE COMPOSITION AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME ELECTROLYTE

US20260128370A1US 20260128370 A1US20260128370 A1US 20260128370A1US-20260128370-A1

Abstract

A solid electrolyte composition according to the present disclosure comprises an amine-based compound represented by the following Chemical Formula 1; a multifunctional isocyanate; and a lithium salt, wherein the content of the lithium salt is 40 to 80 parts by weight based on 100 parts by weight of the amine-based compound. [Chemical Formula 1] In Chemical Formula 1, L 1 and L 2 are each independently selected from one or more of a C 1 -C 12 alkylene group or heteroalkylene group, a C 3 -C 16 cycloalkylene group or cycloheteroalkylene group, a C 6 -C 16 arylene group or heteroarylene group, and [Chemical Formula 2], wherein n is a natural number in the range of 1 to 5,000, and m is a natural number in the range of 1 to 200.

Inventors

  • Jeong Yeol Moon
  • Han Sol CHOE
  • Shin Kim
  • Ji Hun Seo
  • Bit Ga Ram KIM

Assignees

  • KOLON INDUSTRIES, INC.
  • KOREA UNIVERSITY RESEARCH AND BUSINESS FOUNDATION

Dates

Publication Date
20260507
Application Date
20230927
Priority Date
20221005

Claims (8)

  1. 1 . A solid electrolyte composition comprising: an amine-based compound represented by the following Chemical Formula 1; a multifunctional isocyanate; and a lithium salt, wherein the content of the lithium salt is 40 to 80 parts by weight based on 100 parts by weight of the amine-based compound. In Chemical Formula 1, each of L 1 and L 2 independently includes one or more selected from the group consisting of C 1 -C 12 alkylene or heteroalkylene groups, C 3 -C 16 cycloalkylene or cycloheteroalkylene groups, C 6 -C 16 arylene or heteroarylene groups, and n is a natural number in the range of 1 to 5,000; and m is a natural number in the range of 1 to 200.
  2. 2 . The solid electrolyte composition of claim 1 , wherein the multifunctional isocyanate is one or more selected from the group consisting of triphenylmethane-4,4,4-triisocyanate, 1,3,5-triisocyanato-2-methylbenzene, tris(6-isocyanatohexyl) isocyanurate, 1,3,5-triisocyanato-2,4,6-trimethylbenzene, and poly(hexamethylene diisocyanate).
  3. 3 . The solid electrolyte composition of claim 1 , wherein the content of the multifunctional isocyanate is 5 to 20 parts by weight based on 100 parts by weight of the amine-based compound.
  4. 4 . The solid electrolyte composition of claim 1 , wherein the lithium salt includes one or more selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium perchlorate (LiClO 4 ), lithium nitrate (LiNO 3 ), and lithium hexafluorophosphate (LiPF 6 ).
  5. 5 . A solid electrolyte comprising: a cured product of the solid electrolyte composition of claim 1 .
  6. 6 . The solid electrolyte of claim 5 , wherein the cured product exhibits at least two inflection points in a strain curve as a function of temperature, as measured by dilatometry.
  7. 7 . The solid electrolyte of claim 5 , the cured product has a topology freezing transition temperature (Tv) higher than its glass transition temperature (Tg), as measured by dilatometry.
  8. 8 . A lithium secondary battery comprising: the solid electrolyte according to claim 5 ; a cathode; and an anode.

Description

TECHNICAL FIELD The present disclosure relates to a solid electrolyte composition, a solid electrolyte formed therefrom, and a lithium secondary battery including the same. More specifically, it pertains to a solid electrolyte characterized by suppressed crystallization at low temperature, thereby improving the low-temperature output characteristics and electrochemical stability of a secondary battery, as well as a composition constituting the same and a lithium secondary battery including the same. BACKGROUND ART Various approaches are being explored to increase the energy density of lithium-ion batteries, one of which involves using lithium metal as the anode. However, lithium-ion batteries with lithium metal anodes suffer from significant performance degradation due to the lithium dendrite phenomenon that occurs during charge and discharge cycles. Additionally, conventional lithium-ion batteries use flammable liquid electrolytes, resulting in low battery stability. To address this, research and development of all-solid-state batteries employing solid electrolytes with high ionic conductivity and electrochemical stability are being actively pursued. In general, in all-solid-state batteries, ion-conductive polymers for forming solid electrolytes, such as linear or cross-linked polymers of homopolymers or copolymers based on ethylene oxide as a basic unit, are commonly used. However, these polymers tend to crystallize easily, leading to low ionic conductivity at low temperatures, which degrades the output characteristics and electrochemical properties of all-solid-state batteries. Therefore, there is a need to develop solid electrolytes that improve output characteristics at low temperatures while maintaining excellent ionic conductivity. PRIOR ART DOCUMENTS Patent Documents (Patent Document 1) Korean Patent Publication No. 10-2023-0018141 (Feb. 7, 2023) DISCLOSURE OF THE INVENTION Technical Problem The present disclosure has been devised to solve the aforementioned problems, and an object of the present disclosure is to provide a solid electrolyte composition and a solid electrolyte formed therefrom, which exhibit improved lithium-ion mobility, suppressed crystallization at low temperatures, excellent ionic conductivity, and superior electrochemical stability. Another object of the present disclosure is to provide a lithium secondary battery incorporating the above-described solid electrolyte, which offers excellent output characteristics at low temperatures, as well as superior electrochemical stability and safety. Technical Solution To solve the above problems, the present disclosure provides a solid electrolyte composition including: an amine-based compound represented by the following Chemical Formula 1; a multifunctional isocyanate; anda lithium salt;wherein the content of the lithium salt is 40 to 80 parts by weight based on 100 parts by weight of the amine-based compound. In Chemical Formula 1, each of L1 and L2 independently includes one or more selected from the group consisting of C1-C12 alkylene or heteroalkylene groups, C3-C16 cycloalkylene or cycloheteroalkylene groups, C6-C16 arylene or heteroarylene groups, and n is a natural number in the range of 1 to 5,000; and m is a natural number in the range of 1 to 200. Here, the multifunctional isocyanate may be one or more selected from the group consisting of triphenylmethane-4,4,4-triisocyanate, 1,3,5-triisocyanato-2-methylbenzene, tris(6-isocyanatohexyl) isocyanurate, 1,3,5-triisocyanato-2,4,6-trimethylbenzene, and poly(hexamethylene diisocyanate). In addition, the content of the multifunctional isocyanate may be 5 to 20 parts by weight based on 100 parts by weight of the amine-based compound. Meanwhile, the lithium salt may include one or more selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium perchlorate (LiClO4), lithium nitrate (LiNO3), and lithium hexafluorophosphate (LiPF6). The present disclosure may also provide a solid electrolyte including a cured product of the above-described solid electrolyte composition. In one example, the solid electrolyte according to the present disclosure may exhibit at least two inflection points in a strain curve as a function of temperature, as measured by dilatometry. In another example, the solid electrolyte according to the present disclosure may have a topology freezing transition temperature (Tv) higher than its glass transition temperature (Tg), as measured by dilatometry. In one embodiment of the present disclosure, a lithium secondary battery comprising the aforementioned solid electrolyte, a cathode, and an anode may be provided. Advantageous Effects The solid polymer electrolyte according to the present disclosure can suppress crystallization, improve lithium ion mobility, enhance ion conductivity, and have excellent electrochemical stability, thereby contributing to the stability and output improvement of lithium secondary batteries. The lithium sec