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CN-122029656-A - Electrolyte, electrochemical device using same and electronic device

CN122029656ACN 122029656 ACN122029656 ACN 122029656ACN-122029656-A

Abstract

An electrolyte, and an electrochemical device and an electronic device using the same. Specifically, the electrolyte comprises a fluorine-containing cyclic carbonate represented by formula I, a first compound including at least one of a compound of formula II and a compound of formula III, and a second compound including at least one of a compound of formula IV and a compound of formula V. The electrolyte can remarkably improve the low-temperature discharge performance and the high-rate discharge performance of an electrochemical device using the same.

Inventors

  • CUI HUI
  • TANG CHAO

Assignees

  • 宁德新能源科技有限公司

Dates

Publication Date
20260512
Application Date
20240929
Priority Date
20230928

Claims (16)

  1. An electrolyte, wherein the electrolyte comprises: (1) A fluorine-containing cyclic carbonate represented by formula I: Wherein R 41 、R 42 、R 43 and R 44 are each independently F, or substituted or unsubstituted C 1 -C 3 alkyl, when substituted, the substituents are each independently halogen, wherein at least one of R 41 、R 42 、R 43 and R 44 comprises F; (2) A first compound comprising at least one of a compound of formula II and a compound of formula III: Wherein R 11 、R 12 、R 21 and R 22 are each independently C 1 -C 10 alkyl, and (3) A second compound comprising at least one of a compound of formula IV and a compound of formula V: Wherein: R 13 and R 14 are each independently substituted or unsubstituted C 1 -C 10 alkyl, wherein at least one of R 13 and R 14 is substituted; R 23 and R 24 are each independently substituted or unsubstituted C 1 -C 10 alkyl, wherein at least one of R 23 and R 24 is substituted; when substituted, each substituent is independently halogen, Based on the mass of the electrolyte, the mass percentage of the first compound is A, the mass percentage of the fluorine-containing cyclic carbonate is B, and the mass percentage of the second compound is C, wherein A, B and C are 30-90 (A+B+C) and 20-61.
  2. The electrolyte according to claim 1, wherein (A+B+C) is more than or equal to 50 and less than or equal to 87.5.
  3. The electrolyte of claim 1, wherein 4≤b≤15.
  4. The electrolyte of claim 1, wherein 2.8≤A+C)/B≤12.
  5. The electrolyte according to any one of claims 1 to 4, wherein the electrolyte further comprises a fluoroether compound represented by formula VI: Wherein R 31 and R 32 are each independently selected from substituted or unsubstituted C 1 -C 8 alkyl or-R' -O-R "; R' is selected from substituted or unsubstituted C 1 -C 8 alkylene; R' is selected from substituted or unsubstituted C 1 -C 8 alkyl; when substituted, the substituents are each independently halogen; At least one of R 31 and R 32 comprises F, and Based on the mass of the electrolyte, the mass percentage of the fluoroether compound is D, and D is more than or equal to 5 and less than or equal to 30.
  6. The electrolyte of claim 5, wherein A, B, C and D satisfy: the ratio of (A+B+C+D) is more than or equal to 50 and less than or equal to 87.5.
  7. The electrolyte of claim 5, wherein A, B, C and D satisfy: the ratio of (A+B+C+D) is more than or equal to 60 and less than or equal to 80.
  8. The electrolyte according to any one of claims 1 to 7, wherein, The compound of formula II comprises at least one of methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate or propyl propionate, and/or The compound of formula III comprises at least one of dimethyl carbonate, diethyl carbonate or ethyl methyl carbonate.
  9. The electrolyte of any one of claims 1 to 8, wherein the fluorine-containing cyclic carbonate comprises at least one of the following compounds:
  10. The electrolyte of any one of claims 1 to 9, wherein the compound of formula IV comprises at least one of the following compounds: And/or The compound of formula V comprises at least one of the following compounds:
  11. The electrolyte of claim 5, wherein the fluoroether compound comprises at least one of the following compounds:
  12. The electrolyte of any one of claims 1 to 11, wherein the electrolyte further comprises a first lithium salt comprising at least one of lithium hexafluorophosphate LiPF 6 or lithium bis-fluorosulfonimide LiFSI; Based on the mass of the electrolyte, the mass percentage of the first lithium salt is E, wherein, the mass percentage of (A+B+C)/E is more than or equal to 2.5 and less than or equal to 8.5.
  13. The electrolyte of claim 12, wherein the electrolyte further comprises a second lithium salt comprising at least one of lithium bistrifluoromethane sulfonyl imide LiTFSI, lithium tetrafluoroborate LiBF 4 , lithium difluorooxalato borate litfob, lithium dioxaoxalato borate LiBOB, or lithium difluorophosphate LiPO 2 F 2 ; Wherein the second lithium salt is contained in an amount of 0.1 to 5% by mass based on the mass of the electrolyte.
  14. The electrolyte according to any one of claims 1 to 13, wherein the electrolyte further comprises a third compound comprising at least one of vinylene carbonate, 1, 3-propane sultone, succinonitrile, adiponitrile or1, 3, 6-hexanetrinitrile; Wherein the mass percentage content of the third compound is 0.5 to 6% based on the mass of the electrolyte.
  15. An electrochemical device comprising a positive electrode, a negative electrode, a separator, and the electrolyte according to any one of claims 1 to 14.
  16. An electronic device comprising the electrochemical device according to claim 15.

Description

Electrolyte, electrochemical device using same and electronic device The present application claims priority from the chinese patent office, application number 202311279437.9, chinese patent application entitled "an electrolyte and electrochemical and electronic devices using the same", filed 28 at 9/2023, the entire contents of which are incorporated herein by reference. Technical Field The present application relates to the field of energy storage technologies, and in particular, to an electrolyte, and an electrochemical device and an electronic device using the same. Background The lithium ion battery is widely applied to the fields of portable electronic products, electric vehicles, aerospace, energy storage and the like because of the advantages of high energy density, good cycle performance, safety, environmental protection, no memory effect and the like. In order to meet the demands of social development, the search for electrochemical devices having higher energy density and power density is a highly-needed problem, and this is causing the positive electrode active material to be developed toward high voltage. Along with the increase of the voltage, the electrolyte is caused to react on the positive electrode interface, so that the performance is rapidly attenuated, and particularly the low-temperature discharge performance and the high-rate discharge performance are caused. Accordingly, it is desirable to provide an electrolyte capable of improving the low-temperature discharge performance and the high-rate discharge performance of an electrochemical device. Disclosure of Invention Embodiments of the present application provide an electrolyte that attempts to solve at least one problem in the related art to at least some extent. The embodiment of the application also provides an electrochemical device and an electronic device using the electrolyte. In one embodiment, the present application provides an electrolyte, wherein the electrolyte comprises: (1) A fluorine-containing cyclic carbonate represented by formula I: Wherein R 41、R42、R43 and R 44 are each independently F, or substituted or unsubstituted C 1-C3 alkyl, when substituted, the substituents are each independently halogen, wherein at least one of R 41、R42、R43 and R 44 comprises F; (2) A first compound comprising at least one of a compound of formula II and a compound of formula III: Wherein R 11、R12、R21 and R 22 are each independently C 1-C10 alkyl, and (3) A second compound comprising at least one of a compound of formula IV and a compound of formula V: Wherein: R 13 and R 14 are each independently substituted or unsubstituted C 1-C10 alkyl, wherein at least one of R 13 and R 14 is substituted; R 23 and R 24 are each independently substituted or unsubstituted C 1-C10 alkyl, wherein at least one of R 23 and R 24 is substituted; when substituted, each substituent is independently halogen, Based on the mass of the electrolyte, the mass percentage of the first compound is A percent, the mass percentage of the fluorine-containing cyclic carbonate is B percent, and the mass percentage of the second compound is C percent, wherein A, B and C satisfy that (A+B+C) is more than or equal to 30 and less than or equal to 90 and C is more than or equal to 20 and less than or equal to 61. In some embodiments of the present invention, in some embodiments, the ratio of (A+B+C) is more than or equal to 50 and less than or equal to 87.5. In some embodiments, 4≤B≤15. In some embodiments, 2.8≤A+C)/B≤12. In some embodiments, the electrolyte further comprises a fluoroether compound of formula VI: Wherein R 31 and R 32 are each independently selected from substituted or unsubstituted C 1-C8 alkyl or-R' -O-R "; R' is selected from substituted or unsubstituted C 1-C8 alkylene; R' is selected from substituted or unsubstituted C 1-C8 alkyl; when substituted, the substituents are each independently halogen; The substituent is halogen, at least one of R 31 and R 32 contains F, and Based on the mass of the electrolyte, the mass percentage of the fluoroether compound is D, and D is more than or equal to 5 and less than or equal to 30. In some embodiments A, B, C and D satisfy: the ratio of (A+B+C+D) is more than or equal to 50 and less than or equal to 87.5. In some embodiments A, B, C and D satisfy: the ratio of (A+B+C+D) is more than or equal to 60 and less than or equal to 80. In some embodiments, the compound of formula II comprises at least one of methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, or propyl propionate, and/or The compound of formula III comprises at least one of dimethyl carbonate, diethyl carbonate or methylethyl carbonate. In some embodiments, the fluorochemical cyclic carbonate comprises at least one of the following compounds: In some embodiments, the compound of formula IV comprises at least one of the following compounds: And/or The compound of formula V comprises at least one of