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CN-121983667-A - Electrolyte, battery and electricity utilization device

CN121983667ACN 121983667 ACN121983667 ACN 121983667ACN-121983667-A

Abstract

The application belongs to the technical field of batteries, and particularly relates to electrolyte, a battery and an electric device. The electrolyte comprises a solvent, electrolyte salt and an additive, wherein the solvent comprises fluoroethylene carbonate, the additive comprises a compound shown in a formula 1 and a first lithium salt additive, and the first lithium salt additive comprises at least one of lithium bisoxalato borate and lithium difluorobisoxalato borate; Formula 1. The electrolyte provided by the application is applied to the battery, and can improve the high-temperature cycle performance and the high-temperature storage performance of the battery.

Inventors

  • TANG PIAOPING
  • ZOU ZHIQUN
  • ZHANG LIN

Assignees

  • 惠州亿纬动力电池有限公司

Dates

Publication Date
20260505
Application Date
20260313

Claims (14)

  1. 1. An electrolyte comprising a solvent, an electrolyte salt, and an additive, wherein the solvent comprises fluoroethylene carbonate; The additive comprises a compound shown in a formula 1 and a first lithium salt additive, wherein the first lithium salt additive comprises at least one of lithium bisoxalato borate and lithium difluoro bisoxalato borate; Formula 1; Wherein 0≤n 1 ≤3,R 1 、R 2 、R 3 、R 4 、R 5 each independently includes at least one of hydrogen, halogen, cyano, amino, benzyl, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 alkylamine, C1-C10 aminoalkyl, C1-C10 cyanoalkyl, C1-C10 cyanoalkoxy, C1-C10 haloalkyl, C1-C10 haloalkoxy, C2-C10 alkenyl, C3-C10 alkynyl, C6-C26 aryl, R 'substituted C6-C26 aryl, R' substituted benzyl; r' is at least one selected from hydroxyl and halogen; r' is at least one selected from alkyl, hydroxy and halogen of C7-C27.
  2. 2. The electrolyte of claim 1, wherein each R 1 、R 2 、R 3 、R 4 、R 5 independently comprises at least one of H, methyl, methoxy.
  3. 3. The electrolyte of claim 2, wherein the compound of formula 1 comprises at least one of the following compounds: A compound of the formula 1-1, Formula 1-2, The formula is 1-3, Formula 1-4, Formula 1-5, Formulas 1-6.
  4. 4. The electrolyte of claim 1 wherein the compound of formula 1, the first lithium salt additive, and the fluoroethylene carbonate satisfy a+b≤2x and 1≤x/(a+b))≤10, wherein a is the mass percentage of the compound of formula 1 based on the total mass of the electrolyte, b is the mass percentage of the first lithium salt additive based on the total mass of the electrolyte, and x is the mass percentage of the fluoroethylene carbonate based on the total mass of the electrolyte.
  5. 5. The electrolyte of claim 4, wherein at least one of the following conditions is satisfied: a/b=1:100~4:1; a/x=1:50~1:1; b/x=1:20~2:1。
  6. 6. The electrolyte of claim 5, wherein at least one of the following conditions is satisfied: based on the total mass of the electrolyte, the mass percentage of the compound shown in the formula 1 is 0.01% -3.0%; based on the total mass of the electrolyte, the mass percentage content of the first lithium salt additive is 0.1% -2.0%; the mass percentage content of the fluoroethylene carbonate is 0.5-30% based on the total mass of the electrolyte.
  7. 7. The electrolyte of any one of claims 1-6 wherein the additive further comprises at least one of the following conditions: a carbonate-based additive comprising at least one of ethylene carbonate, ethylene carbonate; A second lithium salt additive comprising at least one of lithium difluorophosphate, lithium difluorobis oxalato phosphate, lithium tetrafluoroborate, lithium nitrate; A nitrogen-containing additive comprising at least one of propionitrile, succinonitrile, adiponitrile, suberonitrile, 1,3, 6-hexyltrimethylnitrile, 1,2, 3-propyltriacetonitrile, 1,3, 5-benzene tricarbonitrile, (benzene-1, 3, 5-triacyl) triacetonitrile; a sulfur-containing additive comprising at least one of 1, 3-propane sultone, 1, 3-propene sultone, vinyl sulfate, and methylene methane disulfonate.
  8. 8. The electrolyte of claim 7, wherein at least one of the following conditions is satisfied: Based on the total mass of the electrolyte, the mass percentage of the carbonate additive is 0.2% -1.0%; based on the total mass of the electrolyte, the mass percentage of the second lithium salt additive is 0.1% -6.0%; based on the total mass of the electrolyte, the mass percentage of the nitrogen-containing additive is 0.1% -5.0%; Based on the total mass of the electrolyte, the mass percentage of the sulfur-containing additive is 0.3% -2.0%.
  9. 9. The electrolyte of claim 1 wherein the solvent further comprises at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate.
  10. 10. The electrolyte according to claim 9, wherein the fluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and methylethyl carbonate are present in a volume percentage of 4% to 40%, 1% to 30%, 0% to 10%, 30% to 70%, 0% to 10%, and 0% to 35%.
  11. 11. The electrolyte of claim 1, wherein the electrolyte salt comprises at least one of LiPF 6 and LiFSI, and/or the concentration of the electrolyte salt is 0.9mol/L to 1.5mol/L.
  12. 12. A battery comprising the electrolyte of any one of claims 1-11.
  13. 13. The battery of claim 12, further comprising a positive electrode sheet and a negative electrode sheet, the positive electrode sheet comprising a positive electrode active material comprising Li (Ni m Co y Mn z )O 2 , wherein 0.5-0.95, 0-0.3, and m+y+z = 1; and/or the negative electrode sheet comprises a negative electrode active material comprising at least one of silicon carbon, graphite, and silicon.
  14. 14. An electrical device comprising a battery as claimed in any one of claims 12 to 13.

Description

Electrolyte, battery and electricity utilization device Technical Field The application belongs to the technical field of batteries, and particularly relates to electrolyte, a battery and an electric device. Background With the rapid development of new energy technology, batteries are developing toward higher energy density. The battery is widely used by virtue of high energy density, long cycle life, high operating voltage, excellent charge-discharge rate performance and the like. However, fluoroethylene carbonate (FEC) in the electrolyte is poor in stability under a high-temperature circulation working condition, and the capacity and the circulation performance of the battery are affected, so that the further application of the fluoroethylene carbonate (FEC) in the fields of new energy automobiles and the like is severely restricted. Therefore, the electrolyte needs to be further improved. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, the invention provides the electrolyte, the battery and the electricity utilization device, and the electrolyte is applied to the battery, so that the high-temperature cycle performance and the high-temperature storage performance of the battery can be improved. In a first aspect of the application, an electrolyte is provided comprising a solvent, an electrolyte salt, and an additive, the solvent comprising fluoroethylene carbonate; the additive comprises a compound shown in a formula 1 and a first lithium salt additive, wherein the first lithium salt additive comprises at least one of lithium bisoxalato borate and lithium difluoro bisoxalato borate; Formula 1; Wherein 0≤n 1≤3,R1、R2、R3、R4、R5 each independently includes at least one of hydrogen, halogen, cyano, amino, benzyl, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 alkylamine, C1-C10 aminoalkyl, C1-C10 cyanoalkyl, C1-C10 cyanoalkoxy, C1-C10 haloalkyl, C1-C10 haloalkoxy, C2-C10 alkenyl, C3-C10 alkynyl, C6-C26 aryl, R 'substituted C6-C26 aryl, R' substituted benzyl; r' is at least one selected from hydroxyl and halogen; r' is at least one selected from alkyl, hydroxy and halogen of C7-C27. According to the application, the advantages of the solvent, the compound shown in the formula 1 and the first lithium salt additive are fully exerted, so that the three are synergistic, a synergistic protection system of a 'negative electrode-electrolyte-positive electrode' full interface is formed, and the stability of FEC in electrolyte or a battery is synchronously improved while a stable SEI film is constructed in situ, so that the high-temperature cycle performance and the high-temperature storage performance of the battery are improved. According to an embodiment of the application, R 1、R2、R3、R4、R5 each independently comprises at least one of H, methyl, methoxy. According to an embodiment of the application, the compound of formula 1 comprises at least one of the following compounds: A compound of the formula 1-1, Formula 1-2,The formula is 1-3,Formula 1-4,Formula 1-5, Formulas 1-6. According to the embodiment of the application, the compound shown in the formula 1, the first lithium salt additive and the fluoroethylene carbonate satisfy the condition that a+b is less than or equal to 2x and 1 is less than or equal to (x/(a+b))isless than or equal to 10, wherein a is the mass percent of the compound shown in the formula 1 accounting for the total mass of the electrolyte, b is the mass percent of the first lithium salt additive accounting for the total mass of the electrolyte, and x is the mass percent of the fluoroethylene carbonate accounting for the total mass of the electrolyte. According to an embodiment of the present application, the above-described electrolytic solution satisfies at least one of the following conditions: a/b=1:100~4:1; a/x=1:50~1:1; b/x=1:20~2:1。 according to an embodiment of the present application, at least one of the following conditions of the above electrolyte is satisfied: based on the total mass of the electrolyte, the mass percentage of the compound shown in the formula 1 is 0.01% -3.0%; Based on the total mass of the electrolyte, the mass percentage of the first lithium salt additive is 0.1% -2.0%; the mass percentage of fluoroethylene carbonate is 0.5-30 percent based on the total mass of the electrolyte. According to an embodiment of the application, the additive further comprises at least one of the following conditions: a carbonate-based additive comprising at least one of ethylene carbonate and ethylene carbonate; a second lithium salt additive comprising at least one of lithium difluorophosphate, lithium difluorobis oxalato phosphate, lithium tetrafluoroborate, lithium nitrate; A nitrogen-containing additive comprising at least one of propionitrile, succinonitrile, adiponitrile, suberonitrile, 1,3, 6-hexyltrimethylnitrile, 1,2, 3-propyltriacetonitrile, 1,3, 5-benzene tricarbonitrile, (benzene-1, 3, 5-tri