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CN-122000462-A - Electrolyte, battery pack and electric equipment

CN122000462ACN 122000462 ACN122000462 ACN 122000462ACN-122000462-A

Abstract

The invention provides an electrolyte, a battery pack and electric equipment, wherein the electrolyte comprises a first additive and a second additive, the first additive comprises a compound shown in a formula 1, Wherein ,R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 、R 10 in formula 1 is independently H, F, C 1 -C 20 alkyl, C 1 -C 20 fluoroalkyl, C 1 -C 20 fluoroalkenyl, and at least 1 of R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 、R 10 contains F, and the second additive comprises at least one of R-NI, alkali metal salt of iodine, and alkaline earth metal salt of iodine, wherein R is C 1 -C 20 alkyl. The electrolyte provided by the invention can effectively inhibit the lithium precipitation problem of the battery cell in the circulation process, and can also relieve the self-discharge behavior of the battery cell.

Inventors

  • WU YINFU
  • TAN YOUBIN
  • WANG JIE
  • WANG YAQI
  • HUANG JIANTAO

Assignees

  • 比亚迪股份有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (11)

  1. 1. An electrolyte is characterized by comprising a first additive and a second additive, wherein the first additive comprises a compound shown as a formula 1, The method comprises the steps of (1), ,R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 、R 10 In formula 1 are each independently H, F, C 1 -C 20 alkyl, C 1 -C 20 fluoroalkyl, C 1 -C 20 fluoroalkenyl, and at least 1 of R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 、R 10 contains F; The second additive comprises at least one of R-NI, alkali metal salt of iodine and alkaline earth metal salt of iodine, wherein R is C 1 -C 20 alkyl.
  2. 2. The electrolyte of claim 1 wherein ,R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 、R 10 in formula 1 is each independently selected from the group consisting of an alkyl group of H, F, C 1 -C 10 , a fluoroalkyl group of C 1 -C 10 , and a fluoroalkenyl group of C 1 -C 10 .
  3. 3. Electrolyte according to claim 2, characterized in that the first additive is pentafluoroethene and/or decafluorocephem.
  4. 4. The electrolyte according to any one of claims 1 to 3, wherein the mass percentage of the first additive in the electrolyte is 0.1wt% to 5wt%; and/or the mass percentage of the second additive in the electrolyte is 0.1-2 wt%.
  5. 5. The electrolyte of any one of claims 1-4 wherein the molar ratio of the first additive to the second additive is 1-3:1.
  6. 6. The electrolyte of any one of claims 1-5 further comprising a third additive comprising at least one of vinylene carbonate, ethylene carbonate, fluoroethylene carbonate, tris (trisilane) phosphate, triallyl phosphate, tripropyl phosphate, trimethyl phosphate, triethyl phosphate, hexamethylene diisocyanate, methylene methylsulfonate.
  7. 7. The electrolyte of any one of claims 1-6, further comprising an organic solvent comprising at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methylethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylene propylene carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1, 4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, diethyl sulfone.
  8. 8. The electrolyte of any one of claims 1-7, further comprising a lithium salt comprising at least one of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium difluorooxalato borate, lithium difluorodioxaato phosphate, lithium tetrafluorooxalato phosphate, lithium difluorosulfonimide, lithium bis (trifluoromethanesulfonyl) imide, lithium perfluorobutyl sulfonate, and lithium fluoroaliphate.
  9. 9. A battery comprising a positive electrode sheet, a negative electrode sheet, and the electrolyte of any one of claims 1-8.
  10. 10. A battery comprising the battery of claim 9.
  11. 11. A powered device comprising the battery of claim 9 or the battery pack of claim 10.

Description

Electrolyte, battery pack and electric equipment Technical Field The invention relates to the field of batteries, in particular to electrolyte, a battery pack and electric equipment. Background In recent years, with rapid development of portable electronic products, new energy automobiles and the like, higher requirements are put on various performances of lithium ion batteries, wherein the service life of a battery core is particularly important. In the long cycle process of the battery cell, the consumption of active lithium is accelerated by the dissolution of transition metal, the consumption of electrolyte, the lithium precipitation and the like, so that the cycle life of the battery cell is reduced, and the problem of lithium precipitation is an important problem which always puzzles the development work of the battery cell for decades. The use of electrolyte additives to inhibit the generation of lithium dendrites is one of the main measures for delaying the lithium precipitation of the battery cell, but the existing electrolyte additives have a certain effect on inhibiting the generation of dead lithium, but also can introduce the problem of increasing the self-discharge of the battery cell, and the self-discharge of the battery cell can cause the gradual decrease of the capacity of the battery and influence the energy storage efficiency of the battery, so that the aging of the battery is accelerated and the service life of the battery is shortened. Disclosure of Invention The invention provides an electrolyte which can effectively inhibit lithium precipitation of a battery cell in a cyclic process and can also relieve self-discharge behavior of the battery cell. The invention also provides a battery, which has the advantages of long cycle life and high energy storage efficiency because the battery comprises the electrolyte. The invention also provides a battery pack comprising the battery, and the battery pack has the advantages of high energy storage efficiency and long service life. The invention also provides electric equipment, which comprises the battery or the battery pack, so that the electric equipment has good electrical performance and longer service life. In a first aspect, the present invention provides an electrolyte comprising a first additive and a second additive, the first additive comprising a compound of formula 1, The method comprises the steps of (1), ,R1、R2、R3、R4、R5、R6、R7、R8、R9、R10 In formula 1 are each independently H, F, C 1-C20 alkyl, C 1-C20 fluoroalkyl, C 1-C20 fluoroalkenyl, and at least 1 of R1、R2、R3、R4、R5、R6、R7、R8、R9、R10 contains F; The second additive comprises at least one of R-NI, alkali metal salt of iodine and alkaline earth metal salt of iodine, wherein R is C 1-C20 alkyl. Alternatively, ,R1、R2、R3、R4、R5、R6、R7、R8、R9、R10 in formula 1 are each independently selected from the group consisting of an alkyl group of H, F, C 1-C10, a fluoroalkyl group of C 1-C10, a fluoroalkenyl group of C 1-C10, and at least 1 of R1、R2、R3、R4、R5、R6、R7、R8、R9、R10 contains F. Optionally, the first additive is pentafluoroethene and/or decafluorobowl. Optionally, the mass percentage of the first additive in the electrolyte is 0.1wt% to 5wt%; and/or the mass percentage of the second additive in the electrolyte is 0.1-2 wt%. Optionally, the molar ratio of the first additive to the second additive is 1-3:1. Optionally, a third additive is further included, the third additive including at least one of vinylene carbonate, ethylene carbonate, fluoroethylene carbonate, tri (trisilane) phosphate, triallyl phosphate, tripropyl phosphate, trimethyl phosphate, triethyl phosphate, hexamethylene diisocyanate, methylene methylsulfonate. Optionally, the electrolyte further comprises an organic solvent, and the organic solvent comprises at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethylene propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1, 4-butyrolactone, sulfolane, dimethyl sulfone, methyl sulfone and diethyl sulfone. Optionally, the electrolyte further includes a lithium salt including at least one of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium difluorooxalato borate, lithium difluorodioxaoxalato phosphate, lithium tetrafluorooxalato phosphate, lithium difluorosulfimide, lithium bis (trifluoromethanesulfonyl) imide, lithium perfluorobutylsulfonate, and lithium fluoroaliphate. In a second aspect, the present invention provides a battery comprising a positive electrode sheet, a negative electrode sheet and the electrolyte of the first aspect. In a third aspect, the present invention provides a battery pack comprising the battery of the second aspect. In a fourth aspect, the pre