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CN-122000454-A - Lithium fluorocarbon battery electrolyte and application thereof, and lithium fluorocarbon battery

CN122000454ACN 122000454 ACN122000454 ACN 122000454ACN-122000454-A

Abstract

The application discloses a fluorocarbon bond breaking catalyst, lithium fluorocarbon battery electrolyte and a lithium fluorocarbon battery, and belongs to the field of lithium batteries. The fluorocarbon bond cleavage catalyst comprises only one compound of dimethylaluminum chloride (C 2 H 6 AlCl). The fluorocarbon bond breaking catalyst can catalyze C-F bond breaking, so that a large amount of LiF crystal nuclei are pre-generated in electrolyte near the surface of the CF x before the battery is discharged, the crystallization and growth process of LiF crystals in the discharging process of the Li/CF x battery are changed, the LiF crystallization process with huge heat productivity is converted into the LiF crystal growth process with smaller heat productivity, and finally the purpose of reducing the heat productivity in the discharging process of the battery is achieved.

Inventors

  • XI YAONING
  • YANG XIAOFEI
  • LI XIANFENG
  • ZHANG HONGZHANG

Assignees

  • 中国科学院大连化学物理研究所

Dates

Publication Date
20260508
Application Date
20241104

Claims (8)

  1. 1. The lithium fluorocarbon battery electrolyte comprises lithium salt, an ester solvent and an ether solvent, and is characterized by further comprising a fluorocarbon bond breaking catalyst, wherein the fluorocarbon bond breaking catalyst is dimethylaluminum chloride (C 2 H 6 AlCl).
  2. 2. The electrolyte of claim 1, wherein: The mass of the dimethyl aluminum chloride accounts for 0.01-10%, preferably 0.05-5%, more preferably 0.1-2.5% of the total mass of the lithium fluorocarbon battery electrolyte.
  3. 3. Electrolyte according to claim 1 or 2, characterized in that: the lithium salt is one or more than two of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxalate borate, lithium difluorooxalate borate, lithium bistrifluoromethane sulfonyl imide, lithium bisfluoro sulfonyl imide, lithium perchlorate and lithium hexafluoroarsenate; The molar concentration of the lithium salt in the lithium fluorocarbon battery electrolyte is 0.01-10M, preferably 0.05-5M, and more preferably 0.1-3M.
  4. 4. Electrolyte according to claim 1 or 2, characterized in that: The ester solvent is at least one selected from dimethyl carbonate, propylene carbonate, ethylene carbonate, diethyl carbonate and methyl ethyl carbonate; the ether solvent is at least one selected from ethylene glycol dimethyl ether, tetrahydrofuran, 1, 2-dimethoxyethane, 1, 4-dioxane, diglyme and 1, 2-tetrafluoroethyl-2, 3-tetrafluoropropyl ether; The volume ratio of the ester solvent to the ether solvent is 0.01-100:1, preferably 0.05-50:1, and more preferably 0.1-10:1.
  5. 5. Use of the lithium fluorocarbon battery electrolyte of any one of claims 1 to 4 in lithium fluorocarbon batteries.
  6. 6. The use according to claim 5, wherein: The operation temperature of the lithium carbon fluoride battery is-40-150 ℃; And the allowable discharge multiplying power in the operation process of the lithium fluorocarbon battery is 0.01-10 ℃.
  7. 7. A lithium fluorocarbon battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, characterized in that: The electrolyte is selected from the lithium fluorocarbon battery electrolyte as claimed in any one of claims 1 to 4.
  8. 8. The lithium fluorocarbon battery as set forth in claim 7, wherein: The operation temperature of the lithium carbon fluoride battery is-40-150 ℃; And the allowable discharge multiplying power in the operation process of the lithium fluorocarbon battery is 0.01-10 ℃.

Description

Lithium fluorocarbon battery electrolyte and application thereof, and lithium fluorocarbon battery Technical Field The application relates to a fluorocarbon bond breaking catalyst, lithium fluorocarbon battery electrolyte and a lithium fluorocarbon battery, and belongs to the field of lithium batteries. Background Lithium/carbon fluoride (Li/CF x) batteries are primary batteries with ultra-high energy density and long storage life. The battery is particularly suitable for emerging applications such as military equipment, interventional medical devices, aerospace and the like. Current research in Li/CF x batteries is in the critical phase of the transition from small to large scale applications. The most significant obstacle to the movement of Li/CF x batteries to large-scale applications is the problem of abnormal heat generation during battery discharge. Disclosure of Invention In order to solve the problem of abnormal heat generation of the Li/CF x battery, the application provides a fluorocarbon bond breaking catalyst, lithium fluorocarbon battery electrolyte and a lithium fluorocarbon battery. The fluorocarbon bond breaking catalyst can catalyze fluorocarbon bond breaking, so that a large number of LiF crystal nuclei are formed nearby the CF x of the battery in advance, fluoride ions and lithium ions preferentially grow on the surface of the existing LiF crystal nuclei in the battery discharging process, the heat release amount for forming new LiF crystal nuclei is reduced, theoretical calculation shows that the heat release amount in the LiF crystal nucleus generating process is far greater than that in the LiF crystal growing process, and therefore the fluorocarbon bond breaking catalyst can effectively reduce the heat release amount in the battery discharging process, and the purpose of reducing the heat generation amount in the battery discharging process is achieved. According to theoretical calculation, the dimethyl aluminum chloride is an effective fluorocarbon bond breaking catalyst, and the catalyst can effectively reduce the dissociation energy of F ions on the surface of the CF x and obviously reduce the generation energy of LiF after the F ions are dissociated, namely, the catalyst plays a role in catalyzing the F ions to be dissociated and generate LiF. According to another aspect of the present application, there is provided a lithium fluorocarbon battery electrolyte comprising a lithium salt, an ester solvent, an ether solvent, and a fluorocarbon bond cleavage catalyst; the fluorocarbon bond cleavage catalyst is selected from the fluorocarbon bond cleavage catalysts described above. Optionally, the lithium salt is at least one selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxaborate, lithium difluorooxalato borate, lithium bistrifluoro methanesulfonimide, lithium bistrifluoro sulfimide, lithium perchlorate and lithium hexafluoroarsenate. Optionally, the ester solvent is at least one selected from dimethyl carbonate, propylene carbonate, ethylene carbonate, diethyl carbonate and ethylmethyl carbonate. Optionally, the ether solvent is at least one selected from ethylene glycol dimethyl ether, tetrahydrofuran, 1, 2-dimethoxyethane, 1, 4-dioxane, diglyme, 1, 2-tetrafluoroethyl-2, 3-tetrafluoropropyl ether. Optionally, the mass of the dimethyl aluminum chloride accounts for 0.01-10% of the total mass of the lithium fluorocarbon battery electrolyte. Alternatively, the value of dimethylaluminum chloride for the total mass of the lithium fluorocarbon battery electrolyte is independently selected from any of 0.01%, 0.05%, 0.1%, 1%, 2.5%, 5%, 7.5%, 10% or a range of values between any two of the foregoing. Preferably, the mass of the dimethyl aluminum chloride accounts for 0.05-5% of the total mass of the lithium fluorocarbon battery electrolyte. More preferably 0.1 to 2.5%. Optionally, the molar concentration of the lithium salt in the lithium fluorocarbon battery electrolyte is 0.01-10M. Alternatively, the molar concentration of the lithium salt in the lithium fluorocarbon battery electrolyte is independently selected from any of 0.01M, 0.05M, 0.1M, 0.5M, 1M, 3M, 5M, 8M, 10M, or a range of values between any two of the foregoing. Preferably, the molar concentration of the lithium salt in the lithium fluorocarbon battery electrolyte is 0.05-5M, more preferably 0.1-3M. Optionally, the volume ratio of the ester solvent to the ether solvent is 0.01-100:1. Optionally, the volume ratio of the ester solvent to the ether solvent is independently selected from any ratio of 0.01:1, 0.05:1, 0.1:1, 1:1, 2:1, 10:1, 20:1, 40:1, 50:1, 60:1, 80:1, 100:1 or a range value between any two of the above ratios. Preferably, the volume ratio of the ester solvent to the ether solvent is 0.05-50:1, more preferably 0.1-10:1. According to another aspect of the application, there is provided the use of a lithium fluorocarbon battery electrolyte in a lithium fluorocarbon battery. Optionally,