WO2023236198A1 - 电解液和电化学装置 - Google Patents

电解液和电化学装置 Download PDF

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Publication number
WO2023236198A1
WO2023236198A1 PCT/CN2022/098167 CN2022098167W WO2023236198A1 WO 2023236198 A1 WO2023236198 A1 WO 2023236198A1 CN 2022098167 W CN2022098167 W CN 2022098167W WO 2023236198 A1 WO2023236198 A1 WO 2023236198A1
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electrolyte
compound
substituted
mass
unsubstituted
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PCT/CN2022/098167
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English (en)
French (fr)
Inventor
彭谢学
简俊华
唐超
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宁德新能源科技有限公司
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Priority to CN202280053980.4A priority Critical patent/CN117795728A/zh
Priority to PCT/CN2022/098167 priority patent/WO2023236198A1/zh
Publication of WO2023236198A1 publication Critical patent/WO2023236198A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives

Definitions

  • the present application relates to the field of electrochemical energy storage, and specifically to electrolytes and electrochemical devices.
  • electrochemical devices such as lithium-ion batteries
  • users have put forward increasingly higher requirements for the performance of electrochemical devices, especially cycle performance and high-temperature storage performance. Therefore, further improvements are urgently needed to meet people's increasingly high usage requirements.
  • the embodiment of the present application provides an electrolyte solution, which includes a compound of formula I:
  • m, n, k and x are each independently selected from 1, 2 or 3 and R 11 and R 12 are each independently selected from hydrogen, halogen, substituted or unsubstituted C 1 -C 3 alkyl, Substituted or unsubstituted C 2 -C 4 alkenyl group, substituted or unsubstituted C 2 -C 4 alkynyl group, substituted or unsubstituted C 6 -C 10 aryl group, wherein, When substituted, each substituent is independently selected from halogen.
  • the multiple cyano groups (-CN) in the compound of formula I can stabilize the transition metal in the high valence state of the positive electrode and further stabilize the positive electrode interface; the compound of formula I can also be reduced at the negative electrode to protect the negative electrode interface, inhibiting the continued decomposition of the electrolyte and Inhibits gas production.
  • compounds of Formula I include at least one of the following compounds:
  • the mass content of the compound of formula I is 0.01% to 5% based on the mass of the electrolyte.
  • the mass content of the compound of formula I is 0.1% to 3% based on the mass of the electrolyte.
  • the electrolyte also includes compounds containing sulfur and oxygen double bonds.
  • Compounds containing sulfur and oxygen double bonds have strong antioxidant capabilities and can improve the stability of the cathode interface.
  • compounds containing sulfur and oxygen double bonds can The surface of the negative electrode is reduced to form a protective film, which inhibits the decomposition of the electrolyte and further enhances the stability of the negative electrode interface.
  • the mass content of the sulfur-oxygen double bond-containing compound is 0.01% to 10% based on the mass of the electrolyte.
  • the mass content of compounds containing sulfur and oxygen double bonds is 0.1% to 5% based on the mass of the electrolyte.
  • the sulfur-oxygen double bond-containing compound includes a compound of Formula II,
  • R 21 and R 22 are each independently selected from substituted or unsubstituted C 1 -C 5 alkyl group, substituted or unsubstituted C 1 -C 5 alkylene group, substituted or unsubstituted C 2 -C 10 alkenyl group, substituted or unsubstituted C 2 -C 10 alkynyl group, substituted or unsubstituted C 3 -C 10 alicyclic group, substituted or unsubstituted C 6 -C 10 aryl group, substituted or Unsubstituted C 1 -C 6 heterocyclic group, wherein the substituent is at least one of a halogen atom or a heteroatom-containing functional group, and the heteroatom in the heteroatom-containing functional group is selected from B, N, O, At least one of F, Si, P or S.
  • the sulfur-oxygen double bond-containing compound includes 1,3-propanesultone, 1,4-butanesultone, methylene methanedisulfonate, 1,3-propanedisulfonic anhydride, sulfuric acid Vinyl ester, vinyl sulfite, 4-methyl vinyl sulfate, 2,4-butanesultone, 2-methyl-1,3-propanesultone, 1,3-butanesultone, 1-Fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, 3-fluoro-1,3-propanesultone, propenyl-1,3-sultone At least one of acid lactone, propylene sulfate, propylene sulfite or vinyl fluorosulfate.
  • the electrolyte further includes a compound of formula III,
  • R 31 is selected from substituted or unsubstituted C 1 -C 6 alkylene, substituted or unsubstituted C 2 -C 6 alkenylene; when substituted, the substituent is selected from halogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl.
  • the compound of formula III can help enhance the film-forming stability of the negative electrode solid interface film (SEI), increase the flexibility of the SEI film, further enhance the protection of the negative electrode active material, reduce the interface contact probability between the negative electrode active material and the electrolyte, thereby reducing Impedance during cycling.
  • the mass content of the compound of formula III is 0.01% to 15% based on the mass of the electrolyte. If the mass content of the compound of formula III is too low, it cannot fully protect the negative electrode interface or the improvement effect is not obvious; if the mass content of the compound of formula III is too high, for example, more than 15%, the cyclic carbonate compound will have an adverse effect on SEI. The stability enhancement is no longer significantly improved. In some embodiments, the mass content of the compound of formula III is 0.1% to 10% based on the mass of the electrolyte.
  • compounds of Formula III include at least one of the following compounds:
  • the electrolyte also includes a polynitrile compound.
  • the polynitrile compound can form a synergistic effect with the compound of formula I in the electrolyte, and can play a stronger protective role on the cathode interface, further inhibiting the decomposition of the electrolyte, thereby further Improve cycle performance and high-temperature storage performance of electrochemical devices.
  • the mass content of the polynitrile compound is 0.01% to 5% based on the mass of the electrolyte.
  • the mass content of the polynitrile compound is too low, it will not have a good protective effect on the cathode interface, and the improvement effect is relatively limited; if the mass content of the polynitrile compound is too high, for example, more than 5%, the polynitrile compound will have a negative impact on SEI. The stability enhancement is no longer significantly improved.
  • the mass content of the polynitrile compound is 0.1% to 3% based on the mass of the electrolyte.
  • the polynitrile compound includes at least one of the following compounds:
  • the electrolyte also includes a boron-containing lithium salt.
  • the boron-containing lithium salt interacts with the compound of formula I.
  • the boron-containing lithium salt can form a film on the cathode and cooperate with the compound of formula I to stabilize the cathode interface, which can further improve electrochemistry. Cycling performance of the device.
  • the mass content of the boron-containing lithium salt is 0.01% to 1% based on the mass of the electrolyte.
  • the boron-containing lithium salt includes at least one of lithium tetrafluoroborate, lithium dioxaloborate, or lithium difluoroxaloborate.
  • the electrolyte also includes P-O bond-containing compounds.
  • P-O bond compounds can stabilize high-valence transition metals and oxygen atoms in the cathode active material, and play a synergistic role in protecting the cathode interface with the compound of formula I, which can further improve the electrochemical performance of the cathode. High temperature storage performance of chemical devices.
  • the mass content of the P-O bond-containing compound is 0.01% to 1% based on the mass of the electrolyte.
  • the mass content of the P-O bond-containing compound is too low to protect the cathode interface, its role in improving high-temperature storage performance is relatively limited; if the mass content of the P-O bond-containing compound is too high, it will affect the high temperature of the electrochemical device. Storage performance.
  • the P-O bond-containing compound includes lithium difluorophosphate, lithium difluorobisoxalate phosphate, lithium tetrafluorooxalate phosphate, 1,2-bis((difluorophosphino)oxy)ethane, triphenyl Phosphate ester, 3,3,3-trifluoroethyl phosphate, 3,3,3-trifluoroethyl phosphite, tris(trimethylsilane)phosphate or 2-(2,2,2-tris At least one of fluoroethoxy)-1,3,2-dioxaphosphine 2-oxides.
  • An embodiment of the present application also provides an electrochemical device including the above electrolyte.
  • This application introduces a polycyano (-CN) compound represented by formula I into the electrolyte.
  • the compound of formula I has polycyano groups, and there is a certain spatial spacing between the multiple cyano groups, so that it is effective in the positive electrode active material.
  • the transition metal has a strong stabilizing effect and can protect the positive electrode interface.
  • the compound of formula I can also be reduced to form a film on the negative electrode to further protect the negative electrode interface. By adding the compound of formula I, it can inhibit the decomposition of the electrolyte and gas production, thereby significantly improving Cycling performance and high temperature storage performance of electrochemical devices.
  • the main method to improve the energy density of electrochemical devices includes increasing the charging voltage of electrochemical devices.
  • the higher charging voltage will accelerate the electrolysis of high-valence transition metals in the cathode active material.
  • high-valence transition metals will obtain electron compensation from oxygen atoms, resulting in the release of oxygen, further accelerating the decomposition of the electrolyte, causing an increase in gas production of the electrochemical device, and affecting the cycle performance and high-temperature storage performance of the electrochemical device. Therefore, It is necessary to stabilize the high-valence transition metal in the cathode active material and improve the cycle performance and high-temperature storage performance of the electrochemical device.
  • an electrolyte solution which includes a compound of formula I:
  • m, n, k and x are each independently selected from 1, 2 or 3 and R 11 and R 12 are each independently selected from hydrogen, halogen, substituted or unsubstituted C 1 -C 3 alkyl, Substituted or unsubstituted C 2 -C 4 alkenyl group, substituted or unsubstituted C 2 -C 4 alkynyl group, substituted or unsubstituted C 6 -C 10 aryl group, wherein, When substituted, each substituent is independently selected from halogen.
  • the cyano group (-CN) in the compound of formula I can stabilize the transition metal in the high valence state of the positive electrode.
  • the compound of formula I contains multiple cyano groups, and there is a certain spacing between the multiple cyano groups, which can further stabilize the transition metal and better Improve the stability of the positive electrode interface, and the compound of formula I can also be reduced at the negative electrode, forming a protective film on the negative electrode interface, further protecting the negative electrode interface, inhibiting the continued decomposition of the electrolyte and inhibiting gas production, and improving the cycle performance of the electrochemical device under high voltage and high temperature storage performance. Therefore, the electrolyte can significantly improve the cycle performance and high-temperature storage performance of electrochemical devices.
  • compounds of Formula I include at least one of the following compounds:
  • the mass content of the compound of formula I is 0.01% to 5% based on the mass of the electrolyte. If the mass content of the compound of formula I is too low to improve the stability of the electrode interface, the effect of improving the cycle performance and high-temperature storage performance of the electrochemical device is relatively limited; if the mass content of the compound of formula I is too high, the improvement The role of the cycle performance and high-temperature storage performance of the electrochemical device is no longer significantly increased, and may cause the electrolyte viscosity to be excessive, affecting the internal dynamics of the electrochemical device and affecting the cycle performance and high-temperature storage performance of the electrochemical device.
  • the mass content of the compound of formula I is 0.01%, 0.5%, 1%, 2%, 3%, 4%, 5% or other suitable values. In some embodiments, the mass content of the compound of formula I is 0.1% to 3% based on the mass of the electrolyte.
  • the electrolyte further includes a sulfur-oxygen double bond-containing compound.
  • a sulfur-oxygen double bond-containing compound Compounds containing sulfur and oxygen double bonds have strong antioxidant capacity and can improve the stability of the cathode interface.
  • compounds containing sulfur and oxygen double bonds can be reduced on the surface of the negative electrode to form a protective film that inhibits the decomposition of the electrolyte and further enhances the stability of the interface. Therefore, the combined use of sulfur-oxygen double bond-containing compounds can further improve the cycle performance and high-temperature storage performance of electrochemical devices.
  • the sulfur-oxygen double bond-containing compound includes a compound of Formula II,
  • R 21 and R 22 are each independently selected from substituted or unsubstituted C 1 -C 5 alkyl group, substituted or unsubstituted C 1 -C 5 alkylene group, substituted or unsubstituted C 2 -C 10 alkenyl group, substituted or unsubstituted C 2 -C 10 alkynyl group, substituted or unsubstituted C 3 -C 10 alicyclic group, substituted or unsubstituted C 6 -C 10 aryl group, substituted or Unsubstituted C 1 -C 6 heterocyclic group, wherein the substituent is at least one of a halogen atom or a heteroatom-containing functional group, and the heteroatom in the heteroatom-containing functional group is selected from B, N, O, At least one of F, Si, P or S.
  • the sulfur-oxygen double bond-containing compound includes 1,3-propanesultone (PS), 1,4-butanesultone (BS), methylene methane disulfonate (MMDS), 1 ,3-propanedisulfonic anhydride, vinyl sulfate, vinyl sulfite, 4-methylvinyl sulfate, 2,4-butanesultone, 2-methyl-1,3-propanesultone, 1 ,3-butanesultone, 1-fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, 3-fluoro-1,3-propanesultone , at least one of propenyl-1,3-sultone, propylene sulfate, propylene sulfite or vinyl fluorosulfate.
  • the sulfur-oxygen double bond-containing compound includes at least one of the compounds represented by the following chemical formula:
  • the mass content of the sulfur-oxygen double bond-containing compound is 0.01% to 10% based on the mass of the electrolyte. If the mass content of the sulfur-oxygen double bond-containing compound is too low, its effect in mitigating the reaction of the electrolyte at the positive and negative electrodes is relatively limited; if the mass content of the sulfur-oxygen double bond-containing compound is too high, for example, greater than 10%, the The enhancement effect of sulfur-oxygen double bond compounds on the stability of the positive electrode interface and the negative electrode interface is no longer significantly improved, and may cause excessive viscosity of the electrolyte, affecting kinetics, affecting the cycle performance and high-temperature storage performance of the electrochemical device.
  • the mass content of the sulfur-oxygen double bond-containing compound is 0.01%, 0.5%, 1%, 2%, 3%, 4%, 5%, 8%, 10% or other appropriate value. In some embodiments, the mass content of the sulfur-oxygen double bond-containing compound is 0.1% to 5% based on the mass of the electrolyte.
  • the electrolyte further includes a compound of formula III,
  • R 31 is selected from substituted or unsubstituted C 1 -C 6 alkylene, substituted or unsubstituted C 2 -C 6 alkenylene; when substituted, the substituent is selected from halogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl.
  • the compound of formula III can assist in enhancing the film-forming stability of the negative electrode solid interface film (SEI).
  • SEI negative electrode solid interface film
  • the use of compounds of formula III can increase the flexibility of the SEI film, further enhance the protection of active materials, reduce the probability of interface contact between active materials and electrolytes, reduce side reactions between electrolytes and active materials, thereby reducing by-products during the cycle. Accumulated impedance.
  • compounds of Formula III include at least one of the following compounds:
  • the mass content of the compound of formula III is 0.01% to 15% based on the mass of the electrolyte. If the mass content of the compound of formula III is too low, it cannot fully protect the interface, and the performance improvement of the electrochemical device is limited; if the mass content of the compound of formula III is too high, for example, more than 15%, the cyclic carbonate compound The enhancement of the stability of the SEI is no longer significantly improved.
  • the mass content of the compound of formula III is 0.01%, 0.5%, 1%, 2%, 3%, 4%, 5%, 8%, 10%, 12%, 15% % or other suitable value. In some embodiments, the mass content of the compound of formula III is 0.1% to 10% based on the mass of the electrolyte.
  • the electrolyte further includes polynitrile compounds.
  • Polynitrile compounds can form a synergistic effect with the compound of formula I in the electrolyte, which can play a stronger protective role on the cathode interface and further inhibit the decomposition of the electrolyte, thereby further improving the cycling and high-temperature storage performance of the electrochemical device.
  • the polynitrile compound includes at least one of the following compounds:
  • the mass content of the polynitrile compound is 0.01% to 5% based on the mass of the electrolyte. If the mass content of the polynitrile compound is too low, it will not have a good protective effect on the cathode interface, and the effect of improving the performance of the electrochemical device will not be significant; if the mass content of the polynitrile compound is too high, for example, greater than 5%, then too much Nitrile compounds no longer significantly improve the performance of electrochemical devices, causing the viscosity of the electrolyte to increase, affecting kinetics, and affecting the cycling and high-temperature storage performance of electrochemical devices.
  • the mass content of the polynitrile compound is 0.01%, 0.5%, 1%, 2%, 3%, 4%, 5% or other suitable values. In some embodiments, the mass content of the polynitrile compound is 0.1% to 3% based on the mass of the electrolyte.
  • the electrolyte further includes a boron-containing lithium salt. The boron-containing lithium salt can form a film on the cathode interface to protect the cathode interface, and has a synergistic effect with the compound of formula I, which can further improve the cycle performance of the electrochemical device.
  • the boron-containing lithium salt includes at least one of lithium tetrafluoroborate (LiBF 4 ), lithium dioxaloborate (LiBOB), or lithium difluorooxaloborate (LiDFOB).
  • the mass content of the boron-containing lithium salt is 0.01% to 1% based on the mass of the electrolyte. If the mass content of the boron-containing lithium salt is too low to protect the cathode interface, its effect on improving cycle performance is relatively limited; if the mass content of the boron-containing lithium salt is too high, for example, greater than 1%, the boron-containing lithium salt will have a limited effect on the cathode interface. The improvement in cycle performance is no longer significant.
  • the mass content of the boron-containing lithium salt is 0.01%, 0.5%, 1% or other suitable values.
  • the electrolyte further includes a PO bond-containing compound.
  • PO bond-containing compounds can stabilize high-valence transition metals and oxygen atoms in the cathode active material, stabilize the cathode interface, and work synergistically with the compound of formula I to further improve the high-temperature storage performance of electrochemical devices.
  • the PO bond-containing compound includes lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorodioxalate phosphate (LiDFOP), lithium tetrafluorooxalate phosphate (LiTFOP), 1,2-bis((difluorophosphate) Phosphino)oxy)ethane, triphenyl phosphate, 3,3,3-trifluoroethyl phosphate, 3,3,3-trifluoroethyl phosphite, tris(trimethylsilane)phosphoric acid At least one of ester or 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphosphine 2-oxide.
  • LiPO 2 F 2 lithium difluorodioxalate phosphate
  • LiTFOP lithium tetrafluorooxalate phosphate
  • 1,2-bis((difluorophosphate) Phosphino)oxy)ethane triphenyl phosphate, 3,3,
  • the mass content of the PO bond-containing compound is 0.01% to 1% based on the mass of the electrolyte. If the mass content of the PO bond-containing compound is too low to stabilize the interface, its role in improving high-temperature storage performance is relatively limited; if the mass content of the PO bond-containing compound is too high, for example, greater than 1%, the content The improvement effect of PO bond compounds on high-temperature storage performance is no longer significantly improved.
  • the electrolyte solution may also include other non-aqueous organic solvents and electrolyte salts.
  • the non-aqueous organic solvent may include at least one of carbonates, carboxylates, ethers or other aprotic solvents.
  • Examples of carbonate solvents include dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, dipropyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, Bis(2,2,2-trifluoroethyl) carbonate, etc.
  • carboxylic acid ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, and methyl butyrate , ethyl butyrate, propyl butyrate, butyl butyrate, ⁇ -butyrolactone, 2,2-difluoroethyl acetate, valerolactone, butyrolactone, 2-fluoroethyl acetate, 2,2 -Ethyl difluoroacetate, ethyl trifluoroacetate, ethyl 2,2,3,3,3-pentafluoropropionate, 2,2,3,3,4,4,4,4-heptafluorobutyric acid Methyl ester, methyl 4,4,4-trifluoro-3-(trifluoromethyl)butyrate, ethyl
  • ether solvents include glycol dimethyl ether, diglyme, tetraglyme, dibutyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, bis(2,2,2-tris Fluoroethyl) ether, etc.
  • the electrolyte salt of the present application includes at least one of an organic lithium salt or an inorganic lithium salt.
  • the electrolyte salt includes lithium hexafluorophosphate LiPF 6 , lithium bistrifluoromethanesulfonyl imide LiN(CF 3 SO 2 ) 2 (abbreviated as LiTFSI), lithium bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 ) (abbreviated as LiFSI) or at least one of lithium hexafluorocsate (LiCsF 6 ), lithium perchlorate LiClO 4 and lithium trifluoromethanesulfonate LiCF 3 SO 3 .
  • LiTFSI lithium bistrifluoromethanesulfonyl imide LiN(CF 3 SO 2 ) 2
  • LiFSI lithium bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )
  • LiFSI lithium hexafluorocsate
  • the mass percentage of the electrolyte salt is 10% to 15% based on the mass of the electrolyte. If the electrolyte salt concentration is too low, the ionic conductivity of the electrolyte will be low, which will affect the rate and cycle performance of the electrochemical device; if the electrolyte salt concentration is too high, the electrolyte viscosity will be too high, which will affect the rate performance of the electrochemical device.
  • the mass percentage of electrolyte salt is 12% to 15%.
  • Embodiments of the present application also provide electrochemical devices.
  • the electrochemical device includes an electrode assembly, which includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte.
  • the electrolyte is the electrolyte described above.
  • the negative electrode may include a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector.
  • the negative active material layer may be disposed on one side or both sides of the negative current collector.
  • the negative electrode current collector may be at least one of copper foil, aluminum foil, nickel foil or carbon-based current collector.
  • the thickness of the negative electrode current collector may be 1 ⁇ m to 200 ⁇ m.
  • the negative active material layer may be coated on only a partial area of the negative current collector.
  • the thickness of the negative active material layer may be 10 ⁇ m to 500 ⁇ m. It should be understood that these are exemplary only and other suitable thicknesses may be used.
  • the negative active material layer includes a negative active material.
  • the negative active material in the negative active material layer includes at least one of lithium metal, natural graphite, artificial graphite, or silicon-based materials.
  • the silicon-based material includes at least one of silicon, silicon oxide compounds, silicon carbon compounds, or silicon alloys.
  • a conductive agent and/or a binder may also be included in the negative active material layer.
  • the conductive agent in the negative active material layer may include at least one of carbon black, acetylene black, Ketjen black, flake graphite, graphene, carbon nanotubes, carbon fibers or carbon nanowires.
  • the binder in the negative active material layer may include carboxymethylcellulose (CMC), polyacrylic acid, polyacrylate, polyacrylate, polyvinylpyrrolidone, polyaniline, polyimide, At least one of polyamide-imide, polysiloxane, styrene-butadiene rubber, epoxy resin, polyester resin, polyurethane resin or polyfluorene.
  • the materials disclosed above are only exemplary, and any other suitable materials may be used for the negative active material layer.
  • the mass ratio of the negative active material, the conductive agent and the binder in the negative active material layer may be (80 ⁇ 99):(0.5 ⁇ 10):(0.5 ⁇ 10). It should be understood that this is only are illustrative and not intended to limit the application.
  • the positive electrode includes a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector.
  • the cathode active material layer may be located on one side or both sides of the cathode current collector.
  • aluminum foil can be used as the positive electrode current collector.
  • the thickness of the cathode current collector may be 1 ⁇ m to 200 ⁇ m.
  • the cathode active material layer may be coated on only a partial area of the cathode current collector.
  • the thickness of the cathode active material layer may be 10 ⁇ m to 500 ⁇ m. It should be understood that these are exemplary only and other suitable thicknesses may be used.
  • the positive active material layer includes a positive active material.
  • the positive active material includes LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCo 1-y M y O 2 , LiNi 1-y M y O 2 , LiMn 2-y M y O 4 , LiN x Co y Mn z M 1-xyz O 2 , wherein M is selected from at least one of Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, And 0 ⁇ y ⁇ 1, 0 ⁇ x ⁇ 1, 0 ⁇ z ⁇ 1, x+y+z ⁇ 1.
  • the positive active material may include at least one of lithium cobalt oxide, lithium manganate, lithium iron phosphate, lithium iron manganese phosphate, lithium nickel cobalt manganate, lithium nickel cobalt aluminate, or lithium nickel manganate,
  • the above-mentioned positive active material may be doped and/or coated.
  • the positive active material layer further includes a binder and a conductive agent.
  • the binder in the positive active material layer may include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, styrene-acrylate copolymer, styrene-butadiene copolymer, Polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethylcellulose, polyvinyl acetate, polyvinylpyrrolidone, polyvinyl ether, polymethylmethacrylate, polytetrafluoroethylene At least one of vinyl fluoride or polyhexafluoropropylene.
  • the conductive agent in the cathode active material layer may include at least one of conductive carbon black, acetylene black, Ketjen black, flake graphite, graphene, carbon nanotubes or carbon fibers.
  • the mass ratio of the cathode active material, the conductive agent and the binder in the cathode active material layer may be (70 ⁇ 98):(1 ⁇ 15):(1 ⁇ 15). It should be understood that the above is only an example, and the positive active material layer may adopt any other suitable materials, thicknesses and mass ratios.
  • the release film includes at least one of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polyimide, or aramid.
  • polyethylene includes at least one selected from high-density polyethylene, low-density polyethylene, or ultra-high molecular weight polyethylene.
  • the thickness of the isolation film ranges from about 3 ⁇ m to 500 ⁇ m.
  • the surface of the isolation membrane may further include a porous layer.
  • the porous layer is disposed on at least one surface of the isolation membrane.
  • the porous layer includes at least one of inorganic particles or binders.
  • the inorganic particles are selected from alumina (Al).
  • the pores of the isolation film have a diameter in the range of about 0.01 ⁇ m to 1 ⁇ m.
  • the binder of the porous layer is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethylcellulose, poly At least one of vinylpyrrolidone, polyvinyl ether, polymethylmethacrylate, polytetrafluoroethylene or polyhexafluoropropylene.
  • the porous layer on the surface of the isolation membrane can improve the heat resistance, oxidation resistance and electrolyte wetting performance of the isolation membrane, and enhance the adhesion between the isolation membrane and the pole piece.
  • the electrode assembly of the electrochemical device is a wound electrode assembly or a stacked electrode assembly.
  • the electrochemical device is a lithium-ion battery, but the application is not limited thereto.
  • the positive electrode, separator, and negative electrode are wound or stacked in order to form an electrode assembly, and are then packaged in, for example, an aluminum-plastic film case, and the electrolyte is injected. Formation and packaging make lithium-ion batteries. Then, the prepared lithium-ion battery was tested for performance.
  • electrochemical devices eg, lithium-ion batteries
  • electrochemical devices eg, lithium-ion batteries
  • Other methods commonly used in the art can be used without departing from the content disclosed in this application.
  • Embodiments of the present application also provide an electronic device including the above electrochemical device.
  • the electronic device in the embodiment of the present application is not particularly limited and may be used in any electronic device known in the prior art.
  • electronic devices may include, but are not limited to, laptop computers, pen computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, stereo headsets, Video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, Lighting appliances, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
  • Preparation of the positive electrode Dissolve the positive active material lithium cobalt oxide LiCoO 2 , the conductive agent conductive carbon black, and the binder polyvinylidene fluoride (PVDF) in N-methylpyrrolidone (NMP) in a weight ratio of 97.9:0.9:1.2 ) solution to form a positive electrode slurry.
  • a 13 ⁇ m aluminum foil is used as the positive electrode current collector, the positive electrode slurry is coated on the positive electrode current collector, and the positive electrode is obtained after drying, cold pressing, and cutting.
  • the compacted density of the positive electrode is 4.15g/cm 3 .
  • Preparation of the negative electrode Dissolve the negative active material artificial graphite, the binder styrene-butadiene rubber (SBR), and the thickener sodium carboxymethylcellulose (CMC) in deionized water in a weight ratio of 97.4:1.4:1.2 to form Negative electrode slurry.
  • SBR styrene-butadiene rubber
  • CMC thickener sodium carboxymethylcellulose
  • a 10 ⁇ m thick copper foil is used as the negative electrode current collector, the negative electrode slurry is coated on the negative electrode current collector, and the negative electrode is obtained after drying, cold pressing, and cutting.
  • the compacted density of the negative electrode is 1.8g/cm 3 .
  • the base material of the isolation film is 5 ⁇ m thick polyethylene (PE).
  • PE polyethylene
  • An alumina ceramic layer with a thickness of 2 ⁇ m is coated on one side of the isolation film base material.
  • a single layer of ceramic layer is coated on the isolation film.
  • PVDF adhesive polyvinylidene fluoride
  • EC ethylene carbonate
  • PC propylene carbonate
  • DEC diethyl carbonate
  • EP ethyl propionate
  • PP propyl propionate
  • a certain amount of additives are then added to the above electrolyte to obtain the electrolyte in each embodiment.
  • the difference between various embodiments lies in the types and/or contents of additives used in the electrolyte.
  • the specific types of additives and their mass percentages in the electrolyte are as shown in Tables 1 to 3 below.
  • the contents of the additives are based on the electrolyte. Mass Calculated mass percent.
  • Preparation of lithium-ion battery Stack the positive electrode, isolation film, and negative electrode in order so that the isolation film is between the positive electrode and the negative electrode for isolation, and wind it to obtain the electrode assembly.
  • the electrode assembly is placed in the outer packaging aluminum plastic film, and after the moisture is removed at 80°C, the above-mentioned electrolyte is injected and packaged. After formation, degassing, trimming and other processes, a lithium-ion battery is obtained.
  • the testing methods for each parameter of this application are described below.
  • the lithium-ion battery Charge the lithium-ion battery to 4.5V at 0.7C at 25°C, and charge to 0.05C at constant voltage at 4.5V. Then it is discharged to 3.0V with a current of 0.7C, and the cycle is carried out for 800 cycles with a process of charging at 0.7C and discharging at 1C.
  • the third cycle discharge capacity is used as the benchmark, and the capacity retention rate is used as the index to evaluate the cycle performance of lithium-ion batteries.
  • Cycle capacity retention rate discharge capacity at the 800th cycle/discharge capacity at the 3rd cycle ⁇ 100%.
  • Table 1 shows the respective parameters and evaluation results of Comparative Example 1 and Examples 1 to 23.
  • the compound of formula I containing polycyano group (-CN) can improve the cycle performance and high-temperature storage performance of lithium-ion batteries. As its mass content increases, the degree of improvement becomes greater. large, and eventually tends to balance.
  • the cyano group (-CN) in the compound of formula I can stabilize the high-valence transition metal in the cathode active material, and the appropriate chain length in the compound of formula I can adjust the spatial spacing between the cyano groups to better stabilize the cathode active material.
  • the transition metal in the battery can better protect the electrode interface and inhibit electrolyte consumption, thereby improving the cycle performance and high-temperature storage performance of lithium-ion batteries. After adding sulfur-oxygen double bond-containing compounds, the high-temperature storage performance of lithium-ion batteries is further improved.
  • Table 2 shows the respective parameters and evaluation results of Examples 3 and 24 to 45.
  • Example 3 By comparing Examples 24 to 45 with Example 3, it can be seen that the combination of the compound of formula I with a sulfur-oxygen double bond-containing compound can improve the high-temperature storage performance of lithium-ion batteries, and the combination with a boron-containing lithium salt can improve the cycle performance of lithium-ion batteries. , combined with polynitrile compounds can improve the high-temperature storage performance and cycle performance of lithium-ion batteries. Combining a variety of additives can better obtain lithium-ion batteries with excellent cycle performance and high-temperature storage performance.
  • Table 3 shows the respective parameters and evaluation results of Examples 4, 46 to 57.

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Abstract

本申请提供了电解液和电化学装置。电解液包括式Ⅰ化合物，其中，m、n、k和x各自独立地选自1、2或3，R11、R12各自独立地选自氢、卤素、经取代或未经取代的C1-C3的烷基、经取代或未经取代的C 2-C 4的烯基、经取代或未经取代的C 2-C4的炔基、经取代或未经取代的C6-C10的芳基，其中，经取代时，取代基各自独立地选自卤素。通过在电解液中引入式I所示的多氰基(-CN)化合物，多氰基可以稳定正极活性材料中的过渡金属，保护正极界面，式Ⅰ化合物还可以在负极还原保护负极界面，起到抑制电解液的持续分解以及抑制产气的作用。通过加入这种化合物可以显著改善电化学装置的循环性能和高温存储性能。

Description

电解液和电化学装置 技术领域
本申请涉及电化学储能领域，具体地，涉及电解液和电化学装置。
背景技术
随着电化学装置(例如，锂离子电池)在各类电子产品中的广泛应用，用户对于电化学装置的性能也提出了越来越高的要求，特别是循环性能和高温存储性能。因此，亟需作出进一步改进以满足人们越来越高的使用需求。
发明内容
本申请的实施例提供了一种电解液，其包括式Ⅰ化合物：
Figure PCTCN2022098167-appb-000001
其中，m、n、k和x各自独立地选自1、2或3，R 11、R 12各自独立地选自氢、卤素、经取代或未经取代的C 1-C 3的烷基、经取代或未经取代的C 2-C 4的烯基、经取代或未经取代的C 2-C 4的炔基、经取代或未经取代的C 6-C 10的芳基，其中，经取代时，取代基各自独立地选自卤素。式Ⅰ化合物中的多个氰基(-CN)可以稳定正极高价态的过渡金属，进一步稳定正极界面；式Ⅰ化合物还可以在负极发生还原进而保护负极界面，起到抑制电解液的持续分解以及抑制产气的作用。
在一些实施例中，式Ⅰ化合物包括以下化合物中的至少一种：
Figure PCTCN2022098167-appb-000002
Figure PCTCN2022098167-appb-000003
Figure PCTCN2022098167-appb-000004
在一些实施例中，基于电解液的质量，式Ⅰ化合物的质量含量为0.01％至5％。式Ⅰ化合物的质量含量太低时，则改善电化学装置的循环性能和高温存储性能的作用相对有限；若式Ⅰ化合物的质量含量太高时，则改善循环性能和高温存储性能的作用不再显著增加，继续增加其含量可能会导致电解液粘度过大，影响电化学装置的循环性能和高温存储性能。在一些实施例中，基于电解液的质量，式Ⅰ化合物的质量含量为0.1％至3％。
在一些实施例中，电解液还包括含硫氧双键化合物，含硫氧双键化合物的抗氧化能力较强，可以提高正极界面的稳定性；另一方面，含硫氧双键化合物可以在负极表面还原，形成一层保护膜，抑制电解液的分解，进一步增强负极界面的稳定性。在一些实施例中，基于电解液的质量，含硫氧双键化合物的质量含量为0.01％至10％。含硫氧双键化合物的质量含量太低时，不足以保护正、负极与电解液的界面，起不到改善正极界面和负极界面的稳定性的作用或者作用效果不明显；含硫氧双键化合物的质量含量太高时，例如，高于10％，则含硫氧双键化合物对正极界面和负极界面的稳定性的增强作用不再显著提高，且可能会导致电解液粘度和正负极界面阻抗过大，影响动力学，影响电化学装置的循环性能和高温存储性能。在一些实施例中，基于电解液的质量，含硫氧双键化合物的质量含量为0.1％至5％。
在一些实施例中，含硫氧双键化合物包括式II化合物，
Figure PCTCN2022098167-appb-000005
其中，R 21和R 22各自独立地选自取代或未取代的C 1-C 5的烷基、取代或未取代的C 1-C 5的亚烷基、取代或未取代的C 2-C 10的烯基、取代或未取代的 C 2-C 10的炔基、取代或未取代的C 3-C 10的脂环基、取代或未取代的C 6-C 10的芳基、取代或未取代的C 1-C 6的杂环基团，其中，取代基为卤素原子或者含杂原子的官能团中的至少一种，含杂原子的官能团中的杂原子选自B、N、O、F、Si、P或S中的至少一种。在一些实施例中，含硫氧双键化合物包括1,3-丙磺酸内酯、1,4-丁磺内酯、甲烷二磺酸亚甲酯、1,3-丙二磺酸酐、硫酸乙烯酯、亚硫酸乙烯酯、4-甲基硫酸乙烯酯、2,4-丁磺内酯、2-甲基-1,3-丙磺酸内酯、1,3-丁磺酸内酯、1-氟-1,3-丙磺酸内酯、2-氟-1,3-丙磺酸内酯、3-氟-1,3-丙磺酸内酯、丙烯基-1,3-磺酸内酯、硫酸丙烯酯、亚硫酸丙烯酯或氟代硫酸乙烯酯中的至少一种。
在一些实施例中，电解液还包括式Ⅲ化合物，
Figure PCTCN2022098167-appb-000006
其中，R 31选自经取代或未经取代的C 1-C 6亚烷基、经取代或未经取代的C 2-C 6亚烯基；经取代时，取代基选自卤素、C 1-C 6烷基、C 2-C 6烯基。
式Ⅲ化合物可以辅助增强负极固态界面膜(SEI)的成膜稳定性，以及增加SEI膜的柔性，进一步增强对负极活性材料的保护作用，降低负极活性材料与电解液的界面接触几率，从而降低循环过程中的阻抗。在一些实施例中，基于电解液的质量，式Ⅲ化合物的质量含量为0.01％至15％。如果式Ⅲ化合物的质量含量太低，起不到充分保护负极界面的作用或者改善效果不明显；如果式Ⅲ化合物的质量含量太高，例如，大于15％，则环状碳酸酯化合物对SEI的稳定性的增强作用不再显著提高。在一些实施例中，基于电解液的质量，式Ⅲ化合物的质量含量为0.1％至10％。
在一些实施例中，式Ⅲ化合物包括以下化合物中的至少一种：
Figure PCTCN2022098167-appb-000007
在一些实施例中，电解液还包括多腈化合物，多腈化合物能够与电解液中的式I化合物形成协同作用，可以对正极界面起到更强的保护作用，进一步抑制电解液分解，从而进一步改善电化学装置的循环性能和高温存储性能。在一些实施例中，基于电解液的质量，多腈化合物的质量含量为0.01％至5％。如果多腈化合物的质量含量太低，对正极界面起不到很好的保护作用，改善作用相对有限；如果多腈化合物的质量含量太高，例如，大于5％，则多腈化合物对SEI的稳定性的增强作用不再显著提高。在一些实施例中，基于电解液的质量，多腈化合物的质量含量为0.1％至3％。在一些实施例中，多腈化合物包括以下化合物中的至少一种：
Figure PCTCN2022098167-appb-000008
在一些实施例中，电解液还包括含硼锂盐，含硼锂盐与式I化合物相互作用，含硼锂盐可以在正极成膜，与式I化合物协同稳定正极界面，可以进一步改善电化学装置的循环性能。在一些实施例中，基于电解液的质量，含硼锂盐的质量含量为0.01％至1％。如果含硼锂盐的质量含量太低，不足以起到稳定正极界面的作用，改善循环性能的作用相对有限；如果含硼锂盐的质量含量太高，例如，大于1％，则含硼锂盐对循环性能的改善作用不再显著提高。在一些实施例中，含硼锂盐包括四氟硼酸锂、二草酸硼酸锂或二氟草酸硼酸锂中的至少一种。
在一些实施例中，电解液还包括含P-O键化合物，P-O键化合物可以稳定正极活性材料中高价态的过渡金属以及氧原子，与式I化合物起到协同保护正极界面的作用，可以进一步改善电化学装置的高温存储性能。在一些实施例中，基于电解液的质量，含P-O键化合物的质量含量为0.01％至1％。如果含P-O键化合物的质量含量太低，不足以起到保护正极界面的作用，则其改善高温存储性能的作用相对有限；如果含P-O键化合物的质量含量太高，会影响电化学装置的高温存储性能。在一些实施例中，含P-O键化合物包括二氟磷酸锂、二氟双草酸磷酸锂、四氟草酸磷酸锂、1,2-双((二氟膦基)氧基)乙烷、三苯基磷酸酯、3,3,3-三氟乙基磷酸酯、3,3,3-三氟乙基亚磷酸酯、三(三甲基硅烷)磷酸酯或2-(2,2,2-三氟乙氧基)-1,3,2-二氧杂膦烷2-氧化物中的至少一种。
本申请的实施例还提供了一种电化学装置，包括上述电解液。
本申请通过在电解液中引入式I所示的多氰基(-CN)化合物，式I化合物中具有多氰基，且多个氰基间具有一定的空间间距，使其对正极活性材料中的过渡金属有强的稳定作用，可保护正极界面，式I化合物还可以在负极发生还原成膜，进一步保护负极界面，通过加入式I化合物可以抑制电解液分解及抑制产气，从而可以显著改善电化学装置的循环性能和高温存储性能。
具体实施方式
下面的实施例可以使本领域技术人员更全面地理解本申请，但不以任何方式限制本申请。
目前，提高电化学装置的能量密度的主要方法包括提高电化学装置的充电电压，但当提高电化学装置的充电电压时，较高的充电电压会加速正极活性材料中高价态的过渡金属对电解液的氧化分解，高价态过渡金属会从氧原子中获得电子补偿，导致释氧，进一步加速电解液的分解，导致电化学装置产气增加，影响电化学装置的循环性能和高温存储性能，故需稳定正极活性材料中的高价态的过渡金属，改善电化学装置的循环性能和高温存储性能。
本申请的实施例提供了一种电解液，该电解液包括式Ⅰ化合物：
Figure PCTCN2022098167-appb-000009
其中，m、n、k和x各自独立地选自1、2或3，R 11、R 12各自独立地选自氢、卤素、经取代或未经取代的C 1-C 3的烷基、经取代或未经取代的C 2-C 4的烯基、经取代或未经取代的C 2-C 4的炔基、经取代或未经取代的C 6-C 10的芳基，其中，经取代时，取代基各自独立地选自卤素。式Ⅰ化合物中的氰基(-CN)可以稳定正极高价态的过渡金属，式Ⅰ化合物中含有多个氰基，多个氰基间具有一定的空间间距，可进一步稳定过渡金属，更好地提升正极界面稳定性，且式Ⅰ化合物还可以在负极发生还原，在负极界面形成保护膜，进一步保护负极界面，抑制电解液的持续分解以及抑制产气，改善高电压下电化学装置的循环性能和高温存储性能。因此，该电解液可以显著改善电化学装置的循环性能和高温存储性能。
在一些实施例中，式Ⅰ化合物包括以下化合物中的至少一种：
Figure PCTCN2022098167-appb-000010
Figure PCTCN2022098167-appb-000011
Figure PCTCN2022098167-appb-000012
在一些实施例中，基于电解液的质量，式Ⅰ化合物的质量含量为0.01％至5％。如果式Ⅰ化合物的质量含量太低，不足以提高电极界面的稳定性，则起到的改善电化学装置的循环性能和高温存储性能的作用相对有限；如果式Ⅰ化合物的质量含量太高，改善电化学装置的循环性能和高温存储性能的作用不再显著增加，且可能会会导致电解液粘度过大，影响电化学装置内部动力学，影响电化学装置的循环性能和高温存储性能。在一些实施例中，基于电解液的质量，式Ⅰ化合物的质量含量为0.01％、0.5％、1％、2％、3％、4％、5％或其他合适的值。在一些实施例中，基于电解液的质量，式Ⅰ化合物的质量含量为0.1％至3％。
在一些实施例中，电解液还包括含硫氧双键化合物。含硫氧双键化合物的抗氧化能力较强，可以提高正极界面的稳定性。另一方面，含硫氧双键化合物可以在负极表面还原，形成一层保护膜，抑制电解液的分解，进一步增强界面的稳定性。因此，联合使用含硫氧双键化合物，可以进一步改善电化学装置的循环性能和高温存储性能。在一些实施例中，含硫氧双键化合物包括式II化合物，
Figure PCTCN2022098167-appb-000013
其中，R 21和R 22各自独立地选自取代或未取代的C 1-C 5的烷基、取代或未取代的C 1-C 5的亚烷基、取代或未取代的C 2-C 10的烯基、取代或未取代的C 2-C 10的炔基、取代或未取代的C 3-C 10的脂环基、取代或未取代的C 6-C 10的芳基、取代或未取代的C 1-C 6的杂环基团，其中，取代基为卤素原子或者含杂原子的官能团中的至少一种，含杂原子的官能团中的杂原子选自B、N、O、F、Si、P或S中的至少一种。在一些实施例中，含硫氧双键化合物包括1,3-丙磺酸内酯(PS)、1,4-丁磺内酯(BS)、甲烷二磺酸亚甲酯(MMDS)、 1,3-丙二磺酸酐、硫酸乙烯酯、亚硫酸乙烯酯、4-甲基硫酸乙烯酯、2,4-丁磺内酯、2-甲基-1,3-丙磺酸内酯、1,3-丁磺酸内酯、1-氟-1,3-丙磺酸内酯、2-氟-1,3-丙磺酸内酯、3-氟-1,3-丙磺酸内酯、丙烯基-1,3-磺酸内酯、硫酸丙烯酯、亚硫酸丙烯酯或氟代硫酸乙烯酯中的至少一种。在一些实施例中，含硫氧双键化合物包括以下化学式所示的化合物中的至少一种：
Figure PCTCN2022098167-appb-000014
在一些实施例中，基于电解液的质量，含硫氧双键化合物的质量含量为0.01％至10％。如果含硫氧双键化合物的质量含量太低，则其缓解电解液在正负极的反应的作用相对有限；如果含硫氧双键化合物的质量含量太高，例如，大于10％，则含硫氧双键化合物对正极界面和负极界面的稳定性的增强作用不再显著提高，而且可能会导致电解液粘度过大，影响动力学，影响电化学装置的循环性能和高温存储性能。在一些实施例中，基于电解液的质量，含硫氧双键化合物的质量含量为0.01％、0.5％、1％、2％、3％、4％、5％、8％、10％或其他合适的值。在一些实施例中，基于电解液的质量，含硫氧双键化合物的质量含量为0.1％至5％。
在一些实施例中，电解液还包括式Ⅲ化合物，
Figure PCTCN2022098167-appb-000015
其中，R 31选自经取代或未经取代的C 1-C 6亚烷基、经取代或未经取代的C 2-C 6亚烯基；经取代时，取代基选自卤素、C 1-C 6烷基、C 2-C 6烯基。式Ⅲ化合物可以辅助增强负极固态界面膜(SEI)的成膜稳定性。使用式Ⅲ化合物可以增加SEI膜的柔性，进一步增强对活性材料的保护作用，降低活性材料与电解液的界面接触几率，减少电解液与活性材料间的副反应，从而降低循环过程中因副产物累积产生的阻抗。在一些实施例中，式Ⅲ化合物包括以下化合物中的至少一种：
Figure PCTCN2022098167-appb-000016
在一些实施例中，基于电解液的质量，式Ⅲ化合物的质量含量为0.01％至15％。如果式Ⅲ化合物的质量含量太低，起不到充分保护界面的作用，对电化学装置的性能提升有限；如果式Ⅲ化合物的质量含量太高，例如，大于15％，则环状碳酸酯化合物对SEI的稳定性的增强作用不再显著提高。在一些实施例中，基于电解液的质量，式Ⅲ化合物的质量含量为0.01％、0.5％、1％、2％、3％、4％、5％、8％、10％、12％、15％或其他合适的值。在一些实施例中，基于电解液的质量，式Ⅲ化合物的质量含量为0.1％至10％。
在一些实施例中，电解液还包括多腈化合物。多腈化合物能够与电解液中的式I化合物形成协同作用，可以对正极界面起到更强的保护作用，进一步抑制电解液分解，从而进一步改善电化学装置的循环循环和高温存储性能。在一些实施例中，多腈化合物包括以下化合物中的至少一种：
Figure PCTCN2022098167-appb-000017
Figure PCTCN2022098167-appb-000018
在一些实施例中，基于电解液的质量，多腈化合物的质量含量为0.01％至5％。如果多腈化合物的质量含量太低，对正极界面起不到很好的保护作用，改善电化学装置性能的效果不显著；如果多腈化合物的质量含量太高，例如，大于5％，则多腈化合物对电化学装置性能的提升作用不再显著提高，会导致电解液粘度增大，影响动力学，影响电化学装置的循环循环和高温存储性能。在一些实施例中，基于电解液的质量，多腈化合物的质量含量为0.01％、0.5％、1％、2％、3％、4％、5％或其他合适的值。在一些实施例中，基于电解液的质量，多腈化合物的质量含量为0.1％至3％。在一些实施例中，电解液还包括含硼锂盐。含硼锂盐可以在正极界面成膜，保护正极界面，与式I化合物产生协同作用，可以进一步改善电化学装置的循环性能。在一些实施例中，含硼锂盐包括四氟硼酸锂(LiBF 4)、二草酸硼酸锂(LiBOB)或二氟草酸硼酸锂(LiDFOB)中的至少一种。在一些实施例中，基于电解液的质量，含硼锂盐的质量含量为0.01％至1％。如果含硼锂盐的质量含量太低，不足以保护正极界面，则其改善循环性能的作用相对有限；如果含硼锂盐的质量含量太高， 例如，大于1％，则含硼锂盐对循环性能的改善作用不再显著提高。在一些实施例中，基于电解液的质量，含硼锂盐的质量含量为0.01％、0.5％、1％或其他合适的值。
在一些实施例中，电解液还包括含P-O键化合物。含P-O键化合物可以稳定正极活性材料中高价态的过渡金属以及氧原子，起到稳定正极界面的作用，与式I化合物起到协同作用，进一步改善电化学装置的高温存储性能。在一些实施例中，含P-O键化合物包括二氟磷酸锂(LiPO 2F 2)、二氟双草酸磷酸锂(LiDFOP)、四氟草酸磷酸锂(LiTFOP)、1,2-双((二氟膦基)氧基)乙烷、三苯基磷酸酯、3,3,3-三氟乙基磷酸酯、3,3,3-三氟乙基亚磷酸酯、三(三甲基硅烷)磷酸酯或2-(2,2,2-三氟乙氧基)-1,3,2-二氧杂膦烷2-氧化物中的至少一种。在一些实施例中，基于电解液的质量，含P-O键化合物的质量含量为0.01％至1％。如果含P-O键化合物的质量含量太低，不足以起到稳定界面的作用，则其改善高温存储性能的作用相对有限；如果含P-O键化合物的质量含量太高，例如，大于1％，则含P-O键化合物对高温存储性能的改善作用不再显著提高。
在一些实施例中，电解液还可以包括其他非水有机溶剂和电解质盐。非水有机溶剂可以包含碳酸酯、羧酸酯、醚类或其他非质子溶剂中的至少一种。碳酸酯类溶剂的示例包括碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸二丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、二(2,2,2-三氟乙基)碳酸酯等。羧酸酯类溶剂的示例包括乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸正丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、γ-丁内酯、乙酸2,2-二氟乙酯、戊内酯、丁内酯、2-氟乙酸乙酯、2,2-二氟乙酸乙酯、三氟乙酸乙酯、2,2,3,3,3-五氟丙酸乙酯、2,2,3,3,4,4,4,4-七氟丁酸甲酯、4,4,4-三氟-3-(三氟甲基)丁酸甲酯、2,2,3,3,4,4,5,5,5,5-九氟戊酸乙酯、2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-十七氟壬酸甲酯、2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-十七氟壬酸乙酯等。醚类溶剂的示例包括乙二醇二甲醚、二乙二醇二甲醚、四乙二醇二甲醚、二丁醚、四氢呋喃、2-甲基四氢呋喃、双(2,2,2-三氟乙基)醚等。
在一些实施例中，本申请的电解质盐包括有机锂盐或无机锂盐中的至少一种。在一些实施例中，电解质盐包括六氟磷酸锂LiPF 6、双三氟甲烷磺酰亚 胺锂LiN(CF 3SO 2) 2(简写为LiTFSI)、双(氟磺酰)亚胺锂Li(N(SO 2F) 2)(简写为LiFSI)或六氟铯酸锂(LiCsF 6)、高氯酸锂LiClO 4、三氟甲磺酸锂LiCF 3SO 3中的至少一种。
在一些实施例中，基于电解液的质量，电解质盐的质量百分含量为10％至15％。电解质盐浓度过低，电解液的离子电导率低，会影响电化学装置的倍率和循环性能；电解质盐浓度过高，电解液粘度过大，影响电化学装置的倍率性能。可选的，电解质盐的质量百分含量为12％至15％。
本申请的实施例还提供了电化学装置。电化学装置包括电极组件，电极组件包括正极、负极、设置在正极和负极之间的隔离膜以及电解液。在一些实施例中，电解液为以上描述的电解液。
在一些实施例中，负极可以包括负极集流体和设置在负极集流体上的负极活性材料层。负极活性材料层可以设置在负极集流体的一侧或两侧上。在一些实施例中，负极集流体可以采用铜箔、铝箔、镍箔或碳基集流体中的至少一种。在一些实施例中，负极集流体的厚度可以为1μm至200μm。在一些实施例中，负极活性材料层可以仅涂覆在负极集流体的部分区域上。在一些实施例中，负极活性材料层的厚度可以为10μm至500μm。应该理解，这些仅是示例性的，可以采用其他合适的厚度。
在一些实施例中，负极活性材料层包括负极活性材料。在一些实施例中，负极活性材料层中的负极活性材料包括锂金属、天然石墨、人造石墨或硅基材料中的至少一种。在一些实施例中，硅基材料包括硅、硅氧化合物、硅碳化合物或硅合金中的至少一种。
在一些实施例中，负极活性材料层中还可以包括导电剂和/或粘结剂。负极活性材料层中的导电剂可以包括炭黑、乙炔黑、科琴黑、片层石墨、石墨烯、碳纳米管、碳纤维或碳纳米线中的至少一种。在一些实施例中，负极活性材料层中的粘结剂可以包括羧甲基纤维素(CMC)、聚丙烯酸、聚丙烯酸盐、聚丙烯酸酯、聚乙烯基吡咯烷酮、聚苯胺、聚酰亚胺、聚酰胺酰亚胺、聚硅氧烷、丁苯橡胶、环氧树脂、聚酯树脂、聚氨酯树脂或聚芴中的至少一种。应该理解，以上公开的材料仅是示例性，负极活性材料层可以采用任何其他合适的材料。在一些实施例中，负极活性材料层中的负极活性材 料、导电剂和粘结剂的质量比可以为(80～99):(0.5～10):(0.5～10)，应该理解，这仅是示例性的，而不用于限制本申请。
在一些实施例中，正极包括正极集流体和设置在正极集流体上的正极活性材料层。正极活性材料层可以位于正极集流体一侧或两侧上。在一些实施例中，正极集流体可以采用铝箔，当然，也可以采用本领域常用的其他正极集流体。在一些实施例中，正极集流体的厚度可以为1μm至200μm。在一些实施例中，正极活性材料层可以仅涂覆在正极集流体的部分区域上。在一些实施例中，正极活性材料层的厚度可以为10μm至500μm。应该理解，这些仅是示例性的，可以采用其他合适的厚度。
在一些实施例中，正极活性材料层包括正极活性材料。在一些实施例中，正极活性材料包括LiCoO 2、LiNiO 2、LiMn 2O 4、LiCo 1-yM yO 2、LiNi 1-yM yO 2、LiMn 2-yM yO 4、LiNi xCo yMn zM 1-x-y-zO 2，其中M选自Fe、Co、Ni、Mn、Mg、Cu、Zn、Al、Sn、B、Ga、Cr、Sr、V或Ti中的至少一种，且0≤y≤1，0≤x≤1，0≤z≤1，x+y+z≤1。在一些实施例中，正极活性材料可以包括钴酸锂、锰酸锂、磷酸铁锂、磷酸锰铁锂、镍钴锰酸锂、镍钴铝酸锂或镍锰酸锂中的至少一种，上述正极活性材料可以经过掺杂和/或包覆处理。
在一些实施例中，正极活性材料层还包括粘结剂和导电剂。在一些实施例中，正极活性材料层中的粘结剂可以包括聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、苯乙烯-丙烯酸酯共聚物、苯乙烯-丁二烯共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、羧甲基纤维素钠、聚醋酸乙烯酯、聚乙烯呲咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯或聚六氟丙烯中的至少一种。在一些实施例中，正极活性材料层中的导电剂可以包括导电炭黑、乙炔黑、科琴黑、片层石墨、石墨烯、碳纳米管或碳纤维中的至少一种。在一些实施例中，正极活性材料层中的正极活性材料、导电剂和粘结剂的质量比可以为(70～98):(1～15):(1～15)。应该理解，以上所述仅是示例，正极活性材料层可以采用任何其他合适的材料、厚度和质量比。
在一些实施例中，隔离膜包括聚乙烯、聚丙烯、聚偏氟乙烯、聚对苯二甲酸乙二醇酯、聚酰亚胺或芳纶中的至少一种。例如，聚乙烯包括选自高密度聚乙烯、低密度聚乙烯或超高分子量聚乙烯中的至少一种。尤其是 聚乙烯和聚丙烯，它们对防止短路具有良好的作用，并可以通过关断效应改善电池的稳定性。在一些实施例中，隔离膜的厚度在约3μm至500μm的范围内。
在一些实施例中，隔离膜表面还可以包括多孔层，多孔层设置在隔离膜的至少一个表面上，多孔层包括无机颗粒或粘结剂中的至少一种，无机颗粒选自氧化铝(Al 2O 3)、氧化硅(SiO 2)、氧化镁(MgO)、氧化钛(TiO 2)、二氧化铪(HfO 2)、氧化锡(SnO 2)、二氧化铈(CeO 2)、氧化镍(NiO)、氧化锌(ZnO)、氧化钙(CaO)、氧化锆(ZrO 2)、氧化钇(Y 2O 3)、碳化硅(SiC)、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种。在一些实施例中，隔离膜的孔具有在约0.01μm至1μm的范围的直径。多孔层的粘结剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、羧甲基纤维素钠、聚乙烯呲咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯或聚六氟丙烯中的至少一种。隔离膜表面的多孔层可以提升隔离膜的耐热性能、抗氧化性能和电解质浸润性能，增强隔离膜与极片之间的粘接性。
在本申请的一些实施例中，电化学装置的电极组件为卷绕式电极组件或堆叠式电极组件。在一些实施例中，电化学装置为锂离子电池，但是本申请不限于此。
在本申请的一些实施例中，以锂离子电池为例，将正极、隔离膜、负极按顺序卷绕或堆叠成电极组件，之后装入例如铝塑膜壳体中进行封装，注入电解液，化成、封装，即制成锂离子电池。然后，对制备的锂离子电池进行性能测试。
本领域的技术人员将理解，以上描述的电化学装置(例如，锂离子电池)的制备方法仅是实施例。在不背离本申请公开的内容的基础上，可以采用本领域常用的其他方法。
本申请的实施例还提供了包括上述电化学装置的电子装置。本申请实施例的电子装置没有特别限定，其可以是用于现有技术中已知的任何电子装置。在一些实施例中，电子装置可以包括，但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、 便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
下面列举了一些具体实施例和对比例以更好地对本申请进行说明，其中，采用锂离子电池作为示例。
锂离子电池的制备
正极的制备：将正极活性材料钴酸锂LiCoO 2、导电剂导电炭黑、粘结剂聚偏氟二乙烯(PVDF)按重量比97.9：0.9：1.2的比例溶于N-甲基吡咯烷酮(NMP)溶液中，形成正极浆料。采用13μm的铝箔作为正极集流体，将正极浆料涂覆于正极集流体上，经过干燥、冷压、裁切后得到正极。正极的压实密度为4.15g/cm 3。
负极的制备：将负极活性材料人造石墨、粘结剂丁苯橡胶(SBR)、增稠剂羧甲基纤维素钠(CMC)按重量比97.4：1.4：1.2的比例溶于去离子水中，形成负极浆料。采用10μm厚度铜箔作为负极集流体，将负极浆料涂覆于负极集流体上，干燥、冷压、裁切后得到负极。负极的压实密度为1.8g/cm 3。
隔离膜的制备：隔离膜基材为5μm厚的聚乙烯(PE)，在隔离膜基材的其中一面上涂覆厚度为2μm的氧化铝陶瓷层，最后在涂布单层陶瓷层的隔离膜的两面上各涂覆2.5mg的粘结剂聚偏二氟乙烯(PVDF)，烘干。隔离膜的孔隙率为39％。
电解液的制备：在含水量小于10ppm的环境下，将碳酸乙烯酯(简写为EC)、碳酸丙烯酯(简写为PC)、碳酸二乙酯(简写为DEC)、丙酸乙酯(简写为EP)、丙酸丙酯(简写为PP)按照1:1:1:1:1的质量比混合均匀，再将电解质盐LiPF 6溶解于上述非水溶剂，混合均匀后形成电解液，其中，基于电解液的质量，LiPF 6的质量百分含量为12.5％。再向上述电解液中加入一定量的添加剂，得到各个实施例中的电解液。各个实施例的区别在于电解液中所用到的添加剂种类和/或含量不同，添加剂的具体种类以及在电解液中的质量百分含量如下表1至3所示，添加剂的含量为基于电解液的质量计算 得到的质量百分数。其中一些添加剂的简写的对应关系如下：丁二腈(SN)、己二腈(ADN)、1,4-二氰基-2-丁烯(HEDN)、1,2-二(2-氰乙氧基)乙烷(DENE)、1,3,6-己烷三腈(HTCN)、1,2,3-三(2-氰乙氧基)丙烷(TCEP)、3,3',3”-膦三基三丙腈(PTPN)、3,3',3”-(氧代-膦三基)三丙腈(POTPN)、1,2,3,4-四(β-氰基乙氧基)丁烷(TCEB)、1,2,3,4,5-五(β-氰基乙氧基)戊烷(PCEP)、1,2,3,4,5,6-六(β-氰基乙氧基)己烷(HCEH)。
锂离子电池的制备：将正极、隔离膜、负极按顺序依次叠好，使隔离膜处于正极和负极中间起到隔离的作用，并卷绕得到电极组件。将电极组件置于外包装铝塑膜中，在80℃下脱去水分后，注入上述电解液并封装，经过化成，脱气，切边等工艺流程得到锂离子电池。下面描述本申请的各个参数的测试方法。
25℃循环性能测试：
在25℃条件下，将锂离子电池以0.7C充电至4.5V，4.5V条件下恒压充电至0.05C。之后以0.7C的电流放电至3.0V，并以0.7C充电和1C放电的流程，循环进行800圈。其中以第3圈循环放电容量作为基准，以容量保持率作为评价锂离子电池循环性能的指标。
循环容量保持率＝第800次循环的放电容量/第3圈循环的放电容量×100％。
高温存储性能测试：
将锂离子电池在25℃下以0.5C恒流充电至4.5V，然后恒压充电至电流为0.05C，测试锂离子电池的厚度并记为d0，放置到85℃烘箱当中6h，监控此时厚度，记为d。锂离子电池高温存储6h后的厚度膨胀率(％)＝(d-d0)/d0×100％，厚度膨胀率超过50％，停止测试。
表1示出了对比例1、实施例1至23的各个参数和评估结果。
表1
Figure PCTCN2022098167-appb-000019
Figure PCTCN2022098167-appb-000020
Figure PCTCN2022098167-appb-000021
通过表1的实施例和对比例1可以看出，包含多氰基(-CN)的式I化合物可以改善锂离子电池的循环性能和高温存储性能，随着其质量含量增加，改善程度都越大，最后趋于平衡。式I化合物中的氰基(-CN)能够稳定正极活性材料中高价态的过渡金属，且式I化合物中合适的链长可实现氰基间的空间间距的调整，更好的稳定正极活性材料中的过渡金属，起到更好的电极界面保护作用，抑制电解液消耗，从而改善锂离子电池的循环性能和高温存储性能。加入含硫氧双键化合物后，锂离子电池的高温存储性能得到进一步改善。
表2示出了实施例3和24至45的各个参数和评估结果。
表2
Figure PCTCN2022098167-appb-000022
Figure PCTCN2022098167-appb-000023
通过比较实施例24至45与实施例3可以看出，式I化合物与含硫氧双键化合物组合可以改善锂离子电池的高温存储性能，与含硼锂盐组合可以改善锂离子电池的循环性能，与多腈化合物组合可以改善锂离子电池的高温存储性能和循环性能，将多种添加剂进行组合可以更好的获得循环性能与高温存储性能兼优的锂离子电池。
表3示出了实施例4、46至57的各个参数和评估结果。
表3
Figure PCTCN2022098167-appb-000024
Figure PCTCN2022098167-appb-000025
通过比较实施例4、46至57可以看出，式I化合物与式III化合物组合可以显著改善锂离子电池的循环性能，同时可以协调高温存储性能。另外，电解液中进一步加入含P-O键化合物能够进一步改善锂离子电池的高温存储性能。
以上描述仅为本申请的较佳实施例以及对所运用技术原理的说明。本领域技术人员应当理解，本申请中所涉及的公开范围，并不限于上述技术特征的特定组合而成的技术方案，同时也应涵盖由上述技术特征或其等同特征进行任意组合而形成的其它技术方案。例如上述特征与本申请中公开的具有类似功能的技术特征进行互相替换而形成的技术方案。

Claims (16)

  1. 一种电解液，其包括式Ⅰ化合物：
    Figure PCTCN2022098167-appb-100001
    其中，m、n、k和x各自独立地选自1、2或3，R 11、R 12各自独立地选自氢、卤素、经取代或未经取代的C 1-C 3的烷基、经取代或未经取代的C 2-C 4的烯基、经取代或未经取代的C 2-C 4的炔基、经取代或未经取代的C 6-C 10的芳基，其中，经取代时，取代基各自独立地选自卤素。
  2. 根据权利要求1所述的电解液，其中，所述式Ⅰ化合物包括以下化合物中的至少一种：
    Figure PCTCN2022098167-appb-100002
    Figure PCTCN2022098167-appb-100003
  3. 根据权利要求1所述的电解液，其中，基于所述电解液的质量，所述式Ⅰ化合物的质量含量为0.01％至5％。
  4. 根据权利要求1所述的电解液，所述电解液还包括含硫氧双键化合物，其中，基于所述电解液的质量，所述含硫氧双键化合物的质量含量为0.01％至10％。
  5. 根据权利要求4所述的电解液，其中，所述含硫氧双键化合物包括式II化合物，
    Figure PCTCN2022098167-appb-100004
    其中，R 21和R 22各自独立地选自取代或未取代的C 1-C 5的烷基、取代或未取代的C 1-C 5的亚烷基、取代或未取代的C 2-C 10的烯基、取代或未取代的C 2-C 10的炔基、取代或未取代的C 3-C 10的脂环基、取代或未取代的C 6-C 10的芳基、取代或未取代的C 1-C 6的杂环基团，其中，取代基为卤素原子或者含杂原子的官能团中的至少一种，含杂原子的官能团中的杂原子选自B、N、O、F、Si、P或S中的至少一种。
  6. 根据权利要求4所述的电解液，其中，所述含硫氧双键化合物包括1,3-丙磺酸内酯、1,4-丁磺内酯、甲烷二磺酸亚甲酯、1,3-丙二磺酸酐、硫酸乙烯酯、亚硫酸乙烯酯、4-甲基硫酸乙烯酯、2,4-丁磺内酯、2-甲基-1,3-丙磺酸内酯、1,3-丁磺酸内酯、1-氟-1,3-丙磺酸内酯、2-氟-1,3-丙磺酸内酯、3-氟-1,3-丙磺酸内酯、丙烯基-1,3-磺酸内酯、硫酸丙烯酯、亚硫酸丙烯酯或氟代硫酸乙烯酯中的至少一种。
  7. 根据权利要求1所述的电解液，所述电解液还包括式Ⅲ化合物，
    Figure PCTCN2022098167-appb-100005
    其中，R 31选自经取代或未经取代的C 1-C 6亚烷基、经取代或未经取代的C 2-C 6亚烯基；经取代时，取代基选自卤素、C 1-C 6烷基、C 2-C 6烯基；
    基于所述电解液的质量，所述式Ⅲ化合物的质量含量为0.01％至15％。
  8. 根据权利要求7所述的电解液，所述式Ⅲ化合物包括以下化合物中的至少一种：
    Figure PCTCN2022098167-appb-100006
  9. 根据权利要求1所述的电解液，所述电解液还包括除了所述式Ⅰ化合物之外的多腈化合物，其中，基于所述电解液的质量，所述多腈化合物的质量含量为0.01％至5％。
  10. 根据权利要求9所述的电解液，其中，所述多腈化合物包括以下化合物中的至少一种：
    Figure PCTCN2022098167-appb-100007
    Figure PCTCN2022098167-appb-100008
  11. 根据权利要求1所述的电解液，所述电解液还包括含硼锂盐，其中，基于所述电解液的质量，所述含硼锂盐的质量含量为0.01％至1％。
  12. 根据权利要求11所述的电解液，所述含硼锂盐包括四氟硼酸锂、二草酸硼酸锂或二氟草酸硼酸锂中的至少一种。
  13. 根据权利要求1所述的电解液，所述电解液还包括含P-O键化合物，其中，基于所述电解液的质量，所述含P-O键化合物的质量含量为0.01％至1％。
  14. 根据权利要求13所述的电解液，所述含P-O键化合物包括二氟磷酸锂、二氟双草酸磷酸锂、四氟草酸磷酸锂、1,2-双((二氟膦基)氧基)乙烷、三苯基磷酸酯、3,3,3-三氟乙基磷酸酯、3,3,3-三氟乙基亚磷酸酯、三(三甲基硅烷)磷酸酯或2-(2,2,2-三氟乙氧基)-1,3,2-二氧杂膦烷2-氧化物中的至少一种。
  15. 根据权利要求1至14中任一项所述的电解液，其满足以下条件至少一者：
    (1)基于所述电解液的质量，所述式Ⅰ化合物的质量含量为0.1％至3％；
    (2)基于所述电解液的质量，所述含硫氧双键化合物的质量含量为0.1％至5％；
    (3)基于所述电解液的质量，所述式Ⅲ化合物的质量含量为0.1％至10％；
    (4)基于所述电解液的质量，所述多腈化合物的质量含量为0.1％至3％。
  16. 一种电化学装置，其包括根据权利要求1至15中任一项所述的电解液。
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Publication number Priority date Publication date Assignee Title
JP2010073367A (ja) * 2008-09-16 2010-04-02 Sony Corp 非水電解質および非水電解質電池
CN106654128A (zh) * 2017-01-18 2017-05-10 宁德新能源科技有限公司 二次电池
CN109301323A (zh) * 2018-09-21 2019-02-01 宁德新能源科技有限公司 一种电解液及包含该电解液的电化学装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010073367A (ja) * 2008-09-16 2010-04-02 Sony Corp 非水電解質および非水電解質電池
CN106654128A (zh) * 2017-01-18 2017-05-10 宁德新能源科技有限公司 二次电池
CN109301323A (zh) * 2018-09-21 2019-02-01 宁德新能源科技有限公司 一种电解液及包含该电解液的电化学装置

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