WO2022022519A1 - 一种隔膜及其应用 - Google Patents

一种隔膜及其应用 Download PDF

Info

Publication number
WO2022022519A1
WO2022022519A1 PCT/CN2021/108696 CN2021108696W WO2022022519A1 WO 2022022519 A1 WO2022022519 A1 WO 2022022519A1 CN 2021108696 W CN2021108696 W CN 2021108696W WO 2022022519 A1 WO2022022519 A1 WO 2022022519A1
Authority
WO
WIPO (PCT)
Prior art keywords
separator
functional particles
oxides
porous substrate
coating layer
Prior art date
Application number
PCT/CN2021/108696
Other languages
English (en)
French (fr)
Inventor
潘跃德
李素丽
李俊义
徐延铭
Original Assignee
珠海冠宇电池股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 珠海冠宇电池股份有限公司 filed Critical 珠海冠宇电池股份有限公司
Publication of WO2022022519A1 publication Critical patent/WO2022022519A1/zh
Priority to US18/147,220 priority Critical patent/US20230134434A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/417—Polyolefins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/42—Acrylic resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/423—Polyamide resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H01M50/434—Ceramics
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/44—Fibrous material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/454—Separators, membranes or diaphragms characterised by the material having a layered structure comprising a non-fibrous layer and a fibrous layer superimposed on one another
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/457—Separators, membranes or diaphragms characterised by the material having a layered structure comprising three or more layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the invention relates to a diaphragm and its application, and relates to the technical field of electrochemical devices.
  • lithium ion batteries have become a very widely used secondary battery at present. Since the electrolyte of lithium ion battery needs to use lithium hexafluorophosphate as the electrolyte, during the preparation process of the electrolyte, hydrofluoric acid will inevitably be entrained into the lithium ion battery; and during the working process of the lithium ion battery, the lithium salt in the electrolyte It is also inevitable that acidic substances will be produced, for example, lithium difluorooxalate borate and lithium bisoxalate borate may produce boric acid.
  • the invention provides a separator for solving the damage to the cycle performance and safety performance of a lithium ion battery caused by an acidic substance.
  • a first aspect of the present invention provides a separator, the separator includes a porous substrate, functional particles and a coating layer, the functional particles are filled in the internal pores of the porous substrate, and the coating layer is provided on the the upper and lower surfaces of the porous substrate;
  • the functional particles are oxides whose outer layers include -NH- or -NH 2 groups.
  • the present invention provides a separator comprising a porous substrate, functional particles and a coating layer, wherein the porous substrate can be selected from existing materials, for example, a polymer separator commonly used in the prior art. It has certain pores, therefore, the application uses oxides whose outer layer includes -NH- or -NH2 groups as functional particles, and fills them in the inner pores of the porous substrate, and the -NH- Or -NH 2 groups can effectively adsorb the acidic substances inside the lithium-ion battery, thereby reducing the acid content and reducing the impact of acidic substances on the lithium-ion battery.
  • a coating layer is arranged on the bottom surface of the porous substrate, so that the functional particles are effectively encapsulated inside the porous substrate.
  • the material of the coating layer can also be selected according to the prior art, such as polymer particles or ceramics.
  • the separator provided by the present application contains functional particles inside, and the -NH- or -NH 2 groups on the outer layer of the functional particles can effectively adsorb the acidic substances inside the lithium-ion battery, reduce the acid content in the lithium-ion battery, and reduce the acidity
  • the hydrophilic group in the outer layer of the functional particle can improve the wettability of the electrolyte, increase the lithium ion channel, and improve the liquid retention rate of the separator. Therefore, the separator provided by the present invention can improve the cycle performance of the lithium ion battery. and safety performance.
  • the functional particles are filled in the internal pores of the porous substrate, the thickness of the separator will not be increased, so the energy density of the lithium-ion battery will not be greatly affected.
  • the average pore size of the porous substrate is D1
  • the Dv50 of the functional particles is D2
  • the Dv50 of the material of the coating layer is D3, wherein 1.2*D2 ⁇ D1 ⁇ 0.8* D3.
  • the Dv50 of the material of the coating layer is less than or equal to 1 ⁇ m.
  • the porous substrate in the present application can be selected from the common polymer separators in the prior art, specifically, the porous substrate can be polyethylene, polypropylene, polyvinylidene fluoride, aramid, polyethylene terephthalate One or more of alcohol ester, polytetrafluoroethylene, polyacrylonitrile, polyimide, polyamide, polyester, and natural fibers.
  • the material of the coating layer in the present application can also be selected according to the prior art, for example, the material of the coating layer is one or both of polymer particles or ceramics.
  • the thickness of the coating layer is too low to achieve the expected effect; if the thickness of the coating layer is too high, the thickness and weight of the separator will increase, which is not conducive to the energy density of the lithium-ion battery.
  • the thickness is 0.1-6 ⁇ m.
  • the functional particles are oxides whose outer layers include -NH- or -NH 2 groups, the functional particles contain elements such as C, H, O, N, Si, and the functional particles are prepared by a preparation method comprising the following process get:
  • the functional particles are obtained by grafting the chlorosilane-containing oxide with the hydroxyl group on the outer layer, and then reacting with an organic substance containing -NH- or -NH 2 .
  • the functional particles provided in this application are oxides whose outer layer includes -NH- or -NH 2 groups. Specifically, an inorganic oxide with a hydroxyl group in the outer layer is selected as the substrate. For most inorganic oxides, the outer layer is The layers all contain hydroxyl groups, and those skilled in the art can directly carry out the next step, or they can also perform acid treatment on the inorganic oxide to increase the content of hydroxyl groups in the outer layer.
  • Acid treatment increases the hydroxyl content of the outer layer of SiO 2 ; secondly, the oxide with hydroxyl groups in the outer layer is reacted with chlorosilane, and after the reaction is completed, the reaction product is then reacted with an organic substance containing -NH- or -NH 2 to obtain the Functional particles, for the convenience of expression, use -NH- or -NH 2 -containing organic matter-oxide to represent the functional particles, such as PEI-SiO 2 , that is, the oxide in the functional particles is SiO 2 , and the organic matter is PEI (polyethylene sub-oxide). amine).
  • the oxides are Al oxides, AlOOH, Si oxides, Ti oxides, Zn oxides, Mg oxides, Ni oxides, Zr oxides, Ca oxides, One or more of the oxides of Ba.
  • the organic matter containing -NH- or -NH 2 is a polyamine compound and its derivatives.
  • the organic matter containing -NH- or -NH 2 is Hexamethylene diamine (HMDA), p-Phenylenediamine (PDA), methyl m-phenylenediamine (N-Methyl-m -phenylenediamine (MPDA), diethylenetriamine (DETA), triethylenetetramine (TETA), poly-m-aminostyrene, polyethyleneimine (PEI), hexadecylamine (1-Hexadecylamine, one or more of HDA).
  • HMDA Hexamethylene diamine
  • PDA p-Phenylenediamine
  • MPDA methyl m-phenylenediamine
  • DETA diethylenetriamine
  • TETA triethylenetetramine
  • PEI polyethyleneimine
  • hexadecylamine (1-Hexadecylamine, one or more of HDA hexadecylamine
  • the preparation method of the functional particles includes:
  • the oxide SiO2 was added to the HNO3 solution for acid treatment to increase the hydroxyl content of the SiO2 outer layer; secondly, a certain amount of toluene was added to the acidified SiO2 , and under the protection of N2 , continued to slowly Add toluene and chlorosilane, for example: 3-chloropropyltriethoxysilane, after the reaction, filter and dry to obtain grafted chlorosilane-containing silica; finally, the obtained grafted chlorosilane
  • the silica is added to the aqueous solution of methanol and polyethyleneimine (PEI), the reaction is terminated after stirring and refluxing, and the functional particle PEI-SiO 2 can be obtained after suction filtration, washing and drying.
  • PEI polyethyleneimine
  • the separator provided by the present application can be prepared according to the prior art, which specifically includes the following steps:
  • a dispersion system of functional particles is prepared, and then the functional particles are filled into the internal pores of the porous substrate, for example, the porous substrate is immersed in the dispersion system containing the functional particles, or by spraying In this way, the functional particles enter the internal pores of the porous substrate separator, and finally the separator is obtained by coating the coating material on the upper and lower surfaces of the porous substrate according to the prior art.
  • the functional particles can usually be dissolved in a solvent to obtain a dispersion system containing functional particles, and the applicant has found that when the solid content of the dispersion system is less than 0.1%, the functional particles filled into the pores of the porous substrate The particle content is low, and too much solvent is not conducive to the subsequent volatilization of the solvent; when the solid content of the dispersion system is higher than 10%, it is difficult to distribute the functional particles uniformly in the pores of the porous substrate, which may lead to blockage of the functional particles. Therefore, in the preparation process, the solid content of the dispersion system of the functional particles needs to be controlled to be 0.1%-10%.
  • the solvent used in the dispersion system is a non-aqueous liquid, and it should be noted that the boiling point of the solvent should be within 60-99 °C (measured under the condition of 0.1MPa).
  • the boiling point of the solvent is lower than 60 °C, the solvent is extremely high at room temperature. It is easy to volatilize, which is not conducive to operation, and may also lead to the aggregation and accumulation of functional particles; when the boiling point of the solvent is higher than 99 °C, it is not conducive to the subsequent volatilization of the solvent, and it is difficult to completely volatilize the solvent.
  • the polarity and dielectric constant of the non-aqueous liquid should be in an appropriate range.
  • the dielectric constant of the non-aqueous liquid is lower than 10, the The polarity of the liquid is too weak, and it is difficult to form effective wetting with the active material; when the dielectric constant is higher than 40, the polarity of the solvent is too strong, and may contain strong polar groups such as carboxylic acids, which are easy to Reacts with the positive active material, so the dielectric constant of the solvent at room temperature should be 10-40.
  • the solvent can be hexane, tetrahydrofuran, trifluoroacetic acid, 1,1,1-trichloroethane, carbon tetrachloride, ethyl acetate, butanone, benzene, acetonitrile, 1,2-dichloroethyl
  • alkane methanol, ethanol, ethylene glycol dimethyl ether, trichloroethylene, triethylamine, propionitrile, heptane.
  • the drying solvent can be dried under reduced pressure or heated by blasting, and those skilled in the art can select an appropriate method according to the prior art.
  • the applicant found that when the porosity of the porous substrate is lower than 20%, the liquid absorption performance of the separator is poor, resulting in the congestion of lithium ion conduction channels, thus affecting the kinetic performance of lithium ion batteries;
  • the porosity of the porous substrate is higher than 90%, the mechanical properties of the separator will be deteriorated, reducing the production yield of lithium ion batteries, such as the winding process, therefore, the porosity of the porous substrate is 20%-90% .
  • the air permeability (Gurley) of the separator is 120s-600s. Air permeability is an indicator that characterizes the gas permeability of the diaphragm, which can indirectly reflect the permeability of ions.
  • Gurley value is used as the evaluation standard, that is, when the diaphragm is placed in the air permeability detector, a certain volume of air can pass through the specified pressure under a certain pressure.
  • the time of the area diaphragm The Japanese industrial standard of the diaphragm industry is used here, that is, the time required for 100ml of air to pass through a 1 square inch diaphragm under a pressure of 1.22kPa is measured by a Gurley 4110N air permeability detector.
  • the present invention provides a separator. Since the separator contains functional particles, the -NH- or -NH 2 groups on the outer layer of the functional particles can effectively adsorb the acidic substances inside the lithium ion battery and reduce the acidity in the lithium ion battery. content, thereby reducing the influence of acidic substances, and at the same time, the hydrophilic group in the outer layer of the functional particle can improve the wettability of the electrolyte, increase the lithium ion channel, and improve the liquid retention rate of the separator. Therefore, the separator provided by the present invention can improve the lithium ion Cycling performance and safety performance of ion batteries. In addition, since the functional particles are filled in the internal pores of the porous substrate, the thickness of the separator will not be increased, so the energy density of the lithium-ion battery will not be greatly affected.
  • a second aspect of the present invention provides a preparation method of any of the above-mentioned diaphragms, comprising the following steps:
  • the porous substrate is contacted with the dispersion system containing the functional particles, and then a coating layer is provided on the upper surface and the lower surface of the porous substrate to obtain the separator.
  • a dispersion system of functional particles is prepared, and then the functional particles are filled into the internal pores of the porous substrate, for example, the porous substrate is immersed in the dispersion system of functional particles, or sprayed by spraying In this way, the functional particles are allowed to enter the internal pores of the porous substrate separator, and finally the separator is obtained by coating the coating material on the upper and lower surfaces of the porous substrate according to the prior art.
  • the preparation method provided by the present application has a lower preparation cost, which is beneficial to reducing the preparation cost and large-scale production.
  • a third aspect of the present invention provides a lithium ion battery, comprising any of the separators described above.
  • a third aspect of the present invention provides a lithium ion battery.
  • the separator provided by the present invention those skilled in the art can prepare a lithium ion battery with a positive electrode piece, a negative electrode piece and an electrolyte solution according to the prior art.
  • the lithium ion battery provided by the present invention contains functional particles in the separator, and the -NH- or -NH 2 groups on the outer layer of the functional particles can effectively adsorb the acidic substances inside the lithium ion battery, thereby reducing the acid content in the lithium ion battery.
  • the hydrophilic group on the outer layer of the functional particle can improve the wettability of the electrolyte, increase the lithium ion channel, and improve the liquid retention rate of the separator. Therefore, the present invention provides a lithium ion battery with better performance. Cycle performance and safety performance.
  • the separator provided by this application contains functional particles inside, the -NH- or -NH 2 groups on the outer layer of the functional particles can effectively adsorb the acidic substances inside the lithium-ion battery and reduce the acid content in the lithium-ion battery, thereby At the same time, the hydrophilic group on the outer layer of the functional particle can improve the wettability of the electrolyte, increase the lithium ion channel, and improve the liquid retention rate of the separator. Therefore, the separator provided by the present invention can improve the lithium ion battery. Cycle performance and safety performance. In addition, since the functional particles are filled in the internal pores of the porous substrate, the thickness of the separator will not be increased, so the energy density of the lithium-ion battery will not be greatly affected.
  • a coating layer is arranged on the upper surface and the lower surface of the porous substrate, so that the functional particles are effectively encapsulated inside the porous substrate, and the cycle performance of the lithium ion battery is ensured.
  • the preparation method provided by the present invention has low cost and is suitable for large-scale production.
  • the lithium ion battery provided by the present invention has better cycle performance and safety performance.
  • the porous substrate is Celgard 2320 separator (thickness is 20 ⁇ m, Gurley value is 530 s, porosity is 39%, average pore size is 27 nm, and areal density is 10 g/m 2 ); Kemar Reagent Co., Ltd.; the chemical reagents required for the preparation of functional particles were purchased from alfa-aesar Reagent Co., Ltd.; the pore size was measured by pore size analyzer PMI CFP-1500AE.
  • the separator provided in this embodiment includes a porous substrate, functional particles and a coating layer, wherein:
  • the functional particles are PEI-SiO 2 , the Dv50 is 20 nm, and the areal density is 0.2 g/m 2 ;
  • the material of the coating layer is PVDF-HFP, the Dv50 is 105 nm, and the thickness of the coating layer arranged on the upper surface and the lower surface of the porous substrate is 1 ⁇ m;
  • the air permeability of the diaphragm is 620s.
  • the preparation method of functional particles includes:
  • deionized water, 1 mol/L sulfuric acid, deionized water, 1 mol/L ammonia water and deionized water are used for washing in sequence until neutrality, and finally methanol is used for washing.
  • the functional particles obtained by the above method are dissolved in absolute ethanol to obtain a dispersion system containing functional particles, and the porous substrate is immersed in the dispersion system containing functional particles, so that the functional particles enter the internal pores of the substrate diaphragm, and then the porous substrate is immersed in the porous substrate.
  • the upper and lower surfaces of the substrate are provided with coating layers PVDF-HFP to obtain a separator.
  • the separator provided in this embodiment includes a porous substrate, functional particles and a coating layer, wherein:
  • the functional particles are PEI-Al 2 O 3 , the Dv50 is 10 nm, and the areal density is 0.1 g/m 2 ;
  • the material of the coating layer is PVDF-HFP, the Dv50 is 40 nm, and the thickness of the coating layer arranged on the upper surface and the lower surface of the porous substrate is 0.1 ⁇ m;
  • the air permeability of the diaphragm is 570s.
  • the preparation method of the functional particle PEI-Al 2 O 3 of this embodiment includes:
  • PEI-Al 2 O 3 was obtained by vacuum drying at 80° C. for 12 h, wherein the washing process used deionized water, 0.01 mol/L sulfuric acid, deionized water, 0.5 mol/L ammonia water, deionized water in sequence. Ionized water, methanol.
  • the preparation method of the diaphragm in this example is similar to that in Example 1, except that the materials used are different.
  • the separator provided in this embodiment includes a porous substrate, functional particles and a coating layer, wherein:
  • the functional particles are PEI-TiO 2 , the Dv50 is 5 nm, and the areal density is 0.05 g/m 2 ;
  • the material of the coating layer is PVDF-HFP, the Dv50 is 1000 nm, and the thickness of the coating layer arranged on the upper surface and the lower surface of the porous substrate is 6 ⁇ m;
  • the air permeability of the diaphragm is 650s.
  • Example 2 For the preparation method of the functional particles in this example, reference may be made to Example 2, the difference is that the oxide used is TiO 2 (Dv50 is 5 nm).
  • the preparation method of the diaphragm in this example is similar to that in Example 1, except that the materials used are different.
  • the separator provided in this embodiment includes a porous substrate, functional particles and a coating layer, wherein:
  • the functional particles are HDA-AlOOH, the Dv50 is 10 nm, and the areal density is 0.1 g/m 2 ;
  • the material of the coating layer is PVDF-HFP/AlOOH (mass ratio 1:1), the Dv50 of PVDF-HFP is 600 nm, the Dv50 of AlOOH is 450 nm, and the thickness of the coating layer arranged on the upper and lower surfaces of the porous substrate is equal. is 2 ⁇ m;
  • the air permeability of the diaphragm is 580s.
  • the difference is that the used organic substance containing -NH- or -NH 2 is HDA, and the used oxide is AlOOH (Dv50 is 10 nm).
  • the preparation method of the diaphragm in this example is similar to that in Example 1, except that the materials used are different.
  • the separator provided by this comparative example includes a porous substrate.
  • the separator provided in this comparative example includes a porous substrate and a double-sided coating, wherein:
  • the material of the coating layer is PVDF-HFP, the Dv50 is 105 nm, and the thickness of the coating layer arranged on the upper surface and the lower surface of the porous substrate is both 1 ⁇ m.
  • the present invention further prepares the separators provided in the above-mentioned Examples 1-4 and Comparative Examples 1-2 into a lithium ion battery, and the specific preparation method includes:
  • the positive pole piece, the separator and the negative pole piece are stacked in sequence, the separator is in the middle of the positive pole piece and the negative pole piece, and then rolled into a bare cell with a thickness of 35mm, a width of 50mm and a length of 75mm.
  • Put the bare cell into an aluminum-plastic film packaging bag bake it in a vacuum at 75°C for 10h, inject the electrolyte, vacuum package, stand for 24h, and then charge it to 3.75V with a constant current of 0.05C, and then charge it to 0.2C.
  • the preparation method of the positive pole piece includes:
  • the preparation method of the negative pole piece includes:
  • the negative active material artificial graphite, conductive agent acetylene black (SP), binder styrene-butadiene rubber (SBR), thickener sodium carboxymethyl cellulose (CMC) are mixed in a weight ratio of 96:1:1.5:1.5, add Solvent deionized water, stir and mix evenly to obtain negative electrode slurry; uniformly coat the above negative electrode slurry on the upper and lower surfaces of the negative electrode current collector copper foil, dry at 90°C, and then cold-press and trim the edges. , cutting, slitting, and drying under vacuum conditions at 110°C for 4 hours to obtain negative pole pieces.
  • the preparation method of electrolyte includes:
  • DMC Dimethyl carbonate
  • EMC ethyl methyl carbonate
  • EC ethylene carbonate
  • the test method of high temperature cycle capacity retention rate of lithium ion battery includes:
  • the capacity retention rate corresponding to the 500th cycle capacity 100%*Cn/C1.
  • Test methods for high temperature storage gas production of lithium-ion batteries include:

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Composite Materials (AREA)
  • Ceramic Engineering (AREA)
  • Cell Separators (AREA)

Abstract

本发明提供了一种隔膜及其应用。本发明第一方面提供了一种隔膜，所述隔膜包括多孔基材、功能粒子和涂覆层，所述功能粒子填充在所述多孔基材的内部孔隙中，所述涂覆层设置在所述多孔基材的上表面和下表面；其中，所述功能粒子为外层包括-NH-或-NH 2基团的氧化物。本发明提供的隔膜，由于其内部含有功能粒子，功能粒子外层的-NH-或-NH 2基团可有效吸附锂离子电池内部的酸性物质，降低锂离子电池中的酸含量，从而减轻酸性物质的影响，同时，功能粒子外层的亲水基团可提高电解液的浸润性，增加锂离子通道，提高隔膜的保液率，因此，本发明提供的隔膜可提高锂离子电池的循环性能和安全性能。

Description

一种隔膜及其应用
本申请要求于2020年07月27日提交中国专利局、申请号为202010731437.8、申请名称为“一种隔膜及其应用”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及一种隔膜及其应用，涉及电化学装置技术领域。
背景技术
随着锂离子电池相关技术的不断发展，目前锂离子电池已成为一种用途非常广泛的二次电池。由于锂离子电池的电解液需要使用到六氟磷酸锂作为电解质，在电解液的制备过程中，不可避免的会夹带氢氟酸进入锂离子电池；并且在锂离子电池工作过程中，电解液中的锂盐也不可避免的会有酸性物质产生，例如二氟草酸硼酸锂和双草酸硼酸锂都可能会产生硼酸。当锂离子电池中酸含量超过一定浓度时，会开始消耗锂离子，使电池的不可逆容量增大，使得锂离子电池的循环性能恶化，并且反应所产生的气体也会导致锂离子电池内压力增大，影响锂离子电池的安全性。
由于锂离子电池中大量的电解液吸附在隔膜中，因此，针对电解液中酸性物质对锂离子电池循环性能和安全性能的损害，如何提供一种可改善锂离子电池性能的隔膜，受到了越来越多的关注。
发明内容
本发明提供了一种隔膜，用于解决酸性物质对锂离子电池循环性能和安全性能的损害。
本发明第一方面提供了一种隔膜，所述隔膜包括多孔基材、功能粒子和涂覆层，所述功能粒子填充在所述多孔基材的内部孔隙中，所述涂覆层设置在所述多孔基材的上表面和下表面；
其中，所述功能粒子为外层包括-NH-或-NH 2基团的氧化物。
本发明提供了一种隔膜，包括多孔基材、功能粒子以及涂覆层，其中，多孔基材可选择现有的材料，例如，现有技术中常用的聚合物隔膜，由于多孔基材结构内部具有一定的孔隙，因此，本申请使用外层包括-NH-或-NH 2基团的氧化物作为功能粒子，并将其填充在多孔基材的内部孔隙中，功能粒子外层的-NH-或-NH 2基团可有效吸附锂离子电池内部的酸性物质，从而降低酸含量，减轻酸性物质对锂离子电池的影响，为了进一步保证功能粒子的作用效果，本申请在多孔基材的上表面和下表面设置涂覆层，使得功能粒子有效封装在多孔基材的内部，涂覆层的材料也可依据现有技术进行选择，例如聚合物颗粒或陶瓷。本申请提供的隔膜，由于其内部含有功能粒子，功能粒子外层的-NH-或-NH 2基团可有效吸附锂离子电池内部的酸性物质，降低锂离子电池中的酸含量，从而减轻酸性物质的影响；同时，功能粒子外层的亲水基团可提高电解液的浸润性，增加锂离子通道，提高隔膜的保液率，因此，本发明提供的隔膜可提高锂离子电池的循环性能和安全性能。此外，由于功能粒子填充在多孔基材的内部孔隙中，并不会增加隔膜的厚度，因此对锂离子电池的能量密度不会造成太大的影响。
在一种具体实施方式中，所述多孔基材的平均孔径为D1，所述功能粒子的Dv50为D2，所述涂覆层的材料的Dv50为D3，其中，1.2*D2<D1<0.8*D3。
进一步地，所述涂覆层的材料的Dv50小于等于1μm。
本申请中的多孔基材可选择现有技术中常见的聚合物隔膜，具体地，所述多孔基材可以为聚乙烯、聚丙烯、聚偏氟乙烯、芳纶、聚对苯二甲酸乙二醇酯、聚四氟乙烯、聚丙烯腈、聚酰亚胺、聚酰胺、聚酯、和天然纤维中的一种或多种。
本申请中涂覆层的材料也可依据现有技术进行选择，例如所述涂覆层的材料为聚合物颗粒或陶瓷中的一种或两种。
经研究发现，涂覆层厚度过低，无法起到预期的效果；涂覆层厚度过高，则会增加隔膜的厚度和重量，不利于锂离子电池的能量密度，因此所述涂覆层的厚度为0.1-6μm。
进一步地，所述功能粒子为外层包括-NH-或-NH 2基团的氧化物，功能粒子含有C、H、O、N、Si等元素，所述功能粒子通过包括以下过程的制备方法得到：
将外层带羟基的氧化物接枝含氯硅烷后，再与含-NH-或-NH 2的有机物反 应得到所述功能粒子。
本申请提供的功能粒子为外层包括-NH-或-NH 2基团的氧化物，具体地，首先选择外层带羟基的无机氧化物为底物，对于大多数无机氧化物来说，外层均含有羟基，本领域技术人员可直接进行下一步处理，或者也可以对无机氧化物进行酸处理，提高其外层的羟基的含量，例如当氧化物为SiO 2时，可首先对其进行酸处理提高SiO 2外层的羟基含量；其次，待外层带羟基的氧化物与含氯硅烷反应，反应结束后，再将反应产物与含-NH-或-NH 2的有机物反应，得到该功能粒子，为了表述方便，使用含-NH-或-NH 2的有机物-氧化物表示该功能粒子，例如PEI-SiO 2，即该功能粒子中氧化物为SiO 2，有机物为PEI(聚乙烯亚胺)。
进一步地，所述氧化物为Al的氧化物、AlOOH、Si的氧化物、Ti的氧化物、Zn的氧化物、Mg的氧化物、Ni的氧化物、Zr的氧化物、Ca的氧化物、Ba的氧化物中的一种或多种。
所述含-NH-或-NH 2的有机物为多元胺类化合物及其衍生物。
具体地，所述含-NH-或-NH 2的有机物为己二胺(Hexamethylene diamine，HMDA)、对苯二胺(p-Phenylenediamine，PDA)、甲基间苯二胺(N-Methyl-m-phenylenediamine，MPDA)、二乙烯三胺(Diethylenetriamine，DETA)、三乙烯四胺(Triethylenetetramine，TETA)、聚间氨基苯乙烯、聚乙烯亚胺(Polyethyleneimine，PEI)、十六胺(1-Hexadecylamine，HDA)中的一种或多种。
以PEI-SiO 2为例，所述功能粒子的制备方法包括：
首先将氧化物SiO 2加入到HNO 3溶液中进行酸处理，以提高SiO 2外层的羟基含量；其次，在酸化后的SiO 2中加入一定量的甲苯，并在N 2保护下，继续缓慢加入甲苯和含氯硅烷，例如：3-氯丙基三乙氧基硅烷，反应结束后经抽滤、干燥后得到接枝含氯硅烷的二氧化硅；最后，将得到的接枝含氯硅烷的二氧化硅加入到甲醇和聚乙烯亚胺(PEI)的水溶液中，搅拌回流后终止反应，经抽滤、洗涤、干燥后即可得到该功能粒子PEI-SiO 2。
在制备得到功能粒子和选择多孔基材和涂覆层的材料后，可依据现有技术制备得到本申请提供的隔膜，具体包括以下步骤：
将所述多孔基材与含有所述功能粒子的分散体系接触，使所述功能粒子填充至所述多孔基材的内部孔隙中，随后在所述多孔基材的上表面和下表面 设置涂覆层，得到所述隔膜。
本申请提供的制备方法中，首先，制备得到功能粒子的分散体系，其次将功能粒子填充至多孔基材的内部孔隙中，例如将多孔基材浸泡在含有功能粒子的分散体系中，或者通过喷洒的方式，使功能粒子进入多孔基材隔膜的内部孔隙中，最后依据现有技术将涂覆层材料涂布在多孔基材的上表面和下表面即可得到该隔膜。
具体在制备过程中，通常可将功能粒子溶于溶剂中得到含功能粒子的分散体系，并且申请人研究发现，当分散体系的固含小于0.1％时，填充至多孔基材内部孔隙中的功能粒子含量较低，且溶剂过多不利于后续溶剂的挥发；当分散体系的固含高于10％时，则功能粒子在多孔基材内部孔隙中分布难以均匀，可能会导致功能粒子的堵塞，因此，在制备过程中，需控制功能粒子的分散体系的固含为0.1％-10％。
此外，分散体系中使用的溶剂为非水液体，并且需要注意溶剂的沸点应当在60-99℃(0.1MPa条件下测定)之内，当溶剂的沸点低于60℃时，溶剂在室温下极易挥发，不利于操作，也可能会导致功能粒子的聚集堆积；当溶剂的沸点高于99℃时，不利于后续溶剂的挥发，难以将溶剂挥发完全。
由于活性层中正极活性物质都是含有氧元素的极性无机物，因此非水液体的极性以及介电常数要在合适的范围，当非水液体的介电常数低于10时，非水液体的极性太弱，难以和活性物质形成有效润湿；当介电常数高于40时，溶剂的极性太强，可能含有羧酸等强极性基团，这些强极性基团容易和正极活性物质发生反应，因此，溶剂在室温下的介电常数应当为10-40。
可以理解的是，溶剂不能与功能粒子发生反应。
具体的，溶剂可以为己烷，四氢呋喃，三氟代乙酸，1,1,1-三氯乙烷，四氯化碳，乙酸乙酯，丁酮，苯，乙腈，1,2-二氯乙烷，甲醇，乙醇，乙二醇二甲醚，三氯乙烯，三乙胺，丙腈，庚烷中的一种或多种。
烘干溶剂可采用减压烘干或鼓风加热的方法，本领域技术人员可依据现有技术选择适当的方法。
为了进一步提高隔膜的性能，申请人研究发现当多孔基材的孔隙率低于20％时，隔膜的吸液性能较差，导致锂离子传导通道拥堵，从而影响锂离子电池的动力学性能；当多孔基材的孔隙率高于90％时，隔膜的机械性能会变差，降低锂离子电池的制备良率，例如卷绕工序，因此，所述多孔基材的孔 隙率为20％-90％。
所述多孔基材孔隙率的测定方法为：将隔膜裁剪出一定的面积，在80℃真空干燥箱中烘干2h，取出置于干燥器中冷却后再测试。先使用万分尺测量样品的厚度，根据样品表面积和厚度来计算样品的表观体积，记为V1；再使用AccuPycⅡ真密度仪测得隔膜的真实体积，记为V2；可以得出：多孔基材的孔隙率＝100％×(V1-V2)/V1。
所述隔膜的透气度(Gurley)为120s-600s。透气性是表征隔膜气体透过能力的一个指标，能够间接地反映离子的透过性，使用Gurley值作为评判标准，即将隔膜至于透气度检测仪内，一定体积的空气在一定压力下透过规定面积隔膜的时间。这里采用隔膜行业的日本工业标准，即在1.22kPa压力下测试100ml空气通过1平方英寸隔膜所需要的时间，采用Gurley 4110N型透气度检测仪进行检测。
综上，本发明提供了一种隔膜，由于其内部含有功能粒子，功能粒子外层的-NH-或-NH 2基团可有效吸附锂离子电池内部的酸性物质，降低锂离子电池中的酸含量，从而减轻酸性物质的影响，同时，功能粒子外层的亲水基团可提高电解液的浸润性，增加锂离子通道，提高隔膜的保液率，因此，本发明提供的隔膜可提高锂离子电池的循环性能和安全性能。此外，由于功能粒子填充在多孔基材的内部孔隙中，并不会增加隔膜的厚度，因此对锂离子电池的能量密度不会造成太大的影响。
本发明第二方面提供了一种上述任一所述隔膜的制备方法，包括以下步骤：
将所述多孔基材与含有所述功能粒子的分散体系接触，随后在所述多孔基材的上表面和下表面设置涂覆层，得到所述隔膜。
本申请提供的制备方法中，首先，制备得到功能粒子的分散体系，其次将功能粒子填充至多孔基材的内部孔隙中，例如将多孔基材浸泡在功能粒子的分散体系中，或者通过喷洒的方式，使功能粒子进入多孔基材隔膜的内部孔隙中，最后依据现有技术将涂覆层材料涂布在多孔基材的上表面和下表面即可得到该隔膜。本申请提供的制备方法制备成本较低，有利于降低制备成本和大规模生产。
本发明第三方面提供了一种锂离子电池，包括上述任一所述的隔膜。
本发明第三方面提供了一种锂离子电池，在本发明提供的隔膜的基础上， 本领域技术人员可依据现有技术，搭配正极极片、负极极片以及电解液制备得到锂离子电池。本发明提供的锂离子电池，由于其隔膜中含有功能粒子，功能粒子外层的-NH-或-NH 2基团可有效吸附锂离子电池内部的酸性物质，降低锂离子电池中的酸含量，从而减轻酸性物质的影响，同时，功能粒子外层的亲水基团可提高电解液的浸润性，增加锂离子通道，提高隔膜的保液率，因此，本发明提供锂离子电池具有较好的循环性能和安全性能。
本发明的实施，至少具有以下优势：
1、本申请提供的隔膜，由于其内部含有功能粒子，功能粒子外层的-NH-或-NH 2基团可有效吸附锂离子电池内部的酸性物质，降低锂离子电池中的酸含量，从而减轻酸性物质的影响，同时，功能粒子外层的亲水基团可提高电解液的浸润性，增加锂离子通道，提高隔膜的保液率，因此，本发明提供的隔膜可提高锂离子电池的循环性能和安全性能。此外，由于功能粒子填充在多孔基材的内部孔隙中，并不会增加隔膜的厚度，因此对锂离子电池的能量密度不会造成太大的影响。
2、本申请在多孔基材的上表面和下表面设置涂覆层，使得功能粒子有效封装在多孔基材的内部，保证了锂离子电池的循环性能。
3、本发明提供的制备方法成本较低，适合大规模生产。
4、本发明提供的锂离子电池具有较好的循环性能和安全性能。
具体实施方式
为使本发明的目的、技术方案和优点更加清楚，下面将结合本发明的实施例，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
以下各实施例中，多孔基材为Celgard 2320隔膜(厚度为20μm，Gurley值为530s，孔隙率为39％，平均孔径为27nm，面密度为10g/m 2)；涂覆层材料购自阿科玛试剂有限公司；制备功能粒子所需的化学试剂均购自alfa-aesar 试剂有限公司；孔径通过孔径分析仪PMI CFP-1500AE测试得到。
实施例1
本实施例提供的隔膜包括多孔基材、功能粒子和涂覆层，其中：
功能粒子为PEI-SiO 2，Dv50为20nm，面密度为0.2g/m 2；
涂覆层的材料为PVDF-HFP，Dv50为105nm，设置在多孔基材上表面和下表面的涂覆层的厚度均为1μm；
隔膜的透气度为620s。
其中，功能粒子的制备方法包括：
1、将15g纳米二氧化硅(Dv50＝20nm)加入到125mL的HNO 3溶液中，在60℃下搅拌6h，减压抽滤，用去离子水洗涤至中性，晾干后得到活化二氧化硅，其中HNO 3溶液的浓度为1mol/L；
2、称量2g活化二氧化硅并加入80mL甲苯，N 2保护下，在100℃条件下搅拌，再缓慢加入70mL甲苯和5mL的3-氯丙基三乙氧基硅烷，反应48h，随后经抽滤、甲醇索氏提取6h、抽滤、50℃真空干燥12h后得到接枝含氯硅烷的二氧化硅。
3、称量1g接枝含氯硅烷的二氧化硅并加入100mL甲醇，升温至60℃，再加入5mL 50％的聚乙烯亚胺(PEI)水溶液，搅拌回流24h后终止反应，经抽滤、洗涤至中性后再50℃真空干燥12h得到功能粒子PEI-SiO 2；
其中洗涤依次使用去离子水、1mol/L的硫酸、去离子水、1mol/L的氨水、去离子水洗涤至中性，最后再用甲醇洗涤。
本实施例提供的隔膜制备方法包括：
将上述方法得到的功能粒子溶于无水乙醇中得到含有功能粒子的分散体系，并将多孔基材浸泡在含有功能粒子的分散体系中，使功能粒子进入基材隔膜的内部孔隙，随后在多孔基材的上表面和下表面设置涂覆层PVDF-HFP，得到隔膜。
实施例2
本实施例提供的隔膜包括多孔基材、功能粒子和涂覆层，其中：
功能粒子为PEI-Al 2O 3，Dv50为10nm，面密度为0.1g/m 2；
涂覆层的材料为PVDF-HFP，Dv50为40nm，设置在多孔基材上表面和 下表面的涂覆层的厚度均为0.1μm；
隔膜的透气度为570s。
本实施例的功能粒子PEI-Al 2O 3的制备方法包括：
1、称取2g纳米Al 2O 3(Dv50为10nm)加入50mL甲苯，在N 2保护下105℃边搅拌边加入50mL甲苯与10mL的3-氯丙基三乙氧基硅烷，反应12h，经抽滤、甲醇索氏提取3h、抽滤、80℃真空干燥24h后得到接枝含氯硅烷的Al 2O 3；
2、称取2g接枝含氯硅烷的Al 2O 3并加入150mL甲醇，升温至70℃，再加入5mL 50％的聚乙烯亚胺(PEI)水溶液，搅拌回流6h后终止反应，并经抽滤、洗涤至中性后在80℃真空干燥12h后得到PEI-Al 2O 3，其中洗涤过程依次使用去离子水、0.01mol/L的硫酸、去离子水、0.5mol/L的氨水、去离子水、甲醇。
本实施例中隔膜的制备方法与实施例1类似，区别在于使用材料不同。
实施例3
本实施例提供的隔膜包括多孔基材、功能粒子和涂覆层，其中：
功能粒子为PEI-TiO 2，Dv50为5nm，面密度为0.05g/m 2；
涂覆层的材料为PVDF-HFP，Dv50为1000nm，设置在多孔基材上表面和下表面的涂覆层的厚度均为6μm；
隔膜的透气度为650s。
本实施例的功能粒子的制备方法可参考实施例2，区别在于所使用的氧化物为TiO 2(Dv50为5nm)。
本实施例中隔膜的制备方法与实施例1类似，区别在于使用材料不同。
实施例4
本实施例提供的隔膜包括多孔基材、功能粒子和涂覆层，其中：
功能粒子为HDA-AlOOH，Dv50为10nm，面密度为0.1g/m 2；
涂覆层的材料为PVDF-HFP/AlOOH(质量比1:1)，PVDF-HFP的Dv50为600nm，AlOOH的Dv50为450nm，设置在多孔基材上表面和下表面的涂覆层的厚度均为2μm；
隔膜的透气度为580s。
本实施例的功能粒子的制备方法可参考实施例2，区别在于所使用的含-NH-或-NH 2的有机物为HDA，所使用的氧化物为AlOOH(Dv50为10nm)。
本实施例中隔膜的制备方法与实施例1类似，区别在于使用材料不同。
对比例1
本对比例提供的隔膜包括多孔基材。
对比例2
本对比例提供的隔膜包括多孔基材和双面涂覆层，其中：
涂覆层的材料为PVDF-HFP，Dv50为105nm，设置在多孔基材上表面和下表面的涂覆层的厚度均为1μm。
本发明进一步将上述实施例1-4和对比例1-2提供的隔膜制备成锂离子电池，具体制备方法包括：
将正极极片、隔膜、负极极片依次叠放，隔膜处于正极极片和负极极片中间，然后卷绕成厚度为35mm、宽度为50mm、长度为75mm的裸电芯。将裸电芯装入铝塑膜包装袋，在75℃下真空烘烤10h，注入电解液、经过真空封装、静置24h之后用0.05C的恒定电流充电至3.75V，然后以0.2C充电到4.4V恒压充电至电流下降到0.05C，然后以0.2C的恒定电流放电至3V，最后以1C的恒定电流充电至3.8V，即完成锂离子电池的制备。
其中，正极极片的制备方法包括：
将正极活性物质(LCO)、导电剂乙炔黑(SP)、粘结剂聚偏氟乙烯(PVDF)混合，三者混合的重量比为97：1.5：1.5，加入溶剂N-甲基吡咯烷酮，混合搅拌均匀后得到正极浆料；随后将正极浆料均匀的涂覆在正极集流体铝箔的上表面和下表面上，在120℃下烘干，得到正极极片。
负极极片的制备方法包括：
将负极活性物质人造石墨、导电剂乙炔黑(SP)、粘结剂丁苯橡胶(SBR)、增稠剂羧甲基纤维素钠(CMC)按照重量比96：1：1.5：1.5混合，加入溶剂去离子水，搅拌混合均匀后得到负极浆料；将上述负极浆料均匀涂覆在负极集流体铜箔的上表面和下表面上，在90℃下烘干后，进行冷压、切边、裁片、分条、110℃真空条件下干燥4h，得到负极极片。
电解液的制备方法包括：
将碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)和碳酸乙烯酯(EC)按照质量比2:1:1混合得到电解液，然后加入电解质盐，电解液中六氟磷酸锂浓度为1mol/L。
本申请对实施例1-4以及对比例1-2基础上得到的锂离子电池的容量保持率以及高温存储产气性能进行测试，测试结果见表1：
其中，锂离子电池的高温循环容量保持率的测试方法包括：
在60℃恒温箱中，以1C倍率横流充电至电压为4.4V，之后以4.3V恒压充电至电流为0.05C，然后以1C倍率恒定电流放电至电压为3.0V，得到的放电容量记为该第一个循环所测试的电池容量C1，如此反复得到第500圈循环容量分别为Cn。
第500圈循环容量对应的容量保持率＝100％*Cn/C1。
锂离子电池的高温存储产气的测试方法包括：
将每组实施例和对比例提供的锂离子电池各取6块，在常温下以0.2C倍率的恒定电流充电至电压高于4.4V，进一步在4.4V恒定电压下充电至电流低于0.05C，使其处于4.4V满充状态。测试存储前的满充电池内压并记为P1。再将满充状态的电池置于85℃烘箱存储15天后取出，冷却电芯1小时后测试电芯存储后的内压并记为Pn。
根据公式：△P＝Pn-P1，计算电池存储前后的压力变化值。
表1 实施例1-4和对比例1-2提供的锂离子电池的性能测试结果
  容量保持率(％) 高温存储产气(MPa)
实施例1 94.6 0.19
实施例2 93.7 0.24
实施例3 93.2 0.27
实施例4 93.9 0.25
对比例1 89.5 0.36
对比例2 92.1 0.34
由表1可知，实施例1-4提供的锂离子电池的容量保持率均高于对比例1-2，且高温存储产气变化值也低于对比文件1-2，可见本申请提供的隔膜，可有效提高锂离子电池的循环性能和安全性能。
最后应说明的是：以上各实施例仅用以说明本发明的技术方案，而非对其限制；尽管参照前述各实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的范围。

Claims (10)

  1. 一种隔膜，其特征在于，所述隔膜包括多孔基材、功能粒子和涂覆层，所述功能粒子填充在所述多孔基材的内部孔隙中，所述涂覆层设置在所述多孔基材的上表面和下表面；
    其中，所述功能粒子为外层包括-NH-或-NH 2基团的氧化物。
  2. 根据权利要求1所述的隔膜，其特征在于，所述多孔基材的平均孔径为D1，所述功能粒子的Dv50为D2，所述涂覆层的材料的Dv50为D3，其中，1.2*D2<D1<0.8*D3。
  3. 根据权利要求1或2所述的隔膜，其特征在于，所述功能粒子通过包括以下过程的制备方法得到：
    将外层带羟基的氧化物接枝含氯硅烷后，再与含-NH-或-NH 2的有机物反应得到所述功能粒子。
  4. 根据权利要求3所述的隔膜，其特征在于，所述氧化物为Al的氧化物、AlOOH、Si的氧化物、Ti的氧化物、Zn的氧化物、Mg的氧化物、Ni的氧化物、Zr的氧化物、Ca的氧化物、Ba的氧化物中的一种或多种。
  5. 根据权利要求3所述的制备方法，其特征在于，所述含-NH-或-NH 2的有机物为多元胺类化合物及其衍生物。
  6. 根据权利要求5所述的制备方法，其特征在于，所述含-NH-或-NH 2的有机物为己二胺、对苯二胺、甲基间苯二胺、二乙烯三胺、三乙烯四胺、聚间氨基苯乙烯、聚乙烯亚胺、十六胺中的一种或多种。
  7. 根据权利要求1-6任一项所述的隔膜，其特征在于，所述多孔基材为聚乙烯、聚丙烯、聚偏氟乙烯、芳纶、聚对苯二甲酸乙二醇酯、聚四氟乙烯、聚丙烯腈、聚酰亚胺、聚酰胺、聚酯、和天然纤维中的一种或多种。
  8. 根据权利要求1-7任一项所述的隔膜，其特征在于，所述涂覆层的材料为聚合物颗粒或陶瓷中的一种或两种。
  9. 根据权利要求1-8任一项所述的隔膜，其特征在于，通过包括以下过程的制备方法得到：
    将所述多孔基材与含有所述功能粒子的分散体系接触，随后在所述多孔基材的上表面和下表面设置涂覆层，得到所述隔膜。
  10. 一种锂离子电池，其特征在于，包括权利要求1-9任一项所述的隔膜。
PCT/CN2021/108696 2020-07-27 2021-07-27 一种隔膜及其应用 WO2022022519A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US18/147,220 US20230134434A1 (en) 2020-07-27 2022-12-28 Separator, preparation method and battery

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010731437.8A CN111900313A (zh) 2020-07-27 2020-07-27 一种隔膜及其应用
CN202010731437.8 2020-07-27

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/147,220 Continuation US20230134434A1 (en) 2020-07-27 2022-12-28 Separator, preparation method and battery

Publications (1)

Publication Number Publication Date
WO2022022519A1 true WO2022022519A1 (zh) 2022-02-03

Family

ID=73189636

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/108696 WO2022022519A1 (zh) 2020-07-27 2021-07-27 一种隔膜及其应用

Country Status (3)

Country Link
US (1) US20230134434A1 (zh)
CN (1) CN111900313A (zh)
WO (1) WO2022022519A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111900313A (zh) * 2020-07-27 2020-11-06 珠海冠宇电池股份有限公司 一种隔膜及其应用

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106299199A (zh) * 2016-08-22 2017-01-04 深圳市星源材质科技股份有限公司 一种锂电池隔膜的制备方法
CN109411670A (zh) * 2017-08-17 2019-03-01 宁德时代新能源科技股份有限公司 一种隔离膜，其制备方法及使用该隔离膜的二次电池
CN109950452A (zh) * 2019-02-21 2019-06-28 威海星宜新材料科技有限公司 一种锂离子电池陶瓷涂布隔膜及其制备方法
CN111029514A (zh) * 2019-11-14 2020-04-17 珠海冠宇电池有限公司 一种隔膜及包括该隔膜的高电压电池
CN111384345A (zh) * 2020-03-20 2020-07-07 中航锂电技术研究院有限公司 隔膜、制备方法及包含它的锂离子电池
CN111900313A (zh) * 2020-07-27 2020-11-06 珠海冠宇电池股份有限公司 一种隔膜及其应用

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105958000B (zh) * 2016-07-11 2019-05-03 东莞市魔方新能源科技有限公司 一种锂离子电池复合隔膜及其制备方法
CN109935769A (zh) * 2018-12-29 2019-06-25 深圳中兴新材技术股份有限公司 一种耐电解液陶瓷涂层隔膜及其制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106299199A (zh) * 2016-08-22 2017-01-04 深圳市星源材质科技股份有限公司 一种锂电池隔膜的制备方法
CN109411670A (zh) * 2017-08-17 2019-03-01 宁德时代新能源科技股份有限公司 一种隔离膜，其制备方法及使用该隔离膜的二次电池
CN109950452A (zh) * 2019-02-21 2019-06-28 威海星宜新材料科技有限公司 一种锂离子电池陶瓷涂布隔膜及其制备方法
CN111029514A (zh) * 2019-11-14 2020-04-17 珠海冠宇电池有限公司 一种隔膜及包括该隔膜的高电压电池
CN111384345A (zh) * 2020-03-20 2020-07-07 中航锂电技术研究院有限公司 隔膜、制备方法及包含它的锂离子电池
CN111900313A (zh) * 2020-07-27 2020-11-06 珠海冠宇电池股份有限公司 一种隔膜及其应用

Also Published As

Publication number Publication date
US20230134434A1 (en) 2023-05-04
CN111900313A (zh) 2020-11-06

Similar Documents

Publication Publication Date Title
WO2016107564A1 (zh) 一种高倍率性能锂硫电池的复合正极材料及制备方法
CN107959049B (zh) 凝胶电解质的制备方法、凝胶电解质及锂离子电池
WO2022041702A1 (zh) 一种凝胶电解质前驱体及其应用
CN110660959B (zh) 正极极片及钠离子电池
CN109659500B (zh) 降低固态电解质/锂负极界面阻抗的锂片、制备方法及应用
CN111653717A (zh) 一种复合隔膜的制备方法、复合隔膜和锂离子电池
CN109075324A (zh) 负极和用于制备负极的方法
CN103545523A (zh) 一种多孔炭微球、制备方法及锂离子电池负极材料
CN106941174B (zh) 一种氮掺杂硅炭复合负极材料及其制备方法
CN115954616B (zh) 一种基于mof材料的涂层隔膜及其制备方法
CN114464908B (zh) 用于锂离子电池的三维多孔涂层及其制备和应用
CN109920991A (zh) 三元正极材料及其制备方法及包含该材料的锂离子电池
WO2020107287A1 (zh) 多孔复合隔膜，其制备方法和包含其的锂离子电池
CN105322145A (zh) 一种磷酸铁锰锂/石墨烯/碳复合材料及制备方法和应用
US20230134434A1 (en) Separator, preparation method and battery
CN114649560A (zh) 一种Zn-MOF/PAN@PAN复合隔膜材料及其制备方法和应用
CN114420995A (zh) 一种基于三维有序多孔碳光晶的富硒锂硒电池及其制备方法
CN114551789A (zh) 电化学装置以及电子装置
CN112467138B (zh) 一种铝掺杂多孔硅碳复合材料的制备方法、锂离子电池
CN105789574B (zh) 一种高温型锂离子电池石墨负极材料的制备方法
CN114665146A (zh) 电化学装置、电子装置和制备负极极片的方法
CN114824206A (zh) 一种长寿命高首效硬碳复合材料及其制备方法
CN107814964A (zh) 一种水性浆料及制备方法、电池隔膜与锂离子电池
CN109088055B (zh) 硫锂电池
CN112563669A (zh) 一种高浸润性隔膜及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21848555

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 09.06.2023)

122 Ep: pct application non-entry in european phase

Ref document number: 21848555

Country of ref document: EP

Kind code of ref document: A1