WO2024174066A1 - Séparateur, batterie secondaire et dispositif alimenté - Google Patents

Séparateur, batterie secondaire et dispositif alimenté Download PDF

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Publication number
WO2024174066A1
WO2024174066A1 PCT/CN2023/077202 CN2023077202W WO2024174066A1 WO 2024174066 A1 WO2024174066 A1 WO 2024174066A1 CN 2023077202 W CN2023077202 W CN 2023077202W WO 2024174066 A1 WO2024174066 A1 WO 2024174066A1
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WO
WIPO (PCT)
Prior art keywords
optionally
barrier layer
diaphragm
negative electrode
positive electrode
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PCT/CN2023/077202
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English (en)
Chinese (zh)
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WO2024174066A9 (fr
Inventor
彭畅
陈培培
吴得贵
黄雨铭
刘姣
Original Assignee
宁德时代新能源科技股份有限公司
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Priority to PCT/CN2023/077202 priority Critical patent/WO2024174066A1/fr
Publication of WO2024174066A1 publication Critical patent/WO2024174066A1/fr
Publication of WO2024174066A9 publication Critical patent/WO2024174066A9/fr

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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
    • 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
    • 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 present application belongs to the technical field of secondary batteries, and specifically relates to a diaphragm, a secondary battery and an electrical device.
  • Secondary batteries are widely used in various consumer electronic products and electric vehicles due to their outstanding features such as light weight, no pollution, and no memory effect. With the continuous development of the new energy industry, users have put forward higher requirements for the use of secondary batteries. For example, high energy density, longer cycle life, and greater environmental adaptability; however, under conditions such as high energy density design, long cycle, and high temperature, the electrodes are often severely damaged, causing battery capacity decay.
  • the present application provides a diaphragm, a secondary battery and an electrical device, aiming to reduce the damage to the electrodes and reduce the battery capacity attenuation.
  • a first aspect of the present application provides a membrane, comprising a barrier layer, wherein the barrier layer comprises a polymer layer and a barrier material at least partially embedded in the polymer layer;
  • the barrier material includes one or more of a micro-mesoporous material and an ion-conducting inorganic material; the volume average particle size Dv50 of the barrier material is denoted as D, the thickness of the barrier layer is denoted as d1, and the volume average particle size Dv50 of the barrier material and the thickness of the barrier layer satisfy: 0.2 ⁇ d1/D ⁇ 1000;
  • the air permeability of the barrier layer is ⁇ 300s/100mL.
  • the present application at least has the following beneficial effects:
  • the diaphragm of the present application includes a barrier layer, which includes a polymer layer and a barrier material.
  • a barrier layer which includes a polymer layer and a barrier material.
  • the air permeability of the barrier layer is ⁇ 300s/100mL. It is more difficult for gas to pass through the barrier layer, indicating that most of the pores in the polymer layer have been filled with the barrier material; compared with gas, the solvent, additive and interface reaction by-products in the positive electrode electrolyte and the negative electrode electrolyte are more difficult to pass through the barrier layer. Only lithium ions can penetrate the barrier layer through the barrier material, which greatly inhibits the solvent, additive and by-product in the electrolyte from passing through the barrier layer, eliminating the battery capacity decay caused by the interaction between the positive and negative electrodes.
  • the air permeability of the barrier layer is ⁇ 500s/100mL; optionally, the air permeability of the barrier layer is ⁇ 800s/100mL.
  • the volume average particle size Dv50 of the barrier material and the thickness of the barrier layer satisfy: 1 ⁇ d1/D ⁇ 500; optionally 1 ⁇ d1/D ⁇ 300.
  • the volume average particle size Dv50 of the barrier material satisfies: 0.005 ⁇ m ⁇ D ⁇ 10 ⁇ m; optionally 0.007 ⁇ m ⁇ D ⁇ 5 ⁇ m; further optionally 0.01 ⁇ m ⁇ D ⁇ 1 ⁇ m.
  • the thickness of the barrier layer satisfies: 0.007 ⁇ m ⁇ d1 ⁇ 50 ⁇ m; optionally, 0.2 ⁇ m ⁇ d1 ⁇ 15 ⁇ m.
  • the micro-mesoporous material comprises one or more of a covalent organic framework material and a metal organic framework material;
  • the ion-conducting inorganic material includes LLZO, LLTO, LATP, LAGP, LSPS, and one or more of coatings, dopants and/or dopants with coating layers of the above substances.
  • the pore size of the internal pores of the micro-mesoporous material is denoted as d2, and the pore size of the internal pores of the micro-mesoporous material satisfies: 0.04nm ⁇ d2 ⁇ 5nm; optionally, 0.3nm ⁇ d2 ⁇ 2nm.
  • the conductivity of the ion-conducting inorganic material is ⁇ 0.0001 mS ⁇ cm -1 at 25°C;
  • the electrical conductivity of the ion-conducting inorganic material is ⁇ 0.001 mS ⁇ cm -1 at 25° C.;
  • the electrical conductivity of the ion-conducting inorganic material is ⁇ 0.01 mS ⁇ cm ⁇ 1 .
  • the area proportion of the barrier material in the barrier layer is 30%-99%; optionally 50%-99%; further optionally 70%-99%.
  • the polymer layer has at least one of the following features (1)-(3):
  • the polymer layer comprises a polymer having a swelling degree ⁇ 10%
  • the polymer includes one or more of polyethylene, polypropylene, polyimide and polyvinylidene fluoride;
  • the mass proportion of the polymer layer in the barrier layer is ⁇ 50%
  • the mass of the polymer layer in the barrier layer is 2%-30%; further optionally, 5%-15%;
  • the polymer layer comprises a polymer having a weight average molecular weight of 1W-200W;
  • the polymer layer comprises a polymer having a weight average molecular weight of 2W-150W;
  • the polymer layer includes a polymer with a weight average molecular weight of 10W-100W.
  • the diaphragm further comprises a supporting layer, and the barrier layer is located on at least one side of the supporting layer.
  • the support layer has at least one of the following features (1)-(3):
  • the support layer has pores, and the average pore size of the pores of the support layer is 20nm-1000nm; optionally 100nm-500nm;
  • the material of the support layer includes one or more of polyethylene, polypropylene, polyimide and polyvinylidene fluoride.
  • the thickness of the diaphragm is 2 ⁇ m-12 ⁇ m; optionally 3 ⁇ m-10 ⁇ m; further optionally 5 ⁇ m-7 ⁇ m.
  • the diaphragm has at least one of the following features:
  • the air permeability of the diaphragm is ⁇ 300s/100mL; optionally, the air permeability of the diaphragm is ⁇ 500s/100mL; further optionally, the air permeability of the diaphragm is ⁇ 800s/100mL;
  • the tensile strength of the diaphragm is ⁇ 1000 MPa; optionally, the tensile strength of the diaphragm is ⁇ 1200 MPa; further optionally, the tensile strength of the diaphragm is ⁇ 1500 MPa.
  • the second aspect of the present application provides a secondary battery, comprising a positive electrode sheet, a negative electrode sheet, a positive electrode electrolyte, a negative electrode electrolyte, and a separator as described in the first aspect of the present application;
  • the isolation membrane is located between the positive electrode plate and the negative electrode plate, the positive electrode electrolyte is located between the positive electrode plate and the isolation membrane, and the negative electrode electrolyte is located between the negative electrode plate and the isolation membrane; one or more of the solvents, lithium salts and additives contained in the positive electrode electrolyte and the negative electrode electrolyte are different.
  • the solvent of the positive electrode electrolyte is different from the solvent of the negative electrode electrolyte
  • the solvent of the positive electrode electrolyte includes one or more of carbonate solvents, fluorocarbonate solvents, fluorocarboxylate solvents, sulfone solvents, fluorosulfone solvents, phosphate solvents, borate solvents and nitrile solvents;
  • the solvent of the negative electrode electrolyte includes one or more of carbonate solvents, carboxylate solvents, ether solvents, fluorinated carboxylate solvents and fluorinated carbonate solvents.
  • the fluorocarbonate solvent includes one or more of methyl trifluoroethyl carbonate, di(trifluoromethyl) carbonate, di(trifluoroethyl) carbonate, 4-trifluoromethyl ethylene carbonate, bisfluoroethylene carbonate, trifluoromethyl trifluoroethyl carbonate, trifluoropropyl carbonate and 2,2-difluoroethyl methyl carbonate;
  • the fluorocarboxylic acid ester solvent includes one or more of trifluoroethyl 3,3,3-trifluoroacetate, 2,2-difluoroethyl acetate, ethyl difluoroacetate and 2,2,2-trifluoroethyl acetate;
  • the sulfone solvent includes one or more of sulfolane, dimethyl sulfone, diethyl sulfone, methyl ethyl sulfone, methyl isopropyl sulfone, dimethyl sulfoxide, diethyl sulfoxide and methyl ethyl sulfoxide;
  • the fluorinated sulfone solvent includes one or more of methyl trifluoromethyl sulfone, ethyl trifluoromethyl sulfone, propyl trifluoromethyl sulfone, methyl trifluoroethyl sulfone, methyl trifluoropropyl sulfone, 1,1,2,2-tetrafluoropropyl methyl sulfone, trifluoromethyl isopropyl sulfone and methyl hexafluoroisopropyl sulfone;
  • the phosphate ester solvent includes one or more of trimethyl phosphate, triethyl phosphate, tripropyl phosphate, isopropyl phosphate, tris(hexafluoroisopropyl) phosphate and tris(2,2,2-trifluoroethyl) phosphate;
  • the borate ester solvent includes one or more of trimethyl borate, triethyl borate, tri(hexafluoroisopropyl) borate and tri(2,2,2-trifluoroethyl) borate;
  • the nitrile solvent includes one or more of acetonitrile, succinonitrile, succinonitrile, glutaronitrile, adiponitrile, 1,4-dicyano-2-butene, 1,3,6-hexanetrinitrile, ethylene glycol dipropionitrile ether and 1,2,3-tricyanoethoxy;
  • the carbonate solvent includes one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and ethylene carbonate;
  • the carboxylate solvent includes one or more of methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and propyl propionate;
  • the ether solvent includes one or more of 1,2-dimethoxyethane, tetraethanol dimethyl ether, ⁇ -butyrolactone and tetrahydrofuran.
  • the lithium salt of the positive electrode electrolyte is different from the lithium salt of the negative electrode electrolyte
  • the lithium salt of the positive electrode electrolyte includes one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide and lithium bis(oxalatoborate);
  • the lithium salt of the negative electrode electrolyte includes lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide and dioxalatoboric acid.
  • lithium hexafluorophosphate lithium tetrafluoroborate
  • lithium bis(fluorosulfonyl)imide lithium bis(fluorosulfonyl)imide and dioxalatoboric acid.
  • One or more of lithium is lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide and dioxalatoboric acid.
  • a third aspect of the present application provides an electrical device, comprising the secondary battery of the second aspect of the present application.
  • FIG. 1 is a schematic diagram of the structure of COF-1 provided in one embodiment of the present application.
  • FIG. 2 is a schematic diagram of the structure of COF-2 provided in one embodiment of the present application.
  • FIG3 is a schematic diagram of the COF-3 structure provided in one embodiment of the present application.
  • FIG. 4 is a schematic diagram of the structure of COF-4 provided in one embodiment of the present application.
  • FIG. 5 is a schematic diagram of the structure of COF-5 provided in one embodiment of the present application.
  • FIG. 6 is a schematic diagram of the structure of COF-6 provided in one embodiment of the present application.
  • FIG. 7 is a schematic diagram of the structure of COF-7 provided in one embodiment of the present application.
  • FIG. 8 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 9 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 8 .
  • FIG. 10 is a schematic diagram of an electric device using a secondary battery according to an embodiment of the present application as a power source.
  • any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and any upper limit can be combined with any other upper limit to form an unspecified range.
  • each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.
  • “Scope” disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range.
  • the scope limited in this way can be including end values or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.
  • the numerical range "a-b" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers.
  • the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application represent open-ended or closed-ended expressions.
  • the “include” and “comprising” may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive. That is, the phrase “A or (or) B” means “A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
  • the terms used in this application have the well-known meanings commonly understood by those skilled in the art.
  • the numerical values of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the embodiments of this application).
  • the compatibility of some electrolyte components with the positive and negative electrodes is often different. They may have a positive effect on one side and a side effect on the other side. In order to balance the two, the electrolyte design has gradually become more complicated, which limits the personalized design of the battery and also increases the cost of the battery. In order to take into account both the positive and negative electrodes, the solvents and lithium salts that can be selected for the electrolyte are very limited, and the advantages of each electrolyte component cannot be brought into play.
  • the diaphragm provided in the present application includes a barrier layer, which includes a polymer layer and a barrier material at least partially embedded in the polymer layer; wherein the barrier material includes one or more of a micro-mesoporous material and an ion-conducting inorganic material; the volume average particle size Dv50 of the barrier material is denoted as D, and the thickness of the barrier layer is denoted as d1; the volume average particle size Dv50 of the barrier material and the thickness of the barrier layer satisfy: 0.2 ⁇ d1/D ⁇ 1000; the air permeability of the barrier layer is ⁇ 300s/100mL.
  • the barrier material mentioned in this application only allows lithium ions to pass through, while the solvent, additives and interfacial reaction by-products in the electrolyte cannot pass through.
  • the barrier material can be completely embedded in the polymer layer, in which case the thickness of the barrier layer is the same as the thickness of the polymer layer; it can also be partially embedded in the polymer layer and partially exposed outside the polymer layer, in which case the thickness of the barrier layer is the sum of the thickness of the polymer layer and the thickness of the barrier material exposed outside the polymer layer.
  • the polymer layer has a similar function to that of a substrate and can provide space to accommodate the barrier material.
  • the barrier layer may include one barrier material, or may include two or more barrier materials at the same time; when the barrier layer includes two or more barrier materials, the barrier materials may all be micro-mesoporous materials, or may all be ion-conducting inorganic materials, or may include both micro-mesoporous materials and ion-conducting inorganic materials.
  • Micro-mesoporous materials refer to materials having microporous structures and/or mesoporous structures; micropores refer to pores with a pore size less than 2nm, and mesopores refer to pores with a pore size of 2nm-50nm.
  • Ion-conducting inorganic materials refer to materials that can conduct metal ions.
  • the diaphragm of the present application includes a barrier layer, which includes a polymer layer and a barrier material.
  • a barrier layer which includes a polymer layer and a barrier material.
  • the air permeability of the barrier layer is ⁇ 300s/100mL. It is more difficult for gas to pass through the barrier layer, indicating that most of the pores in the polymer layer have been filled with the barrier material; compared with gas, the solvent, additive and interface reaction by-products in the positive electrode electrolyte and the negative electrode electrolyte are more difficult to pass through the barrier layer. Only lithium ions can penetrate the barrier layer through the barrier material, which greatly inhibits the solvent, additive and by-product in the electrolyte from passing through the barrier layer, eliminating the battery capacity decay caused by the interaction between the positive and negative electrodes.
  • the volume average particle size Dv50 of the barrier material and the thickness of the barrier layer mentioned above satisfy: 0.2 ⁇ d1/D ⁇ 1000; for example, it may be 0.2 ⁇ d1/D ⁇ 900, 0.2 ⁇ d1/D ⁇ 800, 0.2 ⁇ d1/D ⁇ 700, 0.2 ⁇ d1/D ⁇ 600, 0.2 ⁇ d1/D ⁇ 500, 0.2 ⁇ d1/D ⁇ 400, 0.2 ⁇ d1/D ⁇ 300, 0.2 ⁇ d1/D ⁇ 200, 0.2 ⁇ d1/D ⁇ 100 or 0.2 ⁇ d1/D ⁇ 50, etc.
  • d1/D When d1/D is less than the above range, the barrier layer is easy to rupture; when d1/D is greater than the above range, the barrier material particles may be stacked too closely, and the barrier material particles may have too many contact surfaces with each other, which may slow down the transmission speed of lithium ions through the barrier material and worsen the battery impedance.
  • d1/D can be 0.2, 1, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900 or 1000, etc.
  • the Dv50 of the barrier material mentioned above refers to the particle size corresponding to 50% of the barrier material in the volume distribution.
  • it can be tested by the following method: laser particle size analysis; place the barrier layer sample in deionized water, ultrasonicate for 5 minutes to ensure that the sample is completely dispersed, and then place the dispersion in the sample tank for testing to obtain the volume average particle size Dv50 of the barrier material.
  • the mass of the barrier layer can be 0.05g-2g
  • the volume of deionized water can be 10mL-20mL.
  • the thickness of the barrier layer mentioned above can be measured by the following method: first calibrate the micrometer, then place the barrier layer sample between the double anvils, gently rotate the sleeve until a sound is heard, and read and record the thickness of the barrier layer.
  • the air permeability of the barrier layer mentioned above is ⁇ 300s/100mL; optionally, the air permeability of the barrier layer is 300s/100mL-5000s/100mL; for example, it can be 300s/100mL-4500s/100mL, 300s/100mL-4000s/100mL, 300s/100mL-3500s/100mL, 300s/100mL-3000s/100mL, 300s/100mL-25 00s/100mL, 300s/100mL-2000s/100mL, 300s/100mL-1900s/100mL, 300s/100mL-1800s/100mL, 300s/100mL-1700s/100mL, 300s/100mL-1600s/100mL, 300s/10 0mL-1500s/100mL, 300s/100mL-1400s/100mL, 300s/100mL-1300s/100mL, 300s/100mL-1200s/100mL, 300s
  • the air permeability of the barrier layer can be 300s/100mL, 400s/100mL, 500s/100mL, 600s/100mL, 700s/100mL, 800s/100mL, 900s/100mL, 1000s/100mL, 1100s/100mL, 1200s/100mL, 1300s/100mL, 1400s/100mL, 1500s/100mL, 1600s/100mL, 1700s/100mL.
  • the air permeability of the above-mentioned diaphragm can be tested by the following method: spread the barrier layer flat, select a flat and oil-free position, place it on the air outlet of the air compressor, and tighten it; after the barrier layer is fixed in the work station, use the gravity of the cylinder floating on the liquid to compress the air in the cylinder. As the air passes through the sample, the cylinder will fall steadily. Measure the time required for a certain volume of air to pass through the sample, and calculate the air permeability based on this. Among them, the volume of the air column is 100CC; the test area is 6.45cm2 ; the sample area is> 6cm ⁇ 6cm.
  • the inventors of the present application have found through in-depth research that when the separator of the present application satisfies the above-mentioned design conditions and optionally satisfies one or more of the following conditions, the storage performance and cycle performance of the secondary battery can be further improved.
  • the air permeability of the barrier layer is ⁇ 500 s/100 mL; optionally, the air permeability of the barrier layer is ⁇ 800 s/100 mL.
  • the air permeability of the barrier layer is 500s/100mL-5000s/100mL; alternatively, the air permeability of the barrier layer is 800s/100mL-5000s/100mL.
  • the volume average particle size Dv50 of the barrier material and the thickness of the barrier layer satisfy: 1 ⁇ d1/D ⁇ 500; optionally 1 ⁇ d1/D ⁇ 300.
  • the volume average particle size Dv50 of the barrier material satisfies: 0.005 ⁇ m ⁇ D ⁇ 10 ⁇ m; for example, it may be 0.005 ⁇ m ⁇ D ⁇ 9 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 8 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 7 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 6 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 5 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 4 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 3 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 2 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 1 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 0.5 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 0.1 ⁇ m, 0.005 ⁇ m ⁇ D ⁇ 0.01 ⁇ m, etc.
  • the barrier material particles When the volume average particle size Dv50 of the barrier material is lower than the above range, the barrier material particles may be stacked too tightly, and there may be too many contact surfaces between the barrier material particles, which may slow down the transmission rate of lithium ions through the barrier material.
  • the volume average particle size Dv50 of the barrier material is within the above range, the possibility of lithium ions penetrating the diaphragm through the barrier material is high, and the contact surface between the barrier material particles can be reduced, reducing the impact on the lithium ion transmission rate.
  • the volume average particle size Dv50 of the barrier material can be 0.005 ⁇ m, 0.01 ⁇ m, 0.05 ⁇ m, 0.1 ⁇ m, 0.5 ⁇ m, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m or 10 ⁇ m, etc.
  • the volume average particle size Dv50 of the barrier material satisfies: 0.007 ⁇ m ⁇ D ⁇ 5 ⁇ m.
  • the volume average particle size Dv50 of the barrier material satisfies: 0.01 ⁇ m ⁇ D ⁇ 1 ⁇ m.
  • the thickness of the barrier layer satisfies: 0.007 ⁇ m ⁇ d1 ⁇ 50 ⁇ m; for example, it may be 0.007 ⁇ m ⁇ L ⁇ 45 ⁇ m, 0.01 ⁇ m ⁇ L ⁇ 40 ⁇ m, 0.05 ⁇ m ⁇ L ⁇ 35 ⁇ m, 0.1 ⁇ m ⁇ L ⁇ 30 ⁇ m, 0.1 ⁇ m ⁇ L ⁇ 25 ⁇ m, 0.1 ⁇ m ⁇ L ⁇ 20 ⁇ m, 0.1 ⁇ m ⁇ L ⁇ 15 ⁇ m, 0.1 ⁇ m ⁇ L ⁇ 10 ⁇ m, 0.1 ⁇ m ⁇ L ⁇ 5 ⁇ m or 0.1 ⁇ m ⁇ L ⁇ 1 ⁇ m, etc.
  • the thickness of the barrier layer may be 0.007 ⁇ m, 0.01 ⁇ m, 0.05 ⁇ m, 0.1 ⁇ m, 0.5 ⁇ m, 1 ⁇ m, 3 ⁇ m, 5 ⁇ m, 7 ⁇ m, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 30 ⁇ m, 40 ⁇ m or 50 ⁇ m, etc.
  • the thickness of the barrier layer satisfies: 0.2 ⁇ m ⁇ d1 ⁇ 15 ⁇ m.
  • the micro-mesoporous material includes one or more of a covalent organic framework material and a metal organic framework material.
  • covalent organic framework materials are a type of crystalline organic porous materials that connect functional units in the form of covalent bonds into a highly ordered two-dimensional stacked layer structure or a specific three-dimensional topological structure based on reversible chemical reactions.
  • COF materials can be homopolymers of multiple monomers or copolymers of multiple monomers.
  • the type of monomers that form the COF material and the number of functional groups that the monomers have that can participate in the polymer reaction determine the configuration of the COF material and also determine the pore size of the internal pores of the COF material; the larger the pore size of the internal pores of the COF material, the more conducive it is to lithium ion transmission, and the smaller the pore size of the internal pores of the COF material, the better the effect of inhibiting the passage of substances other than lithium ions in the electrolyte.
  • the above-mentioned connecting group refers to the connecting group between two adjacent monomer units in the covalent organic framework material.
  • the monomers and the connecting groups between the monomers mentioned above that are polymerized to form the COF material can be determined by the following method: take the barrier layer and soak it in NMP or water for 24 hours; filter the dissolved material powder, and soak it in new NMP solvent or water for 2 hours, and then ultrasonicate it for 2 hours to fully disperse the particles, repeat the cleaning and ultrasonication process for more than 3 times, and finally obtain the COF material, and put it into a vacuum drying oven at 80°C for 24 hours.
  • the X-ray diffraction spectrum is measured by an X-ray powder diffractometer, and the Fourier infrared spectrum and nuclear magnetic resonance spectrum are measured by an infrared spectrometer and a nuclear magnetic resonance spectrometer.
  • the structure of the COF material contained in the isolation film is determined by combining the X-ray diffraction spectrum, Fourier infrared spectrum and nuclear magnetic resonance spectrum of the isolation film, and then the type of monomers forming the COF material and the connecting groups between the monomers are determined.
  • the X-ray powder diffractometer may be a Science Ultima IV X-ray powder diffractometer
  • the infrared spectrometer may be a Bruker ALPHA infrared spectrometer with a wavelength range of 400 cm -1 to 4000 cm -1
  • the nuclear magnetic resonance spectrometer may be a Bruker AV III 400 nuclear magnetic resonance spectrometer.
  • Metal-organic framework materials are a type of crystalline porous materials with a periodic network structure formed by the self-assembly of inorganic metal centers and bridging organic ligands.
  • the inorganic metal centers can be one or more of metal ions and metal clusters.
  • the ion-conducting inorganic material includes LLZO, LLTO, LATP, LAGP, LSPS, and one or more of coatings, dopants, and/or dopants with coating layers thereof.
  • LLZO is a lithium lanthanum zirconium oxide solid electrolyte
  • LLTO is a lithium lanthanum titanium oxide solid electrolyte
  • LATP is a lithium aluminum titanium phosphate solid electrolyte
  • LAGP is Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3
  • LSPS is a sulfide solid electrolyte.
  • LLZO, LLTO, LATP, and LAGP have synthetic conductivity and good stability, and LSPS has significantly high conductivity and good ion-conducting performance.
  • the above-mentioned ion-conducting inorganic materials can conduct lithium ions to allow them to penetrate the barrier layer.
  • the coating refers to a substance obtained by forming a coating layer on at least part of the outer surface of each of the above-mentioned materials.
  • the dopant refers to a substance formed by adding one or more transition metal elements and non-transition metal elements to each of the above-mentioned materials.
  • the dopant with a coating layer refers to a substance obtained by forming a coating layer on at least part of the outer surface of the dopant of each of the above-mentioned materials.
  • the pore size of the internal pores of the micro-mesoporous material is recorded as d2, and the pore size of the internal pores of the micro-mesoporous material satisfies: 0.04nm ⁇ d2 ⁇ 5nm; for example, it can be 0.04nm ⁇ d2 ⁇ 4.5nm, 0.1nm ⁇ d2 ⁇ 4nm, 0.1nm ⁇ d2 ⁇ 3nm, 0.1nm ⁇ d2 ⁇ 2nm, 0.1nm ⁇ d2 ⁇ 1nm or 0.1nm ⁇ d2 ⁇ 0.5nm, etc.
  • the pore size of the internal pores of the micro-mesoporous material satisfies the above range, only the desolvated lithium ions are allowed to penetrate the diaphragm through the internal pores of the micro-mesoporous material, and other substances other than lithium ions in the electrolyte are prevented from penetrating the diaphragm, thereby inhibiting the interaction between the positive electrode and the negative electrode.
  • the pore size of the internal pores of the micro-mesoporous material may be 0.04 nm, 0.1 nm, 0.3 nm, 0.4 nm, 0.7 nm, 1 nm, 1.3 nm, 1.5 nm, 1.8 nm, 2 nm, 3 nm, 4 nm or 5 nm, etc.
  • the pore size of the internal pores of the micro-mesoporous material satisfies: 0.3 nm ⁇ d2 ⁇ 2 nm, which can further enhance the inhibitory effect on the interaction between the positive and negative electrodes.
  • the pore size of the internal pores of the COF material mentioned above can be measured by the following method: take the barrier layer and soak it in NMP or water for 24 hours; filter the dissolved material powder and soak it in new NMP solvent or water for 2 hours, then ultrasonicate it for 2 hours to fully disperse the particles, repeat the ultrasonic cleaning process for more than 3 times, and finally obtain the COF material, and put it into a vacuum drying oven at 80°C for 24 hours.
  • NLDFT delocalized density functional theory model
  • the inorganic metal center and the organic ligands forming the MOF material determine the structure of the MOF material, and the structure of the MOF material determines the pore size of the internal pores.
  • the pore size of the internal pores of the MOF material mentioned above can be measured by the following method: soak the barrier layer in NMP or water for 24 hours; filter the dissolved material powder and soak it in new NMP solvent or water for 2 hours, and then ultrasonicate it for 2 hours. To make the particles fully dispersed, the ultrasonic cleaning process was repeated more than 3 times, and finally the MOF material was obtained and placed in a vacuum drying oven at 80°C for 24 hours.
  • the adsorption of N 2 by the MOF material was tested at standard atmospheric pressure (101kPa) using a gas adsorption instrument, and the purity of the gas used in the test was 99.999%; 100 mg of MOF material was added to a quartz sample tube and vacuum degassed at 120°C for 6 hours on the pretreatment station of the rapid specific surface area analyzer.
  • the gas adsorption experiment was carried out on the MOF material using a gas adsorption instrument.
  • NLDFT delocalized density functional theory model
  • the conductivity of the ion-conducting inorganic material is ⁇ 0.0001 mS ⁇ cm -1 at 25°C; when the conductivity of the ion-conducting inorganic material is lower than the above range, the battery impedance may increase and the battery kinetic performance may deteriorate.
  • the conductivity of the ion-conducting inorganic material is ⁇ 0.001 mS ⁇ cm -1 at 25°C. Further optionally, the conductivity of the ion-conducting inorganic material is ⁇ 0.01 mS ⁇ cm -1 at 25°C.
  • the conductivity of the ion-conducting inorganic material mentioned above can be measured by the following method: the ion-conducting inorganic material is made into a solid electrolyte ceramic sample, and the solid electrolyte ceramic sample is subjected to an AC impedance test by a CHI660E electrochemical workstation, and the sample with conductive silver paste as an electrode is clamped with a test clip (i.e., silver is plated on both sides of the electrolyte disc), and the test frequency range is 10 ⁇ 6Hz-0.1Hz.
  • the total impedance value is obtained by analyzing the impedance spectrum obtained by the test, and then the corresponding total ion conductivity is calculated.
  • ⁇ is the ionic conductivity, in units of mS ⁇ cm -1
  • d is the thickness of the electrolyte sheet, in units of cm
  • R is the impedance value of the electrolyte sheet measured by the electrochemical workstation, in units of ohms
  • P is the bottom area of the electrolyte sheet, in units of cm2 .
  • the area ratio of the barrier material in the barrier layer is 30%-99%; for example, it can be 35%-99%, 40%-99%, 50%-99%, 60%-99%, 70%-99%, 80%-99% or 90%-99%.
  • the unit area ratio of the barrier material in the barrier layer is lower than the above range, it may result in too few lithium ion transmission channels, which may increase the battery impedance.
  • the unit area ratio of the barrier material in the barrier layer is 30%, 40%, 50%0, 60%0, 70%, 80%, 90% or 99%, etc.
  • the unit area ratio of the barrier material in the barrier layer is 50%-99%.
  • the unit area ratio of the barrier material in the barrier layer is 70%-99%.
  • the area ratio refers to the ratio of the area of the barrier material to the total area of the barrier layer.
  • the area ratio of the barrier material in the barrier layer can be tested by the following method: use a scanning electron microscope to take a SEM image of the barrier layer, and calculate the total area of the barrier material and the area of the barrier layer based on the SEM image of the barrier layer; according to the formula: total area of the barrier material/area of the barrier layer, calculate the area ratio of the barrier material in the barrier layer.
  • the polymer layer includes a polymer with a swelling degree of ⁇ 10%.
  • the swelling degree of the polymers contained in the polymer layer is ⁇ 10%. When the swelling degree of the polymer meets the above range, it may not swell in the electrolyte solvent, has good stability, and can inhibit the electrolyte from penetrating the barrier layer.
  • the polymer includes one or more of polyethylene, polypropylene, polyimide and polyvinylidene fluoride.
  • the polymer layer may include only one polymer, or may include two or more polymers at the same time.
  • the mass proportion of the polymer layer in the barrier layer is ⁇ 50%; when the mass proportion of the polymer in the barrier layer exceeds the above range, the lithium ion transmission speed may be significantly slowed down and the battery impedance may be deteriorated.
  • the mass of the polymer layer in the barrier layer accounts for 2%-30%, for example, 2%-25%, 2%-20%, 2%-15%, 2%-10% or 2%-5%, etc.
  • the mass of the polymer layer in the barrier layer may account for 2%, 5%, 10%, 15%, 20%, 25% or 30%, etc. Further optionally, the mass of the polymer layer in the barrier layer accounts for 5%-15%.
  • the mass proportion of the above-mentioned polymer layer in the barrier layer can be tested by the following method: Use a thermogravimetric-differential scanning calorimeter to analyze the components of the barrier layer: Take 15-25 mg of the barrier layer, place it in an alumina crucible, use nitrogen as a protective gas, preheat at 25°C for 30 minutes, and then heat to 600°C at a rate of 2°C/10min. Determine the content of each component based on the weight change and heat change.
  • the polymer layer includes a polymer having a weight average molecular weight of 1W-200W.
  • the weight average molecular weight of the polymer contained in the polymer layer is 1W-200W; for example, it can be 1W-180W, 1W-160W, 1W-140W, 1W-120W, 1W-100W, 1W-80W, 1W-60W, 1W-40W or 1W-20W, etc.
  • the weight average molecular weight of the polymer contained in the polymer layer is lower than the above range, it may not meet the strength requirements of the barrier layer.
  • the weight average molecular weight of the polymer contained in the polymer layer is The amount can be 1W, 10W, 20W, 30W, 40W, 50W, 60W, 70W, 80W, 90W, 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W or 200W, etc.
  • the polymer layer includes a polymer with a weight average molecular weight of 2W-150W. Further optionally, the polymer layer includes a polymer with a weight average molecular weight of 10W-100W.
  • the weight average molecular weight of the above-mentioned polymers can be measured by gel permeation chromatography (GPC).
  • the diaphragm further comprises a support layer, and the barrier layer is located on at least one side of the support layer.
  • the support layer has pores, and the average pore size of the pores of the support layer is 20nm-1000nm; for example, it can be 20nm-900nm, 20nm-800nm, 20nm-700nm, 20nm-600nm, 20nm-500nm, 20nm-400nm, 20nm-300nm, 20nm-200nm or 20nm-100nm, etc.
  • the average pore size of the pores of the support layer can be 20nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm or 1000nm, etc.
  • the average pore size of the pores of the support layer is 100nm-500nm.
  • the average pore size of the pores in the support layer mentioned above can be tested by the following method: the pore size of the diaphragm is tested using an pore size testing instrument, the sample to be tested is cut into discs with a diameter of 0.5 cm, soaked in the infiltration liquid for 10 minutes, transferred to the fixture with tweezers, the pressure range is set to 0-500PSI, and the pore size test is performed.
  • the material of the support layer includes one or more of polyethylene, polypropylene, polyimide and polyvinylidene fluoride.
  • the thickness of the diaphragm is 2 ⁇ m-12 ⁇ m; for example, it can be 2 ⁇ m-11 ⁇ m, 2 ⁇ m-10 ⁇ m, 2 ⁇ m-9 ⁇ m, 2 ⁇ m-8 ⁇ m, 2 ⁇ m-7 ⁇ m, 2 ⁇ m-6 ⁇ m, 2 ⁇ m-5 ⁇ m, 2 ⁇ m-4 ⁇ m or 2 ⁇ m-3 ⁇ m, etc.
  • the strength of the diaphragm can be further improved.
  • the thickness of the diaphragm can be 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m, 10 ⁇ m, 11 ⁇ m or 12 ⁇ m, etc.
  • the thickness of the diaphragm is 3 ⁇ m-10 ⁇ m. Further optionally, the thickness of the diaphragm is 5 ⁇ m-7 ⁇ m.
  • the thickness of the above-mentioned diaphragm can be tested by the following method: first calibrate the micrometer, then place the diaphragm between the double anvils, gently rotate the sleeve until a sound is heard, and read and record the thickness of the diaphragm.
  • the air permeability of the separator is ⁇ 300s/100mL.
  • the air permeability of the separator meets the above range, it can promote close contact between the polymer layer and the barrier material, the barrier layer has no gaps, reduce the transmission of the positive electrode electrolyte, the negative electrode electrolyte and the interface byproducts, and inhibit the interaction between the positive and negative electrodes.
  • the air permeability of the separator is ⁇ 400s/100mL; further optionally, the air permeability of the separator is ⁇ 500s/100mL.
  • air permeability refers to the time it takes for a certain volume of air to pass through a membrane per unit area under unit pressure.
  • the air permeability of the above-mentioned diaphragm can be tested by the following method: flatten the diaphragm, select a flat and oil-free position, place it at the outlet of the air compressor cylinder, and tighten it; after the diaphragm is fixed in the workstation, use the gravity of the cylinder floating on the liquid to compress the air in the cylinder. As the air passes through the sample, the cylinder will fall steadily. Measure the time required for a certain volume of air to pass through the sample, and calculate the air permeability based on this. Among them, the volume of the air column is 100CC; the test area is 6.45cm2 ; the sample area is>6cm ⁇ 6cm.
  • the tensile strength of the separator is ⁇ 1000MPa.
  • the strength of the barrier layer can be further improved, so that the barrier layer can maintain good structural strength during the use of the battery cell.
  • the tensile strength of the separator is ⁇ 1200MPa; further optionally, the tensile strength of the separator is ⁇ 1500MPa.
  • the tensile strength of the above-mentioned diaphragm can be tested by the following method: cut the diaphragm into 15cm*2cm and measure its thickness as A; then clamp the diaphragm on the universal tester, input the parameters A and 15cm, and start measuring; when the diaphragm is broken, the tensile strength will be displayed and the tensile strength can be read.
  • the present application also provides a method for preparing a diaphragm, comprising the following steps: preparing a solution containing a polymer; loading the solution on a carrier to prepare a polymer layer; loading a barrier material on the surface of the polymer layer before the polymer layer is formed into a film; embedding the barrier material into the polymer layer by rolling, drying, and removing the carrier to prepare the barrier layer.
  • the mass percentage concentration of the solution containing the polymer can be 2%-20%, optionally 3%-7%.
  • the solvent used in preparing the solution containing the polymer includes N-methylpyrrolidone.
  • the carrier includes a glass plate.
  • the thickness of the polymer layer is 4 ⁇ m-6 ⁇ m.
  • the solution is loaded on the carrier by a scraping method. Further optionally, the height of the scraper used in scraping is 10 ⁇ m, and the speed of the coater is 25mm/s-35mm/s.
  • the drying temperature is 75°C-85°C, and the drying time is 10h-14h.
  • the preparation method of the diaphragm includes the following steps: dissolving a polymer in a solvent until it is clear to obtain a solution with a mass percentage concentration of 3%-7%; applying the solution on a glass plate with a coating thickness of 4 ⁇ m-6 ⁇ m to obtain a polymer layer loaded on the glass plate, wherein the height of the scraper used in the scraping is 10 ⁇ m, and the coating machine drives the scraper to move at a speed of 25mm/s-35mm/s; Before the polymer layer is formed into a film, the barrier material is evenly sprayed on the surface of the polymer layer, and then the barrier material is embedded in the polymer layer by rolling. The polymer layer is placed in a vacuum drying oven at 75°C-85°C for 10h-14h, and the glass plate is removed to obtain the barrier layer.
  • the present application also provides a method for preparing a diaphragm, comprising the following steps: preparing a slurry containing a polymer and a barrier material; placing the base membrane in a filtration device; adding the slurry to the filtration device, filtering, and drying to prepare a barrier layer.
  • the solvent used in preparing the slurry containing the polymer and the barrier material includes N-methylpyrrolidone.
  • the mixed solution of the polymer, the barrier material and the solvent is dispersed at 800rpm-1200rpm for 10h-14h.
  • the base film includes a PE film.
  • the filtration equipment includes a Buchner funnel.
  • the filtration time is 1.5h-2.5h.
  • the drying temperature is 75°C-85°C, and the drying time is 10h-14h.
  • the preparation method of the diaphragm includes the following steps: dissolving the polymer in a solvent until it is clear, adding a barrier material, dispersing at 800rpm-1200rpm for 10h-14h to obtain a slurry; placing a PE film on a Buchner funnel, spreading it flat in the Buchner funnel, adding the slurry, and filtering for 1.5h-2.5h; then adding deionized water to the Buchner funnel to wash away the residual slurry; removing the PE film from the Buchner funnel and placing it in a vacuum drying oven at 75°C-85°C for 10h-14h to obtain a barrier layer.
  • the present application also provides a method for preparing a diaphragm, comprising the following steps: preparing a solution containing a polymer; placing the solution on at least one side of a support layer to prepare a polymer layer; before the polymer layer is formed into a film, loading a barrier material on the surface of the polymer layer; embedding the barrier material into the polymer layer by rolling, and drying to prepare a diaphragm.
  • the mass percentage concentration of the solution containing the polymer can be 2%-20%, optionally 3%-7%.
  • the solvent used in preparing the solution containing the polymer includes N-methylpyrrolidone.
  • the carrier includes a glass plate.
  • the thickness of the polymer layer is 4 ⁇ m-6 ⁇ m.
  • the solution is loaded on the carrier by a scraping method. Further optionally, the height of the scraper used in scraping is 10 ⁇ m, and the speed of the coater is 25mm/s-35mm/s.
  • the drying temperature is 75°C-85°C, and the drying time is 10h-14h.
  • the above-mentioned preparation method can be used to prepare a diaphragm comprising both a barrier layer and a support layer.
  • the preparation method of the diaphragm includes the following steps: dissolving the polymer in a solvent until it is clarified to obtain a solution with a mass percentage concentration of 3%-7%; coating the solution on a PE base film with a coating thickness of 4 ⁇ m-6 ⁇ m to obtain a polymer layer loaded on the PE base film, wherein the height of the scraper used in the scraping is 10 ⁇ m, and the coater drives the scraper to move at a speed of 25mm/s-35mm/s; before the polymer layer is formed into a film, the barrier material is evenly sprayed on the surface of the polymer layer, and the barrier material is embedded in the polymer layer by rolling; and then dried in a vacuum drying oven at 75°C-85°C for 10h-14h to obtain a diaphragm.
  • the present application also provides a method for preparing a diaphragm, comprising the following steps: preparing a slurry containing a polymer and a barrier material; placing the slurry on a support layer, drying, and preparing a primary treatment barrier layer; placing the primary treatment barrier layer in a filtration device; adding a solution containing a polymer to the filtration device, filtering, and drying to prepare a diaphragm.
  • the solvent used in preparing the slurry containing the polymer and the barrier material includes N-methylpyrrolidone.
  • the mixed solution of the polymer, the barrier material and the solvent is dispersed at 1800rpm-2200rpm for 10h-14h.
  • the base film includes a PE film.
  • the filtration equipment includes a Buchner funnel.
  • the filtration time is 1.5h-2.5h.
  • the drying temperature is 75°C-85°C, and the drying time is 10h-14h.
  • the above-mentioned preparation method can be used to prepare a diaphragm comprising both a barrier layer and a support layer.
  • the preparation method of the diaphragm includes the following steps: dissolving the polymer in a solvent until it is clear, adding a barrier material, dispersing at 1800rpm-2200rpm for 10-14h to obtain a slurry; scraping the solution on a PE film with a coating thickness of 1.5 ⁇ m-2.5 ⁇ m, wherein the height of the scraper used in the scraping is 5 ⁇ m, and the coater drives the scraper to move at a speed of 25mm/s-35mm/s; then placing it in a vacuum drying oven at 75°C-85°C for 10h-14h to obtain a once-treated barrier layer loaded on the PE film; spreading the PE film and the once-treated barrier layer in a Buchner funnel, adding a polymer solution with a mass percentage concentration of 3%-5%, and filtering for 1.5h-2.5h; then adding deionized water to the Buchner funnel to wash away the residual polymer solution; removing the PE film from the Buchner funnel and placing it in a vacuum drying oven at 75°
  • the present application also provides a secondary battery, comprising a positive electrode sheet, a negative electrode sheet, a positive electrode electrolyte, a negative electrode electrolyte and the above-mentioned separator of the present application; the separator is located between the positive electrode sheet and the negative electrode sheet, the positive electrode electrolyte is located between the positive electrode sheet and the separator, and the negative electrode electrolyte is located between the negative electrode sheet and the separator; one or more of the solvent, lithium salt and additive contained in the positive electrode electrolyte and the negative electrode electrolyte are different. As a result, the storage performance and cycle performance of the obtained secondary battery are significantly improved.
  • the positive electrode sheet and the negative electrode sheet can be stacked and placed close to the separator, and then the three can be placed in an aluminum-plastic bag with the same length and width as the separator.
  • the separator and the aluminum-plastic bag have the same length and width, the other three sides except the opening of the aluminum-plastic bag can be heat-sealed together with the separator, and the separator and the aluminum-plastic bag form a high-density positive electrode chamber and
  • the positive electrode chamber is formed by injecting the positive electrode electrolyte and the negative electrode electrolyte into the positive electrode chamber and the negative electrode chamber respectively from the opening of the aluminum-plastic bag, and finally the opening of the aluminum-plastic bag is heat-sealed to obtain a battery cell, and the battery cell is placed in a shell, for example, the shell can be a steel shell, to obtain a secondary battery.
  • the positive electrode sheet, the negative electrode sheet and the separator when preparing a secondary battery, can be wound and then put into an aluminum-plastic bag, and the lower end of the aluminum-plastic bag is heat-sealed together with the separator, and the separator and the aluminum-plastic bag form a positive electrode chamber and a negative electrode chamber with a high density, and then the positive electrode electrolyte and the negative electrode electrolyte are respectively injected into the positive electrode chamber and the negative electrode chamber from the opening of the aluminum-plastic bag, and finally the opening of the aluminum-plastic bag is heat-sealed to obtain a battery cell, and the battery cell is placed in a shell, for example, the shell can be a steel shell, to obtain a secondary battery.
  • the shell can be a steel shell
  • the compatibility of solvents, lithium salts and additives with the positive electrode and the negative electrode is often different, so it is usually necessary to use solvents, lithium salts and additives in combination to protect the positive electrode and the negative electrode at the same time.
  • the diaphragm can inhibit the exchange of the positive electrode electrolyte and the negative electrode electrolyte
  • the electrolyte can be designed separately according to the characteristics of the positive electrode and the negative electrode themselves without considering the compatibility with the other side; therefore, the advantages of different electrolytes can be further amplified, the performance of the battery cell can be improved, and the limit design of the electrolyte can be pushed.
  • the solvent of the positive electrode electrolyte is different from the solvent of the negative electrode electrolyte.
  • the separator separates the positive electrode electrolyte from the negative electrode electrolyte
  • the positive electrode electrolyte and the negative electrode electrolyte can use solvent systems that match them respectively.
  • the positive electrode electrolyte can use an oxidation-resistant solvent system, which can greatly reduce electrolyte oxidation and improve battery performance
  • the negative electrode electrolyte can use a solvent system that is compatible with the negative electrode and has a low viscosity, which can significantly improve the interface stability of the negative electrode and increase the transmission rate of lithium ions at the negative electrode.
  • the type of solvent used in the positive electrode electrolyte when the type of solvent used in the positive electrode electrolyte is completely different from the type of solvent used in the negative electrode electrolyte, it belongs to the category of the solvent of the positive electrode electrolyte and the solvent of the negative electrode electrolyte being different. For example, if the solvent used in the positive electrode electrolyte is E and the solvent used in the negative electrode electrolyte is F, then the solvent of the positive electrode electrolyte is different from the solvent of the negative electrode electrolyte.
  • both the positive electrode electrolyte and the negative electrode electrolyte use a mixture of multiple solvents, and the types of solvents used in the positive electrode electrolyte and the negative electrode electrolyte are the same, but the volume ratio or mass ratio of different solvents is different, it also falls into the category of different solvents for the positive electrode electrolyte and the negative electrode electrolyte.
  • the solvent used in the positive electrode electrolyte is a mixture of E and F in a volume ratio of 5:5
  • the solvent used in the negative electrode electrolyte is a mixture of E and F in a volume ratio of 3:7
  • the solvent of the positive electrode electrolyte is different from the solvent of the negative electrode electrolyte.
  • the solvent used in the positive electrode electrolyte and the negative electrode electrolyte When the types of solvents used in the positive electrode electrolyte and the negative electrode electrolyte are partially the same, it also falls into the category of different solvents for the positive electrode electrolyte and the negative electrode electrolyte. For example, if the solvent used in the positive electrode electrolyte is E, and the solvent used in the negative electrode electrolyte is a mixture of E and F, then the solvents for the positive electrode electrolyte and the negative electrode electrolyte are different. If the solvent used in the positive electrode electrolyte is a mixture of E and G, and the solvent used in the negative electrode electrolyte is a mixture of E and F, then the solvents for the positive electrode electrolyte and the negative electrode electrolyte are also different.
  • the solvent of the positive electrode electrolyte includes one or more of carbonate solvents, fluorinated carbonate solvents, fluorinated carboxylate solvents, sulfone solvents, fluorinated sulfone solvents, phosphate solvents, borate solvents and nitrile solvents.
  • the solvent of the negative electrode electrolyte includes one or more of carbonate solvents, carboxylate solvents, ether solvents, fluorinated carboxylate solvents and fluorinated carbonate solvents.
  • the fluorocarbonate solvent includes one or more of methyl trifluoroethyl carbonate, bis(trifluoromethyl) carbonate, bis(trifluoroethyl) carbonate, 4-trifluoromethyl ethylene carbonate, bisfluoroethylene carbonate, trifluoromethyl trifluoroethyl carbonate, trifluoropropyl carbonate and 2,2-difluoroethyl methyl carbonate;
  • the fluorocarboxylate solvent includes one or more of trifluoroethyl 3,3,3-trifluoroacetate, 2,2-difluoroethyl acetate, ethyl difluoroacetate and 2,2,2-difluoroethyl acetate.
  • trifluoroethyl esters include one or more of sulfolane, dimethyl sulfone, diethyl sulfone, methyl ethyl sulfone, methyl isopropyl sulfone, dimethyl sulfoxide, diethyl sulfoxide and methyl ethyl sulfoxide; fluorosulfone solvents include one or more of methyl trifluoromethyl sulfone, ethyl trifluoromethyl sulfone, propyl trifluoromethyl sulfone, methyl trifluoroethyl sulfone, methyl trifluoropropyl sulfone, 1,1,2,2-tetrafluoropropyl methyl sulfone, trifluoromethyl isopropyl sulfone and methyl hexafluoroisopropyl sulfone; phosphate
  • the solvent of the positive electrode electrolyte includes one or more of bis(trifluoromethyl)carbonate, bis(trifluoroethyl)carbonate, bis(trifluoroethylene carbonate), 2,2-difluoroethyl acetate, ethyl difluoroacetate, diethyl sulfone, methyl ethyl sulfone, methyl trifluoromethyl sulfone, ethyl trifluoromethyl sulfone, triethyl phosphate, tripropyl phosphate, acetonitrile, succinonitrile and succinonitrile.
  • the solvent of the negative electrode electrolyte includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and ethylene carbonate, 1,2-dimethyl carbonate, One or more of ethylene oxide and tetraethanol dimethyl ether.
  • the lithium salt of the positive electrode electrolyte is different from the lithium salt of the negative electrode electrolyte.
  • the type of lithium salt contained in the positive electrode electrolyte when the type of lithium salt contained in the positive electrode electrolyte is completely different from the type of lithium salt contained in the negative electrode electrolyte, it belongs to the category of different lithium salts in the positive electrode electrolyte and the negative electrode electrolyte. For example, if the lithium salt contained in the positive electrode electrolyte is a and the lithium salt used in the negative electrode electrolyte is b, then the lithium salt in the positive electrode electrolyte is different from the lithium salt in the negative electrode electrolyte.
  • the lithium salt in the positive electrode electrolyte and the lithium salt in the negative electrode electrolyte are different.
  • the lithium salt contained in the positive electrode electrolyte is a, and the molar concentration is 1 mol/L; the lithium salt used in the negative electrode electrolyte is a, and the molar concentration is 1.5 mol/L, then the lithium salt in the positive electrode electrolyte is different from the lithium salt in the negative electrode electrolyte.
  • the positive electrode electrolyte and the negative electrode electrolyte both use a variety of lithium salts, and the types of lithium salts used in the positive electrode electrolyte and the negative electrode electrolyte are exactly the same, but the mass ratio or molar ratio between the different lithium salts is different, which also falls into the category of different lithium salts in the positive electrode electrolyte and the negative electrode electrolyte.
  • the lithium salt in the positive electrode electrolyte is a mixture of a and b with a molar ratio of 5:5
  • the lithium salt in the negative electrode electrolyte is a mixture of a and b with a molar ratio of 3:7
  • the lithium salt in the positive electrode electrolyte is different from the lithium salt in the negative electrode electrolyte.
  • the types of lithium salts in the positive electrode electrolyte and the molar ratio or mass ratio between the different lithium salts are exactly the same, but the total mass volume concentration or total molar concentration of the lithium salt is different, it also falls into the category of different lithium salts in the positive electrode electrolyte and the negative electrode electrolyte.
  • the lithium salt in the positive electrode electrolyte and the lithium salt in the negative electrode electrolyte are both a mixture of a and b in a molar ratio of 5:5, but the total molar concentration of the lithium salt in the positive electrode electrolyte is 1 mol/L, and the total molar concentration of the lithium salt in the negative electrode electrolyte is 1.5 mol/L, then the lithium salt in the positive electrode electrolyte is different from the lithium salt in the negative electrode electrolyte.
  • the lithium salt of the positive electrode electrolyte is different from the lithium salt of the negative electrode electrolyte.
  • the lithium salt contained in the positive electrode electrolyte is a
  • the lithium salt contained in the negative electrode electrolyte is a mixture of a and b
  • the lithium salt of the positive electrode electrolyte is different from the lithium salt of the negative electrode electrolyte.
  • the lithium salt contained in the positive electrode electrolyte is a mixture of a and c, and the lithium salt contained in the negative electrode electrolyte is a mixture of a and c, then the lithium salt of the positive electrode electrolyte is also different from the lithium salt of the negative electrode electrolyte.
  • the lithium salt of the positive electrode electrolyte includes one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalatoborate).
  • the lithium salt of the positive electrode electrolyte may further include one or more of lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bistrifluoromethanesulfonyl imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalatoborate (LiDFOB), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorobisoxalatophosphate (LiDFOP) and lithium tetrafluorooxalatophosphate (LiTFOP).
  • the concentration of the lithium salt in the positive electrode electrolyte is generally 0.5 mol/L-4 mol/L.
  • the lithium salt of the negative electrode electrolyte includes one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalatoborate).
  • the lithium salt of the negative electrode electrolyte may further include one or more of lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bistrifluoromethanesulfonyl imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalatoborate (LiDFOB), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorobisoxalatophosphate (LiDFOP) and lithium tetrafluorooxalatophosphate (LiTFOP).
  • the concentration of the lithium salt in the negative electrode electrolyte is generally 0.5 mol/L-4 mol/L.
  • the positive electrode electrolyte may further include additives, such as positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the negative electrode electrolyte may further include additives, such as negative electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as negative electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the positive electrode electrolyte and the negative electrode electrolyte play the role of conducting ions between the positive electrode and the negative electrode.
  • the isolation membrane is set between the positive electrode and the negative electrode, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode active material may include a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 , LiMn 2 O 4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ), and LiNi 0.8 Co 0.2 Mn 0.2 O 2 (also referred to as NCM 811 ), lithium
  • lithium phosphates containing olivine structure may include but are not limited to lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • the weight ratio of the positive electrode active material in the positive electrode film layer is 80-100% by weight, based on the total weight of the positive electrode film layer.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy.
  • the polymer material substrate includes but is not limited to at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS) and polyethylene (PE).
  • the positive electrode film layer may also optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • the weight ratio of the binder in the positive electrode film layer is 0-20% by weight, based on the total weight of the positive electrode film layer.
  • the positive electrode film layer may further include a conductive agent.
  • the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the weight ratio of the conductive agent in the positive electrode film layer is 0-20% by weight, based on the total weight of the positive electrode film layer.
  • the positive electrode sheet can be prepared by the following method: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent to form a positive electrode slurry, wherein the positive electrode slurry has a solid content of 40-80wt%, and the viscosity at room temperature is adjusted to 5000-25000mPa ⁇ s, and the solvent may include but is not limited to N-methylpyrrolidone, and the positive electrode slurry is coated on both sides of the positive electrode collector, and after drying, it is cold-pressed by a cold rolling mill to form a positive electrode sheet; the unit surface density of the positive electrode powder coated on one side is 150-450mg/ m2 , and the compaction density of the positive electrode sheet is 2.0-4.3g/ cm3 , and can be optionally 3.5-4.3g/ cm3 .
  • the calculation formula of the compaction density is:
  • Compacted density coating surface density/(thickness of the electrode after extrusion - thickness of the current collector).
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • a metal foil a copper foil may be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • the polymer material substrate includes but is not limited to polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and other substrates.
  • the negative electrode active material may adopt the negative electrode active material for batteries known in the art.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used.
  • These negative electrode active materials may be used alone or in combination of two or more.
  • the weight ratio of the negative electrode active material in the negative electrode film layer is 70-100% by weight, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • SBR styrene-butadiene rubber
  • PAA polyacrylic acid
  • PAAS sodium polyacrylate
  • PAM polyacrylamide
  • PVA polyvinyl alcohol
  • SA sodium alginate
  • PMAA polymethacrylic acid
  • CMCS carboxymethyl chitosan
  • the negative electrode film layer may further include a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the weight ratio of the conductive agent in the negative electrode film layer is 0-20 weight %, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include other additives, such as thickeners, etc., wherein the thickeners include but are not limited to sodium carboxymethyl cellulose (CMC-Na), etc.
  • the weight ratio of the other additives in the negative electrode film layer is 0-15% by weight, based on the total weight of the negative electrode film layer.
  • the negative electrode sheet can be prepared by the following method: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent to form a negative electrode slurry, wherein the solid content of the negative electrode slurry is 30-70wt%, and the viscosity at room temperature is adjusted to 2000-10000mPa ⁇ s, and the solvent may include but is not limited to deionized water; the obtained negative electrode slurry is coated on the surfaces of both sides of the negative electrode current collector, and after a drying process, cold pressing such as rolling, a negative electrode sheet is obtained.
  • the unit area density of the negative electrode powder coated on one side is 75-220mg/ m2
  • the compaction density of the negative electrode sheet is 1.2-2.0g/ m3 .
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the positive electrode sheet and the negative electrode sheet are placed close to the isolation film, and then the three are placed in an aluminum-plastic bag with the same length and width as the isolation film.
  • the other three sides except the opening of the aluminum-plastic bag are heat-sealed together with the isolation film.
  • the isolation film and the aluminum-plastic bag form dense positive electrode chamber and negative electrode chamber, and then the positive electrode electrolyte and the negative electrode electrolyte are respectively injected into the positive electrode chamber and the negative electrode chamber from the opening of the aluminum-plastic bag, and finally the opening of the aluminum-plastic bag is heat-sealed to obtain a battery cell.
  • the positive electrode sheet, the negative electrode sheet and the separator can be wound and then put into an aluminum-plastic bag.
  • the lower end of the aluminum-plastic bag is heat-sealed together with the separator.
  • the separator and the aluminum-plastic bag form dense positive electrode chambers and negative electrode chambers.
  • the positive electrode electrolyte and the negative electrode electrolyte are then injected into the positive electrode chamber and the negative electrode chamber respectively from the opening of the aluminum-plastic bag. Finally, the opening of the aluminum-plastic bag is heat-sealed to obtain a battery cell.
  • the secondary battery may include an outer package, which may be used to encapsulate the battery cell.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • the secondary battery is a lithium ion battery.
  • FIG8 is a secondary battery 1 of a square structure as an example.
  • the outer package may include a shell 11 and a cover plate 13.
  • the shell 11 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 11 has an opening connected to the receiving cavity, and the cover plate 13 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the separator can be wound or laminated to form an electrode assembly 12.
  • the electrode assembly 12 is encapsulated in the housing cavity.
  • the positive electrode electrolyte is immersed between the positive electrode sheet and the separator, and the negative electrode electrolyte is immersed between the negative electrode sheet and the separator.
  • the number of electrode assemblies 12 contained in the secondary battery 1 can be one or more, which can be adjusted according to demand.
  • secondary batteries may be assembled into a battery module.
  • the battery module may contain multiple secondary batteries, and the specific number may be adjusted according to the application and capacity of the battery module.
  • the plurality of secondary batteries may be arranged in sequence along the length direction of the battery module. Of course, they may also be arranged in any other manner. Further, the plurality of secondary batteries may be fixed by fasteners.
  • the battery module may further include a housing having a receiving space, and the plurality of secondary batteries are received in the receiving space.
  • the battery modules described above may also be assembled into a battery pack, and the number of battery modules contained in the battery pack may be adjusted according to the application and capacity of the battery pack.
  • the battery pack may include a battery box and a plurality of battery modules disposed in the battery box.
  • the battery box includes an upper box body and a lower box body, and the upper box body can be covered on the lower box body to form a closed space for accommodating the battery modules.
  • the plurality of battery modules can be arranged in the battery box in any manner.
  • the present application also provides an electric device, which includes at least one of the secondary battery, battery module, or battery pack.
  • the secondary battery, battery module, or battery pack can be used as a power source for the device, or as an energy storage unit for the device.
  • the device can be, but is not limited to, a mobile device, an electric vehicle, an electric train, a ship, a satellite, an energy storage system, etc.;
  • mobile devices may include but are not limited to at least one of mobile phones, laptops, etc.;
  • electric vehicles may include but are not limited to at least one of pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.
  • the device can select a secondary battery, a battery module or a battery pack according to its usage requirements.
  • Fig. 10 is an example of an electric device 2.
  • the electric device 2 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
  • a battery pack or a battery module may be used.
  • the device may be a mobile phone, a tablet computer, a notebook computer, etc.
  • a device is usually required to be light and thin, and a secondary battery may be used as a power source.
  • the gas adsorption instrument of model Quantachrome (ASiQMVH002 5) was used to test the adsorption of N 2 by COF-1 material under standard atmospheric pressure (101 kPa), and the purity of the gas used in the test was 99.999%; the test steps were as follows: 100 mg of COF-1 was added to a quartz sample tube, and vacuum degassed at 120°C for 6 hours on the pretreatment station of the rapid specific surface area analyzer.
  • the gas adsorption instrument was used to conduct a gas adsorption experiment on COF-1. According to the obtained nitrogen adsorption curve, the pore size distribution (PSD) was calculated by the non-local density function theory (NLDFT).
  • NLDFT non-local density function theory
  • the pore size of the internal pores of MOF-1 was measured to be 0.34 nm.
  • the pore size of the internal pores of COF-2 was measured to be 4.8 nm.
  • the pore size of the internal pores of COF-3 was measured to be 0.3 nm.
  • the pore size of the internal pores of COF-4 was measured to be 0.8 nm.
  • the pore size of the internal pores of COF-5 was measured to be 0.97 nm.
  • the pore size of the internal pores of COF-6 was measured to be 2 nm.
  • the pore size of the internal pores of COF-7 was measured to be 5.8 nm.
  • the pore size of the internal pores of the obtained COF material is the same; the volume average particle size Dv50 of the finally obtained COF material can be further adjusted by controlling the reaction conditions such as temperature and time during the preparation of the COF material.
  • COF materials with the same internal pore size synthesized using the same monomers will be uniformly named in this application.
  • Polyvinylidene fluoride (as a polymer) was dissolved in N-methylpyrrolidone until it was clear, and a polymer solution with a mass percentage concentration of 5% was prepared; then COF-1 (as a barrier material) was added and dispersed at a high speed of 1000 rpm for 12 hours to obtain a slurry.
  • a PE membrane with a thickness of 7 ⁇ m and a pore size of 20 nm was spread flat in a Buchner funnel, and the slurry was added and filtered for 2 hours. Deionized water was then added to the Buchner funnel to wash away the residual slurry. The PE membrane was then removed from the Buchner funnel and dried in a vacuum drying oven at 80°C for 12 hours to obtain a diaphragm.
  • the preparation methods of the diaphragms in Examples 2-15, 18, and 22-34 are basically similar to the preparation method of the diaphragm in Example 1, and the main differences are: one or more of the type of barrier material, the volume average particle size Dv50 of the barrier material, the pore size of the internal pores of the barrier material, the thickness of the barrier layer, the ratio of the thickness of the barrier layer to the volume average particle size Dv50 of the barrier material, the air permeability of the barrier layer, the conductivity of the ion-conducting inorganic material, the type and/or weight average molecular weight and/or swelling degree of the polymer, the mass proportion of the polymer layer in the barrier layer, and the area proportion of the barrier material in the barrier layer are different. See Table 1 for details.
  • the preparation method of the diaphragm in Examples 16-17, Examples 19-21 and Examples 35-37 is different from the preparation method of the diaphragm in Example 1, and the type of barrier material, the volume average particle size Dv50 of the barrier material, the pore size of the internal pores of the barrier material, the thickness of the barrier layer, the ratio of the thickness of the barrier layer to the volume average particle size Dv50 of the barrier material, the air permeability of the barrier layer, the conductivity of the ion-conducting inorganic material, the type and/or weight average molecular weight and/or swelling degree of the polymer, the mass proportion of the polymer layer in the barrier layer, the area proportion of the barrier material in the barrier layer, the type of polymer, the type of the support layer, the pore size of the support layer and the thickness of the diaphragm are one or more of the following, see Table 1 for details. It should be noted that the thickness of the diaphragm in Examples 16-17, Examples 19-21 and Examples 36-37 refers to the thickness of the
  • the preparation method of the diaphragm in Example 16 is as follows: polyvinylidene fluoride (as a polymer) is dissolved in N-methylpyrrolidone until it is clear, LATP (as a barrier material) is added and dispersed at a high speed of 2000 rpm for 12 hours to obtain a slurry.
  • the slurry is coated on a PE film with a thickness of 7 ⁇ m (as a support layer) to form a barrier layer with a coating thickness of 2 ⁇ m; wherein the height of the scraper used for scraping is
  • the coating machine drives the scraper to move at a speed of 30mm/s.
  • the PE film loaded with the barrier layer is placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain a once-treated barrier layer.
  • the PE film loaded with the once-treated barrier layer is spread flat in a Buchner funnel, a polyvinylidene fluoride solution with a mass percentage concentration of 5% is added, and filtered for 2 hours; then deionized water is added to the Buchner funnel to wash away the residual polyvinylidene fluoride solution; the PE film is removed from the Buchner funnel and placed in a vacuum drying oven at 80°C for 12 hours to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 17 is as follows: polyvinylidene fluoride (as a polymer) is dissolved in N-methylpyrrolidone until it is clarified, and LLTO (as a barrier material) is added and dispersed at a high speed of 2000rmp for 12 hours to obtain a slurry.
  • the slurry is coated on a PE film (as a support layer) with a thickness of 7 ⁇ m to form a barrier layer, and the coating thickness is 2 ⁇ m; wherein, the height of the scraper used during the scraping is 5 ⁇ m, and the coating machine drives the scraper to move at a speed of 30mm/s.
  • the PE film loaded with the barrier layer is placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain a once-treated barrier layer.
  • Spread the PE film loaded with the once-treated barrier layer in a Buchner funnel add a polyvinylidene fluoride solution with a mass percentage concentration of 5%, and filter for 2 hours; then add deionized water to the Buchner funnel to wash away the residual polyvinylidene fluoride solution; remove the PE film from the Buchner funnel, place it in a vacuum drying oven at 80°C and dry it for 12 hours to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 19 is as follows: polyimide (as a polymer) is dissolved in N-methylpyrrolidone until it is clear, and a polymer solution with a mass percentage concentration of 5% is prepared. The polymer solution is scraped on a PE film (as a support layer) with a thickness of 7 ⁇ m, and the coating thickness is 1 ⁇ m to obtain a polymer layer loaded on the PE film; wherein, the height of the scraper used during scraping is 10 ⁇ m, and the coating machine drives the scraper to move at a speed of 30 mm/s.
  • LSPS as a barrier material
  • LSPS is evenly sprayed on the surface of the polymer layer, and the LSPS is embedded in the polymer layer by rolling, and then dried at 80°C in a vacuum drying oven for 12 hours to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 20 is as follows: polyimide (as a polymer) is dissolved in N-methylpyrrolidone until it is clear, and a polymer solution with a mass percentage concentration of 5% is prepared. The polymer solution is scraped on a PE film (as a support layer) with a thickness of 7 ⁇ m, and the coating thickness is 1 ⁇ m to obtain a polymer layer loaded on the PE film; wherein, the height of the scraper used during scraping is 10 ⁇ m, and the coating machine drives the scraper to move at a speed of 30 mm/s.
  • LATP as a barrier material
  • LATP is evenly sprayed on the surface of the polymer layer, and LATP is embedded in the polymer layer by rolling, and then dried at 80°C in a vacuum drying oven for 12 hours to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 21 is as follows: polyvinylidene fluoride (as a polymer) is dissolved in N-methylpyrrolidone until it is clarified, and a polymer solution with a mass percentage concentration of 5% is prepared. The polymer solution is scraped on a PE film (as a support layer) with a thickness of 7 ⁇ m, and the coating thickness is 1 ⁇ m to obtain a polymer layer loaded on the PE film; wherein, the height of the scraper used during scraping is 10 ⁇ m, and the coating machine drives the scraper to move at a speed of 30 mm/s.
  • LATP as a barrier material
  • LATP is evenly sprayed on the surface of the polymer layer, and LATP is embedded in the polymer layer by rolling, and then dried at 80°C in a vacuum drying oven for 12 hours to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 35 is as follows: polyvinylidene fluoride (as a polymer) is dissolved in N-methylpyrrolidone until it is clear, and a polymer solution with a mass percentage concentration of 5% is prepared. The polymer solution is scraped on a glass plate with a coating thickness of 5 ⁇ m to obtain a polymer layer loaded on the glass plate; wherein, the height of the scraper used for scraping is 10 ⁇ m, and the coating machine drives the scraper to move at a speed of 30 mm/s.
  • COF-1 (as a barrier material) is evenly sprayed on the surface of the polymer layer, and the COF-1 material is embedded in the polymer layer by rolling, and then dried at 80°C in a vacuum drying oven for 12 hours, and the glass plate is removed to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 36 is as follows: polyvinylidene fluoride (as a polymer) is dissolved in N-methylpyrrolidone until it is clear, and a polymer solution with a mass percentage concentration of 5% is prepared. The polymer solution is scraped on a PE film (as a support layer) with a thickness of 7 ⁇ m, and the coating thickness is 1 ⁇ m to obtain a polymer layer loaded on the PE film; wherein, the height of the scraper used during scraping is 10 ⁇ m, and the coating machine drives the scraper to move at a speed of 30 mm/s.
  • COF-1 (as a barrier material) is evenly sprayed on the surface of the polymer layer, and the COF-1 material is embedded in the polymer layer by rolling, and then dried at 80°C in a vacuum drying oven for 12 hours to obtain a diaphragm.
  • the preparation method of the diaphragm in Example 37 is as follows: polyvinylidene fluoride (as a polymer) is dissolved in N-methylpyrrolidone until it is clear, COF-1 (as a barrier material) is added and dispersed at a high speed of 2000rmp for 12 hours to obtain a slurry.
  • the slurry is coated on a PP film (as a support layer) with a thickness of 7 ⁇ m to form a barrier layer with a coating thickness of 2 ⁇ m; wherein the height of the scraper used during the coating is 5 ⁇ m, and the coating machine drives the scraper to move at a speed of 30mm/s.
  • the PP film loaded with the barrier layer is placed in a vacuum drying oven and dried at 80°C for 12 hours to obtain a once-treated barrier layer.
  • the PP film loaded with the once-treated barrier layer was spread flat in a Buchner funnel, and a polyvinylidene fluoride solution with a mass percentage concentration of 5% was added, and the film was filtered for 2 hours; then deionized water was added to the Buchner funnel to wash away the residual polyvinylidene fluoride solution; the PP film was removed from the Buchner funnel and placed in a vacuum drying oven to dry at 80°C for 12 hours to obtain a diaphragm.
  • Comparative Example 1 a common PP film is used as a separator.
  • the preparation method of the diaphragm in Comparative Example 2 is basically similar to the preparation method of the diaphragm in Example 1, with the main difference being that only 1/2 of the area of the PE membrane is filtered, and the rest is not processed.
  • the specific parameter settings are shown in Table 1.
  • the preparation method of the diaphragm in Comparative Example 3 is basically similar to the preparation method of the diaphragm in Example 1, and the main differences are: one or more of the following: the type of barrier material, the volume average particle size Dv50 of the barrier material, the pore size of the internal pores of the barrier material, the thickness of the barrier layer, the ratio of the thickness of the barrier layer to the volume average particle size Dv50 of the barrier material, the air permeability of the barrier layer, the conductivity of the ion-conducting inorganic material, the type and/or weight average molecular weight and/or swelling degree of the polymer, the mass proportion of the polymer layer in the barrier layer, and the area proportion of the barrier material in the barrier layer. For details, see Table 1.
  • volume average particle size Dv50 of the barrier material mentioned above is measured by Microtrac MRB S3500 series laser particle size analysis; the specific process is: take 2g of barrier material, add 20mL of deionized water, and ultrasonicate for 5 minutes to ensure that the sample is completely dispersed to obtain a dispersion, and then put the dispersion into the sample tank for testing to obtain the volume average particle size Dv50 of the barrier material.
  • the pore size of the internal pores of the barrier material COF-1 mentioned above is tested by the following method: take the COF-1 material to be tested, use a gas adsorption instrument of model Quantachrome (ASiQMVH002 5), test the adsorption amount of COF material to N 2 at standard atmospheric pressure (101kPa), and the purity of the gas used in the test is 99.999%; add 100mg COF material into a quartz sample tube, and degas at 120°C for 6h in a vacuum on the pretreatment station of a rapid specific surface area analyzer.
  • ASiQMVH002 5 gas adsorption instrument of model Quantachrome
  • NLDFT delocalized density functional theory model
  • the pore size of the internal pores of the barrier material MOF-1 mentioned above is tested by the following method: Take the MOF-1 material to be tested, use a gas adsorption instrument of model Quantachrome (ASiQMVH002 5), test the adsorption amount of MOF material to N 2 at standard atmospheric pressure (101kPa), and the purity of the gas used in the test is 99.999%; add 100mg MOF material to a quartz sample tube, and degas at 120°C for 6h in a vacuum on the pretreatment station of a rapid specific surface area analyzer.
  • ASiQMVH002 5 gas adsorption instrument of model Quantachrome
  • NLDFT delocalized density functional theory model
  • the conductivity of the barrier materials LLZO, LLTO, LATP, LAGP and LSPS mentioned above was measured by the following method: the ion-conducting inorganic material was made into a solid electrolyte ceramic sample, and the solid electrolyte ceramic sample was subjected to an AC impedance test by a CHI660E electrochemical workstation. The sample with conductive silver paste as an electrode was clamped with a test clip (i.e., silver was plated on both sides of the electrolyte disc), and the test frequency range was 10 ⁇ 6Hz-0.1Hz. The total impedance value was obtained by analyzing the impedance spectrum obtained by the test, and then the corresponding total ionic conductivity was calculated.
  • ⁇ is the ionic conductivity, in mS ⁇ cm -1
  • d is the thickness of the electrolyte sheet, in cm
  • R is the impedance value of the electrolyte sheet measured by the electrochemical workstation, in ohms
  • P is the bottom area of the electrolyte sheet, in cm 2 .
  • the area ratio of the barrier material mentioned above in the barrier layer is tested by the following method: a SEM image of the barrier layer is taken using a scanning electron microscope, and the total area of the barrier material and the area of the barrier layer are calculated based on the SEM image of the barrier layer; the area ratio of the barrier material in the barrier layer is calculated according to the formula: total area of the barrier material/area of the barrier layer.
  • the mass proportion of the above-mentioned polymer layer in the barrier layer is tested by the following method: Use a thermogravimetric-differential scanning calorimeter to analyze the components of the barrier layer: Take 15-25 mg of the barrier layer, place it in an alumina crucible, use nitrogen as a protective gas, preheat at 25°C for 30 minutes, and then heat to 600°C at a rate of 2°C/10min. Determine the content of each component based on the weight change and heat change.
  • the test method for the air permeability of the barrier layer mentioned above is: spread the barrier layer flat, select a flat and oil-free position, place it on the air outlet of the air compressor, and tighten it; after the barrier layer is fixed at the work station, use the gravity of the cylinder floating on the liquid to compress the air in the cylinder. As the air passes through the sample, the cylinder will fall steadily. Test the time required for a certain volume of air to pass through the sample, and calculate the air permeability based on this. Among them, the volume of the air column is 100CC; the test area is 6.45cm2 ; the sample area is> 6cm ⁇ 6cm.
  • the average pore size of the support layer pores mentioned above was tested by the following method: the pore size of the diaphragm was tested using the PMI multifunctional pore size analyzer from PMI, USA; the sample to be tested was cut into discs with a diameter of 0.5 cm, immersed in the infiltration liquid for 10 minutes, and transferred to the fixture with tweezers; the pressure range was set to 0-500PSI for pore size testing.
  • the thickness of the above mentioned diaphragm is measured by the following method: calibrate the micrometer, then place the diaphragm between the double anvils, gently rotate the sleeve until a sound is heard, and read the thickness of the diaphragm.
  • the thickness of the barrier layer mentioned above is measured by the following method: calibrate the micrometer, then place the diaphragm between the double anvils, gently rotate the sleeve until a sound is heard, and read the reading to record the thickness of the diaphragm.
  • the thickness of the barrier layer mentioned above is tested by the following method: first calibrate the micrometer, then place the diaphragm between the double anvils, gently rotate the sleeve until a sound is heard, and read and record the thickness of the diaphragm; remove the diaphragm, remove the barrier layer to obtain the support layer, repeat the above measurement process, and measure the thickness of the support layer; subtract the thickness of the support layer from the thickness of the diaphragm to obtain the thickness of the barrier layer.
  • the weight average molecular weight of the above-mentioned polymers is measured by gel permeation chromatography (GPC).
  • the diaphragm flat, select a flat and oil-free position, place it on the air outlet of the air compressor, and tighten it; after the diaphragm is fixed in the work position, use the gravity of the cylinder floating on the liquid to compress the air in the cylinder. As the air passes through the sample, the cylinder will fall steadily. Measure the time required for a certain volume of air to pass through the sample, and calculate the air permeability based on this. Among them, the volume of the air column is 100CC; the test area is 6.45cm2 ; the sample area is>6cm ⁇ 6cm. The results are detailed in Table 2.
  • LNMO LiNi 0.5 Mn 1.5 O 4 , as the positive electrode active material
  • conductive carbon black as the conductive agent
  • polyvinylidene fluoride as the binder
  • N-methylpyrrolidone was added and stirred to disperse into a positive electrode slurry.
  • the positive electrode slurry was coated on both sides of the aluminum foil, dried, cold pressed and cut to obtain a positive electrode sheet.
  • the unit surface density of the positive electrode powder coated on one side was 0.02g/cm 2 .
  • Artificial graphite (as negative electrode active material), conductive carbon black (as conductive agent), styrene-butadiene rubber (as binder) and sodium carboxymethyl cellulose (as thickener) were mixed in a mass ratio of 96:1:1:2, and then deionized water was added and stirred to disperse into negative electrode slurry.
  • the negative electrode slurry was evenly coated on one side of the copper foil, dried, cold pressed and cut to obtain a negative electrode sheet.
  • the negative electrode powder had a single-side coating unit area density of 0.008 g/ cm2 .
  • Preparation of positive electrode electrolyte In a glove box filled with argon (water content ⁇ 10ppm, oxygen content ⁇ 10ppm), add 1wt% of vinylene sulfate and 1wt% of propane sultone to methyl trifluoroethyl carbonate (FEMC), mix thoroughly, and finally add lithium hexafluorophosphate ( LiPF6 ) to the mixed solution until the molar concentration of LiPF6 is 1mol/L to prepare the positive electrode electrolyte.
  • argon water content ⁇ 10ppm, oxygen content ⁇ 10ppm
  • FEMC methyl trifluoroethyl carbonate
  • LiPF6 lithium hexafluorophosphate
  • the positive electrode sheet, the separator and the negative electrode sheet are stacked in order, so that the separator is between the positive and negative electrode sheets to play a role of isolation, and the three are placed in an aluminum-plastic bag with the same length and width as the separator, and the other three sides of the aluminum-plastic bag except before the opening are heat-sealed together with the separator, and the separator and the aluminum-plastic bag form a dense positive electrode chamber and a negative electrode chamber, and the positive electrode chamber side is injected with a positive electrode electrolyte, and the negative electrode chamber side is injected with a negative electrode electrolyte, and the battery cell is sealed, and then the battery cell is placed in a battery casing, formed, and left to stand to obtain a secondary battery.
  • the secondary batteries in the above embodiments and comparative examples are charged to 4.9V at a constant current of 0.1C, and then charged to a current of 0.05C at a constant voltage of 4.9V; after standing for 5 minutes, the secondary batteries are discharged to 3.5V at a constant current of 0.1C.
  • This is a charge and discharge cycle process, and the discharge capacity at this time is the initial discharge capacity of the secondary battery.
  • the secondary battery is charged and discharged cyclically according to the above method until the discharge capacity after the cycle decays to 80% of the initial discharge capacity, and the test is terminated, and the number of cycles of the secondary battery at this time is recorded.
  • the secondary batteries in the above embodiments and comparative examples are respectively charged to 4.9V at a constant current of 0.1C, and then charged to a current of 0.05C at a constant voltage of 4.9V, at which time the secondary batteries are in a fully charged state.
  • the fully charged secondary batteries are stored in a 25°C environment, taken out every 5 days, and discharged to 3.5V at a constant current of 0.1C to obtain the discharge capacity after storage for a period of time; then the secondary batteries are fully charged in the above manner and stored again in a 25°C environment until the discharge capacity of the secondary batteries after storage decays to 70% of the initial discharge capacity, the test is terminated, and the total number of storage days of the secondary batteries is recorded.
  • the air permeability of the barrier layer is ⁇ 300s/100mL, and the barrier layer can greatly inhibit the penetration of solvents, additives and by-products in the electrolyte, thereby eliminating the battery capacity attenuation caused by the interaction between the positive and negative electrodes.
  • Examples 1-6 lie mainly in the different ratios of the barrier layer thickness and the volume average particle size Dv50 of the barrier material, with the ratio of the two being the largest in Example 6.
  • the number of cycles and storage days in Example 6 are significantly reduced, and the cycle impedance is significantly increased. It is speculated that when d1/D is too large, the barrier material particles may be stacked too closely, and the barrier material particles may have too many contact surfaces with each other, which may slow down the transmission speed of lithium ions through the barrier material.
  • Example 3 and Examples 7-12 The difference between Example 3 and Examples 7-12 is that the pores inside the barrier material have different pore sizes, and the pore size of the pores inside the barrier material is the largest in Example 12. Compared with Example 3 and Examples 7-11, the number of cycles and storage days in Example 12 are significantly reduced. It is speculated that this may be because when the pore size of the barrier material is too large, the barrier effect of the diaphragm is weakened, which may allow some substances other than lithium ions in the electrolyte to penetrate the diaphragm.
  • Example 15 Compared with Example 14, Examples 16-17, and Examples 19-21, the cycle impedance of the secondary battery in Example 15 is significantly increased; it is speculated that this may be due to the poor conductivity of LLZO, which leads to the increase in the impedance of the secondary battery.
  • Example 18 Compared with Example 14, Examples 16-17 and Examples 19-21, the cycle impedance of the secondary battery in Example 18 is significantly increased; it is speculated that this may be due to the excessive ratio of the barrier layer thickness to the barrier material volume average particle size Dv50, which leads to a significant increase in the impedance of the secondary battery.
  • Example 3 and Examples 24-30 The difference between Example 3 and Examples 24-30 is that the area ratio of the barrier material in the barrier layer and the mass ratio of the polymer layer in the barrier layer are different, and the area ratio of the barrier material in the barrier layer is the smallest in Example 28.
  • Example 3 Examples 24-27 and Examples 29-30 the number of cycles of the secondary battery in Example 28 is significantly reduced and the impedance is significantly increased; it is speculated that this may be because when the unit area ratio of the barrier material in the barrier layer is too low, it may lead to a reduction in lithium ion transmission channels, deteriorate the battery impedance, and reduce its cycle performance and storage performance.
  • Example 3 and Examples 31-34 The difference between Example 3 and Examples 31-34 is that the weight average molecular weight of the polymer is different.
  • the weight average molecular weight of the polymer in Example 31 is the smallest.
  • the number of cycles and storage days in Example 31 are significantly reduced; it is speculated that when the weight average molecular weight of the polymer is too low, the density of the barrier layer formed is poor, and the barrier effect of the barrier layer may be weakened, and some substances other than lithium ions in the electrolyte can also penetrate the diaphragm.
  • Example 1 when the air permeability of the barrier layer is lower than 300 s/100 mL, the barrier layer may weaken the interaction inhibition effect between the positive electrode and the negative electrode.

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Abstract

La présente demande concerne un séparateur, une batterie secondaire et un dispositif alimenté. Le séparateur comprend une couche barrière, et la couche barrière comprend une couche polymère et un matériau barrière au moins partiellement intégré dans la couche polymère, le matériau barrière comprenant un ou plusieurs éléments parmi un matériau micro-mésoporeux et un matériau inorganique conducteur d'ions ; la taille de particule moyenne en volume Dv50 du matériau barrière est désignée par D, l'épaisseur de la couche barrière est désignée par d1, et la taille de particule moyenne en volume Dv50 du matériau barrière et l'épaisseur de la couche barrière satisfont : 0,2 ≤ d1/D ≤ 1000 ; la perméabilité à l'air de la couche barrière est ≥ 300 s/100 mL.
PCT/CN2023/077202 2023-02-20 2023-02-20 Séparateur, batterie secondaire et dispositif alimenté WO2024174066A1 (fr)

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Citations (6)

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CN103490027A (zh) * 2013-08-12 2014-01-01 中国科学院化学研究所 锂-硫电池用隔膜及其制备方法
CN103814459A (zh) * 2011-12-27 2014-05-21 株式会社Lg化学 隔膜的制造方法以及配备由所述方法制造的隔膜的电化学装置
CN105789531A (zh) * 2014-12-25 2016-07-20 杭州聚力氢能科技有限公司 阻挡隔膜、其制备方法及包括其的二次电池
CN106062995A (zh) * 2014-02-19 2016-10-26 巴斯夫欧洲公司 使用包含抑制电解质的离子导体的复合物的电极保护
CN109686902A (zh) * 2018-11-29 2019-04-26 西交利物浦大学 锂硫电池用复合隔膜、其制备方法及应用
CN112201845A (zh) * 2020-10-21 2021-01-08 江苏厚生新能源科技有限公司 一种超稳定界面半固态电解质电池复合隔膜及其制备工艺

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103814459A (zh) * 2011-12-27 2014-05-21 株式会社Lg化学 隔膜的制造方法以及配备由所述方法制造的隔膜的电化学装置
CN103490027A (zh) * 2013-08-12 2014-01-01 中国科学院化学研究所 锂-硫电池用隔膜及其制备方法
CN106062995A (zh) * 2014-02-19 2016-10-26 巴斯夫欧洲公司 使用包含抑制电解质的离子导体的复合物的电极保护
CN105789531A (zh) * 2014-12-25 2016-07-20 杭州聚力氢能科技有限公司 阻挡隔膜、其制备方法及包括其的二次电池
CN109686902A (zh) * 2018-11-29 2019-04-26 西交利物浦大学 锂硫电池用复合隔膜、其制备方法及应用
CN112201845A (zh) * 2020-10-21 2021-01-08 江苏厚生新能源科技有限公司 一种超稳定界面半固态电解质电池复合隔膜及其制备工艺

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