CN113725557A - Lithium ion battery diaphragm supporting layer and lithium ion battery diaphragm - Google Patents

Lithium ion battery diaphragm supporting layer and lithium ion battery diaphragm Download PDF

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Publication number
CN113725557A
CN113725557A CN202111027789.6A CN202111027789A CN113725557A CN 113725557 A CN113725557 A CN 113725557A CN 202111027789 A CN202111027789 A CN 202111027789A CN 113725557 A CN113725557 A CN 113725557A
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Prior art keywords
fibers
fiber
lithium ion
woven fabric
ion battery
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CN202111027789.6A
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CN113725557B (en
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陈莉
王艳杰
林陆菁
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Shenzhen Senior Technology Material Co Ltd
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Shenzhen Senior Technology Material Co Ltd
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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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/44—Fibrous material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • 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

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

Abstract

The application relates to the field of lithium batteries, and relates to a lithium ion battery diaphragm supporting layer and a lithium ion battery diaphragm. The supporting layer comprises a non-woven fabric layer, and the non-woven fabric layer comprises first fibers, second fibers and third fibers; the first fiber is organic fiber, and the second fiber is inorganic fiber; the third fibers are organic binder fibers. The longitudinal tensile strength of the non-woven fabric layer is 5.6N/15 mm-65N/15 mm; the transverse tensile strength is 3.5N/15 mm-55N/15 mm; the average pore diameter is not more than 5 μm, and the ratio of the maximum pore diameter to the average pore diameter is not less than 1 and not more than 10. The addition of the inorganic fiber improves the heat resistance of the non-woven fabric layer. The diameters of the first fibers, the second fibers and the third fibers ensure that the nonwoven layer has a relatively thin thickness. The excellent tensile strength of the non-woven fabric layer improves the mechanical strength of the lithium ion battery diaphragm, and is expected to improve the use safety of the lithium ion battery.

Description

Lithium ion battery diaphragm supporting layer and lithium ion battery diaphragm
Technical Field
The application relates to the field of lithium batteries, in particular to a lithium ion battery diaphragm supporting layer and a lithium ion battery diaphragm.
Background
In recent years, driven by explosive development and energy storage of new energy automobile markets and vigorous demands in the 3C field, the demand of lithium ion battery diaphragms is rapidly increased, and meanwhile, higher and higher requirements are provided for the energy density of lithium ion batteries. The diaphragm is used as one of four core materials (positive electrode, negative electrode, electrolyte and diaphragm) of the lithium ion battery, determines the interface structure, internal resistance and the like of the battery, and directly influences the capacity, cycle, safety performance and the like of the battery.
At present, the lithium ion battery diaphragm is mainly a polyolefin diaphragm, but in the application process, if the battery is out of control due to internal short circuit or overcharge and the like, the internal temperature of the battery is rapidly increased, the polyolefin diaphragm cannot ensure the size integrity of the battery at high temperature, so that the large-area contact of positive and negative electrode materials is caused, the battery is exploded, and the safety of the battery is threatened.
The non-woven fabric diaphragm has excellent heat resistance, has excellent performance in various novel diaphragm materials, has long application in the aspect of battery diaphragms, is widely applied to the fields of nickel-cadmium batteries, nickel-hydrogen batteries, lead-acid batteries, alkaline batteries, super capacitors and the like, but is limited by practical difficulties such as technology, cost, other uncertainty and the like, the application of the non-woven fabric diaphragm in lithium ion batteries is still very limited, the non-woven fabric cannot simultaneously meet the requirements of the lithium ion battery diaphragm on both aperture and thickness, and the non-woven fabric diaphragm cannot be directly used as the lithium ion battery diaphragm under the prior art, is generally only suitable for being used as a supporting layer of the lithium ion battery diaphragm, but cannot fully meet the requirements of a high-speed winding process of an assembled battery due to the fact that the tensile mechanical strength of the non-woven fabric is poor compared with a polyolefin porous membrane. In order to increase the strength of the non-woven fabric and reduce the pore diameter to prevent micro short circuit, the thickness of the non-woven fabric needs to be increased; however, the thickness of the non-woven fabric used as the membrane support layer is large, and the thickness of the non-woven fabric membrane formed by coating the coating layer is further increased, so that large loss is brought to the energy density of the battery, and the non-woven fabric membrane cannot fully meet the application requirements of the lithium ion battery membrane at present.
Disclosure of Invention
The embodiment of the application aims to provide a lithium ion battery diaphragm supporting layer and a lithium ion battery diaphragm.
In a first aspect, the present application provides a lithium ion battery separator support layer comprising: a non-woven fabric layer;
the non-woven fabric layer comprises first fibers, second fibers and third fibers; the first fiber is organic fiber, and the second fiber is inorganic fiber; the third fiber is organic bonding fiber;
the longitudinal tensile strength of the non-woven fabric layer is 5.6N/15 mm-65N/15 mm; the transverse tensile strength of the non-woven fabric layer is 3.5N/15 mm-55N/15 mm; the nonwoven fabric layer has an average pore diameter of not more than 5 μm and a ratio of a maximum pore diameter to the average pore diameter of not less than 1 and not more than 10.
The non-woven fabric layer of the application compounds the organic fibers and the inorganic fibers, takes respective advantages of the organic fibers and the inorganic fibers into consideration, has complementary effects, and makes up for the application defect of a single material. Meanwhile, the organic bonding fiber is compounded, so that the bonding strength between the organic fiber and the inorganic fiber is ensured. The addition of the inorganic fiber greatly improves the heat resistance of the non-woven fabric layer, and the non-woven fabric layer can obtain good heat shrinkage performance when applied to the lithium ion battery diaphragm. The diameters of the first fibers, the second fibers and the third fibers are micron-sized, the average pore size of the non-woven fabric layer is not more than 5 microns, and the ratio of the maximum pore size to the average pore size is not less than 1 and not more than 10, so that the non-woven fabric layer is ensured to have a thin thickness and excellent ion permeability. The longitudinal tensile strength of the non-woven fabric layer is 5.6N/15 mm-65N/15 mm; the transverse tensile strength is 3.5N/15 mm-55N/15 mm, the mechanical strength of the lithium ion battery diaphragm can be effectively improved, and the use safety of the lithium ion battery is expected to be improved. The non-woven fabric layer can improve the mechanical strength and the thermal shrinkage performance of the lithium ion battery diaphragm and ensure higher energy density of the battery on the premise of ensuring the thinner ion permeability of the lithium ion battery diaphragm to be excellent.
Influence of longitudinal tensile strength and transverse tensile strength of the non-woven fabric layer on application of the lithium battery diaphragm:
the non-woven fabric layer with the longitudinal tensile strength and the transverse tensile strength within the ranges is used as the base material of the diaphragm, and the longitudinal strength and the transverse strength are cooperatively matched, so that the high mechanical strength of the diaphragm is ensured. Compared with the conventional non-woven fabric, the non-woven fabric can meet the requirement of higher strength under the condition of the same thickness, can realize lower thickness under the condition of the same strength, and the reduction of the thickness of the diaphragm means the reduction of ion transmission difficulty, is beneficial to reducing the internal resistance of the battery, promoting the charge and discharge process of the battery, improving the volume energy density of the battery and lightening the weight of the battery. On the premise of ensuring safety, the light, thin and high-strength diaphragm can more easily meet the requirements of downstream lithium batteries on light, thin, large-capacity and high-energy density.
The addition of the inorganic fiber greatly improves the strength of the non-woven fabric layer, but the inorganic fiber has the defects of poor elasticity and brittle property, and the brittleness of the non-woven fabric layer is easily increased, so the non-woven fabric layer is easily brittle and broken and is not easy to bend.
The high strength of the diaphragm basically guarantees the safety of the battery, and when the battery is assembled, in order to increase the energy density of the battery, the diaphragm needs to be wound on the surface of an electrode material, and meanwhile, all electrodes are compacted, so that the distance between the electrodes is reduced as much as possible. For this reason, the separator must have sufficient strength and good winding characteristics, which are directly related to the characteristics such as the degree of alignment of winding the cell, the degree of tightness, and whether the battery is deformed, and thus directly affect the performance of the battery.
In other embodiments of the present application, the first fiber diameter is in a range of 1 μm to 6 μm; the second fibers have a diameter of not more than 6 μm and the third fibers have a diameter of not more than 10 μm.
In other embodiments of the present application, the nonwoven layer includes fourth fibers; the fourth fiber is an organic fiber, the diameter of the fourth fiber is smaller than that of the first fiber, and the diameter of the fourth fiber is in a nanometer level.
In other embodiments of the present application, the fourth fiber has a diameter greater than 100nm and less than 1 μm.
In another embodiment of the present application, in the non-woven fabric layer, the proportion of the third fibers is 15% to 40% by mass, and the balance is the first fibers, the second fibers, and the fourth fibers;
in the first fiber, the second fiber and the fourth fiber, the proportion of the second fiber is less than or equal to 35 percent; the percentage of the fourth fiber is 0-25% and is not equal to 0.
In other embodiments of the present application, the melting point or softening point of the third fibers is 100 to 220 ℃; the melting point or softening point of the first fiber and the melting point or softening point of the fourth fiber are higher than that of the third fiber by not less than 20 ℃.
In another embodiment of the present application, the first fibers, the second fibers, the third fibers, and the fourth fibers each have a fiber length in a range of 1mm to 6 mm.
In other embodiments of the present application, the density of the nonwoven fabric layer is 0.50g/m3～0.9g/m3(ii) a The thickness of the non-woven fabric layer is 5-35 mu m.
In other embodiments of the present application, the first fiber includes: at least one of polyethylene terephthalate fibers, polybutylene terephthalate fibers, polyethylene fibers, polypropylene fibers, polyvinyl chloride fibers, ES fibers, polyamide fibers, polyimide fibers, polytetrafluoroethylene fibers, polyvinyl alcohol fibers, polyvinylidene fluoride fibers, polyphenylene sulfide fibers, polyether ether ketone fibers, polyacrylonitrile fibers, polycarbonate fibers, or aramid fibers;
optionally, the second fibers comprise: alumina silicate fiber, mullite fiber, forsterite fiber, alumina fiber, quartz fiber, zirconia fiber, SiO2CaO-MgO based fiber and Al2O3CaO-based fiber, Al2O3-SiO2-ZrO2At least one of system fiber, boride fiber, carbide fiber, nitride fiber, magnesium aluminum silicon ternary glass fiber, magnesium aluminum silicon system glass fiber or silicon aluminum calcium magnesium system glass fiber;
optionally, the third fibers comprise: at least one of polyethylene terephthalate undrawn fiber, polybutylene terephthalate undrawn fiber, polyolefin fiber, or sheath-core structure composite fiber.
In a second aspect, the present application provides a lithium ion battery separator comprising the lithium ion battery separator support layer provided in any of the preceding embodiments.
Detailed Description
Hereinafter, embodiments of the present application will be described in detail so that those skilled in the art to which the present application pertains can easily carry out the present application. The embodiments of the present application are provided to more fully explain the present application to those of ordinary skill in the art. Therefore, the embodiments of the present application may be modified into various different forms, and the scope of the present application is not limited to the embodiments described below.
Throughout the specification of the present application, when a portion is described as "including" a certain structural element, it is meant that other structural elements may be included, without excluding other structural elements, unless otherwise noted.
Throughout the specification of the present application, when it is described that a certain step is "on" or "before" other steps, this includes not only a case where a certain step has a direct chronological relationship with other steps but also the same right as a case where an indirect chronological relationship in which the order of two steps such as a mixing step after each step is changeable.
The terms "about," "substantially," and the like, as used throughout this specification to refer to a degree which is indicative of inherent manufacturing and material tolerances, are used in the meaning of a value or close to the value, to prevent the disclosure of an exact or absolute value being unduly employed by an unscrupulous infringer to assist in the invention. The terms "(performed) … … step" or "step of … …" as used throughout the specification of the present application do not imply a "step for … …".
The inventors found that inorganic fibers are characterized by high thermal stability, high mechanical strength, temperature and pressure resistance, and good chemical stability, and compared with inorganic fibers, organic fibers have the advantages of good flexibility and processability, but poor heat resistance and mechanical properties.
Inorganic fibers are doped in organic fiber raw materials, the organic fibers wrap the inorganic fibers to provide bonding strength and form an integral structure, the inorganic fibers serve as reinforcing materials to reinforce the structural strength of the non-woven fabric, the inorganic fibers are uniformly distributed in an organic fiber matrix after the inorganic fibers and the organic fibers are blended, the modulus of the inorganic fibers is larger than that of the organic fiber matrix, and the inorganic fibers are more supported under the same strain; when the diaphragm receives the exogenic action, from inorganic fibre to the organic fibre base member transmission, the effect direction of force can change, follows fibre orientation direction transmission promptly, and this kind of transfer action also plays the dispersion effect of power to a certain extent to strengthened the ability that the membrane material bore exogenic action, showed the improvement by a wide margin of non-woven fabrics mechanical properties in the macro.
The embodiment of the application provides a lithium ion battery diaphragm supporting layer, includes: a non-woven fabric layer.
The non-woven fabric layer comprises first fibers, second fibers and third fibers; the first fiber is organic fiber, and the second fiber is inorganic fiber; the third fibers are organic binder fibers.
The organic fiber and the inorganic fiber are compounded, the respective advantages of the organic fiber and the inorganic fiber are considered, the effects are complementary, the application defect of a single material is made up, the high mechanical strength and the high heat resistance which are not existed in the single fiber material can be developed, and the application requirements of the lithium ion battery diaphragm on the mechanical strength and the heat stability can be met.
In some embodiments of the present application, the first fibers have a diameter in the range of 1 μm to 6 μm. Further optionally, the diameter of the first fibers is in the range of 1.5 μm to 5.5 μm.
Illustratively, the diameters of the first fibers may each be selected to be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or 6 μm.
Further, the diameter of the second fiber is not more than 6 μm, and further optionally, the diameter of the second fiber is 0-6 μm and is not equal to 0. Illustratively, the second fibers have a diameter of 0.1 μm, 0.5 μm, 2 μm, 4 μm, or 5 μm.
Further, the third fibers have a diameter of not more than 10 μm. Further optionally, the diameter of the third fiber is 0-10 μm and is not equal to 0. Illustratively, the third fibers have a diameter of 0.2 μm, 0.4 μm, 1 μm, 7 μm, or 9 μm.
If the diameters of the first fibers and the second fibers are larger than 6 μm, and the diameter of the third fibers is larger than 10 μm, the thickness of the obtained non-woven fabric layer is too large, and for a lithium ion battery with a certain specification and size, the larger the thickness of the non-woven fabric diaphragm is, the smaller the amount of active substances during battery assembly is, and the lower the battery capacity is; meanwhile, too thick fibers also increase the possibility of large holes in the non-woven fabric, which is not favorable for obtaining the expected aperture and distribution thereof, and simultaneously, the coating slurry easily permeates from the upper layer to the lower layer through the through holes, thereby increasing the possibility of generating defects such as pinholes and the like on the coating layer of the diaphragm.
Further, in some embodiments of the present application, the nonwoven layer includes fourth fibers; the fourth fiber is an organic fiber, the diameter of the fourth fiber is smaller than that of the first fiber, and the diameter of the fourth fiber is in a nanometer level.
The nanometer level organic fiber has fine diameter, and when the non-woven fabric with certain quantity is manufactured by papermaking, the nanometer level organic fiber is added, so that the number of the fibers is increased, the contact and combination among the fibers are promoted, the cross combination points of the fibers are increased, and the combination tightness of the fibers in the non-woven fabric is improved. Meanwhile, the fine fibers are beneficial to filling the pores among the fibers, or the pores among the fiber layers in the thickness direction of the non-woven fabric are properly filled, so that the coarse and fine fibers and the organic and inorganic fibers are mutually interwoven and stacked, a firm mixed pore structure with mutually nested large pores and small pores can be formed, the pore diameter of the non-woven fabric is greatly reduced, the regulation of the pore diameter is realized, the pore structure of the non-woven fabric is more fine, and the pores of the non-woven fabric are more uniform and are convenient to regulate and control.
The liquid absorption rate and the liquid retention rate of the non-woven fabric layer with the finer structure to the electrolyte are improved, the affinity of the non-woven fabric diaphragm and the electrolyte is stronger, the non-woven fabric diaphragm and the electrolyte form a stable adsorption layer on the surface of the diaphragm, the interface property of the diaphragm is further improved, the transmission of lithium ions in the reaction process of the battery is promoted, and the performance of the battery is improved. In addition, the phenomenon of electrolyte exhaustion caused by reasons such as leakage and the like in the use process of the non-woven fabric diaphragm can be effectively prevented by high liquid absorption and high liquid retention rate, the filling time of the electrolyte is shortened in the battery assembly production process, and the manufacturing cost is reduced.
In addition, the addition of the nanoscale organic fibers increases the total specific surface area of the fibers of the non-woven fabric layer, and is beneficial to increasing the binding force of the fibers and coating slurry and improving the retention rate of the slurry when coating is carried out on the surface of the non-woven fabric layer subsequently.
Further, in some embodiments of the present application, the fourth fiber has a diameter greater than 100nm and less than 1 μm.
Further optionally, the diameter of the fourth fiber is greater than 110nm and less than 0.9 μm.
Illustratively, the fourth fiber has a diameter of 0.15 μm, 0.20 μm, 0.30 μm, 0.40 μm, 0.50 μm, 0.60 μm, 0.70 μm, or 0.80 μm.
Further, in some embodiments of the present application, the nonwoven fabric layer has an average pore size of not greater than 5 μm.
Further optionally, the average pore diameter of the non-woven fabric layer is 1 μm to 5 μm; further alternatively, the nonwoven fabric layer may have an average pore diameter of 1 to 3 μm.
Illustratively, the nonwoven fabric layer described above has an average pore size of 1.2 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, or 4.5 μm.
Further, in some embodiments of the present application, the ratio of the maximum pore size to the average pore size of the nonwoven fabric layer is not less than 1 and not more than 10. Further optionally, the ratio of the maximum pore size to the average pore size of the nonwoven fabric layer is not less than 1 and not more than 5.
Illustratively, the nonwoven fabric layer has a ratio of the maximum pore size to the average pore size of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
Under the condition of the same thickness, the larger the pore diameter of the diaphragm is, the smaller the resistance to lithium ion migration is, but the mechanical property and the electronic insulating property of the diaphragm are reduced, and the diaphragm is easy to perforate to cause micro short circuit of the battery; too small a pore diameter increases internal resistance, resulting in low ion transmission efficiency. The micropores are not uniformly distributed, and local current is easily formed to be overlarge when the battery works, so that the performance of the battery is influenced, and even the safety problem is caused. The average pore diameter of the non-woven fabric layer is not more than 5 μm, and the ratio of the maximum pore diameter to the average pore diameter is not less than 1 and not more than 10, so that the separator has a rich porous structure. The abundant porous structure is the guarantee that current density is even, and it is crucial to guarantee that the pore structure is even and abundant in the diaphragm preparation process, helps avoiding the attenuation of electrode performance that leads to of the asymmetry of electric current when high-power discharges, guarantees not that inside short circuit or little short circuit takes place, and is more excellent in imbibition rate, liquid retention rate performance, guarantees the high-efficient quick transfer of ion, is favorable to the circulation of electric core.
When the average pore diameter of the nonwoven fabric layer is greater than 5 μm and the maximum pore diameter/average pore diameter ratio is greater than 10, the coating slurry easily permeates from the coating surface to the back surface, through-holes are formed in the coating layer, and finally the coating slurry adheres to the surface of the guide roller, causing foreign matter contamination.
Further, in some embodiments of the present application, the first fiber includes: at least one of polyethylene terephthalate fibers, polybutylene terephthalate fibers, polyethylene fibers, polypropylene fibers, polyvinyl chloride fibers, ES fibers, polyamide fibers, polyimide fibers, polytetrafluoroethylene fibers, polyvinyl alcohol fibers, polyvinylidene fluoride fibers, polyphenylene sulfide fibers, polyether ether ketone fibers, polyacrylonitrile fibers, polycarbonate fibers, or aramid fibers.
In other alternative embodiments of the present application, the first fibers may also be selected from polyethylene fibers, polypropylene fibers, polyvinyl chloride fibers, and other polyolefin fibers besides ES fibers.
Further, the polyamide fiber may be selected from PA66 fiber.
Further, in some embodiments of the present application, the material of the fourth fiber may be selected from various materials as the first fiber. It should be noted that in particular embodiments, the first fibers and the fourth fibers may be identical or different.
Illustratively, when the material of the first fiber and the fourth fiber is the same, the first fiber may be selected from polyethylene terephthalate fiber, and similarly, the fourth fiber may also be selected from polyethylene terephthalate fiber, in which case the two fibers differ only in fiber diameter, and the first fiber is a micron-sized fiber; the fourth fiber is a nano-scale fiber; for example, the diameter of the first fibers is 1.3 μm; the diameter of the fourth fiber was 0.3. mu.m.
Illustratively, when the materials of the first fiber and the fourth fiber are not the same, the first fiber may be selected as an ES fiber; the fourth fiber is selected from polyamide fiber; in this case, the materials are different from each other, and the fiber diameters are different from each other. For example, the diameter of the first fibers is 2.3 μm; the diameter of the fourth fiber was 0.4. mu.m.
Further, in some embodiments of the present application, the second fiber includes: alumina silicate fiber, mullite fiber, forsterite fiber, alumina fiber, quartz fiber, zirconia fiber, SiO2CaO-MgO based fiber and Al2O3CaO-based fiber, Al2O3-SiO2-ZrO2At least one of series fiber, boride fiber, carbide fiber, nitride fiber, magnesium aluminum silicon ternary glass fiber, magnesium aluminum silicon series glass fiber or silicon aluminum calcium magnesium series glass fiber.
Further alternatively, the aluminum silicate fibers may be selected from aluminum silicate fibers containing chromium, zirconium, or boron.
In other alternative embodiments of the present application, the above-mentioned aluminum silicate fibers may also be selected from other aluminum silicate fibers commonly used in the art.
In other alternative embodiments of the present application, the second fiber may be mullite fiber or forsterite fiber.
Further alternatively, the nitride fiber is selected from a silicon nitride fiber or a boron nitride fiber.
Further, in some embodiments of the present application, the third fiber includes: at least one of polyethylene terephthalate undrawn fiber, polybutylene terephthalate undrawn fiber, polyolefin fiber, or sheath-core structure composite fiber.
Further alternatively, the polyolefin fibers may be selected from polyethylene, polypropylene, polyvinyl chloride, and the like.
Further alternatively, the sheath-core structure composite fiber is formed by using polyolefin, copolyester, copolyamide and the like as sheath materials.
Further, in some embodiments of the present application, the nonwoven fabric layer has a third fiber content of 15% to 40% by mass, and the balance of the first fiber, the second fiber, and the fourth fiber; in the first fiber, the second fiber and the fourth fiber, the proportion of the second fiber is less than or equal to 35 percent; the percentage of the fourth fiber is 0-25% and is not equal to 0.
Further optionally, in terms of mass percentage, in the non-woven fabric layer, the proportion of the third fibers is 15% to 39%, and the balance is the first fibers, the second fibers and the fourth fibers; in the first fibers, the second fibers and the fourth fibers, the proportion of the second fibers is 0-34% and is not equal to 0; the percentage of the fourth fiber is 0-24% and is not equal to 0.
Exemplarily, in the non-woven fabric layer, the proportion of the third fibers is 35% by mass, and the balance is the first fibers, the second fibers and the fourth fibers; the proportion of the second fibers in the first fibers, the second fibers and the fourth fibers is 33%; the proportion of the fourth fiber is 23 percent, and the rest is the first fiber.
If the inorganic fiber mass fraction is more than 35 wt%, the nonwoven fabric tends to be brittle, to be weak, to be broken or to be broken during the winding process. The bonding force among the fibers is ensured by the bonding fibers, if the content of the bonding fibers is too low and the content of the organic fibers is too high, the fibers in the non-woven fabric cannot be fully adhered and fixed, the net-shaped structure is loose and difficult to fix and shape, and the mechanical strength of the non-woven fabric is difficult to ensure. On the contrary, if the content of the binder fiber is too high and the content of the organic fiber is too low, the excessive binder fiber melts on the surface of the non-woven fabric, which easily causes severe pore blocking, and makes it difficult to obtain the desired pore structure.
Further, the melting point or the softening point of the third fibers is 100-220 ℃; the melting point or softening point of the first fiber and the melting point or softening point of the fourth fiber are higher than that of the third fiber by not less than 20 ℃.
The third fiber is organic bonding fiber with relatively low melting point or softening point, and the bonding fiber is partially or completely melted when being subjected to hot rolling treatment, so that the fibers in the non-woven fabric are bonded with each other, and a three-dimensional network structure of the firm non-woven fabric is formed after cooling and solidification. If the melting point or softening point of the bonding fiber is too low, the bonding fiber is easy to be excessively melted in the hot pressing process, and the bonding roller is serious; if the melting point or softening point of the binder fiber is too high, the binder fiber cannot be melted in time at the time of hot pressing, and it is difficult to obtain sufficient adhesive strength in the nonwoven fabric.
Further optionally, the melting point or softening point of the third fibers is 110-210 ℃; the melting point or softening point of the first fiber and the melting point or softening point of the fourth fiber are higher than that of the third fiber by not less than 20 ℃.
The melting point or softening point of the first fibers and the melting point or softening point of the fourth fibers may be selected to be the same or different.
Illustratively, the melting or softening point of the third fibers is 200 ℃; the melting point or softening point of the first fibers is the same as the melting point or softening point of the fourth fibers. For example: the melting point or softening point of the first fibers is 230 ℃; the melting or softening point of the fourth fiber is 230 ℃. Or the melting point or softening point of the first fibers is different from the melting point or softening point of the fourth fibers. For example: the melting point or softening point of the first fibers is 240 ℃; the melting or softening point of the fourth fiber was 235 ℃.
Further, the fiber lengths of the first fibers, the second fibers, the third fibers and the fourth fibers are all in the range of 1mm to 6 mm. Further optionally, the fiber lengths of the first, second, third, and fourth fibers are all in the range of 1.1mm to 5.9 mm. Further optionally, the fiber lengths of the first, second, third, and fourth fibers are all in the range of 2.5mm to 5.5 mm.
If the length of the fiber is less than 1mm, the problem of too low strength of the non-woven fabric may exist, and even the fiber cannot be made into paper; if the length of the fiber is more than 6mm, the overlong fiber is easy to be agglomerated and tangled, so that the serious appearance performance defect of the non-woven fabric is caused.
Further, the thickness of the non-woven fabric layer is 5 to 35 μm. Further alternatively, the thickness of the nonwoven fabric layer is 6 μm to 34 μm. Illustratively, the thickness of the nonwoven layer is 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 15 μm, 16 μm, 18 μm, 20 μm, 22 μm, 25 μm, 30 μm, or 33 μm.
The thickness of the non-woven layer directly affects the thickness of the coated separator. If the thickness of the non-woven fabric layer is larger than 35 mu m, the thickness of the diaphragm is too large, so that the internal resistance of the battery is increased, the ion migration is blocked, and the battery cycle performance is poor. If the thickness of the non-woven fabric layer is less than 5 μm, the thermal stability and the mechanical strength of the separator are greatly reduced due to the excessively thin non-woven fabric layer, so that the mechanical requirements of the assembly process are difficult to meet, the battery is easy to break down to cause short circuit, and the stability and the safety of the separator product are challenged.
Further, the density of the nonwoven fabric layer was 0.50g/m3～0.9g/m3(ii) a Further optionally, the nonwoven layer has a density of 0.51g/m3～0.89g/m3(ii) a Illustratively, the density of the nonwoven layer is 0.54g/m3、0.62g/m3、0.73g/m3、0.75g/m3、0.77g/m3、0.80g/m3、0.82g/m3、0.85g/m3。
When the density of the non-woven fabric layer is less than 0.50g/m3In this case, the coating slurry penetrates too much into the surface of the nonwoven fabric layer and penetrates into the back surface. When the density is more than 0.9g/m3In the process, the non-woven fabric layer may have serious pore blocking, so that sufficient porosity cannot be ensured, the transmission efficiency of ions in battery reaction is influenced, and finally, the electrical property of the non-woven fabric diaphragm is insufficient.
Further, in some embodiments of the present application, the nonwoven layer has a machine direction tensile strength of 5.6N/15mm to 65N/15 mm;
further optionally, the nonwoven layer has a machine direction tensile strength of 7.4N/15mm to 50N/15 mm.
Further optionally, the nonwoven layer has a machine direction tensile strength of 9.3N/15mm to 46.7N/15 mm.
Illustratively, the nonwoven layer described above has a tensile strength in the machine direction of 8.23N/15mm, 10.29N/15mm, 14.41N/15mm, 18.52N/15mm, 20.58N/15mm, 22.64N/15mm, 26.46N/15mm, 29.11N/15mm, 33.08N/15mm, 35.35N/15mm, 41.46N/15mm, 44.07N/15mm, 48.23N/15mm, 55.13N/15mm, 64.68N/15 mm.
The transverse tensile strength of the non-woven fabric layer is 3.5N/15 mm-55N/15 mm.
Furthermore, the transverse direction tensile strength of the non-woven fabric layer is 5.4N/15 mm-45N/15 mm.
Further optionally, the nonwoven layer has a transverse direction tensile strength of 7.8N/15mm to 33.1N/15 mm.
Illustratively, the nonwoven layer has a cross-directional tensile strength of 5.88N/15mm, 7.35N/15mm, 10.29N/15mm, 14.72N/15mm, 18.58N/15mm, 20.58N/15mm, 25.73N/15mm, 29.41N/15mm, 33.10N/15 mm.
The longitudinal tensile strength of the non-woven fabric layer is 5.6N/15 mm-65N/15 mm; the transverse tensile strength is 3.5N/15 mm-55N/15 mm, the mechanical strength of the lithium ion battery diaphragm can be effectively improved, and the use safety of the lithium ion battery is expected to be improved.
The nonwoven fabric layer of the present application is not particularly limited in preparation method. For example, a nonwoven fabric preparation method known in the art can be used to prepare a fiber base paper, and then the formed fiber base paper is subjected to a hot calendering treatment, optionally at a temperature in the range of 100 ℃ to 300 ℃.
Some embodiments of the present application provide a lithium ion battery separator comprising a lithium ion battery separator support layer provided in any of the foregoing manners.
The features and properties of the present application are described in further detail below with reference to examples:
example 1
The lithium ion battery diaphragm is prepared according to the following steps:
and step S1, preparing a non-woven fabric layer.
According to the raw material fiber proportion in the table 1, an inclined wire paper machine is adopted to make fiber base paper, and then the fiber base paper is subjected to hot calendering treatment, wherein the treatment temperature is 230 +/-5 ℃; the hot calender adopts a steel roller/soft roller combination.
And step S2, preparing the lithium ion battery diaphragm.
The nonwoven fabric obtained in step S1 was cut into a specimen of a4 size, and then one surface of the nonwoven fabric specimen was coated with alumina ceramic slurry using a wire roll. Wherein, the alumina ceramic slurry comprises 35% of alumina, 10% of PVDF and the balance of water by mass percent. And drying the non-woven fabric sample after coating to finally obtain the lithium ion battery diaphragm.
Examples 2 to 6
A lithium ion battery separator was provided, which was prepared in the same manner as in example 1, with the raw material fiber ratios shown in table 1.
Comparative examples 1 to 6
A lithium ion battery separator was provided, which was prepared in the same manner as in example 1, with the raw material fiber ratios shown in table 1.
TABLE 1
Figure BDA0003244187740000151
Figure BDA0003244187740000161
Figure BDA0003244187740000171
Examples of the experiments
(1) The performance of the nonwoven fabric layers obtained in step S1 of examples 1 to 6 was examined.
The "areal density" of the nonwoven fabric was determined by the method of GB/T451.2-2002. The "density" of the nonwoven fabric was determined by dividing the "areal density" of the nonwoven fabric by the "thickness" of the nonwoven fabric, which was determined according to the method of GB/T451.3-2002. The "pore size" of the nonwoven fabric was determined according to GB/T32361-2015 method. The "tensile strength" of the nonwoven fabric was determined according to the method of GB/T12914-. The "thermal shrinkage" of the nonwoven fabric was measured according to the method of GB/T12027-2004. The "folding strength" of the nonwoven fabric was measured according to the method of GB/T457-.
(2) The lithium ion battery separators prepared in step S2 of examples 1 to comparative example 6 were examined for their performance.
Wherein, the number of the pin holes is tested according to the method; during measurement, a sample to be measured is flatly laid on the upper surface of the lamp box, the condition is observed through human eyes, and the number of visible pinholes in each square meter of non-woven fabric is used as a test result.
Coating thickness, tested according to the method; the thickness of the coated non-woven fabric is subtracted from the thickness of the pure non-woven fabric.
Coating adhesion, tested according to the method; the surface density of the coated non-woven fabric is subtracted from the surface density of the pure non-woven fabric.
The coating solution penetrated to the back side and the test was performed according to the method. When the measurement is carried out, the condition is observed by human eyes, the percentage of the area of the coating liquid on the back surface of the non-woven fabric in each square meter of the non-woven fabric is taken as a detection result, and the evaluation standard is as follows: o: no coating liquid penetrates to the back surface, and the qualified level is achieved; x: the coating liquid penetrated to the back surface to an unacceptable level.
The test results are shown in tables 2-1 and 2-2.
TABLE 2-1
Figure BDA0003244187740000181
Figure BDA0003244187740000191
Tables 2 to 2
Figure BDA0003244187740000192
As can be seen from tables 2-1 and 2-2, the nonwoven fabrics of examples 1-6 of the present application had a longitudinal tensile strength of 152.1N/15mm to 174.3N/15 mm; the transverse tensile strength of the non-woven fabric is 59.2N/15 mm-81.1N/15 mm, the mechanical strength of the lithium ion battery separator is effectively improved, and the non-woven fabric has good thermal shrinkage performance, particularly the high-temperature (200 ℃) thermal shrinkage performance is improved.
Comparing example 7 with comparative example 2, and comparing example 8 with comparative example 4, it is found that when the nonwoven fabric strength is too low (the machine direction tensile strength is less than 5.6N/15mm, and the cross direction strength is less than 3.5N/mm), the folding endurance of the nonwoven fabric film is remarkably lowered, the folding endurance and the bending endurance of the nonwoven fabric are lowered, and the adaptability to the winding process is also deteriorated.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. A lithium ion battery separator support layer, comprising: a non-woven fabric layer;
the non-woven fabric layer comprises first fibers, second fibers and third fibers; the first fibers are organic fibers, and the second fibers are inorganic fibers; the third fibers are organic bonding fibers;
the longitudinal tensile strength of the non-woven fabric layer is 5.6N/15 mm-65N/15 mm; the transverse tensile strength of the non-woven fabric layer is 3.5N/15 mm-55N/15 mm; the nonwoven fabric layer has an average pore diameter of not more than 5 μm and a ratio of a maximum pore diameter to the average pore diameter of not less than 1 and not more than 10.
2. The lithium ion battery separator support layer of claim 1,
the diameter of the first fiber is within the range of 1-6 μm;
the second fibers have a diameter of not more than 6 μm and the third fibers have a diameter of not more than 10 μm.
3. The lithium ion battery separator support layer of claim 1,
the non-woven fabric layer comprises fourth fibers; the fourth fiber is an organic fiber, the diameter of the fourth fiber is smaller than that of the first fiber, and the diameter of the fourth fiber is in a nanometer level.
4. The lithium ion battery separator support layer of claim 3,
the fourth fibers have a diameter greater than 100nm and less than 1 μm.
5. The lithium ion battery separator support layer of claim 3,
in the non-woven fabric layer, the proportion of the third fibers is 15-40% by mass, and the balance is the first fibers, the second fibers and the fourth fibers;
in the first fibers, the second fibers and the fourth fibers, the proportion of the second fibers is less than or equal to 35 percent; the percentage of the fourth fibers is 0-25% and is not equal to 0.
6. The lithium ion battery separator support layer of claim 3,
the melting point or softening point of the third fibers is 100-220 ℃; the melting point or softening point of the first fibers and the melting point or softening point of the fourth fibers are higher than that of the third fibers by not less than 20 ℃.
7. The lithium ion battery separator support layer of claim 3,
the fiber lengths of the first fibers, the second fibers, the third fibers and the fourth fibers are all in the range of 1-6 mm.
8. The lithium ion battery separator support layer of claim 6,
the density of the non-woven fabric layer is 0.50g/m3～0.9g/m3(ii) a The thickness of the non-woven fabric layer is 5-35 mu m.
9. The lithium ion battery separator support layer according to any one of claims 1 to 8,
the first fiber includes: at least one of polyethylene terephthalate fibers, polybutylene terephthalate fibers, polyethylene fibers, polypropylene fibers, polyvinyl chloride fibers, ES fibers, polyamide fibers, polyimide fibers, polytetrafluoroethylene fibers, polyvinyl alcohol fibers, polyvinylidene fluoride fibers, polyphenylene sulfide fibers, polyether ether ketone fibers, polyacrylonitrile fibers, polycarbonate fibers, or aramid fibers;
optionally, the second fibers comprise: alumina silicate fiber, mullite fiber, forsterite fiber, alumina fiber, quartz fiber, zirconia fiber, SiO2CaO-MgO based fiber and Al2O3CaO-based fiber, Al2O3-SiO2-ZrO2At least one of system fiber, boride fiber, carbide fiber, nitride fiber, magnesium aluminum silicon ternary glass fiber, magnesium aluminum silicon system glass fiber or silicon aluminum calcium magnesium system glass fiber;
optionally, the third fibers comprise: at least one of polyethylene terephthalate undrawn fiber, polybutylene terephthalate undrawn fiber, polyolefin fiber, or sheath-core structure composite fiber.
10. A lithium ion battery separator comprising the lithium ion battery separator support layer of any one of claims 1 to 9.
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Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002313305A (en) * 2001-04-18 2002-10-25 Nippon Sheet Glass Co Ltd Separator for use in lead acid battery and lead acid battery using it
US20030054233A1 (en) * 2001-09-20 2003-03-20 Jerry Zucker Reinforced multilayer separator for lead-acid batteries
CN101163828A (en) * 2005-04-19 2008-04-16 帝人株式会社 Carbon fiber composite sheet, use of the same as heat transferring article, and sheet for pitch-based carbon fiber mat for use therein
JP2008227296A (en) * 2007-03-14 2008-09-25 Nippon Sheet Glass Co Ltd Separator for electric double layer capacitor and electric double layer capacitor
JP2010129308A (en) * 2008-11-26 2010-06-10 Tomoegawa Paper Co Ltd Power storage device separator
CN101777635A (en) * 2009-12-30 2010-07-14 莱州联友金浩新型材料有限公司 Sulfonated battery diaphragm
CN102522514A (en) * 2011-12-21 2012-06-27 莱州联友金浩新型材料有限公司 High-temperature resistant micropore thin film material and application thereof
CN103337603A (en) * 2013-07-16 2013-10-02 莱州联友金浩新型材料有限公司 Porous battery diaphragm material and manufacturing method and application of porous battery diaphragm material
CN104205418A (en) * 2012-04-04 2014-12-10 旭化成纤维株式会社 Separator
CN104870156A (en) * 2012-11-14 2015-08-26 布莱恩·G·莫兰 Single-layer lithium-ion battery separators exhibiting low shrinkage
JP5982080B1 (en) * 2015-03-30 2016-08-31 日本板硝子株式会社 Nonaqueous electrolyte secondary battery separator and nonaqueous electrolyte secondary battery
CN108598337A (en) * 2017-12-26 2018-09-28 广州华创化工材料科技开发有限公司 A kind of lithium ion battery separator base material and its preparation method and application
CN110429227A (en) * 2019-07-03 2019-11-08 莱州联友金浩新型材料有限公司 A kind of preparation method of fibrous type lithium ion battery separator
CN111816824A (en) * 2020-06-11 2020-10-23 深圳市星源材质科技股份有限公司 Non-woven fabric used as lithium ion battery diaphragm base film, diaphragm and lithium ion battery

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002313305A (en) * 2001-04-18 2002-10-25 Nippon Sheet Glass Co Ltd Separator for use in lead acid battery and lead acid battery using it
US20030054233A1 (en) * 2001-09-20 2003-03-20 Jerry Zucker Reinforced multilayer separator for lead-acid batteries
CN101163828A (en) * 2005-04-19 2008-04-16 帝人株式会社 Carbon fiber composite sheet, use of the same as heat transferring article, and sheet for pitch-based carbon fiber mat for use therein
JP2008227296A (en) * 2007-03-14 2008-09-25 Nippon Sheet Glass Co Ltd Separator for electric double layer capacitor and electric double layer capacitor
JP2010129308A (en) * 2008-11-26 2010-06-10 Tomoegawa Paper Co Ltd Power storage device separator
CN101777635A (en) * 2009-12-30 2010-07-14 莱州联友金浩新型材料有限公司 Sulfonated battery diaphragm
CN102522514A (en) * 2011-12-21 2012-06-27 莱州联友金浩新型材料有限公司 High-temperature resistant micropore thin film material and application thereof
CN104205418A (en) * 2012-04-04 2014-12-10 旭化成纤维株式会社 Separator
CN104870156A (en) * 2012-11-14 2015-08-26 布莱恩·G·莫兰 Single-layer lithium-ion battery separators exhibiting low shrinkage
CN103337603A (en) * 2013-07-16 2013-10-02 莱州联友金浩新型材料有限公司 Porous battery diaphragm material and manufacturing method and application of porous battery diaphragm material
JP5982080B1 (en) * 2015-03-30 2016-08-31 日本板硝子株式会社 Nonaqueous electrolyte secondary battery separator and nonaqueous electrolyte secondary battery
CN108598337A (en) * 2017-12-26 2018-09-28 广州华创化工材料科技开发有限公司 A kind of lithium ion battery separator base material and its preparation method and application
CN110429227A (en) * 2019-07-03 2019-11-08 莱州联友金浩新型材料有限公司 A kind of preparation method of fibrous type lithium ion battery separator
CN111816824A (en) * 2020-06-11 2020-10-23 深圳市星源材质科技股份有限公司 Non-woven fabric used as lithium ion battery diaphragm base film, diaphragm and lithium ion battery

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