CN110233221A - A kind of battery diaphragm and preparation method thereof and a kind of lithium ion battery and preparation method thereof - Google Patents

A kind of battery diaphragm and preparation method thereof and a kind of lithium ion battery and preparation method thereof Download PDF

Info

Publication number
CN110233221A
CN110233221A CN201810178960.5A CN201810178960A CN110233221A CN 110233221 A CN110233221 A CN 110233221A CN 201810178960 A CN201810178960 A CN 201810178960A CN 110233221 A CN110233221 A CN 110233221A
Authority
CN
China
Prior art keywords
layer
inorganic
conductive polymer
slurries
weight
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201810178960.5A
Other languages
Chinese (zh)
Other versions
CN110233221B (en
Inventor
胡家玲
刘荣华
单军
何龙
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BYD Co Ltd
Original Assignee
BYD Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BYD Co Ltd filed Critical BYD Co Ltd
Priority to CN201810178960.5A priority Critical patent/CN110233221B/en
Publication of CN110233221A publication Critical patent/CN110233221A/en
Application granted granted Critical
Publication of CN110233221B publication Critical patent/CN110233221B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic 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
    • H01M50/44—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
    • H01M50/449—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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

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

Abstract

The invention discloses a kind of battery diaphragm and preparation method thereof and using the lithium ion battery of the battery diaphragm, which contains polyolefin porous film layer, non-conductive polymer fiber non-woven layer of cloth, the first inorganic layer and the second inorganic layer；Polyolefin porous film layer is connected with non-conductive polymer fiber non-woven layer of cloth by the second inorganic layer；First inorganic layer includes second part and optional first part, and first part is located at the surface of the non-conductive polymer fiber non-woven layer of cloth, and second part is located in at least partly hole of the non-conductive polymer fiber non-woven layer of cloth.Battery diaphragm according to the present invention permeability with higher and intensity, are able to maintain its shape and intensity with higher, still at high temperature especially so as to be obviously improved the high temperature safe performance and high/low temperature storge quality of lithium ion battery.

Description

A kind of battery diaphragm and preparation method thereof and a kind of lithium ion battery and preparation method thereof
Technical field
The present invention relates to a kind of battery diaphragms and preparation method thereof, and the invention further relates to the lithium ions using the battery diaphragm Battery and preparation method thereof.
Background technique
Lithium ion battery is mainly made of positive/negative material, electrolyte, diaphragm and battery case packaging material.Diaphragm is The important component of lithium ion battery prevents internal short-circuit of battery for separating anode and cathode；Diaphragm allow electrolyte from Son passes freely through, and completes charge discharge process.The performance of diaphragm determines the interfacial structure of battery, internal resistance etc., direct shadow The characteristics such as high rate performance, cycle performance and the security performance (high temperature resistance) of battery are rung, the diaphragm haveing excellent performance is to raising The comprehensive performance of battery plays an important role.
Due to having the characteristics that simple low in raw material price, preparation process, high mechanical strength, electrochemical stability are strong, machine The polyolefin film of tool pulling method preparation, such as polyethylene, microporous polypropylene membrane are the lithium ion battery separators of main commercialization at present.
But the broken film temperature of said polyolefins film is lower, such as polyethylene film is about 140 DEG C, polypropylene screen is about 160 ℃.In battery improper use, easily causing diaphragm retracts, (wherein, shrinking percentage of the common polythene film at 180-200 DEG C reaches To 80% or more), or even fusing, lead to battery short circuit and causes serious safety accident.
For the disadvantages mentioned above of polyolefin film, researcher develops organic-inorganic composite diaphragm, in polyalkene diaphragm Surface forms inorganic, ceramic layer, which can be improved the security performance of battery at normal temperature, but still be difficult to improve The high temperature safe performance of battery, because inorganic, ceramic layer is attached to polyolefin porous membrane table in the organic-inorganic composite diaphragm The intensity in face, inorganic, ceramic layer itself is low, and polyolefin porous membrane shrinks, even melts at high temperature, cannot keep its original There are shape and intensity, the intensity of inorganic, ceramic layer is also remarkably decreased therewith, or even occurs to be crushed, and causes battery safety significant Decline, or even serious safety accident occurs.
In addition, researcher using non-conductive polymer (such as ethylene glycol terephthalate) non-woven fabrics as basement membrane, Coating ceramic slurry prepares diaphragm, still, using the lithium ion battery of the diaphragm in storage process, particularly high-temperature storage process In, power reservoir capacity is weak and service life is shorter, and reason may is that in the battery diaphragm, the hole of the non-woven fabrics as basement membrane It is big and more, cause the intensity of the battery diaphragm extremely low, during the process of storage, particularly high-temperature storage, easily occurs to put certainly Electricity, the power reservoir capacity for not only resulting in battery die down, and are obviously shortened the service life of battery.
In conclusion widening with lithium ion battery applications field, needs the exploitation more excellent diaphragm of performance, to mention High battery safety and the other service performances for improving battery.
Summary of the invention
It is an object of the invention to overcome the existing organic and inorganic diaphragm using polyolefin as basement membrane easily to shrink at high temperature It even melting, causes battery security poor, the organic and inorganic diaphragm intensity using non-conductive polymer non-woven fabrics as basement membrane is low, The problem for leading to battery low temperature and high-temperature storage performance difference, provides a kind of battery diaphragm, battery diaphragm intensity with higher, It is able to maintain its shape and intensity with higher, still at high temperature especially so as to improve high temperature safety and the storage of battery Performance.
According to the first aspect of the invention, the present invention provides a kind of battery diaphragm, which contains polyolefin Porous membrane layer, non-conductive polymer fiber non-woven layer of cloth, the first inorganic layer and the second inorganic layer；
The polyolefin porous film layer and the non-conductive polymer fiber non-woven layer of cloth pass through second inorganic layer Connect；
First inorganic layer includes second part and optional first part, and the first part is located at described non- The surface of conductive polymer fibers nonwoven layer, the second part are located at the non-conductive polymer fiber non-woven layer of cloth extremely In small part hole.
According to the second aspect of the invention, the present invention provides a kind of preparation method of battery diaphragm, this method includes Following steps:
S11, the first slurries containing binder are coated at least one surface of polyolefin porous membrane, form binder slurry Liquid layer；
S12, it will be dried after non-conductive polymer fabric nonwoven cloth and binder slurry layer pressing；
S13, the second slurries for dispersing organic/inorganic substance in the coating of the surface of non-conductive polymer fabric nonwoven cloth, form second Slurry layer, and pressure is applied to second slurry layer so that the fraction slurries in second slurry layer penetrate into it is described Non-conductive polymer fiber non-woven layer of cloth, obtains wet film；
S14, the wet film is dried.
According to the third aspect of the present invention, invention further provides a kind of preparation method of battery diaphragm, this method packets Include following steps:
S21, the third slurries of dispersion organic/inorganic substance are provided；
S22, third slurry layer is formed on the surface of the first basement membrane with the third slurries；
S23, the second basement membrane and the third slurry layer are pressed, obtains wet film；
S24, the wet film is dried；
First basement membrane and second basement membrane are respectively polyolefin porous membrane or non-conductive polymer fiber non-woven Cloth, and one of first basement membrane and second basement membrane are polyolefin porous membrane, another one is that non-conductive polymer is fine Tie up non-woven fabrics.
According to the fourth aspect of the present invention, the present invention provides by the second aspect of the present invention or third aspect institute The battery diaphragm for the method preparation stated.
According to the fifth aspect of the present invention, the present invention provides a kind of lithium ion battery, which includes just Pole, cathode and diaphragm, diaphragm setting is between the anode and the cathode, wherein the diaphragm is the present invention the Battery diaphragm described in one aspect or the 4th aspect.
According to the sixth aspect of the invention, the present invention provides a kind of preparation method of lithium ion battery, this method packets It includes:
(1) battery diaphragm is prepared using method described in the second aspect of the present invention or third aspect；
(2) between a positive electrode and a negative electrode by battery diaphragm setting, it after forming Battery Pole Core, is packaged.
Battery diaphragm according to the present invention polymerize with only with polyolefin porous membrane as basement membrane or only with non-conductive Object non-woven fabrics forms diaphragm obtained from inorganic layer in membrane surface and compares as basement membrane, has the intensity improved, especially It is still to be able to maintain its shape and intensity with higher at high temperature, so as to be obviously improved the high temperature safety of lithium ion battery Energy and high/low temperature storge quality.
Polyolefin porous membrane and non-conductive polymer non-woven fabrics are passed through inorganic layer phase by battery diaphragm according to the present invention Connect, with by polyolefin porous membrane with non-conductive polymer non-woven fabrics directly by adhesive cementation compared with, have improve it is ventilative Performance.
Specific embodiment
The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or Value should be understood as comprising the value close to these ranges or value.For numberical range, between the endpoint value of each range, respectively It can be combined with each other between the endpoint value of a range and individual point value, and individually between point value and obtain one or more New numberical range, these numberical ranges should be considered as specific open herein.
In the present invention, term is " optional " to indicate inessential, it can be understood as " with or without ", " including or not including ".
According to the first aspect of the invention, the present invention provides a kind of battery diaphragm, which contains polyolefin Porous membrane layer, non-conductive polymer fiber non-woven layer of cloth, the first inorganic layer and the second inorganic layer.
The polyolefin porous film layer can be energy swelling liquid electrolyte and the perforated membrane for transmitting lithium ion.Preferably, Polymer in the polyolefin porous film layer is polyethylene and/or polypropylene.Polymer in polyolefin porous film layer is When polyethylene and polypropylene, the polyolefin porous film layer can be that polyethylene and polyacrylic composite layer, specific example can To include but is not limited to the compound porous film layer of PE/PP/PE.
Battery diaphragm according to the present invention, the thickness of the polyolefin porous film layer can be 1-50 μm, such as: 1 μm, 2 μ m、3μm、4μm、5μm、6μm、7μm、8μm、9μm、10μm、11μm、12μm、13μm、14μm、15μm、16μm、17μm、18μm、19 μm、20μm、21μm、22μm、23μm、24μm、25μm、26μm、27μm、28μm、29μm、30μm、31μm、32μm、33μm、34μ m、35μm、36μm、37μm、38μm、39μm、40μm、41μm、42μm、43μm、44μm、45μm、46μm、47μm、48μm、49μm、 Or 50 μm.Battery diaphragm according to the present invention, even if can also diaphragm be made to have using the lesser polyolefin porous film layer of thickness There is higher intensity.Battery diaphragm according to the present invention, in a preferred embodiment, the polyolefin porous film layer With a thickness of 5-20 μm, preferably 5-15 μm.
The porosity of the polyolefin porous membrane can be 30-50%, such as: 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% or Person 50%.Preferably, the porosity of the polyolefin porous membrane is 35-45%.
In the present invention, porosity is measured using following methods:
Polyolefin porous membrane is cut into the disk that diameter is 17mm, measurement thickness (d) and quality (M0) after, in n-butanol (BuOH) 2h is impregnated in, polyolefin porous membrane is taken out to and blotted with filter paper the liquid of film surface, and it is wet to weigh polyolefin porous membrane The quality (M) of film calculates porosity according to following formula:
Wherein, P is porosity,
M0For the quality of polyolefin porous membrane dry film,
M is the quality that polyolefin porous impregnates the wet film obtained after 2h in n-butanol,
R is the radius of polyolefin porous membrane,
D is the thickness of polyolefin porous membrane,
ρBuOHFor the density of n-butanol.
Battery diaphragm according to the present invention, the non-conductive polymer fiber non-woven layer of cloth is preferably using high-intensitive polymerization The non-woven fabrics that fibres are formed.Polymer in the non-conductive polymer fiber non-woven layer of cloth is preferably polyester (as poly- to benzene Naphthalate, polybutylene terephthalate (PBT)), polyimides, one of polyetherimide and polyether-ether-ketone or It is two or more, more preferably polyethylene terephthalate and/or polybutylene terephthalate (PBT).
Battery diaphragm according to the present invention, non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane is compound as base Film, with individually using non-conductive polymer fabric nonwoven cloth as basement membrane compared with, can be substantially reduced non-conductive polymer fiber without The thickness of woven fabric, to reduce the overall thickness of battery diaphragm.Battery diaphragm according to the present invention, the non-conductive polymer fiber The thickness of nonwoven layer is preferably 5-20 μm, such as: 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm.It is highly preferred that the thickness of the non-conductive polymer fiber non-woven layer of cloth It is 10-18 μm.
Battery diaphragm according to the present invention, non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane is compound as base Film, compared with individually using non-conductive polymer fabric nonwoven cloth as basement membrane, even with the lesser non-woven fabrics of fibre diameter, Also it can make diaphragm intensity with higher.Battery diaphragm according to the present invention, in the non-conductive polymer fiber non-woven layer of cloth The diameter of fiber be preferably 0.5-5 μm, such as: 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, Or 5 μm.It is highly preferred that the diameter of the fiber in the non-conductive polymer fiber non-woven layer of cloth is 2-5 μm.
The porosity of battery diaphragm according to the present invention, the non-conductive polymer fiber non-woven layer of cloth is preferably 35- 70%, such as can be with are as follows: 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% or 70%.Battery diaphragm according to the present invention, it is described non- The porosity of conductive polymer fibers nonwoven layer is more preferably 40-65%, further preferably 45-60%, further excellent It is selected as 50-55%.
Battery diaphragm according to the present invention, first inorganic layer are identical with the inorganic matter in second inorganic layer Or it is different, it respectively can be Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2, carbon nanotube, BN, SiC, Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、PbTiO3、TiB2、CaSiO3, molecular sieve, in clay and kaolin One or more.From further increasing the wellability of the battery diaphragm, and improve the lithium ion battery using the diaphragm The angle of service performance set out, the inorganic matter in first inorganic layer and second inorganic layer is respectively preferably Al2O3And/or SiO2。
Battery diaphragm according to the present invention, inorganic matter in first inorganic layer and second inorganic layer with The form of grain exists.The average grain diameter of first inorganic layer and the particles of inorganic material in second inorganic layer can be 10nm to 3 μm, such as: 10nm, 20nm, 30nm, 40nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm、450nm、500nm、550nm、600nm、650nm、700nm、750nm、800nm、850nm、900nm、950nm、1μm、 1.5 μm, 2 μm, 2.5 μm or 3 μm.Preferably, the inorganic matter in first inorganic layer and second inorganic layer The average grain diameter of grain is respectively 20nm to 1 μm.It is highly preferred that the nothing in first inorganic layer and second inorganic layer The average grain diameter of machine composition granule is respectively 30nm to 800nm.It is further preferred that first inorganic layer and second nothing The average grain diameter of particles of inorganic material in machine nitride layer is respectively 100nm to 400nm.It is further preferred that the inorganic matter Grain contains the first particles of inorganic material and the second particles of inorganic material, and the average grain diameter of first particles of inorganic material is 40-100nm, The average grain diameter of second particles of inorganic material is 300-400nm.First particles of inorganic material and second inorganic matter The weight ratio of grain can be 0.1-10:1, preferably 0.5-5:1, more preferably 1-2:1.
Battery diaphragm according to the present invention, the inorganic matter in first inorganic layer and second inorganic layer is respectively Integral structure is formed by binder.The binder can be oiliness binder, such as polyurethane adhesive, epoxy resin glue It is one of knot agent, Kynoar binder, polytetrafluoroethylene (PTFE) binder and acrylic ester type binder or two or more.
Battery diaphragm according to the present invention, in a preferred embodiment, the binder are water-soluble binder. It is not only more environmentally friendly according to the preferred embodiment, but also compared with using oiliness binder, battery diaphragm has higher Permeability, when reason be may is that using oiliness binder, oiliness binder is easy to penetrate into polyolefin porous membrane In, block the hole of polyolefin porous membrane.
According to the preferred embodiment, the preferred embodiment of the binder includes but is not limited to polyvinyl alcohol (PVA), gathers One or more of ethylene oxide ether (PEO), water-soluble polyacrylate and water soluble compound modified polyacrylate.
" water-soluble polyacrylate " refers to the polyacrylate in molecular structure with water soluble group, such as divides Polyacrylate containing one or more of hydroxyl, amide groups and ehter bond in minor structure.
" the water soluble compound modified polyacrylate " refers to polyacrylate the shape together with water soluble compound At binder, the water soluble compound preferably interacts with polyacrylate, such as: made using water soluble compound It can be used as polyacrylate to obtain water soluble compound modified polyacrylate for the crosslinking agent of polyacrylate The specific example of the water soluble compound of crosslinking agent can include but is not limited to N hydroxymethyl acrylamide, N- hydroxylethyl acyl One or more of amine, (N- methylol) Methacrylamide and (N- ethoxy) Methacrylamide.
Battery diaphragm according to the present invention, first inorganic layer include second part and optional first part, institute The surface that first part is located at the non-conductive polymer fiber non-woven layer of cloth is stated, the second part is located at described non-conductive poly- In at least partly hole for closing fibres nonwoven layer.When first inorganic layer contains first part, described second Divide and is structure as a whole with the first part.
Battery diaphragm according to the present invention, in first inorganic layer, the thickness of first part can be 0-5 μm.? In a kind of preferred embodiment, first inorganic layer contains first part.In the preferred embodiment, described The thickness of a part is preferably 0.1-5 μm, more preferably 1-4.5 μm, further preferably 2-4 μm.
Battery diaphragm according to the present invention, the polyolefin porous film layer and the non-conductive polymer fiber non-woven layer of cloth Connected by the second inorganic layer.Directly pass through binder with by polyolefin porous membrane and non-conductive polymer fiber non-woven layer of cloth It is cementing to compare, the gas permeability of battery diaphragm can be significantly improved.The content of second inorganic layer can become in a wider scope It is dynamic.Generally, the weight ratio of second inorganic layer and first inorganic layer can be 1:2.5-16, such as: 1: 2.5,1:3,1:3.5,1:4,1:4.5,1:5,1:5.5,1:6,1:6.5,1:7,1:7.5,1:8,1:8.5,1:9,1:9.5,1: 10,1:10.5,1:11,1:11.5,1:12,1:12.5,1:13,1:13.5,1:14,1:14.5 and 1:15.Preferably, institute The weight ratio for stating the second inorganic layer and first inorganic layer is 1:3-12.
Battery diaphragm according to the present invention, on the basis of the total amount of the battery diaphragm, first inorganic layer and second The total amount of inorganic matter can be 20-85 weight %, preferably 30-80 weight %, more preferably 35-78 weight in inorganic layer %, further preferably 40-76 weight % are measured, is still more preferably 45-75 weight %.
Battery diaphragm according to the present invention, described another surface of polyolefin porous film layer can be blank surface, can also Can also be connected by inorganic layer with another non-conductive polymer fiber non-woven layer of cloth with inorganic layer.
In one embodiment, another surface of the polyolefin porous film layer is blank surface.According to the implementation The battery diaphragm of mode has the following structure: polyolefin porous film layer | the second inorganic layer | non-conductive polymer fabric nonwoven cloth Layer | the first inorganic layer.
In another embodiment, another surface of the polyolefin porous film layer has third inorganic layer.Root Had the following structure according to the battery diaphragm of the embodiment: third inorganic layer | polyolefin porous film layer | the second inorganic layer | Non-conductive polymer fiber non-woven layer of cloth | the first inorganic layer.
In this embodiment, the inorganic matter in the third inorganic layer can be Al2O3、SiO2、BaSO4、TiO2、 CuO、MgO、LiAlO2、ZrO2, carbon nanotube, BN, SiC, Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、 PbTiO3、TiB2、CaSiO3, molecular sieve, one or more of clay and kaolin, preferably Al2O3And/or SiO2。
In this embodiment, the inorganic matter in the third inorganic layer exists in the form of granules.The third without The average grain diameter of particles of inorganic material in machine nitride layer can be 10nm to 3 μm, such as: 10nm, 20nm, 30nm, 40nm, 50nm, 100nm、150nm、200nm、250nm、300nm、350nm、400nm、450nm、500nm、550nm、600nm、650nm、 700nm, 750nm, 800nm, 850nm, 900nm, 950nm, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm.Preferably, described The average grain diameter of particles of inorganic material in three inorganic layers is 20nm to 1 μm.It is highly preferred that the nothing in the third inorganic layer The average grain diameter of machine composition granule is 30nm to 800nm.It is further preferred that particles of inorganic material in the third inorganic layer Average grain diameter is 100nm to 400nm.It is further preferred that the particles of inorganic material includes the first particles of inorganic material and second Particles of inorganic material, the average grain diameter of first particles of inorganic material are 40-100nm, the average grain of second particles of inorganic material Diameter is 300-400nm.The weight ratio of first particles of inorganic material and second particles of inorganic material can be 0.1-10:1, excellent It is selected as 0.5-5:1, more preferably 1-2:1.
In this embodiment, the thickness of the third inorganic layer can be 0.3-5 μm, preferably 1-4.5 μm.
In this embodiment, the inorganic matter in the third inorganic layer forms integral structure by binder.It is described Binder can be oiliness binder, such as polyurethane adhesive, epoxy adhesive, Kynoar binder, poly- four It is one of vinyl fluoride binder and acrylic ester type binder or two or more.Preferably, the binder is water solubility Binder, preferred embodiment include but is not limited to polyvinyl alcohol (PVA), polyoxyethylene ether (PEO), water-soluble polyacrylate and One or more of water soluble compound modified polyacrylate.
In the preferred embodiment, on the basis of the total amount of battery diaphragm, the content of the third inorganic layer can Think 5-50 weight %, preferably 10-48 weight %, more preferably 20-46 weight %, further preferably 30-45 weight %, It is still more preferably 35-40 weight %.
In yet another embodiment, another surface of the polyolefin porous film layer by inorganic layer with it is another non- Conductive polymer fibers nonwoven layer connects.Had the following structure according to the battery diaphragm of the embodiment: the first inorganic layer | Non-conductive polymer fiber non-woven layer of cloth | the second inorganic layer | polyolefin porous film layer | the second inorganic layer | non-conductive polymerization Fibres nonwoven layer | the first inorganic layer.According to the diaphragm of the embodiment, positioned at polyolefin porous film layer two sides Non-conductive polymer fiber non-woven layer of cloth, the second inorganic layer and the first inorganic layer can be identical, or it is different, It is preferably identical.
Battery diaphragm according to the present invention, the thickness of the battery diaphragm can be conventional selection, such as 10-40 μm.According to Diaphragm of the invention shows the intensity of raising, can intensity with higher with lesser thickness.Battery according to the present invention Diaphragm, the thickness of the battery diaphragm are preferably 15-38 μm, and more preferably 20-36 μm.
According to the second aspect of the invention, the present invention provides a kind of preparation method of battery diaphragm, this method includes Following steps:
S11, the first slurries containing binder are coated at least one surface of polyolefin porous membrane, form binder slurry Liquid layer；
S12, it will be dried after non-conductive polymer fabric nonwoven cloth and binder slurry layer pressing；
S13, the second slurries for dispersing organic/inorganic substance in the coating of the surface of non-conductive polymer fabric nonwoven cloth, form second Slurry layer, and pressure is applied to second slurry layer so that the fraction slurries in second slurry layer penetrate into it is described Non-conductive polymer fiber non-woven layer of cloth, obtains wet film；
S14, the wet film is dried.
Preparation method described in the second aspect according to the present invention, the binder in first slurries can be viscous for oiliness Tie agent, such as polyurethane adhesive, epoxy adhesive, Kynoar binder, polytetrafluoroethylene (PTFE) binder, acrylic acid It is one of ester type binder or two or more.
In a preferred embodiment, the binder in first slurries is water-soluble binder.It is excellent according to this The embodiment of choosing, it is not only more environmentally friendly, but also compared with using oiliness binder, battery diaphragm has higher gas permeability Energy.
According to the preferred embodiment, the preferred embodiment of the binder in first slurries includes but is not limited to poly- second One in enol (PVA), polyoxyethylene ether (PEO), water-soluble polyacrylate and water soluble compound modified polyacrylate Kind is two or more.
" water-soluble polyacrylate " refers to the polyacrylate in molecular structure with water soluble group, such as divides Polyacrylate containing one or more of hydroxyl, amide groups and ehter bond in minor structure.
" the water soluble compound modified polyacrylate " refers to polyacrylate the shape together with water soluble compound At binder, the water soluble compound preferably interacts with polyacrylate, such as: made using water soluble compound It can be used as polyacrylate to obtain water soluble compound modified polyacrylate for the crosslinking agent of polyacrylate The specific example of the water soluble compound of crosslinking agent can include but is not limited to N hydroxymethyl acrylamide, N- hydroxylethyl acyl One or more of amine, (N- methylol) Methacrylamide and (N- ethoxy) Methacrylamide.Relative to 100 Parts by weight of polypropylene acid esters, the content of the water soluble compound can be 1-10 parts by weight.
Method described in the second aspect according to the present invention, the content of binder is can make first in first slurries Slurries have coating performance, while being also able to achieve and being bonded as standard.Generally, the content of binder can be in first slurries 0.1-5 weight %, preferably 0.5-4 weight %, more preferably 1-3 weight %.
The dispersing agent of first slurries can be selected according to the type of binder, be can dissolve dispersion binder It is quasi-.For example, the decentralized medium of first slurries can be when the binder in first slurries is water-soluble binder Water.
Method described in the second aspect according to the present invention, the content of inorganic matter is inorganic can make in second slurries Object is formed subject to stable dispersion liquid.Generally, the content of inorganic matter can be 5-50 weight % in second slurries, preferably For 10-40 weight %, more preferably 20-30 weight %.
Inorganic matter in second slurries can be Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2、 Carbon nanotube, BN, SiC, Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、PbTiO3、TiB2、CaSiO3, molecule One or more of sieve, clay and kaolin, preferably Al2O3And/or SiO2。
In this embodiment, the inorganic matter in second slurries exists in the form of granules.In second slurries Particles of inorganic material average grain diameter can be 10nm to 3 μm, such as: 10nm, 20nm, 30nm, 40nm, 50nm, 100nm, 150nm、200nm、250nm、300nm、350nm、400nm、450nm、500nm、550nm、600nm、650nm、700nm、 750nm, 800nm, 850nm, 900nm, 950nm, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm.Preferably, second slurries In particles of inorganic material average grain diameter be 20nm to 1 μm.It is highly preferred that particles of inorganic material in second slurries is averaged Partial size is 30nm to 800nm.It is further preferred that the average grain diameter of the particles of inorganic material in second slurries be 100nm extremely 400nm.It is further preferred that the particles of inorganic material contains the first particles of inorganic material and the second particles of inorganic material, described The average grain diameter of one particles of inorganic material is 40-100nm, and the average grain diameter of second particles of inorganic material is 300-400nm, described The weight ratio of first particles of inorganic material and second particles of inorganic material is preferably 0.1-10:1, more preferably 0.5-5:1, into one Step is preferably 1-2:1.
Second slurries also contain binder, and inorganic matter is bonded, and form integral structure.In second slurries Binder can be oiliness binder, such as polyurethane adhesive, epoxy adhesive, Kynoar binder, poly- four One or more of vinyl fluoride binder and polyacrylate binder.
In a preferred embodiment, the binder in second slurries is water-soluble binder.It is excellent according to this The embodiment of choosing, it is not only more environmentally friendly, but also compared with using oiliness binder, battery diaphragm has higher gas permeability Energy.
According to the preferred embodiment, the preferred embodiment of the binder in second slurries includes but is not limited to poly- second One in enol (PVA), polyoxyethylene ether (PEO), water-soluble polyacrylate and water soluble compound modified polyacrylate Kind is two or more.
" water-soluble polyacrylate " refers to the polyacrylate in molecular structure with water soluble group, such as divides Polyacrylate containing one or more of hydroxyl, amide groups and ehter bond in minor structure.
" the water soluble compound modified polyacrylate " refers to polyacrylate the shape together with water soluble compound At binder, the water soluble compound preferably interacts with polyacrylate, such as: made using water soluble compound It can be used as polyacrylate to obtain water soluble compound modified polyacrylate for the crosslinking agent of polyacrylate The specific example of the water soluble compound of crosslinking agent can include but is not limited to N hydroxymethyl acrylamide, N- hydroxylethyl acyl One or more of amine, (N- methylol) Methacrylamide and (N- ethoxy) Methacrylamide.Relative to 100 The content of parts by weight of polypropylene acid esters, the water soluble compound can be 1-10 parts by weight, and preferably 2-8 weight % is more excellent It is selected as 3-6 weight %.
The content of binder is subject to and can bond inorganic matter to form integral structure in second slurries.Generally, institute The content for stating binder in the second slurries can be 0.05-10 weight %, preferably 1-8 weight %.
The dispersing agent of second slurries can be selected according to the type of binder, can dissolve binder and make Inorganic matter is formed subject to stable dispersion liquid.For example, when the binder is water-soluble binder, point of second slurries Powder can be water.
Second slurries preferably also containing at least one coupling agent, with improve inorganic matter in polyolefin porous membrane and/or The adhesive force on non-conductive polymer fabric nonwoven cloth surface.The coupling agent is preferably silane coupling agent, and specific example can be with Including but not limited to 3- glycidyl ether oxypropyltrimethoxysilane, 3- aminopropyl triethoxysilane, γ-metering system Acryloxypropylethoxysilane trimethoxy silane, N- β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N- β-(aminoethyl)-γ-ammonia One or more of hydroxypropyl methyl dimethoxysilane and vinyltrimethoxysilane.The dosage of the coupling agent can To be selected according to the content of inorganic matter in second slurries.Generally, in second slurries, relative to 100 weight Part inorganic matter, the dosage of the coupling agent can be 0.5-5 parts by weight, preferably 0.8-4 parts by weight, more preferably 1-3 weight Part.
Second slurries can also contain dispersing agent, to promote inorganic particle dispersion stabilization in a dispersion medium, Its specific example can include but is not limited to polyvinyl alcohol (PVA) and/or Sodium Polyacrylate (PAANa).In second slurries The content of dispersing agent can be conventional selection.Generally, relative to 100 parts by weight of inorganic objects, the content of the dispersing agent can be with For 0.1-10 parts by weight, preferably 0.2-5 parts by weight.
Second slurries can also contain thickener, to further increase the coatability energy of the second slurries.Described Thickener can be cellulose type thickener and/or polyacrylate alkali-swelling type thickener (such as BASF in two slurries Latekoll D thickener).Relative to 100 parts by weight of inorganic objects, the content of the thickener can be 0.1-10 parts by weight, excellent It is selected as 0.5-5 parts by weight, more preferably 0.8-3 parts by weight.
The third slurries can also contain surfactant, to further increase the stability of third slurries.The table Face activating agent can be anionic surfactant, specific example can include but is not limited to neopelex, One or more of Sodium Caprylate, sldium lauryl sulfate and odium stearate.Relative to 100 parts by weight of inorganic objects, the table The content of face activating agent can be 0.1-5 parts by weight, preferably 0.2-4 parts by weight.
The coating weight of second slurries can be according to it is contemplated that the content of the inorganic matter introduced in battery diaphragm be selected It selects.Generally, coating weight of second slurries on non-conductive polymer fabric nonwoven cloth surface, it is preferable that finally prepare In battery diaphragm, be located in non-conductive polymer fabric nonwoven cloth surface and hole and non-conductive polymer fabric nonwoven cloth with The total amount of inorganic matter between polyolefin porous membrane is 20-85 weight %, preferably 30-80 weight %, more preferably 35-78 weight %, further preferably 40-76 weight % are measured, is still more preferably 45-75 weight %.
Method described in the second aspect according to the present invention in step S13, can apply the second slurry layer by roll-in Pressure, so that at least partly slurry infiltration in second slurry layer enters non-conductive polymer fiber non-woven layer of cloth In.By applying pressure to the second slurry layer, the fraction slurries in second slurry layer can also be fine through non-conductive polymer Tie up nonwoven layer so that at least partly inorganic matter be in non-conductive polymer fiber non-woven layer of cloth and polyolefin porous membrane it Between.The condition of the roll-in is in nonconductive polymers fabric nonwoven cloth table preferably so that in the battery diaphragm finally prepared The inorganic layer in face with a thickness of 0-5 μm (preferably 0.1-5 μm, more preferably 1-4.5 μm, further preferably 2-4 μm), place Inorganic matter between non-conductive polymer fiber non-woven layer of cloth and polyolefin porous membrane be located at nonconductive polymers fiber The weight ratio of inorganic matter in nonwoven surface and hole is 1:2.5-16, preferably 1:3-12.
Method described in the second aspect according to the present invention, in step S11 and step S13, can using conventional method into Row coating, such as: the combination of one or more of brushing, roller coating and spraying.In step S11 and step S13, the painting Cloth can carry out once, can also carrying out more than twice.
Method described in the second aspect according to the present invention, in step S12 and step S14, the drying is can remove slurry Volatile materials in liquid layer forms and has subject to figurate layer so that slurry layer loses flowability.Generally, step In S12 and step S14, the drying respectively can 40-80 DEG C at a temperature of carry out, preferably 50-70 DEG C at a temperature of into Row.The drying can carry out under normal pressure (that is, 1 standard atmospheric pressure), can also carry out at reduced pressure, without special It limits.The duration of the drying can be selected according to the temperature being dried, and generally can be 1-60min, preferably For 5-40min, more preferably 10-30min.
Method described in the second aspect according to the present invention, the polyolefin porous membrane can be energy swelling liquid electrolyte And transmit the perforated membrane of lithium ion.Preferably, the polymer in the polyolefin porous film layer is polyethylene and/or polypropylene. When polymer in polyolefin porous film layer is polyethylene and polypropylene, the polyolefin porous film layer can for polyethylene and Polyacrylic composite layer, specific example can include but is not limited to PE/PP/PE composite base material layer.
The thickness of the polyolefin porous film layer can be 1-50 μm, such as: 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μ m、8μm、9μm、10μm、11μm、12μm、13μm、14μm、15μm、16μm、17μm、18μm、19μm、20μm、21μm、22μm、23 μm、24μm、25μm、26μm、27μm、28μm、29μm、30μm、31μm、32μm、33μm、34μm、35μm、36μm、37μm、38μ M, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm or 50 μm.According to the present invention Method described in the second aspect, in a preferred embodiment, the polyolefin porous film layer with a thickness of 5-20 μm, Such as 5-15 μm.
The porosity of the polyolefin porous membrane can be 30-50%, such as: 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% or Person 50%.Preferably, the porosity of the polyolefin porous membrane is 35-45%.
Method described in the second aspect according to the present invention, the non-conductive polymer fiber non-woven layer of cloth preferably use The non-woven fabrics that high strength fibre is formed.Polymer in the non-conductive polymer fiber non-woven layer of cloth be preferably polyester (preferably For polyethylene terephthalate, polybutylene terephthalate (PBT)), polyimides, in polyetherimide and polyether-ether-ketone One or more.
Method described in the second aspect according to the present invention, by non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane It is compound to be used as basement membrane, compared with individually using non-conductive polymer fabric nonwoven cloth as basement membrane, it can be substantially reduced non-conductive poly- The thickness for closing fibres non-woven fabrics, to reduce the overall thickness of battery diaphragm.Method described in the second aspect according to the present invention, The thickness of the non-conductive polymer fiber non-woven layer of cloth is preferably 5-20 μm, such as: 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm.It is highly preferred that the non-conductive polymerization Fibres nonwoven layer with a thickness of 10-18 μm.
Method described in the second aspect according to the present invention, by non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane It is compound be used as basement membrane, with individually using non-conductive polymer fabric nonwoven cloth as basement membrane compared with, even with fibre diameter compared with Small non-woven fabrics can also make diaphragm intensity with higher.Method described in the second aspect according to the present invention, it is described non-to lead The diameter of fiber in electric polymer fiber non-woven layer of cloth is preferably 0.5-5 μm, such as: 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm or 5 μm.It is highly preferred that fiber in the non-conductive polymer fiber non-woven layer of cloth Diameter is 2-5 μm.
The porosity of method described in the second aspect according to the present invention, the non-conductive polymer fiber non-woven layer of cloth is excellent Be selected as 35-70%, such as can be with are as follows: 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% or 70%.The non-conductive polymer is fine The porosity of dimension nonwoven layer is more preferably 40-65%, further preferably 45-60%, is still more preferably 50-55%.
Another surface of method described in the second aspect according to the present invention, the polyolefin porous film layer can be sky White surface, it is possible to have inorganic layer can also pass through inorganic layer and another non-conductive polymer fiber non-woven layer of cloth phase It connects.
In one embodiment, another surface of the polyolefin porous film layer is blank surface.According to the implementation The battery diaphragm of mode has the following structure: polyolefin porous film layer | the second inorganic layer | non-conductive polymer fiber non-woven Layer of cloth | the first inorganic layer.
In another embodiment, another surface of the polyolefin porous film layer has third inorganic layer.Root According to the embodiment, the second slurries can be coated on to another surface of polyolefin porous membrane, and be dried, thus poly- Another surface of alkene perforated membrane forms third inorganic layer.It is had the following structure according to the battery diaphragm of the embodiment: Third inorganic layer | polyolefin porous film layer | the second inorganic layer | non-conductive polymer fiber non-woven layer of cloth | the first inorganic matter Layer.In this embodiment, on the basis of the total amount of battery diaphragm, second slurries are in the polyolefin porous film surface Coating weight preferably so that the third inorganic layer content be 5-50 weight %, preferably 10-48 weight %, more preferably 20-46 weight %, further preferably 30-45 weight % are still more preferably 35-40 weight %.
In yet another embodiment, another surface of the polyolefin porous film layer by inorganic layer with it is another non- Conductive polymer fibers nonwoven layer connects.It, can be in another surface of polyolefin porous film layer weight according to the embodiment Step S11 to S14 is carried out again, thus the battery diaphragm that preparation has the following structure: the first inorganic layer | non-conductive polymer is fine Tie up nonwoven layer | the second inorganic layer | polyolefin porous film layer | the second inorganic layer | non-conductive polymer fiber non-woven layer of cloth | First inorganic layer.According to the diaphragm of the embodiment, the non-conductive polymer positioned at polyolefin porous film layer two sides is fine It can be identical for tieing up nonwoven layer, the second inorganic layer and the first inorganic layer, or it is different, it is preferably identical.
The thickness of preparation method described in the second aspect according to the present invention, the battery diaphragm prepared by the preparation method can Think conventional selection, such as 10-40 μm.Raising is shown using diaphragm prepared by method described in the second aspect of the present invention Intensity, even if having lesser thickness, it may have higher intensity.Preparation method described in the second aspect according to the present invention, The thickness of the battery diaphragm prepared by the preparation method is preferably 15-38 μm, and more preferably 20-36 μm.
According to the third aspect of the present invention, invention further provides a kind of preparation method of battery diaphragm, this method packets Include following steps:
S21, the third slurries of dispersion organic/inorganic substance are provided；
S22, third slurry layer is formed on the surface of the first basement membrane with the third slurries；
S23, the second basement membrane and the third slurry layer are pressed, obtains wet film；
S24, the wet film is dried；
First basement membrane and second basement membrane are respectively polyolefin porous membrane or non-conductive polymer fiber non-woven Cloth, and one of first basement membrane and second basement membrane are polyolefin porous membrane, another one is that non-conductive polymer is fine Tie up non-woven fabrics.
According to the present invention in terms of third described in method, the content of inorganic matter is inorganic can make in the third slurries Object is formed subject to stable dispersion liquid.Generally, the content of inorganic matter can be 5-50 weight % in the third slurries, preferably For 10-40 weight %, more preferably 20-30 weight %.
Inorganic matter in the third slurries can be Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2、 Carbon nanotube, BN, SiC, Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、PbTiO3、TiB2、CaSiO3, molecule One or more of sieve, clay and kaolin, preferably Al2O3And/or SiO2。
In this embodiment, the inorganic matter in the third slurries exists in the form of granules.In the third slurries Particles of inorganic material average grain diameter can be 10nm to 3 μm, such as: 10nm, 20nm, 30nm, 40nm, 50nm, 100nm, 150nm、200nm、250nm、300nm、350nm、400nm、450nm、500nm、550nm、600nm、650nm、700nm、 750nm, 800nm, 850nm, 900nm, 950nm, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm.Preferably, the third slurries In particles of inorganic material average grain diameter be 20nm to 1 μm.It is highly preferred that particles of inorganic material in the third slurries is averaged Partial size is 30nm to 800nm.It is further preferred that the average grain diameter of the particles of inorganic material in the third slurries be 100nm extremely 400nm.It is further preferred that the particles of inorganic material includes the first particles of inorganic material and the second particles of inorganic material, described the The average grain diameter of one particles of inorganic material is 40-100nm, and the average grain diameter of second particles of inorganic material is 300-400nm.It is described The weight ratio of first particles of inorganic material and second particles of inorganic material can be 0.1-10:1, preferably 0.5-5:1, more preferably For 1-2:1.
The third slurries also contain binder, and inorganic matter is bonded, and form integral structure.In the third slurries Binder can be oiliness binder, such as polyurethane adhesive, epoxy adhesive, Kynoar binder, poly- four It is one of vinyl fluoride binder, acrylic ester type binder or two or more.
In a preferred embodiment, the binder in the third slurries is water-soluble binder.It is excellent according to this The embodiment of choosing, it is not only more environmentally friendly, but also compared with using oiliness binder, battery diaphragm has higher permeability.
According to the preferred embodiment, the preferred embodiment of the binder in the third slurries includes but is not limited to poly- second One in enol (PVA), polyoxyethylene ether (PEO), water-soluble polyacrylate and water soluble compound modified polyacrylate Kind is two or more.
" water-soluble polyacrylate " refers to the polyacrylate in molecular structure with water soluble group, such as divides Polyacrylate containing one or more of hydroxyl, amide groups and ehter bond in minor structure.
" the water soluble compound modified polyacrylate " refers to polyacrylate the shape together with water soluble compound At binder, the water soluble compound preferably interacts with polyacrylate, such as: made using water soluble compound It can be used as polyacrylate to obtain water soluble compound modified polyacrylate for the crosslinking agent of polyacrylate The specific example of the water soluble compound of crosslinking agent can include but is not limited to N hydroxymethyl acrylamide, N- hydroxylethyl acyl One or more of amine, (N- methylol) Methacrylamide and (N- ethoxy) Methacrylamide.Relative to 100 The content of parts by weight of polypropylene acid esters, the water soluble compound can be 1-10 parts by weight, and preferably 2-8 weight % is more excellent It is selected as 3-6 weight %.
The content of binder is subject to and can bond inorganic matter to form integral structure in the third slurries.Generally, institute The concentration for stating binder in third slurries can be 0.05-10 weight %, preferably 1-8 weight %.
The dispersing agent of the third slurries can be selected according to the type of binder, can dissolve binder and make Inorganic matter is formed subject to stable dispersion liquid.For example, when the binder is water-soluble binder, point of the third slurries Powder can be water.
The third slurries preferably also containing at least one coupling agent, with improve inorganic matter in polyolefin porous membrane and/or The adhesive force on non-conductive polymer fabric nonwoven cloth surface.The coupling agent is preferably silane coupling agent, and specific example can be with Including but not limited to 3- glycidyl ether oxypropyltrimethoxysilane, 3- aminopropyl triethoxysilane, γ-metering system Acryloxypropylethoxysilane trimethoxy silane, N- β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N- β-(aminoethyl)-γ-ammonia One or more of hydroxypropyl methyl dimethoxysilane and vinyltrimethoxysilane.The dosage of the coupling agent can To be selected according to the content of inorganic matter in the third slurries.Generally, in the third slurries, relative to 100 weight Part inorganic matter, the dosage of the coupling agent can be 0.5-5 parts by weight, preferably 0.8-4 parts by weight, more preferably 1-3 parts by weight.
The third slurries can also contain dispersing agent, to promote inorganic particle dispersion stabilization in a dispersion medium, Its specific example can include but is not limited to polyvinyl alcohol (PVA) and/or Sodium Polyacrylate (PAANa).In the third slurries The content of dispersing agent can be conventional selection.Generally, relative to 100 parts by weight of inorganic objects, the content of the dispersing agent can be with For 0.1-10 parts by weight, preferably 0.2-5 parts by weight.
The third slurries can also contain thickener, to further increase the coatability energy of third slurries.Described Thickener can be cellulose type thickener and/or polyacrylate alkali-swelling type thickener (such as BASF in three slurries Latekoll D thickener).Relative to 100 parts by weight of inorganic objects, the content of the thickener can be 0.1-10 parts by weight, excellent It is selected as 0.5-5 parts by weight, more preferably 0.8-3 parts by weight.
The third slurries can also contain surfactant, to further increase the stability of third slurries.The table Face activating agent can be anionic surfactant, specific example can include but is not limited to neopelex, One or more of Sodium Caprylate, sldium lauryl sulfate and odium stearate.Relative to 100 parts by weight of inorganic objects, the table The content of face activating agent can be 0.1-5 parts by weight, preferably 0.2-4 parts by weight.
The coating weight of the third slurries can be according to it is contemplated that the content of the inorganic matter introduced in battery diaphragm be selected It selects.Generally, coating weight of the third slurries on non-conductive polymer fabric nonwoven cloth surface, it is preferable that finally prepare In battery diaphragm, be located in non-conductive polymer fabric nonwoven cloth surface and hole and non-conductive polymer fabric nonwoven cloth with The total amount of inorganic matter between polyolefin porous membrane is 20-85 weight %, preferably 30-80 weight %, more preferably 35-78 weight %, further preferably 40-76 weight % are measured, is still more preferably 45-75 weight %.
According to the present invention in terms of third described in method can be using various methods in the first basement membrane table in step S22 Face forms third slurry layer, such as: the combination of one or more of dipping, spraying, brushing and roller coating.A kind of preferred Embodiment in, the first basement membrane described in the third slurry, thus the first membrane surface formed third slurry layer.
Method described in third aspect according to the present invention by the second basement membrane and has third slurry layer in step S23 The first basement membrane the pressing of a surface, so that polyolefin porous membrane and non-conductive polymer fabric nonwoven cloth are passed through third slurry Liquid layer engagement.In step S23, from the angle of the profile pattern for the battery diaphragm for further increasing preparation, pressed Before conjunction, preferably the third slurry layer for being used to engage with the second basement membrane is struck off.In step S23, there is the first of third slurry layer Another surface of basement membrane, can also be struck off, to be formed after raising drying on non-conductive polymer fabric nonwoven cloth surface Inorganic layer planarization.
The method according to the third aspect of the present invention is polyolefin porous membrane, the second base in first basement membrane When film is non-conductive polymer fabric nonwoven cloth, one or more of further comprising the steps of combination:
S231, pressure is applied to the third slurry layer, so that described in the fraction slurries transmission in the third slurry layer Non-conductive polymer fabric nonwoven cloth, and slurry layer is formed on the surface of the non-conductive polymer fabric nonwoven cloth；
S232, slurry layer is formed on the surface of the non-conductive polymer fabric nonwoven cloth with the third slurries.
In step S231, pressure can be applied to third slurry layer by roll-in, so that in the third slurry layer Fraction slurries penetrate into non-conductive polymer fiber non-woven layer of cloth.By applying pressure to third slurry layer, described the Fraction slurries in three slurry layers can also penetrate non-conductive polymer fiber non-woven layer of cloth, thus non-conductive polymer fiber without The surface of woven fabric layer forms slurry layer.
Operation S231 and operation S232 may be used alone, can also be used in combination, with can be in non-conductive polymer fiber Nonwoven surface is formed subject to expected inorganic layer.
The condition of step S231 and/or step S232 are in non-conductive preferably so that in the battery diaphragm finally prepared The inorganic layer on polymer fiber non-woven cloth surface with a thickness of 0-5 μm (preferably 0.1-5 μm, more preferably 1-4.5 μm, into One step is preferably 2-4 μm), inorganic matter between non-conductive polymer fiber non-woven layer of cloth and polyolefin porous membrane be located at The weight ratio of inorganic matter in nonconductive polymers fabric nonwoven cloth surface and hole is 1:2.5-16, preferably 1:3-12.
According to the present invention in terms of third described in method, in step S24, the drying is can remove waving in slurry layer Volatile material forms and has subject to figurate layer so that slurry layer loses flowability.Generally, described in step S24 Drying can 40-80 DEG C at a temperature of carry out, preferably 50-70 DEG C at a temperature of carry out.The drying can be in normal pressure It is carried out under (that is, 1 standard atmospheric pressure), can also carry out, be not particularly limited at reduced pressure.The drying it is lasting when Between can be selected according to the temperature being dried, generally can be 1-60min, preferably 5-40min, more preferably 10- 30min。
Method described in third aspect according to the present invention, the polyolefin porous membrane can be energy swelling liquid electrolyte And transmit the perforated membrane of lithium ion.Preferably, the polymer in the polyolefin porous film layer is polyethylene and/or polypropylene. When polymer in polyolefin porous film layer is polyethylene and polypropylene, the polyolefin porous film layer can for polyethylene and Polyacrylic composite layer, specific example can include but is not limited to PE/PP/PE composite base material layer.
The thickness of the polyolefin porous film layer can be 1-50 μm, such as: 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μ m、8μm、9μm、10μm、11μm、12μm、13μm、14μm、15μm、16μm、17μm、18μm、19μm、20μm、21μm、22μm、23 μm、24μm、25μm、26μm、27μm、28μm、29μm、30μm、31μm、32μm、33μm、34μm、35μm、36μm、37μm、38μ M, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm or 50 μm.According to the present invention Method described in terms of third, in a preferred embodiment, the polyolefin porous film layer with a thickness of 5-20 μm, Such as 5-15 μm.
The porosity of the polyolefin porous membrane can be 30-50%, such as: 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% or Person 50%.Preferably, the porosity of the polyolefin porous membrane is 35-45%.
Method described in third aspect, the non-conductive polymer fiber non-woven layer of cloth preferably use according to the present invention The non-woven fabrics that high strength fibre is formed.Polymer in the non-conductive polymer fiber non-woven layer of cloth be preferably polyester (preferably For polyethylene terephthalate, polybutylene terephthalate (PBT)), polyimides, in polyetherimide and polyether-ether-ketone One or more.
Method described in third aspect according to the present invention, by non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane It is compound to be used as basement membrane, compared with individually using non-conductive polymer fabric nonwoven cloth as basement membrane, it can be substantially reduced non-conductive poly- The thickness for closing fibres non-woven fabrics, to reduce the overall thickness of battery diaphragm.Method described in third aspect according to the present invention, The thickness of the non-conductive polymer fiber non-woven layer of cloth is preferably 5-20 μm, such as: 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm.It is highly preferred that the non-conductive polymerization Fibres nonwoven layer with a thickness of 10-18 μm.
Method described in third aspect according to the present invention, by non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane It is compound be used as basement membrane, with individually using non-conductive polymer fabric nonwoven cloth as basement membrane compared with, even with fibre diameter compared with Small non-woven fabrics can also make diaphragm intensity with higher.According to the present invention in terms of third described in method, it is described non-to lead The diameter of fiber in electric polymer fiber non-woven layer of cloth is preferably 0.5-5 μm, such as: 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm or 5 μm.It is highly preferred that fiber in the non-conductive polymer fiber non-woven layer of cloth Diameter is 2-5 μm.
Method described in third aspect, the porosity of the non-conductive polymer fiber non-woven layer of cloth are excellent according to the present invention Be selected as 35-70%, such as can be with are as follows: 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% or 70%.The non-conductive polymer is fine The porosity of dimension nonwoven layer is more preferably 40-65%, further preferably 45-60%, is still more preferably 50-55%.
Another surface of method described in third aspect according to the present invention, the polyolefin porous film layer can be sky White surface, it is possible to have inorganic layer can also be connected by inorganic layer with another non-conductive polymer fiber non-woven layer of cloth.
In one embodiment, another surface of the polyolefin porous film layer is blank surface.According to the implementation The battery diaphragm of mode has the following structure: polyolefin porous film layer | the second inorganic layer | non-conductive polymer fabric nonwoven cloth Layer | the first inorganic layer.
In another embodiment, another surface of the polyolefin porous film layer has third inorganic layer.Root According to the embodiment, third slurries can be coated on to another surface of polyolefin porous membrane, and be dried, thus poly- Another surface of alkene perforated membrane forms third inorganic layer.It is had the following structure according to the battery diaphragm of the embodiment: Third inorganic layer | polyolefin porous film layer | the second inorganic layer | non-conductive polymer fiber non-woven layer of cloth | the first inorganic matter Layer.In this embodiment, on the basis of the total amount of battery diaphragm, the third slurries are in the polyolefin porous film surface Coating weight preferably so that the third inorganic layer content be 5-50 weight %, preferably 10-48 weight %, more preferably 20-46 weight %, further preferably 30-45 weight % are still more preferably 35-40 weight %.
In yet another embodiment, another surface of the polyolefin porous film layer by inorganic layer with it is another non- Conductive polymer fibers nonwoven layer connects.It, can be in another surface of polyolefin porous film layer weight according to the embodiment Step S21 to S24 is carried out again, thus the battery diaphragm that preparation has the following structure: the first inorganic layer | non-conductive polymer is fine Tie up nonwoven layer | the second inorganic layer | polyolefin porous film layer | the second inorganic layer | non-conductive polymer fiber non-woven layer of cloth | First inorganic layer.According to the diaphragm of the embodiment, the non-conductive polymer positioned at polyolefin porous film layer two sides is fine It can be identical for tieing up nonwoven layer, the second inorganic layer and the first inorganic layer, or it is different, it is preferably identical.
Preparation method described in third aspect according to the present invention, the thickness of the battery diaphragm prepared by the preparation method can Think conventional selection, such as 10-40 μm.Raising is shown using diaphragm prepared by method described in third aspect of the present invention Intensity, even if having lesser thickness, it may have higher intensity.Preparation method described in third aspect according to the present invention, The thickness of the battery diaphragm prepared by the preparation method is preferably 15-38 μm, and more preferably 20-36 μm.
According to the fourth aspect of the present invention, the present invention provides by the second aspect of the present invention or third aspect institute The battery diaphragm for the method preparation stated.
According to the fifth aspect of the present invention, the present invention provides a kind of lithium ion battery, which includes just Pole, cathode and diaphragm, diaphragm setting is between the anode and the cathode, wherein the diaphragm is the present invention the Battery diaphragm described in one aspect or the 4th aspect.
Lithium ion battery according to the present invention, by using battery diaphragm according to the present invention, so that lithium ion battery has The high temperature safe performance and high/low temperature storge quality having clear improvement.The anode and cathode can be in lithium ion batteries Conventional selection is not particularly limited.
Generally, the anode contains positive active material, conductive agent and binder.Positive active material used includes The positive electrode that arbitrarily can be used for lithium ion battery, for example, cobalt-lithium oxide (LiCoO2), nickel oxide lithium (LiNiO2), manganese oxide lithium (LiMn2O4) and LiFePO 4 (LiFePO4One or more of).The cathode contains negative electrode active material, conduction Agent and binder.Negative electrode active material used can be one or more of graphite, soft carbon and hard carbon.
Lithium ion battery according to the present invention can contain electrolyte, can also not contain electrolyte.The electrolyte is It is well known to those skilled in the art, contain lithium salts and organic solvent.The lithium salts can be dissociable lithium salts, for example, can be Selected from lithium hexafluoro phosphate (LiPF6), lithium perchlorate (LiClO4) and LiBF4 (LiBF4One or more of).Institute Stating organic solvent can be for selected from ethylene carbonate (EC), propene carbonate (PC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC) and one or more of diethyl carbonate (DEC) and vinylene carbonate (VC).Preferably, the electrolyte In, the concentration of lithium salts can be 0.8-1.5mol/L.
According to the sixth aspect of the invention, the present invention provides a kind of preparation methods of lithium ion battery, this method comprises:
(1) battery diaphragm is prepared using method described in the second aspect of the present invention or third aspect；
(2) between a positive electrode and a negative electrode by membrane for polymer setting, it after forming Battery Pole Core, is packaged.
Step (2) can be carried out using the conventional method of lithium ion battery preparation technical field, and the present invention does not limit especially It is fixed.In step (2), can into Battery Pole Core filling electrolyte, can not also filling electrolyte be directly packaged.
The present invention will be described in detail with reference to embodiments, but does not therefore limit the scope of the invention.
In following embodiment and comparative example, partial size is measured using laser particle analyzer, is volume average particle size.
Embodiment 1-17 is for illustrating the present invention.
Embodiment 1
(1) the first slurries containing binder are prepared
Polyoxyethylene ether (PEO, is purchased from Aladdin, and number-average molecular weight is 1,000,000 (GPC methods)) is dispersed in water, is formed The first slurries containing binder, the concentration of PEO is 1 weight % in the first slurries.
(2) the second slurries of dispersion organic/inorganic substance are prepared
By 2kg aluminum oxide (volume average particle size 400nm), 0.01kg Sodium Polyacrylate, (number-average molecular weight is 9000, be purchased from Guangzhou Yuan Chang trade Co., Ltd) and 0.024kg sodium carboxymethylcellulose (1 weight % solution viscosity is 2500-3000mPaS is purchased from Xinxiang City and Lve Lida power material Co., Ltd, trade mark BTT-3000) it is mixed with water Even, the content for obtaining aluminum oxide is the mixture of 30 weight %.
After the mixture is stirred 1.5 hours at 6000rpm, 0.02kg 3- glycydoxy three is added Methoxy silane continues stirring 1.5 hours, and the polyacrylate binder that 0.1kg contains N hydroxymethyl acrylamide is then added (it is purchased from Shanghai Ai Gao company, the trade mark is 1050 types, and on the basis of the total amount of binder, the content of N hydroxymethyl acrylamide is 4 Weight %), it stirs 1.5 hours at 3,000 rpm, is subsequently added into 0.08kg neopelex, continue at 3,000 rpm Stirring 0.5 hour, obtains the second slurries.
(3) diaphragm is made
By the first slurries be coated in polyethylene porous membrane (be purchased from SK company, Japan, trade mark BD0701, with a thickness of 7 μm, hole Gap rate is to form the first slurry layer on a side surface 38%).Then, by polyethylene terephthalate (PET) non-woven fabrics Film (purchased from Mitsubishi's paper, with a thickness of 10 μm, porosity 55%, fibre diameter is 2-5 μm) is pressed together on polyethylene porous membrane In first slurry layer, then in 60 DEG C and normal pressure (1 standard atmospheric pressure) forced air drying 10min.
Then, the second slurries are coated in PET nonwoven surface, form the second slurry layer.Then, by roll-in by second Fraction slurries pressing in slurry layer enters in the fiber hole of PET non-woven fabrics, obtains wet film.
Finally, obtained wet film is obtained according to the present invention in 60 DEG C and 10min dry under normal pressure (1 standard atmospheric pressure) Battery diaphragm (overall thickness be 22 μm), the structure of the battery diaphragm are as follows: polyethylene porous membrane | the second inorganic layer | PET nonwoven Cloth film | the first inorganic layer, the first inorganic layer include first part and second part, and first part is located at non-conductive polymer fibre The surface of nonwoven layer is tieed up, second part is located in at least partly hole of non-conductive polymer fiber non-woven layer of cloth, and second Point be structure as a whole with first part, first part with a thickness of 4 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:8；On the basis of the total amount of battery diaphragm, the total amount of inorganic matter is 70 weight % in the first inorganic layer and the second inorganic layer.
Embodiment 2
Battery diaphragm is prepared using method same as Example 1, unlike, control carries out roll-in to the second slurry layer Condition so that first part with a thickness of 1 μm, the overall thickness of the battery diaphragm finally prepared is 19 μm.
Embodiment 3
Battery diaphragm is prepared using method same as Example 1, unlike, the concentration of PEO is 10 in the first slurries Weight %.
Embodiment 4
Battery diaphragm is prepared using method same as Example 1, unlike, in the second slurries, aluminum oxide Volume average particle size is 700nm.
Embodiment 5
Battery diaphragm is prepared using method same as Example 1, unlike, in the second slurries, aluminum oxide Volume average particle size is 40nm.
Embodiment 6
Battery diaphragm is prepared using method same as Example 1, unlike, in the second slurries, aluminum oxide is Bulky grain aluminum oxide and little particle aluminum oxide according to weight ratio 1:1 mixture, wherein small aluminum oxide grain Volume average particle size be 40nm, the volume average particle size of bulky grain aluminum oxide is 400nm.
Comparative example 1
Second slurries prepared by embodiment 1 are coated on a side surface of polyethylene porous membrane (with embodiment 1), are formed First slurry layer obtains the battery with inorganic layer then in 60 DEG C and normal pressure (1 standard atmospheric pressure) forced air drying 10min Diaphragm, the structure of the battery diaphragm are as follows: polyethylene porous membrane | inorganic layer, the inorganic layer with a thickness of 4 μm.
Comparative example 2
First slurries are coated on a side surface of polyethylene porous membrane (with embodiment 1), form the first slurry layer.Then, PET non-woven membrane (with embodiment 1) is pressed together in the first slurry layer of polyethylene porous membrane, then in 60 DEG C and normal pressure (1 standard Atmospheric pressure) forced air drying 10min, battery diaphragm is obtained, the structure of the battery diaphragm are as follows: polyethylene porous membrane | PET non-woven membrane.
Comparative example 3
Second slurries (with embodiment 1) is coated in PET non-woven fabrics (with embodiment 1) surface, forms the second slurry layer.So Afterwards, the fraction slurries pressing in the second slurry layer is entered in the fiber hole of PET non-woven fabrics by roll-in, obtains wet film.It will Obtained wet film dry 10min under 60 DEG C and normal pressure (1 standard atmospheric pressure), obtains battery diaphragm, the structure of the battery diaphragm Are as follows: PET non-woven membrane | inorganic layer, the inorganic layer with a thickness of 4 μm.
Comparative example 4
Battery diaphragm is prepared using method same as Example 1, unlike, PET non-woven membrane is more using polyethylene Pore membrane (with embodiment 1) replaces, and obtains battery diaphragm, the structure of the battery diaphragm are as follows: polyethylene porous membrane | the second inorganic layer | polyethylene porous membrane | the first inorganic layer, the first inorganic layer include first part and second part, and first part is located at poly- The surface of ethylene perforated membrane, second part are located in at least partly hole of polyethylene porous membrane, second part and first part Be structure as a whole, first part with a thickness of 4 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:8；With battery On the basis of the total amount of diaphragm, the total amount of inorganic matter is 70 weight % in the first inorganic layer and the second inorganic layer.
Comparative example 5
Battery diaphragm is prepared using method same as Example 1, unlike, polyethylene porous membrane uses PET nonwoven Cloth film (with embodiment 1) replaces, and obtains battery diaphragm, the structure of the battery diaphragm are as follows: PET non-woven membrane | the second inorganic layer | PET non-woven membrane | the first inorganic layer, the first inorganic layer include first part and second part, and first part is located at described The surface of PET non-woven membrane, second part are located in at least partly hole of the PET non-woven membrane, second part and first Part is structure as a whole, first part with a thickness of 4 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:8；With On the basis of the total amount of battery diaphragm, the total amount of inorganic matter is 70 weight % in the first inorganic layer and the second inorganic layer.
Embodiment 7
Battery diaphragm is prepared using method same as Example 1, unlike, the polyoxyethylene ether in the first slurries is used Etc. weight vinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP, be purchased from Acker Ma, the trade mark is by LBG) replace, to prepare root According to battery diaphragm of the invention.
Embodiment 8
By PET non-woven membrane (with embodiment 1), dipping takes out after 0.5 hour in the second slurries (with embodiment 1).With scraping After knife strikes off the slurry of one side surface of PET non-woven membrane, polyethylene porous membrane (with embodiment 1) is pressed together on the surface struck off Afterwards, the dry 10min in 60 DEG C and normal pressure (1 standard atmospheric pressure) air dry oven, it is (total to obtain battery diaphragm according to the present invention With a thickness of 22 μm), the structure of the battery diaphragm are as follows: polyethylene porous membrane | the second inorganic layer | PET non-woven membrane | first is inorganic Nitride layer, the first inorganic layer include first part and second part, and first part is located at non-conductive polymer fiber non-woven layer of cloth Surface, second part is located in at least partly hole of non-conductive polymer fiber non-woven layer of cloth, second part and first Be divided into integral structure, first part with a thickness of 4 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:12；With On the basis of the total amount of battery diaphragm, the total amount of inorganic matter is 75 weight % in the first inorganic layer and the second inorganic layer.
Embodiment 9
Second slurries (with embodiment 1) is coated in a surface of polyethylene porous membrane (with embodiment 1), forms second Slurry layer.PET non-woven membrane (with embodiment 1) is pressed together on the surface of the second slurry layer and partially to starch in the second slurry layer Liquid forms slurry layer by PET non-woven membrane and in PET non-woven membrane layer surface, in 60 DEG C and normal pressure (1 standard atmospheric pressure) drum Dry 10min in wind drying box obtains battery diaphragm according to the present invention (overall thickness is 21 μm), the structure of the battery diaphragm Are as follows: polyethylene porous membrane | the second inorganic layer | PET non-woven membrane | the first inorganic layer, the first inorganic layer include first Divide and second part, first part are located at the surface of non-conductive polymer fiber non-woven layer of cloth, second part is located at non-conductive poly- In at least partly hole for closing fibres nonwoven layer, second part is structure as a whole with first part, the thickness of first part It is 4 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:3；On the basis of the total amount of battery diaphragm, first is inorganic The total amount of inorganic matter is 70 weight % in nitride layer and the second inorganic layer.
Embodiment 10
(1) the first slurries containing binder are prepared
Polyvinyl alcohol (PVA, is purchased from Aladdin, and number-average molecular weight is 100,000 (GPC methods)) is dispersed in water, formation contains First slurries of binder, the concentration of PVA is 2.5 weight % in the first slurries.
(2) the second slurries of dispersion organic/inorganic substance are prepared
By 2kg silica (volume average particle size 100nm), 0.1kg Sodium Polyacrylate (number-average molecular weight 9000, Purchased from Guangzhou Yuan Chang trade Co., Ltd) and 0.05kg sodium carboxymethylcellulose (1 weight % solution viscosity is 3000mPaS is purchased from Xinxiang City and Lve Lida power material Co., Ltd, trade mark BTT-3000) it is uniformly mixed with water, it obtains The mixture that content to silica is 20 weight %.
After the mixture is stirred 2 hours at 6000rpm, 0.05kg 3- glycydoxy front three is added Oxysilane continues stirring 2 hours, and the polyacrylate binder (purchase that 0.5kg contains N hydroxymethyl acrylamide is then added From Aladdin, on the basis of the total amount of binder, the content of N hydroxymethyl acrylamide is 5 weight %), 2 are stirred at 3,000 rpm Hour, it is subsequently added into 0.005kg neopelex, continues to stir 0.5 hour at 3,000 rpm, obtains the second slurries.
(3) diaphragm is made
First slurries are coated in polypropylene porous film (being purchased from celegard, with a thickness of 12 μm, porosity 40%) On one side surface, the first slurry layer is formed.Then, by PET non-woven membrane, (purchased from Mitsubishi's paper, with a thickness of 15 μm, porosity is 50%, fibre diameter is 2-5 μm) it is pressed together in the first slurry layer of polypropylene porous film, then in 50 DEG C and normal pressure (1 standard Atmospheric pressure) dry 20min in air dry oven.
Then, the second slurries are coated in PET nonwoven surface, form the second slurry layer.Then, by roll-in by second Fraction slurries pressing in slurry layer enters in the fiber hole of PET non-woven fabrics, obtains wet film.By obtained wet film 50 DEG C in Dry 20min in air dry oven.
The second slurries are coated in another side surface of the polypropylene porous film for the film being dried to obtain, then in 50 DEG C of air blast Dry 20min in drying box obtains battery diaphragm according to the present invention (overall thickness is 31 μm), the structure of the battery diaphragm are as follows: Third inorganic layer | polypropylene porous film | the second inorganic layer | PET non-woven membrane | the first inorganic layer, the first inorganic layer Including first part and second part, first part is located at the surface of non-conductive polymer fiber non-woven layer of cloth, second part position In at least partly hole of non-conductive polymer fiber non-woven layer of cloth, second part is structure as a whole with first part, and first It is partial with a thickness of 3 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:12.Third inorganic layer with a thickness of 1μm；On the basis of the total amount of battery diaphragm, the total amount of inorganic matter is 45 weights in the first inorganic layer and the second inorganic layer % is measured, the content of third inorganic layer is 40 weight %.
Embodiment 11
By PET non-woven membrane (with embodiment 10), dipping takes out after 0.5 hour in the second slurries (with embodiment 10).With After scraper strikes off the slurry of one side surface of PET non-woven membrane, polypropylene porous film (with embodiment 10) is pressed together on and is struck off Behind surface, the dry 10min in 60 DEG C of air dry ovens.Then, in the second slurry of another side surface of polypropylene porous film coating After liquid, the dry 20min in 50 DEG C of air dry oven obtains battery diaphragm according to the present invention (overall thickness is 32 μm), should The structure of battery diaphragm are as follows: third inorganic layer | polypropylene porous film | the second inorganic layer | PET non-woven membrane | first is inorganic Nitride layer, the first inorganic layer include first part and second part, and first part is located at non-conductive polymer fiber non-woven layer of cloth Surface, second part is located in at least partly hole of non-conductive polymer fiber non-woven layer of cloth, second part and first Be divided into integral structure, first part with a thickness of 3 μm, the weight ratio of the second inorganic layer and the first inorganic layer is 1:12.The Three inorganic layers with a thickness of 1 μm；It is inorganic in the first inorganic layer and the second inorganic layer on the basis of the total amount of battery diaphragm The total amount of object is 45 weight %, and the content of third inorganic layer is 40 weight %.
Using the performance of the following methods testing example 1-11 and comparative example 1-5 diaphragm prepared, as a result listed in table 1.
(1) gas permeability (grignard value) is tested
Diaphragm is cut into area 6.45cm2Square diaphragm sample, utilize grignard value tester GURLEY-4110 survey 100mL gas (air) is determined through the time (s/100mL) required for diaphragm sample, numerical value is smaller, show that gas permeability is better, Wherein, pressure is (water column is high) 12.39cm.
(2) test of peel strength
Diaphragm two sides is separately fixed at stationary fixture with adhesive tape and activity is pressed from both sides by the diaphragm sample for cutting 40mm × 100mm On tool, measuring 180 DEG C of negative drawings makes PET nonwoven layer and polyolefin film in diaphragm remove required pulling force, required drawing Power is bigger, then the peel strength of composite membrane is higher, illustrates that adhesion strength is also higher.
(3) ambient temperature mechanical properties are tested
It is pierced using tensile property and needle of the auspicious universal testing machine of Shenzhen monarch (calibrating) to lithium ion battery separator strong Degree is measured, wherein test temperature is 25 DEG C, and when carrying out needle thorn experiment, the diameter of the steel needle used is 3mm.
(4) percent thermal shrinkage is tested
Diaphragm is cut into the sample of 6cm × 6cm, is placed in baking oven, respectively in 120 DEG C, 140 DEG C, 160 DEG C, 180 DEG C of bakings 1h measures the length and width of sample, and calculates percent thermal shrinkage according to following formula:
Percent thermal shrinkage=(length/6 of sample after 1- is heat-shrinked) × 100%.
(5) test of ionic conductivity
Using ac impedance measurement, specifically, diaphragm is cut into the disk that diameter is 17mm respectively, is dried in vacuo at 80 DEG C It in case after dry 24 hours, is placed between two stainless steel (SS) electrodes, absorbing the electrolyte of sufficient amount, (electrolyte contains The ethylene carbonate (EC) of 32.5 weight %, the ethyl methyl carbonate (EMC) of 32.5 weight %, 32.5 weight % dimethyl The vinylene carbonate (VC) and 1mol/L LiPF of carbonic ester (DMC), 2.5 weight %6(lithium hexafluoro phosphate)), then it is sealed in After 2016 type button cells, AC impedance experiment is carried out, linearly with the intersection point of real axis is the bulk resistance of electrolyte, and use Ionic conductivity (σ) is calculated in following formula:
σ=L/AR
Wherein, L is the thickness (cm) of diaphragm,
A is the contact area (cm of stainless steel plate and diaphragm2),
R is the bulk resistance (mS) of electrolyte.
(6) elevated temperature strength
Diaphragm is cut into the sample of 15cm × 10cm, is placed in baking oven, in 180 DEG C of baking 1h, is cut into 10cm after cooling The batten of × 1cm, then using the auspicious universal testing machine (calibrating) of Shenzhen monarch to the tensile property of lithium ion battery separator It is measured, wherein test temperature is 25 DEG C.
Diaphragm according to the present invention not only has good gas permeability and room temperature mechanical property it can be seen from the result of table 1 Can, and preferable intensity and lower shrinking percentage are still maintained at high temperature.
Embodiment 12-17
The diaphragm prepared respectively with embodiment 1 and 7-11, prepares lithium ion battery using following methods.
(1) by LiCoO2, PVDF binder and carbon black be tuned into slurry according to mass ratio 100:0.8:0.5 and be coated on aluminium foil And dry the LiCoO being made with a thickness of 0.114mm2Anode pole piece.
Butadiene-styrene rubber (SBR) and carboxymethyl cellulose (CMC) are dispersed in water, with artificial graphite, conductive agent according to matter The material being stirred is applied on copper foil and is dried than being 2.5:1.5:90:6 at room temperature (25 DEG C) high-speed stirred 3.5 hours by amount The graphite cathode pole piece with a thickness of 0.135mm is made.
(2) in drying shed, by LiCoO2Anode pole piece, graphite cathode pole piece and diaphragm are prepared in a winding manner CSL454187 type LiCoO2/ graphite soft bag lithium ionic cell pole piece is packaged to obtain lithium ion battery after filling electrolyte； Wherein, the electrolyte in electrolyte is lithium hexafluoro phosphate, and concentration 1mol/L, organic solvent EC, EMC and DEC are by weight The mixed liquor being mixed to get than 1:1:1.
Comparative example 6-10
Lithium ion battery is prepared using method identical with embodiment 12-17, unlike, diaphragm is respectively comparative example 1- The diaphragm of 5 preparations.
The performance of the lithium ion battery of embodiment 12-17 and comparative example 6-10 preparation is measured using following methods.
(1) battery normal-temperature circulating performance is tested
Using (Guangzhou is blue odd, BK6016) performance of lithium ion battery test cabinet, embodiment and comparative example is prepared Lithium ion battery after partial volume carries out 25 DEG C of cycle performance tests, and the specific method is as follows: by battery respectively with 0.7C, 0.2C charging End to 4.40V；10min is shelved, is put with 0.7C or 0.2C to 3.0V, is so recycled.
Table 2
1: diaphragm (similarly hereinafter) is used as using polyethylene porous membrane (with embodiment 1)
The test result of table 2 shows: lithium ion battery according to the present invention shows excellent cycle performance.
Specifically, embodiment 12 and comparative example 7,8 and 10 are compared as can be seen that using the lithium of diaphragm of the invention The capacity retention ratio of ion battery at normal temperature is higher, thus has more excellent normal-temperature circulating performance.
(3) self-discharge of battery is tested
Using (Guangzhou is blue odd, BK6016) performance of lithium ion battery test cabinet, embodiment and comparative example is prepared Lithium ion battery after partial volume carries out self-discharge performance test, and the specific method is as follows.
(1) it is melted into 70% electric power storage state (SOC) and measures the open-circuit voltage of lithium ion battery after (25 DEG C) of room temperature are aged 3 days (OCV1)；
(2) lithium ion battery being aged through room temperature is measured into the open circuit of lithium ion battery after high temperature (45 DEG C) aging 3 days Voltage (OCV2)；
(3) it is calculated using the following equation the voltage drop of battery, is as a result listed in table 3: voltage drop=OCV1-OCV2。
Table 3
Number Diaphragm source Voltage drop (mV)
Embodiment 12 Embodiment 1 10.8
Reference examples / 10.7
Comparative example 6 Comparative example 1 11.2
Comparative example 7 Comparative example 2 11.5
Comparative example 8 Comparative example 3 33.8
Comparative example 9 Comparative example 4 10.8
Comparative example 10 Comparative example 5 32.5
Embodiment 13 Embodiment 7 10.4
Embodiment 14 Embodiment 8 10.7
Embodiment 15 Embodiment 9 10.6
Embodiment 16 Embodiment 10 11.2
Embodiment 17 Embodiment 11 10.3
The numerical value of voltage drop is bigger, shows that the self discharge degree of lithium ion battery is high, the storge quality of battery is bad.By table 3 result can be seen that voltage drop according to the present invention is small, show excellent storge quality.By embodiment 12 and comparative example 8 It is compared with 10 as can be seen that using the voltage drop of the lithium ion battery of diaphragm of the invention significant lower, thus have more For excellent storge quality.
(4) battery high-temperature storge quality is tested
85 DEG C of 4h storge quality tests are carried out to the lithium ion battery that embodiment and comparative example obtains.Test method is as follows.
1) battery is charged to 0.5C by 4.40V using (Guangzhou is blue odd, BK6016) performance of lithium ion battery test cabinet, 0.02C cut-off；5min is shelved, 3.0V is discharged to 0.2C, discharge capacity before recording；
2) battery is charged into 4.40V, 0.02C cut-off with 0.5C；Preceding voltage, internal resistance, thickness are tested after shelving 1h；
3) battery is put into 85 DEG C of oven storage 4h；
4) thickness immediately is tested after storing, and cooling thickness, rear voltage, rear internal resistance are tested after room temperature 2h；
5) battery is discharged to 3.0V with 0.2C；
6) fully charged with 0.5C, 5min is shelved, 3.0V is discharged to 0.2C, record restores capacity, and calculates capacity restoration Rate (restores capacity and removes former capacity).
Test result is shown in Table 4.As shown in Table 4: in capacity restoration rate after high-temperature lithium ion battery storage according to the present invention It is high.Embodiment 12 is compared with comparative example 8 and 10 as can be seen that the lithium ion battery using diaphragm of the invention is shown Higher capacity restoration rate shows that lithium ion battery has more excellent high-temperature storage performance.
Table 4
Number Diaphragm source Capacity restoration rate
Embodiment 12 Embodiment 1 0.99
Reference examples / 0.97
Comparative example 6 Comparative example 1 0.97
Comparative example 7 Comparative example 2 0.97
Comparative example 8 Comparative example 3 0.92
Comparative example 9 Comparative example 4 0.96
Comparative example 10 Comparative example 5 0.93
Embodiment 13 Embodiment 7 0.95
Embodiment 14 Embodiment 8 0.99
Embodiment 15 Embodiment 9 0.98
Embodiment 16 Embodiment 10 0.99
Embodiment 17 Embodiment 11 0.99
The preferred embodiment of the present invention has been described above in detail, and still, the present invention is not limited thereto.In skill of the invention In art conception range, can with various simple variants of the technical solution of the present invention are made, including each technical characteristic with it is any its Its suitable method is combined, and it should also be regarded as the disclosure of the present invention for these simple variants and combination, is belonged to Protection scope of the present invention.

Claims (32)

1. a kind of battery diaphragm, which contains polyolefin porous film layer, non-conductive polymer fiber non-woven layer of cloth, first Inorganic layer and the second inorganic layer；
The polyolefin porous film layer is connected with the non-conductive polymer fiber non-woven layer of cloth by second inorganic layer；
First inorganic layer includes second part and optional first part, and the first part is located at described non-conductive The surface of polymer fiber non-woven layer of cloth, the second part are located at at least portion of the non-conductive polymer fiber non-woven layer of cloth Divide in hole.
2. battery diaphragm according to claim 1, wherein the porosity of the non-conductive polymer fiber non-woven layer of cloth is 35-70%.
3. battery diaphragm according to claim 1 or 2, wherein the fibre in the non-conductive polymer fiber non-woven layer of cloth The diameter of dimension is 0.5-5 μm.
4. battery diaphragm described in any one of -3 according to claim 1, wherein the non-conductive polymer fabric nonwoven cloth Polymer in layer is one or more of polyester, polyimides, polyetherimide and polyether-ether-ketone, preferably poly- pair Ethylene terephthalate and/or polybutylene terephthalate (PBT).
5. battery diaphragm described in any one of -4 according to claim 1, wherein the non-conductive polymer fabric nonwoven cloth Layer with a thickness of 5-20 μm.
6. battery diaphragm according to claim 1, wherein the polyolefin porous film layer with a thickness of 1-50 μm, preferably It is 5-20 μm；
Preferably, the porosity of the polyolefin porous film layer is 30-50%；
Preferably, the polyolefin in the polyolefin porous film layer is polyethylene and/or polypropylene.
7. battery diaphragm according to claim 1, wherein second inorganic layer is one with first inorganic layer Body structure.
8. battery diaphragm according to claim 7, wherein in first inorganic layer and second inorganic layer Inorganic matter is identical or different, respectively Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2, carbon nanotube, BN, SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、PbTiO3、TiB2、CaSiO3, molecular sieve, clay and kaolinite One or more of soil.
9. according to claim 1, battery diaphragm described in any one of 7 and 8, wherein first inorganic layer and described Inorganic matter in second inorganic layer exists in the form of granules, and the average grain diameter of the particle is 10nm to 3 μm, preferably 20nm to 1 μm, more preferably 30nm to 800nm, further preferably 100nm to 400nm；
Preferably, the particles of inorganic material contains the first particles of inorganic material and the second particles of inorganic material, first inorganic matter The average grain diameter of grain is 40-100nm, and the average grain diameter of second particles of inorganic material is 300-400nm.First inorganic matter The weight ratio of particle and second particles of inorganic material is preferably 0.1-10:1, more preferably 0.5-5:1, further preferably 1- 2:1.
10. battery diaphragm according to claim 9, wherein in first inorganic layer and second inorganic layer Inorganic matter each by binder formed integral structure, the binder is preferably water-soluble binder.
11. battery diaphragm according to claim 10, wherein the binder is polyvinyl alcohol, polyoxyethylene ether, water-soluble Property one or more of polyacrylate and water soluble compound modified polyacrylate.
12. according to claim 1 with the battery diaphragm described in any one of 8-11, wherein the first part with a thickness of 0-5μm。
13. battery diaphragm according to claim 12, wherein first inorganic layer contains first part, and described The thickness of a part is preferably 0.1-5 μm, more preferably 1-4.5 μm, further preferably 2-4 μm.
14. battery diaphragm according to claim 13, wherein the first part and the second part are integrated knot Structure.
15. according to claim 1 with the battery diaphragm described in any one of 8-14, wherein second inorganic layer and institute The weight ratio for stating the first inorganic layer is 1:2.5-16, preferably 1:3-12；
Preferably, on the basis of the total amount of the battery diaphragm, inorganic matter is total in first inorganic layer and the second inorganic layer Amount is 20-85 weight %, preferably 30-80 weight %, more preferably 35-78 weight %, further preferably 40-76 weight % is measured, is still more preferably 45-75 weight %.
16. a kind of preparation method of battery diaphragm, method includes the following steps:
S11, the first slurries containing binder are coated at least one surface of polyolefin porous membrane, form binder slurries Layer；
S12, it will be dried after non-conductive polymer fabric nonwoven cloth and binder slurry layer pressing；
S13, the second slurries for dispersing organic/inorganic substance in the coating of the surface of non-conductive polymer fabric nonwoven cloth, form the second slurries Layer, and pressure is applied to second slurry layer, so that the fraction slurries in second slurry layer penetrate into described non-lead Electric polymer fiber non-woven layer of cloth, obtains wet film；
S14, the wet film is dried.
17. preparation method according to claim 16, wherein the binder is water-soluble binder, preferably poly- second One or both of enol, polyoxyethylene ether, water-soluble polyacrylate and water soluble compound modified polyacrylate with On.
18. a kind of preparation method of battery diaphragm, method includes the following steps:
S21, the third slurries of dispersion organic/inorganic substance are provided；
S22, third slurry layer is formed on the surface of the first basement membrane with the third slurries；
S23, the second basement membrane and the third slurry layer are pressed, obtains wet film；
S24, the wet film is dried；
First basement membrane and second basement membrane are respectively polyolefin porous membrane or non-conductive polymer fabric nonwoven cloth, and One of first basement membrane and second basement membrane are polyolefin porous membrane, and another one is non-conductive polymer fiber non-woven Cloth.
19. according to the method for claim 18, wherein in first basement membrane be polyolefin porous membrane, the second basement membrane is When non-conductive polymer fabric nonwoven cloth, combination that one or more of this method is further comprising the steps of:
S231, pressure is applied to the third slurry layer, so that fraction slurries in the third slurry layer non-are led through described Electric polymer fabric nonwoven cloth, and slurry layer is formed on the surface of the non-conductive polymer fabric nonwoven cloth；
S232, slurry layer is formed on the surface of the non-conductive polymer fabric nonwoven cloth with the third slurries.
20. preparation method described in any one of 6-19 according to claim 1, wherein second slurries and the third The content of inorganic matter is respectively 5-50 weight %, preferably 10-40 weight %, more preferably 20-30 weight % in slurries.
21. preparation method described in any one of 6-20 according to claim 1, wherein second slurries and third slurries In inorganic matter exist in the form of granules, the average grain diameter of the particle is 10nm to 3 μm, preferably 20nm to 1 μm, more excellent It is selected as 30nm to 800nm, further preferably 100nm to 400nm；
Preferably, the particles of inorganic material contains the first particles of inorganic material and the second particles of inorganic material, first inorganic matter The average grain diameter of grain is 40-100nm, and the average grain diameter of second particles of inorganic material is 300-400nm.First inorganic matter The weight ratio of particle and second particles of inorganic material is preferably 0.1-10:1, more preferably 0.5-5:1, further preferably 1- 2:1.
22. preparation method described in any one of 6-21 according to claim 1, wherein second slurries and third slurries In inorganic matter be respectively Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2, carbon nanotube, BN, SiC, Si3N4、 WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、PbTiO3、TiB2、CaSiO3, molecular sieve, one in clay and kaolin Kind is two or more.
23. method described in any one of 6-22 according to claim 1, wherein second slurries or third slurry The coating weight of liquid makes in the battery diaphragm finally prepared, be located in non-conductive polymer fabric nonwoven cloth surface and hole and The total amount of inorganic matter between non-conductive polymer fabric nonwoven cloth and polyolefin porous membrane is the 20-85 of composite diaphragm total weight Weight %, preferably 30-80 weight %, more preferably 35-78 weight %, further preferably 40-76 weight %, further Preferably 45-75 weight %.
24. method described in any one of 6-23 according to claim 1, wherein in the battery diaphragm finally prepared, at least portion Point inorganic matter be in the hole of nonconductive polymers fabric nonwoven cloth and non-conductive polymer fiber non-woven layer of cloth with gather Between alkene perforated membrane, optionally, part inorganic matter is in the surface of non-conductive polymer fabric nonwoven cloth；
Preferably, inorganic layer in nonconductive polymers fabric nonwoven cloth surface with a thickness of 0-5 μm, preferably 0.1- 5 μm, more preferably 1-4.5 μm, further preferably 2-4 μm are more in non-conductive polymer fiber non-woven layer of cloth and polyolefin Inorganic matter between pore membrane and the weight ratio in nonconductive polymers fabric nonwoven cloth surface and the inorganic matter in hole Preferably 1:2.5-16, more preferably 1:3-12.
25. preparation method described in any one of 6-24 according to claim 1, wherein the non-conductive polymer fiber without Polymer in woven fabric layer is one or more of polyester, polyimides, polyetherimide and polyether-ether-ketone, preferably Polyethylene terephthalate and/or polybutylene terephthalate (PBT).
26. preparation method described in any one of 6-25 according to claim 1, wherein the non-conductive polymer fiber without Woven fabric layer with a thickness of 5-20 μm.
27. preparation method described in any one of 6-26 according to claim 1, wherein the non-conductive polymer fiber without The porosity of woven fabric layer is 35-70%.
28. preparation method described in any one of 6-27 according to claim 1, wherein the non-conductive polymer fiber without The diameter of fiber in woven fabric layer is 0.5-5 μm.
29. preparation method described in any one of 6-28 according to claim 1, wherein the thickness of the polyolefin porous film layer Degree is 1-50 μm, preferably 5-20 μm；
Preferably, the porosity of the polyolefin porous film layer is 30-50%；
Preferably, the polyolefin in the polyolefin porous film layer is polyethylene and/or polypropylene.
30. the battery diaphragm of the preparation of the preparation method as described in any one of claim 16-29.
31. a kind of lithium ion battery, which includes anode, cathode and diaphragm, the diaphragm setting it is described just Between pole and the cathode, which is characterized in that the diaphragm be battery described in any one of claim 1-15 and 30 every Film.
32. a kind of preparation method of lithium ion battery, this method comprises:
(1) battery diaphragm is prepared using method described in any one of claim 16-29；
(2) between a positive electrode and a negative electrode by diaphragm setting, it after forming Battery Pole Core, is packaged.
CN201810178960.5A 2018-03-05 2018-03-05 Battery diaphragm and preparation method thereof, and lithium ion battery and preparation method thereof Active CN110233221B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810178960.5A CN110233221B (en) 2018-03-05 2018-03-05 Battery diaphragm and preparation method thereof, and lithium ion battery and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810178960.5A CN110233221B (en) 2018-03-05 2018-03-05 Battery diaphragm and preparation method thereof, and lithium ion battery and preparation method thereof

Publications (2)

Publication Number Publication Date
CN110233221A true CN110233221A (en) 2019-09-13
CN110233221B CN110233221B (en) 2022-01-07

Family

ID=67862012

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810178960.5A Active CN110233221B (en) 2018-03-05 2018-03-05 Battery diaphragm and preparation method thereof, and lithium ion battery and preparation method thereof

Country Status (1)

Country Link
CN (1) CN110233221B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110911611A (en) * 2019-10-26 2020-03-24 浙江锋锂新能源科技有限公司 Composite diaphragm and preparation method thereof
CN112259911A (en) * 2020-09-30 2021-01-22 上海恩捷新材料科技有限公司 Electrochemical device, novel non-woven fabric ceramic diaphragm and preparation method thereof

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10238941A1 (en) * 2002-08-24 2004-03-04 Creavis Gesellschaft Für Technologie Und Innovation Mbh Electrical separator, process for its production and use in high-performance lithium batteries
DE102005029124A1 (en) * 2005-06-23 2006-12-28 Degussa Ag Electrolyte/separator system, useful for producing electro-chemical energy-storage systems e.g. lithium metal batteries, comprises electrolytes comprising base component, ionic liquid, water, additive, lead salt and ceramic separator
CN102388485A (en) * 2009-04-10 2012-03-21 株式会社Lg化学 Separator including porous coating layer, method for manufacturing the separator and electrochemical device including the separator
KR20150141403A (en) * 2014-06-10 2015-12-18 주식회사 아모그린텍 Complex fibrous separator, manufacturing method thereof and secondary battery using the same
CN106898718A (en) * 2015-12-18 2017-06-27 比亚迪股份有限公司 A kind of composite membrane of polymer and preparation method thereof, lithium ion battery
KR20170086423A (en) * 2016-01-18 2017-07-26 주식회사 엘지화학 Coating method of secondary battery separator
KR20180006816A (en) * 2016-07-11 2018-01-19 울산과학기술원 Separator for electrochemical device, method for manufacturing the same, and electrochemical device comprising the same
US20180062143A1 (en) * 2016-08-29 2018-03-01 Electronics And Telecommunications Research Instit Ute Lithium battery electrode and method of manufacturing the same

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10238941A1 (en) * 2002-08-24 2004-03-04 Creavis Gesellschaft Für Technologie Und Innovation Mbh Electrical separator, process for its production and use in high-performance lithium batteries
DE102005029124A1 (en) * 2005-06-23 2006-12-28 Degussa Ag Electrolyte/separator system, useful for producing electro-chemical energy-storage systems e.g. lithium metal batteries, comprises electrolytes comprising base component, ionic liquid, water, additive, lead salt and ceramic separator
CN102388485A (en) * 2009-04-10 2012-03-21 株式会社Lg化学 Separator including porous coating layer, method for manufacturing the separator and electrochemical device including the separator
KR20150141403A (en) * 2014-06-10 2015-12-18 주식회사 아모그린텍 Complex fibrous separator, manufacturing method thereof and secondary battery using the same
CN106898718A (en) * 2015-12-18 2017-06-27 比亚迪股份有限公司 A kind of composite membrane of polymer and preparation method thereof, lithium ion battery
KR20170086423A (en) * 2016-01-18 2017-07-26 주식회사 엘지화학 Coating method of secondary battery separator
KR20180006816A (en) * 2016-07-11 2018-01-19 울산과학기술원 Separator for electrochemical device, method for manufacturing the same, and electrochemical device comprising the same
US20180062143A1 (en) * 2016-08-29 2018-03-01 Electronics And Telecommunications Research Instit Ute Lithium battery electrode and method of manufacturing the same

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110911611A (en) * 2019-10-26 2020-03-24 浙江锋锂新能源科技有限公司 Composite diaphragm and preparation method thereof
CN112259911A (en) * 2020-09-30 2021-01-22 上海恩捷新材料科技有限公司 Electrochemical device, novel non-woven fabric ceramic diaphragm and preparation method thereof
CN112259911B (en) * 2020-09-30 2021-08-06 上海恩捷新材料科技有限公司 Electrochemical device, non-woven fabric ceramic diaphragm and preparation method thereof
WO2022068178A1 (en) * 2020-09-30 2022-04-07 上海恩捷新材料科技有限公司 Electrochemical device, new non-woven fabric ceramic separator, and preparation method therefor

Also Published As

Publication number Publication date
CN110233221B (en) 2022-01-07

Similar Documents

Publication Publication Date Title
JP4832430B2 (en) Lithium ion secondary battery separator and lithium ion secondary battery
CN104124427B (en) Electrode, electrochemical device comprising electrode, and manufacture method of electrode
CN101276895B (en) Composition for lithium ion secondary battery porous diaphragm layer and lithium ion secondary battery
CN110197922B (en) Separator and lithium ion battery
EP3627586B1 (en) Separator for non-aqueous secondary batteries, non-aqueous secondary battery, and method for producing non-aqueous secondary battery
JPWO2005117169A1 (en) Winding type non-aqueous secondary battery and electrode plate used therefor
WO2022141448A1 (en) Electrochemical device, electronic device and electrochemical device manufacturing method
WO2005098997A1 (en) Nonaqueous electrolyte secondary battery
JP4414165B2 (en) Electronic component separator and electronic component
WO2022141508A1 (en) Electrochemical device and electronic device
US20180233727A1 (en) Separator for a non-aqueous secondary battery and non-aqueous secondary battery
CN109841785A (en) A kind of battery diaphragm and preparation method thereof and the lithium ion battery comprising the diaphragm
JPWO2014021292A1 (en) Nonaqueous electrolyte battery separator and nonaqueous electrolyte battery
KR20190062310A (en) Composition for gel polymer electrolyte, gel polymer electrolyte and lithium secondary battery comprising the same
JP2018198199A (en) Aqueous binder resin composition, slurry for nonaqueous battery, nonaqueous battery electrode, nonaqueous battery separator, and nonaqueous battery
CN105655525B (en) Separator for nonaqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery
CN113826252A (en) Electrode assembly, electrochemical device comprising the same, and electronic device
CN101826640B (en) Pole core for lithium ion battery and lithium ion battery using pole core
EP3683860A1 (en) Separator for non-aqueous secondary battery and non-aqueous secondary battery
CN104752683B (en) Positive electrode composition and slurry and preparation method and positive electrode and positive pole and preparation method and lithium ion battery
JP2010225561A (en) Lithium ion secondary battery
US20230261201A1 (en) Electrochemical apparatus and electronic apparatus
CN110233221A (en) A kind of battery diaphragm and preparation method thereof and a kind of lithium ion battery and preparation method thereof
CN105655524A (en) Separator for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
CN109428034A (en) A kind of battery diaphragm and preparation method thereof and lithium ion battery

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant