CN108666512A - A kind of lithium ion battery composite separation membrane and preparation method thereof - Google Patents
A kind of lithium ion battery composite separation membrane and preparation method thereof Download PDFInfo
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- CN108666512A CN108666512A CN201810481759.4A CN201810481759A CN108666512A CN 108666512 A CN108666512 A CN 108666512A CN 201810481759 A CN201810481759 A CN 201810481759A CN 108666512 A CN108666512 A CN 108666512A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/001—Combinations of extrusion moulding with other shaping operations
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/001—Combinations of extrusion moulding with other shaping operations
- B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
- B29C48/50—Details of extruders
- B29C48/505—Screws
- B29C48/625—Screws characterised by the ratio of the threaded length of the screw to its outside diameter [L/D ratio]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C71/00—After-treatment of articles without altering their shape; Apparatus therefor
- B29C71/02—Thermal after-treatment
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/04—Polymers of ethylene
- B29K2023/06—PE, i.e. polyethylene
- B29K2023/0608—PE, i.e. polyethylene characterised by its density
- B29K2023/065—HDPE, i.e. high density polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
- B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
- B29K2027/16—PVDF, i.e. polyvinylidene fluoride
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2007/00—Flat articles, e.g. films or sheets
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2009/00—Layered products
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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Abstract
The present invention relates to a kind of lithium ion battery composite separation membranes.The composite diaphragm includes skin/core/surface layer sandwich diaphragm structure, the sandwich layer includes high density polyethylene (HDPE), the surface layer includes PVDF and inorganic filler blend, and the composite diaphragm is made by the raw material of the surface layer and the sandwich layer by dry process coextrusion casting.The composite diaphragm of the present invention can tightly stick together with battery plus-negative plate film, effectively prevent pole piece to deform during circulating battery, and can keep the ion permeability of diaphragm, while also having the advantages that mechanical property is good, heat-resist and safety is good.The invention further relates to a kind of method preparing the lithium ion battery composite separation membrane using dry process, this method has the advantages that efficient, at low cost.
Description
Technical field
The invention belongs to lithium ion battery separator fields, and in particular to a kind of lithium ion battery composite separation membrane and its preparation side
Method.
Background technology
Lithium ion battery separator be lithium ion battery four big crucial main materials (positive electrode, negative material, electrolyte, every
One of film).Diaphragm is placed between battery positive and negative polarities, plays the insulating effect for preventing positive and negative anodes contact short circuit in the battery, together
When in charge and discharge process provide ion transmission channel effect, be the core component of lithium ion battery, performance is to battery
The characteristics such as internal resistance, capacity, cycle performance and security performance all have a certain impact.As technology content highest, realize the latest
The material of production domesticization, the development of domestic diaphragm play the role of the development of China's lithium ion battery vital.
Lithium ion battery on consumer electronics product other than being widely used, also in electric vehicle, electric tool, energy storage neck
It is more and more applied in domain.With the expansion of application field, the performance and use environment of lithium ion battery are proposed more
High requirement.For example, not requiring nothing more than lithium ion battery has high-energy density, and there is long circulation life.High-energy density
Lithium ion battery plus-negative plate material especially negative material compacted density is especially big, and electric core winding tension is very big, so pole
Piece internal stress is very big.During circulating battery, pole piece, which expands, causes pole piece vertical and horizontal Direction distortion serious, and by
It is polyolefin macromolecular material in common diaphragm, easily causes loose between battery core inner pole piece and diaphragm, fold occurs, from
And interface difference is generated, influence the cycle life of lithium ion battery.
In order to solve this problem, it is common practice to coat organic or inorganic painting on traditional polyalkene diaphragm surface
Layer, is made sticky composite diaphragm.At present there are mainly three types of the preparation methods of viscosity composite diaphragm, applied first, dimple version is mixed, second is that
Surface intaglio plate gluing, third, dotted spraying.Three of the above way is there is also some problems, first, coating falls off and largely bonds
The addition of agent causes plug-hole, influences the ion permeability of diaphragm, is affected to the long-acting cycle of lithium battery and use, second is that system
It is discontinuous to make process, multiple working procedure disconnection causes less efficient, is unfavorable for the reduction of cost.
Therefore, there is still a need for improved preparation methods to prepare the especially sticky composite diaphragm of composite diaphragm for this field.
Invention content
In order to solve above-mentioned problems of the prior art, the present invention provides a kind of lithium ion battery composite separation membrane and
Preparation method.The composite diaphragm can be well bonded to together with electrode slice, overcome and dredged between battery core inner pole piece and diaphragm
Pine and lead to the problem of interface difference, and the ion permeability of diaphragm can be kept well.
According on one side, the present invention provides a kind of lithium ion battery composite separation membrane, which includes surface layer/core
Layer/surface layer sandwich diaphragm structure, the surface layer include PVDF and inorganic filler blend, which includes high density polyethylene (HDPE),
The composite diaphragm is made by the raw material on the surface layer and the sandwich layer by dry process coextrusion casting.
Expected for surface layer through double screw extruder melting extrusion by the mixture of PVDF and inorganic filler and additive on the surface layer
Stream is made.The crystallinity of the PVDF is 65%-78%, density 1.77-1.80g/cm3, fusing point is 171-173 DEG C, molecular weight
Between 200,000-40 ten thousand.
The sandwich layer is that sandwich layer stream is made through single screw extrusion machine melting extrusion by high density polyethylene materials.The high density
The density of polyethylene raw material is in 0.94-0.96g/cm3Between, fusing point is between 137-139 DEG C, and molecular weight is between 40-50 ten thousand.
The skin/core/surface layer sandwich diaphragm structure be by by the surface layer stream and the sandwich layer stream simultaneously from three
Layer die head, which squeezes out, to be made.
PVDF and the ratio of inorganic filler are 60-90 parts by weight:10-40 parts by weight, preferably 70-80 parts by weight:20-30 weights
Measure part.
The inorganic filler is silica, titanium dioxide, barium sulfate, alundum (Al2O3) or one or more in them
Combination.
The additive is melting extrusion additive commonly used in the art, such as levelling agent, plasticiser, slipping agent.Additive
To be enough to promote PVDF and the addition of the amount of inorganic filler melting extrusion.In general, the additive amount of additive makes PVDF raw materials, inorganic
The ratio of filler and additive is 60-90 parts by weight:10-40 parts by weight:0.5-2 parts by weight, preferably 70-80 parts by weight:20-30
Parts by weight:0.1-1.5 parts by weight.
The thickness of the diaphragm is 8-40 microns, and the thickness proportion on three layers of the skin/core/surface layer is arbitrarily adjustable.
Further, the thickness of the diaphragm is 8-40 microns, and the thickness on the surface layer is about 1.5-3 microns, the thickness of sandwich layer
It is about 9-12 microns.
According on the other hand, the present invention provides a kind of method preparing lithium ion battery composite separation membrane, and this method includes
Following steps：
A. material preparation step：High density polyethylene materials are provided, and PVDF raw materials, inorganic filler raw material and additive are provided
Raw material and the mixture for being configured to PVDF and inorganic filler and additive；
B. three layers of extrusion step：High density polyethylene materials are melted using the single screw extrusion machine of draw ratio L/D >=34
It squeezes out, is filtered through coarse filtration, delicate metering, essence, to three layers of die entrance as sandwich layer stream, will be walked using double screw extruder
The mixture melting extrusion for the PVDF and inorganic filler and additive that rapid a is prepared is filtered through coarse filtration, delicate metering, essence, and arriving should
The surface layer stream and the sandwich layer stream are squeezed out from three layers of die head as surface layer stream, form tool by three layers of die entrance simultaneously
There is the high-temperature fusant of skin/core/surface layer three-layer composite structure；
C. slab processing step：It is thin that high-temperature fusant obtained by step b by slab is cooled into height-oriented curtain coating
Film, 8-40 microns of film thickness, film after slab after traction, thickness measurement online, surface blemish passed examination further across receiving
Volume；
D. heat treatment crystallization：After casting films obtained by step c to be placed in 120-132 DEG C of oven cooking cycle 8-10 hours, make
It is perfect to be cast membrane crystallization, it is cooling；
E. composite steps：The film handled well through step d is superimposed as multilayered structure by compounding machine；
F. stretching step：It will be unreeled through the compound good multilayer film processes of step e, cold drawing forms microdefect, hot-drawn reaming, heat
The lithium ion battery composite separation membrane of the three-layer composite structure with skin/core/surface layer is formed after sizing, cooling.
The density of high density polyethylene (HDPE) in step a is in 0.94-0.96g/cm3Between, fusing point between 137-139 DEG C,
For molecular weight between 40-50 ten thousand, the crystallinity of PVDF is 65%-78%, density 1.77-1.80g/cm3, fusing point 171-
173 DEG C, molecular weight is between 200,000-40 ten thousand.
The ratio of PVDF raw materials, inorganic filler and additive in step a is 60-90 parts by weight:10-40 parts by weight:
0.5-2 parts by weight, preferably 70-80 parts by weight:20-30 parts by weight:1-1.5 parts by weight.
Inorganic filler in step a be silica, titanium dioxide, barium sulfate, alundum (Al2O3) or in them one
Kind or a variety of combinations.
Additive in step a is melting extrusion additive commonly used in the art, such as levelling agent, plasticiser, slipping agent.
The advantageous effects of the present invention
The lithium ion battery composite separation membrane of the present invention is made through dry process coextrusion casting, and sandwich layer is higher with having
The high density polyethylene (HDPE) of molecular weight and molecualr weight distribution is formed, and is capable of providing higher mechanical mechanics property and the energy of stretch-proof
Power, surface layer are formed with the blend of inorganic filler and additive with PVDF, and inorganic particulate is wrapped in centre, is not present
The risk to fall off greatly reduces the puncture of Li dendrite, and enhances the heat resistance of diaphragm, to improve the safety of lithium ion battery
Property.
Importantly, the surface layer of composite diaphragm produced by the present invention is being blended with PVDF and inorganic filler and additive
Object is formed, and causes surface layer at a kind of island structure, and PVDF has viscosity.Therefore the present invention composite diaphragm be viscosity every
Film, by hot pressing by positive and negative anodes and the composite diaphragm it is tightly glutinous together with, pole piece can be effectively prevented in circulating battery process
In deform；And the island structure on surface layer so that although positive and negative anodes and the composite diaphragm tightly stick together with, will not be because
The ion permeability of diaphragm is influenced for adhesive effect.
On the other hand, the composite diaphragm using composite diaphragm preparation method of the present invention dry process coextrusion casting once at
Type has efficient, cost compared with existing dimple version mixes coating method, surface intaglio plate glue spreading method and dotted spraying method
Low advantage.
Description of the drawings
Fig. 1 is to show that the composite diaphragm of the present invention has the schematic diagram of skin/core/surface layer sandwich diaphragm structure,
Center core layer is high-density polyethylene layer, and surface layer is PVDF and inorganic particle blended nitride layer.
Fig. 2 is scanning electron microscope (SEM) photo on the surface layer of the composite diaphragm of the present invention, it is shown that surface layer has island
Shape structure.
Fig. 3 is the comparison of the battery core and the battery core prepared using composite diaphragm of the invention of the prior art, and wherein left figure is aobvious
Show that battery core inner pole piece and the diaphragm of the prior art are loose, inside battery core of the right figure display using the composite diaphragm preparation of the present invention
Pole piece and diaphragm flatness are preferable.
Specific implementation mode
Clear, complete explanation is further made to the present invention with reference to specific embodiment.
The scientific terminology used herein has meaning well known in the art, unless otherwise defined.Particularly, it is used to form this
The high density polyethylene materials of the high-density polyethylene layer of invention have meaning well known in the art.In general, high density polyethylene (HDPE)
The density of raw material is in 0.94-0.96g/cm3Between, fusing point between molecular weight 300,000 to 500,000, has between 137-139 DEG C
Higher softening temperature and melting temperature have the characteristics that intensity is big, good toughness, rigidity is big, heat-resisting, cold resistance is good.Particularly,
The PVDF for being used to form the present invention and the PVDF raw materials of inorganic filler blended layer have meaning well known in the art.Usual PVDF knots
Brilliant degree 65%~78%, density are 1.77~1.80g/cm3, fusing point is 171-173 DEG C, and molecular weight is between 200,000 to 400,000.
In non-limiting embodiment below, prepared using the method for the preparation lithium ion battery composite separation membrane of the present invention
The compound sticky diaphragm of lithium ion battery of the present invention.The composite diaphragm of gained is using following methods test heat resistance, air permeability
With 1C cycle performances, to be compared.
(1) test of heat resistance (being indicated with the percent thermal shrinkage of composite diaphragm)：
Test equipment：Baking oven, straight steel ruler
Test philosophy：Percent thermal shrinkage refers to the percentage of diaphragm contraction of size under certain temperature certain time.This hair
Bright made composite diaphragm normal temperature is 105 DEG C/2 hours.
Test method：Transversely the direction (TD) cuts the test specimens of 3 10cm*10cm, and test specimens are put into baking oven,
It is toasted 2 hours at 105 DEG C.With straight steel ruler measure test specimens the front and back width of baking (being respectively a, a1), length (be respectively b,
B1), percent thermal shrinkage is calculated, it is (a-a1)/a*100% that length, which is heat-shrinked, and it is (b-b1)/b*100% that width, which is heat-shrinked, and is calculated
The percent thermal shrinkage average value of 3 test specimens.
(2) test of air permeability
Test equipment：ASAHI Wang Yan formula permeating degree testers
Test philosophy：Air permeability refers to 100mL gases under a certain pressure by the time needed for diaphragm, unit second.
Test method：Make 100mL air along the diaphragm side TD with the pressure of 5KG with ASAHI Wang Yan formula permeating degree testers
To the air permeability values measured at 3 positions, and calculate average value.
(3) test of 1C cycle performances
The cycle life testing standard of lithium battery：GB/T 18287-2013
Embodiment 1
A. material preparation step：Use density for 0.94-0.96g/cm3, molecular weight be 400,000 high density polyethylene (HDPE) as core
The high density polyethylene materials of layer.Use density for 1.78g/cm3, molecular weight be 300,000 PVDF as surface layer PVDF original
The PVDF and silica and additive (such as levelling agent, are plasticized by material, the inorganic filler using silica as surface layer
Agent, slipping agent) raw material of the mixing as surface layer, in the wherein PVDF and the mixture of inorganic filler and additive, PVDF and nothing
The ratio of machine filler and additive is 60 parts by weight:40 parts by weight:1 parts by weight.
B. three layers of extrusion step：High density polyethylene materials are melted using the single screw extrusion machine of draw ratio L/D >=34
It squeezes out, is filtered through coarse filtration, delicate metering, essence, to three layers of die entrance as sandwich layer stream.It will be walked using double screw extruder
The mixture melting extrusion for the PVDF and inorganic filler and additive that rapid a is prepared is filtered through coarse filtration, delicate metering, essence, and arriving should
Three layers of die entrance are as surface layer stream.The surface layer stream and the sandwich layer stream are squeezed out from three layers of die head simultaneously, form tool
There is the high-temperature fusant of skin/core/surface layer three-layer composite structure.
C. slab processing step：It is thin that high-temperature fusant obtained by step b by slab is cooled into height-oriented curtain coating
Film, 8-40 microns of film thickness, film after slab after traction, thickness measurement online, surface blemish passed examination further across receiving
Volume.
D. heat treatment crystallization：After casting films obtained by step c to be placed in 120-132 DEG C of oven cooking cycle 8-10 hours, make
It is perfect to be cast membrane crystallization, it is cooling.
E. composite steps：The film handled well through step d is superimposed as multilayered structure by compounding machine.
F. stretching step：It will be unreeled through the compound good multilayer film processes of step e, cold drawing forms microdefect, hot-drawn reaming, heat
The lithium ion battery composite separation membrane of the three-layer composite structure with skin/core/surface layer is formed after sizing, cooling.
The lithium ion battery composite separation membrane of gained is through Heat-tolerance Determination, and 2 hours percent thermal shrinkages are 0.4% at 105 DEG C；
Air permeability is measured through air permeability 460 seconds；Battery core is made and carries out 1C loop tests, capacity keeps 96% after 2000 weeks.
Embodiment 2
Using material and processing step same as Example 1, but the PVDF in step a and inorganic filler and additive
In mixture, PVDF and the ratio of inorganic filler and additive are 75 parts by weight:25 parts by weight:1 parts by weight, prepare lithium-ion electric
Pond composite diaphragm.The composite diaphragm of gained is through Heat-tolerance Determination, and 2 hours percent thermal shrinkages are 0.45% at 105 DEG C；Through ventilative
Degree measures, and air permeability is 480 seconds；Battery core is made and carries out 1C loop tests, capacity keeps 95% after 2000 weeks.
Embodiment 3
Using material and processing step same as Example 1, but the PVDF in step a and inorganic filler and additive
In mixture, PVDF and the ratio of inorganic filler and additive are 90 parts by weight:10 parts by weight:1 parts by weight, prepare lithium-ion electric
Pond composite diaphragm.The composite diaphragm of gained is through Heat-tolerance Determination, and 2 hours percent thermal shrinkages are 0.60% at 105 DEG C；Through ventilative
Degree measures, and air permeability is 430 seconds；Battery core is made and carries out 1C loop tests, capacity keeps 93% after 2000 weeks.
Embodiment 4
It replaces silica as inorganic filler using processing step same as Example 1, but using titanium dioxide, and walks
For PVDF in rapid a with the mixture of inorganic filler and additive, PVDF and the ratio of inorganic filler and additive are 75 weight
Part:25 parts by weight:1 parts by weight prepare lithium ion battery composite separation membrane.The composite diaphragm of gained is through Heat-tolerance Determination, at 105 DEG C
Lower 2 hours percent thermal shrinkages are 0.48%；It is measured through air permeability, air permeability is 420 seconds；Battery core is made and carries out 1C loop tests,
Capacity keeps 97% after 2000 weeks.
Embodiment 5
Replace silica as inorganic filler using processing step same as Example 1, but using barium sulfate, and step
For PVDF in a with the mixture of inorganic filler and additive, PVDF and the ratio of inorganic filler and additive are 75 parts by weight:
25 parts by weight:1 parts by weight prepare lithium ion battery composite separation membrane.The composite diaphragm of gained is through Heat-tolerance Determination, 2 at 105 DEG C
The percent thermal shrinkage of hour is 0.53%；It is measured through air permeability, air permeability is 410 seconds；Be made battery core carry out 1C loop tests, 2000
Capacity keeps 97% after week.
Embodiment 6
Replace silica as inorganic filler using processing step same as Example 1, but using alundum (Al2O3), and
For PVDF in step a with the mixture of inorganic filler and additive, PVDF and the ratio of inorganic filler and additive are 75 weights
Measure part:25 parts by weight:1 parts by weight prepare lithium ion battery composite separation membrane.The composite diaphragm of gained is through Heat-tolerance Determination, 105
2 hours percent thermal shrinkages are 0.63% at DEG C；It is measured through air permeability, air permeability is 430 seconds；Battery core is made and carries out 1C cycle surveys
Examination, capacity keeps 94% after 2000 weeks.Comparative example 1
Using processing step same as Example 1, compared with common PE diaphragms, common PE diaphragm is 2 small at 105 DEG C
When percent thermal shrinkage be about 2%.For gained diaphragm after fluid injection recycles, diaphragm corrugation is serious, influences the cycle life of battery.
Comparative example 2
Using processing step same as Example 1, by common PE film by traditional micro- rotogravure application obtain coating every
Film.The air permeability that the tradition coats diaphragm is about 1000 seconds.The same playback electrical property for influencing battery, moreover multiple working procedure, shadow
Ring efficiency and cost.
The testing program and result of above example and comparative example are summarized in table 1 below：
Table 1
By table 1, as it can be seen that the composite diaphragm of the present invention is no matter after percent thermal shrinkage, air permeability, 1C are recycled 2000 weeks, capacity is protected
All it is much better than common PE diaphragms and common micro- rotogravure application diaphragm in terms of holdup, it is shown that the protrusion of composite diaphragm of the present invention is excellent
Point.
The description of this invention above for illustration purposes only, is not meant to the model limiting the invention in any way
It encloses.Under the introduction of the spirit of the present invention, those skilled in the art can make under the premise without departing from the essence of the invention
Many modifications and equivalent program.These modifications and equivalent program each fall within right as long as not conflicting with the prior art
In the scope of the present invention that claim is covered.
Claims (10)
1. a kind of lithium ion battery composite separation membrane, which is characterized in that the composite diaphragm includes that three layers of skin/core/surface layer is multiple
Close membrane structure, the sandwich layer includes high density polyethylene (HDPE), and the surface layer includes PVDF and inorganic filler blend, it is described it is compound every
Film is made by the raw material of the surface layer and the sandwich layer by dry process coextrusion casting.
2. lithium ion battery composite separation membrane according to claim 1, which is characterized in that the density of the high density polyethylene (HDPE)
In 0.94-0.96g/cm3Between, fusing point is between 137-139 DEG C, and molecular weight is between 40 to 500,000, the crystallization of the PVDF
Degree is 65%-78%, density 1.77-1.80g/cm3, fusing point is 171-173 DEG C, and molecular weight is between 200,000 to 400,000.
3. lithium ion battery composite separation membrane according to claim 1, which is characterized in that the PVDF and the inorganic filler
Ratio be 60-90 parts by weight:10-40 parts by weight, preferably 70-80 parts by weight:20-30 parts by weight.
4. lithium ion battery composite separation membrane according to claim 1, which is characterized in that the inorganic filler is titanium dioxide
Silicon, titanium dioxide, barium sulfate, alundum (Al2O3) or one or more combinations in them.
5. according to the lithium ion battery composite separation membrane described in any one of claim 1-4, which is characterized in that the thickness of the diaphragm
Degree is 8-40 microns, and the thickness proportion on three layers of the skin/core/surface layer is arbitrarily adjustable.
6. lithium ion battery composite separation membrane according to claim 5, which is characterized in that the thickness of the diaphragm is that 8-40 is micro-
The thickness of rice, the surface layer is 1.5-3 microns, and the thickness of the sandwich layer is 9-12 microns.
7. a kind of method preparing lithium ion battery composite separation membrane, it is characterised in that the described method comprises the following steps：
A. material preparation step：High density polyethylene materials are provided, and PVDF raw materials, inorganic filler raw material and additive raw material are provided
And it is configured to the mixture of PVDF and inorganic filler and additive；
B. three layers of extrusion step：Using the single screw extrusion machine of draw ratio L/D >=34 by high density polyethylene materials melting extrusion,
Through coarse filtration, delicate metering, essence filtering, to three layers of die entrance as sandwich layer stream, step a is matched using double screw extruder
The mixture melting extrusion of the PVDF and inorganic filler and additive of system filter through coarse filtration, delicate metering, essence, arrive this three layers
Die entrance squeezes out the surface layer stream and the sandwich layer stream, being formed has table as surface layer stream from three layers of die head simultaneously
The high-temperature fusant of layer/sandwich layer/surface layer three-layer composite structure；
C. slab processing step：High-temperature fusant obtained by step b is cooled into height-oriented cast film by slab, it is thin
8-60 microns of film thickness, film after slab after traction, thickness measurement online, surface blemish passed examination further across winding；
D. heat treatment crystallization：After casting films obtained by step c to be placed in 120-132 DEG C of oven cooking cycle 8-10 hours, make curtain coating
Membrane crystallization is perfect, cooling；
E. composite steps：The film handled well through step d is superimposed as multilayered structure by compounding machine；
F. stretching step：Will through the compound good multilayer films of step e by unreel, that cold drawing forms microdefect, hot-drawn reaming, heat is fixed
The lithium ion battery composite separation membrane of the three-layer composite structure with skin/core/surface layer is formed after type, cooling.
8. the method according to claim 7 for preparing lithium ion battery composite separation membrane, which is characterized in that in the step a
High density polyethylene (HDPE) density in 0.94-0.96g/cm3Between, fusing point is between 137-139 DEG C, and molecular weight is 40 to 500,000
Between, the crystallinity of PVDF is 65%-78%, density 1.77-1.80g/cm3, fusing point is 171-173 DEG C, and molecular weight is 20
Between ten thousand to 400,000.
9. the method according to claim 7 for preparing lithium ion battery composite separation membrane, which is characterized in that in the step a
PVDF raw materials, inorganic filler and additive ratio be 60-90 parts by weight:10-40 parts by weight:0.5-2 parts by weight, preferably
70-80 parts by weight:20-30 parts by weight:1-1.5 parts by weight.
10. the method according to claim 7 for preparing lithium ion battery composite separation membrane, which is characterized in that described inorganic to fill out
Material is optionally silica, titanium dioxide, barium sulfate, alundum (Al2O3) or one or more combinations in them.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110391384A (en) * | 2019-07-19 | 2019-10-29 | 深圳中兴新材技术股份有限公司 | A kind of high rigidity lithium ion battery separator preparation method and diaphragm obtained |
| CN111435761A (en) * | 2019-01-11 | 2020-07-21 | 中信国安盟固利动力科技有限公司 | All-solid-state lithium ion battery and hot-pressing preparation method of multilayer electrolyte membrane thereof |
| CN111816822A (en) * | 2020-06-18 | 2020-10-23 | 中国科学院化学研究所 | Functional lithium-supplementing diaphragm and preparation method thereof |
| EP4037050A4 (en) * | 2019-10-18 | 2022-12-21 | LG Energy Solution, Ltd. | Separator for electrochemical device, electrochemical device comprising separator and method for preparing separator |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101536221A (en) * | 2006-11-17 | 2009-09-16 | 赛尔格有限责任公司 | Co-extruded, multi-layered battery separator |
| CN101997102A (en) * | 2009-08-26 | 2011-03-30 | 比亚迪股份有限公司 | Lithium ion battery diaphragm and manufacturing method thereof |
| CN102738427A (en) * | 2012-07-19 | 2012-10-17 | 河南义腾新能源科技有限公司 | Inorganic composite microporous membrane serving as lithium ion battery diaphragm and preparation method thereof |
| US20170191189A1 (en) * | 2015-12-31 | 2017-07-06 | University Of Tartu | Separators, electrodes, half-cells, and cells of electrical energy storage devices |
-
2018
- 2018-05-18 CN CN201810481759.4A patent/CN108666512A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101536221A (en) * | 2006-11-17 | 2009-09-16 | 赛尔格有限责任公司 | Co-extruded, multi-layered battery separator |
| CN101997102A (en) * | 2009-08-26 | 2011-03-30 | 比亚迪股份有限公司 | Lithium ion battery diaphragm and manufacturing method thereof |
| CN102738427A (en) * | 2012-07-19 | 2012-10-17 | 河南义腾新能源科技有限公司 | Inorganic composite microporous membrane serving as lithium ion battery diaphragm and preparation method thereof |
| US20170191189A1 (en) * | 2015-12-31 | 2017-07-06 | University Of Tartu | Separators, electrodes, half-cells, and cells of electrical energy storage devices |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111435761A (en) * | 2019-01-11 | 2020-07-21 | 中信国安盟固利动力科技有限公司 | All-solid-state lithium ion battery and hot-pressing preparation method of multilayer electrolyte membrane thereof |
| CN111435761B (en) * | 2019-01-11 | 2021-08-10 | 荣盛盟固利新能源科技有限公司 | All-solid-state lithium ion battery and hot-pressing preparation method of multilayer electrolyte membrane thereof |
| CN110391384A (en) * | 2019-07-19 | 2019-10-29 | 深圳中兴新材技术股份有限公司 | A kind of high rigidity lithium ion battery separator preparation method and diaphragm obtained |
| CN110391384B (en) * | 2019-07-19 | 2022-11-08 | 深圳中兴新材技术股份有限公司 | Preparation method of high-rigidity lithium ion battery diaphragm and diaphragm prepared by preparation method |
| EP4037050A4 (en) * | 2019-10-18 | 2022-12-21 | LG Energy Solution, Ltd. | Separator for electrochemical device, electrochemical device comprising separator and method for preparing separator |
| CN111816822A (en) * | 2020-06-18 | 2020-10-23 | 中国科学院化学研究所 | Functional lithium-supplementing diaphragm and preparation method thereof |
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