CN108172745A - A kind of preparation method of lithium ion battery separator - Google Patents
A kind of preparation method of lithium ion battery separator Download PDFInfo
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- CN108172745A CN108172745A CN201810011523.4A CN201810011523A CN108172745A CN 108172745 A CN108172745 A CN 108172745A CN 201810011523 A CN201810011523 A CN 201810011523A CN 108172745 A CN108172745 A CN 108172745A
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- basement membrane
- extractant
- preparation
- lithium ion
- ion battery
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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
- H01M50/411—Organic material
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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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- 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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- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Cell Separators (AREA)
Abstract
The preparation method of lithium ion battery separator provided by the invention, including extractant and polymer dielectric are stirred to obtain slurry；Polyolefin is mixed extruded, cooling with pore former to be separated, obtains the basement membrane ontology containing micropore；Basement membrane ontology is stretched into 9 100 times of area ratios, after extracted in extractant, obtain wet basis film；Slurrying material is coated on wet basis film, and through drying, secondary horizontal drawing, thermal finalization, winding, lithium ion battery separator is prepared.The present invention puies forward the preparation method of lithium ion battery separator, prepares basement membrane and is carried out at the same time with coating, and intermittently operated is become streamlined operation, improves production efficiency, and eliminate winding, unreel process.The slurry solvent used during coating is the extractant prepared during basement membrane, and the wet basis film being obtained by extraction is not required to drying, and polymer dielectric slurry and wet basis binding force of membrane are stronger, improve the adhesive property of coating and basement membrane.Extractant and slurry solvent reduce capital construction cost using same regenerative system.
Description
Technical field
The present invention relates to field of lithium ion battery more particularly to a kind of preparation methods of lithium ion battery separator.
Background technology
In lithium battery structure, diaphragm is one of its crucial internal component, and the main function of diaphragm is make battery positive and negative
Pole is separated, and is prevented the two poles of the earth from contacting and is led to the generation of short circuit phenomenon, also acts as the effect of electrolyte ion channel in addition.Cause
This, the performance of diaphragm determines the interfacial structure of lithium battery, internal resistance size, and directly affect the capacity of battery, cycle-index with
And the characteristics such as security performance.
Since the electrolyte in lithium battery structure is organic system, it is therefore desirable to the diaphragm material of organic solvent-resistant, at present,
Generally use the polyolefin porous membrane of high-strength thin-film.The production technology of polyolefin porous membrane can be divided into dry method (fusion drawn
Method, MSCS) and two kinds of wet method (thermally induced phase separation, TIPS).Wherein, the basic principle of wet method is to dissolve a polymer in into first
In the agent of hole, then cooling down is separated, and to remove most of pore former, then with effumability extractant extracts pore-forming
Agent removes extractant, so as to obtain the porous membranes with certain porosity finally by seasoning.
As lithium battery applications range constantly expands, from number to electric vehicle, the various aspects such as electric tool.To lithium electricity
The requirement of pond diaphragm is also continuously improved, and traditional polyolefin porous membrane can not meet the requirement of electrical property and safety simultaneously.Cause
This many lithium battery diaphragm manufacturing firm and research institution all propose the mode with coating to improve the safety of battery.
Coating can be divided into aqueous coating and oiliness is coated with two kinds of techniques, and aqueous coating is to utilize glue, wetting agent, dispersant
Deng by slurry microballoon prepared composition dispersion liquid in aqueous solution, being then coated on porous membranes (calling basement membrane in the following text) surface.Due to
Polymer dielectric to be coated exists with spherical shape, therefore adhesive force of the coating prepared on porous membranes is limited, right
Battery electrical property is promoted little.
Oil-based solvent frequently with acetone, n-methyl-2-pyrrolidone (NMP) as slurry solvent, because oil-based solvent can be with
Dissolving, so the coating that coating is formed can be combined with base material film well, electrical property is preferable.But there are environment to ask because of oil-based solvent
Topic, and health is had an impact, solvent recovery and the increase that administers and can cause cost.
In addition, basement membrane and coating separate operation, program complexity, and cannot be carried out continuously in the prior art, reduce production
Efficiency.
Invention content
The present invention in view of the defects existing in the prior art, provide a kind of basement membrane prepare the lithium that is carried out at the same time with coating process from
The preparation method of sub- battery diaphragm, it is the preparation method simple production process, at low cost, efficient.
The preparation method of lithium ion battery separator provided by the invention, includes the following steps：
By extractant and polymer dielectric stirring, it is mixed with to obtain slurry, it is spare；
Polyolefin with pore former is mixed, squeezes out, cool down, is separated, obtains the sheet material containing micropore；
The sheet material of preparation is stretched along one and/or both direction, draw ratio is obtained in 9-100 times of area ratio
To basement membrane ontology；
The basement membrane ontology that will be prepared is immersed in extractant, is extracted remaining pore former, is struck off by liquid sweeping roller
The extractant on surface obtains wet basis film；
The slurry being prepared is coated on to the one or both sides of the wet basis film, and in the boiling point of the extractant
On dry, secondary horizontal drawing, thermal finalization, winding, the lithium ion battery separator is prepared.
In a preferred embodiment, the preparation method, includes the following steps：
By polymer dielectric and extractant according to weight ratio 1：2-1：4 room temperature are mixed, and slurry is prepared, standby
With；
By polyolefin and pore former by weight 1：1-1：6 mixing, and in a diameter of 100mm, draw ratio is 50 double spiral shells
In bar extruder, shear at high temperature, plasticizing, blending obtain blend melt, and the blend melt is delivered in shape of the mouth as one speaks die head,
It is cooled and solidified on chilling roller, and carries out solid-liquid or liquid liquid phase separation, obtain the sheet material containing micropore；
5-7 times of multistage stretching, lateral 5-7 times of multistage stretching along longitudinal direction successively by the sheet material of preparation, the temperature of stretching-machine
It is 125 DEG C to spend, and obtains basement membrane ontology, the porosity of the basement membrane ontology is 45-55%；
The basement membrane ontology being prepared is introduced into from bottom in extraction tower, multistage disturbance extraction is carried out, extracts residual
Remaining pore former obtains the basement membrane containing extractant, by the extractant of liquid sweeping roller scraper surface, obtains wet basis film；
The slurry being prepared is coated on to the one or both sides of the wet basis film, obtains coated film, and by described in
Coated film is dried on the boiling point of the extractant to constant weight, preferably in 40-45 DEG C of drying, and is transversely carried out diaphragm
The lithium ion battery separator is prepared in 1.0-2.0 times of stretching, thermal finalization, winding.
In a preferred embodiment, the sheet material is along longitudinal direction during multistage stretching, the stretching of adjacent tensile roller part
Gap is 60-80mm, and the quantity of tensile roller is 10-20, and adjacent roller is alternately arranged, and is stretched step by step, is drawn with improving
The flatness of basement membrane ontology after stretching, and improve the uniformity in basement membrane gap.
In a preferred embodiment, the top of the extraction tower is equipped with extractant spray equipment, and a side at top is set
There is basement membrane outlet, bottom is equipped with extractant storage tank, and the opposite side of bottom is equipped with basement membrane import, two row bases are equipped in the extraction tower
Film is oriented to roll shaft, and the quantity that each column basement membrane is oriented to roll shaft is 5-10, and basement membrane guiding roll shaft is horizontally arranged, cross arrangement, basement membrane
Ontology introduces the inside of the extraction tower from the basement membrane import, and is oriented to roll shaft successively around two row basement membranes, in multi-level S
Type track leaves the extraction tower from basement membrane outlet, completes the extraction of pore former.
In a preferred embodiment, steam (vapor) outlet, the steam (vapor) outlet and gas are additionally provided at the top of the extraction tower
Retracting device connects, to recycle extractant.
In a preferred embodiment, it further includes and basement membrane after stretching horizontally is stopped into 0.5-6min at 120-150 DEG C,
To eliminate the stress of drawing process generation.
In a preferred embodiment, the mode of the dry coated film is the heated-air drying in baking oven, in the baking oven
Temperature be 35-40 DEG C.
In a preferred embodiment, cutting is further included after winding, the lithium ion battery separator is prepared.
In a preferred embodiment, the mode of the coating can be dip-coating, micro- gravure, extrusion coated, scrape
Any one or a few in cutter painting cloth, and preferably micro- gravure.
In a preferred embodiment, the thickness of side coating is 1-4 μm in the lithium ion battery separator.
In a preferred embodiment, the polyolefin be selected from ethylene, propylene, 1- butylene, 4-methyl-1-pentene, 1- oneself
Any one or a few combination in the homopolymer of alkene and 1- octenes, copolymer, multi-stage polymers.
Preferably, the polyolefin is selected from the high density polyethylene (HDPE), superhigh molecular weight polyethylene that molecular weight is 500,000-200 ten thousand
Any one or a few combination in alkene.
In a preferred embodiment, the pore former is is the non-volatile of liquid more than the fusing point of the polyolefin
Substance, the pore former be preferably under room temperature for liquid, as paraffin oil, dioctyl phthalate, dibutyl phthalate,
Any one or a few combination in oleyl alcohol, stearyl alcohol.
In a preferred embodiment, the extractant can be dichloromethane, chloroform, trichloroethanes, three chloroethenes
Any one or a few combination in alkene, hydrofluoroether, ethyl alcohol, acetone, butanone, appointing preferably in dichloromethane, chloroform
It anticipates a kind of or combination.
In a preferred embodiment, antioxidant, delustering agent, nucleating agent, quiet can also be included in the basement membrane ontology
The additives such as electric remover.
In a preferred embodiment, the polymer dielectric includes that all solid state poly- of the extractant can be dissolved in
Appointing in polymer electrolyte, gel polymer electrolyte, porous polymer electrolyte and inorganic matter enhanced polymer electrolyte
Meaning one or more combination.
In a preferred embodiment, the polymer dielectric is polymethyl methacrylate (PMMA), polycyclic oxygen second
Any one or combination in alkene.
The preparation method of lithium ion battery separator provided by the invention relative to the prior art, mainly has following beneficial to it
Place：
1) it prepares basement membrane to be carried out at the same time with coating process, intermittently operated is changed into streamlined operation, traditional system is omitted
In standby technique, unreeling, planarize the techniques such as pretreatment before the winding after basement membrane and coating is prepared, production is greatly improved and imitates
Rate.
2) slurry solvent used when being coated with is the extractant prepared during basement membrane, therefore the wet basis film obtained after extracting
Drying is not required to, and is directly coated, the polymer dielectric in slurry and wet basis binding force of membrane are stronger, improve coating and basement membrane
Adhesive property.
3) extractant and slurry solvent are dry simultaneously, are recycled into same regenerative system, reduce capital construction
Facility quantity, land occupation area are less.
Description of the drawings
Fig. 1 is the structure chart of transverse drawing mill；
Fig. 2 is the structure chart of extraction tower.
Specific embodiment
The preparation of lithium ion battery separator
Embodiment one is to embodiment seven
It being squeezed out after raw material is mixed in proportion by double screw extruder, extrusion temperature is (200-220) DEG C, such as 210 DEG C,
Chill-roll temperature is 25 DEG C, obtains basement membrane ontology of the thickness for (1000-1200) μm.Then successively along stretching as shown in Figure 1
5 times, 6 times or 7 times of machine longitudinal stretching, the temperature of longitudinal stretching machine is graded.Then 5 times, 6 times or 7 times of cross directional stretch, it is horizontal
It it is 125 DEG C to the temperature of stretching-machine.Stretched basement membrane ontology is imported in extraction tower, it is abundant with extractant in extraction tower
Contact extracts pore former totally, and the basement membrane containing extractant for exporting out from extraction tower basement membrane is through liquid sweeping roller scraper surface
Extractant, obtain wet basis film, wet basis film is not required to drying, is directly coated.
Polymer dielectric, extractant by content in table 1 with the rotating speed of 100-200rpm are stirred, obtained uniform
Slurry, mixing temperature are 25 DEG C.And slurry is uniformly coated on to the obverse and reverse sides of wet basis film, and in 40-45 DEG C of drying, to remove
Extractant is removed, obtains membrane precursor.
Membrane precursor is imported into transverse stretching machine, is bounced back after being transversely stretched to 1.4 times of membrane precursor, make final outlet be every
1.2 times of film precursor width, temperature stretching in the transverse direction are 130 DEG C, are heat-treated in 135 DEG C of baking ovens, wound later later,
Lithium ion battery separator provided by the invention is obtained, the weight content and process conditions of each component are as shown in table 1.
Each component content in table 1, embodiment one to embodiment seven
Wherein, component 1 is the high density polyethylene (HDPE) of molecular weight 500,000, and component 2 is the super high molecular weight that molecular weight is 1,500,000
Polyethylene, component 3 are the ultra-high molecular weight polyethylene that molecular weight is 2,000,000；
Pore former is paraffin oil, and antioxidant is four-[3- (3,5- di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythrites
Ester；
Extractant 1 is dichloromethane, and extractant 2 is chloroform；
Electrolyte 1 is polymethyl methacrylate (PMMA), electrolyte 2 is Pluronic F-127；
Coating 1 is two-sided micro- gravure, and coating 2 is the micro- gravure of single side, and coating 3 is extrusion coated,
Coating 4 is coated with for dip coating.
Longitudinal stretching machine
As shown in Figure 1, the longitudinal stretching machine includes 14 tensile rollers, it is arranged in two rows, between adjacent tensile roller
Gap for 60-80mm, such as 70mm, the sheet material that extruded machine squeezes out enters stretching-machine from the left side of longitudinal stretching machine, most left
The temperature of the tensile roller of side is 110 DEG C, and the temperature of the tensile roller of the rightmost side is 130 DEG C, the temperature of the tensile roller at middle part
It is gradually increased by left and right, stroke temperature gradient, the pore size of basement membrane ontology stretched by the longitudinal stretching machine is more
Add uniformly, the porosity of basement membrane ontology is 55%-65%, and more than 50% hole concentrates on 60% or so, and due to sheet material by
Grade stretches, and stretching is relatively more slow, and the thickness of the basement membrane ontology after stretching is more uniform, membrane surface more flatness.
Extraction tower
As shown in Fig. 2, the cylinder that extraction tower provided by the invention is reduced for cylindrical or top, tower top is equipped with extractant
Spray equipment 3, extraction tower upper portion side wall are equipped with basement membrane and export 2, on extraction tower lower sides, it is preferable that with basement membrane outlet 2
Opposite one side wall is equipped with basement membrane import 1, and the bottom of extraction tower is equipped with extractant and exports 4, and extraction tower is internally provided with two row
Basement membrane is oriented to roll shaft 6.
Extractant is equipped in extraction tower, the inside bottom of extraction tower is equipped with disturbance device 5, and the upper surface of disturbance device 5 is set
There are multiple zigzag structures, external impetus structure driving disturbance device 5 is reciprocating in the horizontal direction, and disturbance device 5 is being transported
During dynamic, the extractant into extraction tower provides disturbance.
The extractant spray equipment 3 includes multiple spray ports, and extractant spray equipment 3 connects with external fresh extractant storage tank
It is logical.The number that each column basement membrane is oriented to roll shaft 6 can be 5-10, and in Fig. 1, each column is equipped with 4 basement membranes and is oriented to roll shaft 6, basement membrane
It is horizontally disposed to be oriented to roll shaft 6, and from down to up, laterally adjacent two basement membranes are oriented to the distance between roll shaft 6 and are gradually reduced.
Using the extraction tower extract basement membrane ontology when, basement membrane ontology from basement membrane import 1 enter extraction tower inside, from down toward
On, roll shaft 6 is oriented to around each basement membrane successively, is gone into S type motion tracks.The basement membrane ontology of lower part is immersed in what is fallen from top
In extractant, basement membrane ontology is tentatively extracted, partial extraction agent leaves extraction tower from the extractant outlet 4 of bottom, enters
Extractant recovery system.The basement membrane ontology on top is exposed in air, the fresh extractant come from extractant storage tank, such as dichloromethane
Alkane, under the spray of extractant spray equipment 3, fresh extractant is sprayed at the basement membrane body surface by tentatively extracting, to basement membrane
Ontology further extracts, and the removal rate of pore former is improved to more than 99%.
Comparative example one
By weight, the supra polymer for being 1,500,000 by the high density polyethylene (HDPE) of 20 parts of molecular weight 500,000,10 parts of molecular weight
Weight northylen, 70 parts of paraffin oils, 0.3 part four-[3- (3,5- di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester pass through double
Screw-type extruder squeezes out, 210 DEG C of extrusion temperature, and chill-roll temperature is 25 DEG C, thus obtains the basement membrane sheet that thickness is 1200 μm
Body.Then it is longitudinally stretched 5-7 times successively, 5-7 times of cross directional stretch, the temperature of stretching-machine is 125 DEG C.It is then introduced into dichloromethane
In extraction tank, it is sufficiently impregnated in dichloromethane clean paraffin oil to be extracted.Hereafter, the drying of dichloromethane is carried out.It leads again
Enter transverse stretching machine, retraction makes final outlet be 1.2 times after transversely stretching 1.4 times, and horizontal drawing temperature is 130 DEG C, later in 135 DEG C of bakings
It is heat-treated in case, winding obtains basement membrane.
It is entitled using application number 201110002330.0：Diaphragm and nonaqueous electrolyte battery, described in coating
Mode, by weight ratio 20：After 1 alundum (Al2O3) and Kynoar mixing, it is uniformly mixed in N-Methyl pyrrolidone, and
The two sides of basement membrane is coated on by desk-top coating machine, after 50 DEG C dry, obtains lithium ion battery separator.
Comparative example 2
By weight, the supra polymer for being 1,500,000 by the high density polyethylene (HDPE) of 20 parts of molecular weight 500,000,10 parts of molecular weight
Weight northylen, 70 parts of paraffin oils, 0.3 part four-[3- (3,5- di-tert-butyl-hydroxy phenyl) propionic acid] pentaerythritol ester pass through double
Screw-type extruder squeezes out, 210 DEG C of extrusion temperature, and chill-roll temperature is 25 DEG C, thus obtains the basement membrane sheet that thickness is 1200 μm
Body.Then it is longitudinally stretched 5-7 times successively, 5-7 times of cross directional stretch, the temperature of stretching-machine is 125 DEG C.It is then introduced into dichloromethane
In extraction tank, it is sufficiently impregnated in dichloromethane clean paraffin oil to be extracted.Hereafter, the drying of dichloromethane is carried out.It leads again
Enter transverse stretching machine, retraction makes final outlet be 1.2 times after transversely stretching 1.4 times, and horizontal drawing temperature is 130 DEG C, later in 135 DEG C of bakings
It is heat-treated in case, winding obtains basement membrane, and the basement membrane after winding is transferred to coating station, after unreeling, pre-processing, is
Coating process is prepared.
6 parts of PMMA are added in 1200 parts of acetone solvents, heating stirring is complete to boiling 20min to PMMA is boiling for
Portion is dissolved, and is subsequently cooled to room temperature；And Kynoar (PVDF) stirring to the solution for adding in 15 parts is clarified；Add in 60 parts of positive fourths
Alcohol stirs to clarify.Obtain polymer solution.
Polymer gel solution with dip coating is coated on to the surface of basement membrane, is dried under the conditions of 50 DEG C, obtains lithium ion
Battery diaphragm.
The performance detection of lithium ion battery separator
To embodiment one to embodiment seven, lithium ion battery separator prepared by comparative example one, comparative example two does performance respectively
Detection, the results are shown in Table 2：
The performance of table 2, lithium ion battery separator
As shown in Table 2, the thickness of lithium ion battery separator provided by the invention and the comparison in comparative example one, comparative example two
It is close, the requirement to lithium ion battery separator thickness in the market or the as needed other draw ratios of selection can be met, it will be thick
Degree control is in a specific range.
In addition, the air permeability mean value for the lithium ion battery separator that embodiment one to embodiment seven is prepared is 375/sec/
The air permeability of lithium ion battery separator prepared by 100cc, particularly example IV, embodiment one, embodiment two is respectively less than 350/
Sec/100cc, hence it is evident that less than comparative example one, comparative example two prepare lithium ion battery separator air permeability 560/sec/100cc,
780/sec/100cc, i.e., compared to the lithium ion battery separator using prior art preparation, lithium ion battery provided by the invention
The permeability of diaphragm is significantly superior, has lower electricity comprising the lithium ion battery of lithium ion battery separator prepared by the present invention
Resistance.
Compare lithium ion battery separator prepared by the embodiment of the present invention one to embodiment seven and comparative example one, comparative example two
Liquid absorption amount, it is known that, the liquid absorption amount of lithium ion battery separator prepared by the present invention is not less than the lithium-ion electric of prior art preparation
The liquid absorption amount of pond diaphragm, wherein, the liquid absorption amount of lithium ion battery separator prepared by embodiment three, embodiment seven is in 20/g/m2,
It is apparently higher than liquid absorption amount 17.5, the 17.0/g/m of the lithium ion battery separator prepared in comparative example one, comparative example two2。
The splitting power for the lithium ion battery separator that the embodiment of the present invention one is prepared to embodiment seven is bright in more than 3N
The aobvious splitting power 1N higher than battery diaphragm in comparative example one, two illustrates lithium ion battery separator prepared by the present invention, relatively
For the prior art, the adhesive property between coating and basement membrane is stronger, and coating is not easily to fall off, improves lithium ion battery separator
Stability in use.
In addition, using preparation method provided by the invention, production efficiency 5-10% can be significantly improved, there is apparent warp
Ji benefit.The preparation method of lithium ion battery separator provided by the invention is coated technique during basement membrane is prepared, and applies
Cloth equipment is directly installed on the top of basement membrane, makes full use of upper space, has saved space.And eliminate conventional preparation techniques
In, unreeling, to basement membrane before winding and coating after basement membrane is prepared existing for when prepared by basement membrane separate progress with being coated with
Preprocessing process simplifies technological process.And the slurry solvent used when being coated with is the extractant prepared during basement membrane, is only needed
Coating apparatus is mounted in the space communicated with drying process after extraction tank or extraction, you can solve coating process slurry
The recycling problem of solvent.In addition, since slurry solvent is communicated with extractant type, can also save as needed dry after extraction
Dry process, and extractant and slurry solvent reduce capital construction facility quantity, land occupation area more using same regenerative system
Few, production technology cost is lower, and improves production efficiency 5-10%.
Specific embodiments of the present invention are described in detail above, but it is intended only as example, it is of the invention and unlimited
It is formed on particular embodiments described above.To those skilled in the art, it is any to the equivalent modifications that carry out of the present invention and
It substitutes also all among scope of the invention.Therefore, the impartial conversion made without departing from the spirit and scope of the invention and
Modification, all should be contained within the scope of the invention.
Claims (10)
1. a kind of preparation method of lithium ion battery separator, which is characterized in that include the following steps：
By extractant and polymer dielectric stirring, it is mixed with to obtain slurry, it is spare；
Polyolefin with pore former is mixed, squeezes out, cool down, is separated, obtains the sheet material containing micropore；
The sheet material of preparation is stretched along one and/or both direction, draw ratio obtains base in 9-100 times of area ratio
Membrane body；
The basement membrane ontology that will be prepared is immersed in extractant, remaining pore former is extracted, by liquid sweeping roller scraper surface
Extractant, obtain wet basis film；
The slurry being prepared is coated on to the one or both sides of the wet basis film, and on the boiling point of the extractant
Dry, secondary horizontal drawing, thermal finalization, winding, are prepared the lithium ion battery separator.
2. preparation method according to claim 1, which is characterized in that include the following steps：
By polymer dielectric and extractant according to weight ratio 1：2-1：4 room temperature are mixed, and slurry is prepared, spare；
By polyolefin and pore former by weight 1：1-1：6 mixing, and in a diameter of 100mm, draw ratio is than the twin-screw for 50
In extruder, shear at high temperature, plasticizing, blending obtain blend melt, the blend melt are delivered in shape of the mouth as one speaks die head, in urgency
It is cooled and solidified in chilling roller, and carries out solid-liquid or liquid liquid phase separation, obtain the sheet material containing micropore；
By the sheet material of preparation, 5-7 times of multistage stretching, lateral 5-7 times of multistage stretching, the temperature of stretching-machine are along longitudinal direction successively
125 DEG C, basement membrane ontology is obtained, the porosity of the basement membrane ontology is 45-55%；
The basement membrane ontology being prepared is introduced into from bottom in extraction tower, multistage disturbance extraction is carried out, extracts remnants'
Pore former obtains the basement membrane containing extractant, by the extractant of liquid sweeping roller scraper surface, obtains wet basis film；
The slurry being prepared is coated on to the one or both sides of the wet basis film, obtains coated film, and by the coating
Film is dried on the boiling point of the extractant to constant weight, preferably in 40-45 DEG C of drying, and diaphragm transversely is carried out 1.0-
The lithium ion battery separator is prepared in 2.0 times of stretching, thermal finalization, winding.
3. preparation method according to claim 1 or 2, which is characterized in that the sheet material is along longitudinal direction during multistage stretching,
The drawing gap of adjacent tensile roller part is 60-80mm, and the quantity of tensile roller is 10-20, and adjacent roller is alternately arranged, into
Row stretches step by step.
4. preparation method according to claim 2, which is characterized in that the top of the extraction tower is equipped with extractant spray dress
It puts, a side at top is exported equipped with basement membrane, and bottom is equipped with extractant storage tank, and the opposite side of bottom is equipped with basement membrane import, described
Two row basement membranes are equipped in extraction tower and are oriented to roll shaft, it is horizontally arranged that basement membrane is oriented to roll shaft, cross arrangement, and basement membrane ontology is from the basement membrane
Import introduces the inside of the extraction tower, and is oriented to roll shaft successively around two row basement membranes, in multi-level S types track, from basement membrane
Leave the extraction tower in outlet.
5. preparation method according to claim 4, which is characterized in that steam (vapor) outlet is additionally provided at the top of the extraction tower,
The steam (vapor) outlet is connected with gas concentration unit.
6. preparation method according to claim 1, which is characterized in that in the lithium ion battery separator, side coating
Thickness is 1-4 μm.
7. preparation method according to claim 1, which is characterized in that the polyolefin be selected from ethylene, propylene, 1- butylene,
Any one or a few combination in 4-methyl-1-pentene, the homopolymer of 1- hexenes and 1- octenes, copolymer, multi-stage polymers.
8. preparation method according to claim 1, which is characterized in that the extractant is dichloromethane, in chloroform
Any one or combination.
9. preparation method according to claim 1, which is characterized in that the polymer dielectric includes that institute can be dissolved in
State full solid state polymer electrolyte, gel polymer electrolyte, porous polymer electrolyte and the inorganic matter enhancement of extractant
Any one or a few combination in polymer dielectric.
10. preparation method according to claim 1 or 2, which is characterized in that antioxygen can also be included in the basement membrane ontology
The additives such as agent, delustering agent, nucleating agent, electrical static eliminator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810011523.4A CN108172745B (en) | 2018-01-05 | 2018-01-05 | Preparation method of lithium ion battery diaphragm |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810011523.4A CN108172745B (en) | 2018-01-05 | 2018-01-05 | Preparation method of lithium ion battery diaphragm |
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| Publication Number | Publication Date |
|---|---|
| CN108172745A true CN108172745A (en) | 2018-06-15 |
| CN108172745B CN108172745B (en) | 2021-08-06 |
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| CN201810011523.4A Active CN108172745B (en) | 2018-01-05 | 2018-01-05 | Preparation method of lithium ion battery diaphragm |
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Cited By (9)
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| CN109301130A (en) * | 2018-09-17 | 2019-02-01 | 湖北江升新材料有限公司 | A kind of preparation method with high temp resistance lithium ion cell diaphragm |
| CN110038319A (en) * | 2019-02-13 | 2019-07-23 | 江苏北星新材料科技有限公司 | A kind of wet process lithium ion battery separator extraction equipment overflow mechanism |
| CN111129395A (en) * | 2019-12-12 | 2020-05-08 | 中材锂膜有限公司 | Transverse stretching and shrinking shaping process after extraction of wet lithium battery diaphragm |
| CN111589334A (en) * | 2020-05-29 | 2020-08-28 | 苏州捷力新能源材料有限公司 | Antioxidant adding device and method for wet lithium battery diaphragm |
| CN112803118A (en) * | 2021-01-13 | 2021-05-14 | 山东工业陶瓷研究设计院有限公司 | Battery separator, preparation method and polyimide porous membrane impregnation equipment |
| CN112820939A (en) * | 2019-11-18 | 2021-05-18 | 青岛蓝科途膜材料有限公司 | Gel electrolyte and lithium ion battery |
| CN114024092A (en) * | 2021-11-09 | 2022-02-08 | 江苏厚生新能源科技有限公司 | Ice crystallization induced self-assembly porous coating diaphragm and preparation process thereof |
| CN115347322A (en) * | 2022-08-30 | 2022-11-15 | 新乡市中科膜材料科技有限公司 | Preparation method and application of porous polyolefin composite membrane |
| CN115475408A (en) * | 2022-08-31 | 2022-12-16 | 中材锂膜(宁乡)有限公司 | Wet-process diaphragm extraction device and process |
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| CN103264500A (en) * | 2013-05-21 | 2013-08-28 | 武汉博盛科技有限公司 | Lithium battery diaphragm stretching forming device and method as well as lithium battery diaphragm |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109301130A (en) * | 2018-09-17 | 2019-02-01 | 湖北江升新材料有限公司 | A kind of preparation method with high temp resistance lithium ion cell diaphragm |
| CN110038319B (en) * | 2019-02-13 | 2023-12-26 | 江苏北星新材料科技有限公司 | Overflow device for wet lithium ion battery diaphragm extraction equipment |
| CN110038319A (en) * | 2019-02-13 | 2019-07-23 | 江苏北星新材料科技有限公司 | A kind of wet process lithium ion battery separator extraction equipment overflow mechanism |
| CN112820939B (en) * | 2019-11-18 | 2024-03-12 | 青岛蓝科途膜材料有限公司 | Gel electrolyte and lithium ion battery |
| CN112820939A (en) * | 2019-11-18 | 2021-05-18 | 青岛蓝科途膜材料有限公司 | Gel electrolyte and lithium ion battery |
| CN111129395A (en) * | 2019-12-12 | 2020-05-08 | 中材锂膜有限公司 | Transverse stretching and shrinking shaping process after extraction of wet lithium battery diaphragm |
| CN111589334A (en) * | 2020-05-29 | 2020-08-28 | 苏州捷力新能源材料有限公司 | Antioxidant adding device and method for wet lithium battery diaphragm |
| CN112803118A (en) * | 2021-01-13 | 2021-05-14 | 山东工业陶瓷研究设计院有限公司 | Battery separator, preparation method and polyimide porous membrane impregnation equipment |
| CN114024092A (en) * | 2021-11-09 | 2022-02-08 | 江苏厚生新能源科技有限公司 | Ice crystallization induced self-assembly porous coating diaphragm and preparation process thereof |
| CN115347322A (en) * | 2022-08-30 | 2022-11-15 | 新乡市中科膜材料科技有限公司 | Preparation method and application of porous polyolefin composite membrane |
| CN115347322B (en) * | 2022-08-30 | 2024-02-02 | 新乡市中科膜材料科技有限公司 | Preparation method and application of porous polyolefin composite membrane |
| CN115475408A (en) * | 2022-08-31 | 2022-12-16 | 中材锂膜(宁乡)有限公司 | Wet-process diaphragm extraction device and process |
| CN115475408B (en) * | 2022-08-31 | 2024-01-19 | 中材锂膜(宁乡)有限公司 | Wet diaphragm extraction device and process |
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