CN109285981A - Lithium battery diaphragm and preparation method thereof - Google Patents
Lithium battery diaphragm and preparation method thereof Download PDFInfo
- Publication number
- CN109285981A CN109285981A CN201710596538.7A CN201710596538A CN109285981A CN 109285981 A CN109285981 A CN 109285981A CN 201710596538 A CN201710596538 A CN 201710596538A CN 109285981 A CN109285981 A CN 109285981A
- Authority
- CN
- China
- Prior art keywords
- solvent
- battery diaphragm
- lithium battery
- film forming
- polyethylene
- 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.)
- Pending
Links
Classifications
-
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—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
- H01M50/431—Inorganic 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
Abstract
The invention discloses a kind of novel lithium battery diaphragm preparation methods, wherein preparation method includes: that polyethylene and the film forming solvent of a variety of different boilings are carried out melting mixing in extruder；The extrusion raw material is subjected to mixing extrusion and cooling and shaping, to obtain sheet material；The sheet material is subjected to longitudinal stretching and cross directional stretch, and some or all of film forming solvent is made to volatilize, to obtain film；Under the conditions of necessary, the film is extracted to remaining film forming solvent in extractant, to obtain microporous barrier；The microporous barrier is coated with online, is dried and thermal finalization, to form coating on the surface of the microporous barrier, and obtains the lithium battery diaphragm.Preparing battery diaphragm using this method can effectively improve line speed, increases production capacity, reduces energy consumption and production costs, and the battery diaphragm yield being prepared is high.
Description
Technical field
The present invention relates to battery material fields, specifically, the present invention relates to lithium battery diaphragms and preparation method thereof.
Background technique
Lithium battery has obtained swift and violent development as the nova of new energy industry recent years.Lithium battery mainly includes four big
Class material: electrode, electrolyte, diaphragm and encapsulating material.Wherein, diaphragm due to production technology it is more demanding, early stage always
It is monopolized and is produced by developed countries such as America and Japan.In recent years the fast development of New Energy Sources In China industry has expedited the emergence of what large quantities of China had by oneself
Diaphragm manufacturing enterprise.Production capacity and quality are increasingly approached to international high-end manufacturer.
The manufacturing of current lithium battery diaphragm basement membrane mainly has two kinds of dry and wet.Dry method does not use solvent, squeezes out
Uniaxial direct tensile pore-forming after film forming.Low with production cost, non-environmental-pollution, the good advantage of lateral thermal stability, representative products are such as
Three layers of compound die of dry method of U.S. Celgard production.Its disadvantage is that product is easy cracking (simple tension), vertical mixing coefficient
Difference, homogeneity are poor.Wet process film uses film forming solvent, can melt the super high molecular weight high score subtree much higher than dry method molecular weight
Rouge.Pass through extraction wash-off film forming solvent after stretching pore-forming, product homogeneity is preferable, and intensity is high.Such as Japanese Asahi Chemical Industry of representative products
The polyethylene wet process basement membrane of production.The disadvantage is that manufacturing cost is high, for production process not as good as dry method environmental protection, basement membrane percent thermal shrinkage is high.
In recent years, wet process diaphragm production technology has significant progress.Solvent has obtained effective recycling, both reduces
Environmental pollution reduces production cost simultaneously.However, existing lithium battery diaphragm and preparation method thereof still has much room for improvement.
Summary of the invention
The present invention is directed to solve at least some of the technical problems in related technologies.For this purpose, of the invention
One purpose is to propose lithium battery diaphragm and preparation method thereof.Preparing battery diaphragm using this method can effectively improve production
Linear velocity increases production capacity, reduces energy consumption and production costs, and the battery diaphragm yield being prepared is high.
In the first aspect of the present invention, the invention proposes a kind of methods for preparing lithium battery diaphragm.It is according to the present invention
Embodiment, this method comprises: polyethylene and film forming solvent are carried out melting mixing, to obtain squeezing out raw material；By the extrusion
Raw material carries out mixing extrusion and cooling and shaping, to obtain sheet material；The sheet material is subjected to longitudinal stretching and cross directional stretch, makes portion
Divide or all the film forming solvent volatilizees, to obtain film；The film is extracted in extractant, so as to
To microporous barrier；And the microporous barrier is coated with online, is dried and thermal finalization, to be formed on the surface of the microporous barrier
Coating, and obtain the lithium battery diaphragm.
The method according to an embodiment of the present invention for preparing lithium battery diaphragm can effectively improve line speed, increases and produces
It can, reduce energy consumption and production costs, and the battery diaphragm yield being prepared is high.
In addition, the method according to the above embodiment of the present invention for preparing lithium battery diaphragm can also have following additional skill
Art feature:
In some embodiments of the invention, the mass ratio of the polyethylene and the film forming solvent is (15~40): (60
~85).
In some embodiments of the invention, the film forming solvent by least one boiling point be lower than 200 degrees Celsius first
The second solvent of solvent and/or at least one boiling point higher than 200 degrees Celsius forms.
In some embodiments of the invention, first solvent is a kind of C10-14Hydrocarbon solvent or a variety of be selected from
C10-14Hydrocarbon solvent composition mixed solvent, second solvent be selected from paraffin oil, solid paraffin, soybean oil, peanut oil,
At least one of olive oil, phthalic acid ester, dioctyl phthalate, dibutyl phthalate and glyceride.
In some embodiments of the invention, the polyethylene weight average molecular weight is lower than 500,000, first solvent and institute
The volume ratio for stating the second solvent is (90~100): (0~10)；Or the weight average molecular weight of the polyethylene is 50~1,000,000,
The volume ratio of first solvent and second solvent is (50~70): (30~50)；Or the polyethylene is divided equally again
Son amount is, greater than 1,000,000, the volume ratio of first solvent and second solvent is (0~10): (90~100).
In some embodiments of the invention, the mixing extrusion is carried out according to the following steps: by polyethylene and accounting for film forming
The film forming solvent of solvent total weight 60~80% is first pre-mixed, and carries out melt blending extrusion in an extruder；Carry out
Downstream during the melt blending extrusion, injects the extruder for remaining film forming solvent.
In some embodiments of the invention, the temperature that the melt blending squeezes out is 150~270 degrees Celsius, described cold
But rate is not less than 15 degrees seconds Celsius.
In some embodiments of the invention, the temperature of the drying and thermal finalization is 40~135 degrees Celsius.
In some embodiments of the invention, the stretching of the longitudinal stretching and the draw ratio stretching in the transverse direction are all larger than
5 times, the longitudinal stretching and the cross directional stretch be 90~125 degrees Celsius at a temperature of carry out.
In some embodiments of the invention, the extractant is selected from methylene chloride, pentane, hexane, heptane, tetrachloro
Change at least one of carbon, diethyl ether, dioxanes and methyl ethyl ketone.
In the second aspect of the present invention, the invention proposes a kind of lithium battery diaphragms.According to an embodiment of the invention, the lithium
Battery diaphragm is prepared by the method for preparing lithium battery diaphragm of above-described embodiment.The lithium battery diaphragm has intensity height, thick
Degree and ventilative homogeneity are good, and pore size distribution is narrow, the good feature of thermal stability.
In addition, lithium battery diaphragm according to the above embodiment of the present invention can also have the following additional technical features:
In some embodiments of the invention, the lithium battery diaphragm include basement membrane and be formed in the basement membrane upper surface and
The coating of lower surface, the coating with a thickness of 0.2~10 micron.
Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description
Obviously, or practice through the invention is recognized.
Detailed description of the invention
Above-mentioned and/or additional aspect of the invention and advantage will become from the description of the embodiment in conjunction with the following figures
Obviously and it is readily appreciated that, in which:
Fig. 1 is the method flow schematic diagram according to an embodiment of the invention for preparing lithium battery diaphragm；
Fig. 2 is aluminum oxide coating layer electromicroscopic photograph according to an embodiment of the invention；
Fig. 3 is boehmite according to an embodiment of the invention (Boehmite) coating electromicroscopic photograph；
Fig. 4 is PVDF coating electromicroscopic photograph according to an embodiment of the invention.
Specific embodiment
The embodiment of the present invention is described below in detail, examples of the embodiments are shown in the accompanying drawings, wherein from beginning to end
Same or similar label indicates same or similar element or element with the same or similar functions.Below with reference to attached
The embodiment of figure description is exemplary, it is intended to is used to explain the present invention, and is not considered as limiting the invention.
In the description of the present invention, it is to be understood that, term " first ", " second " are used for description purposes only, and cannot
It is interpreted as indication or suggestion relative importance or implicitly indicates the quantity of indicated technical characteristic.Define as a result, " the
One ", the feature of " second " can explicitly or implicitly include at least one of the features.
In the first aspect of the present invention, the invention proposes a kind of methods for preparing lithium battery diaphragm.It is according to the present invention
Embodiment, this method comprises: polyethylene and film forming solvent are carried out melting mixing, to obtain squeezing out raw material；Raw material will be squeezed out
Mixing extrusion and cooling and shaping are carried out, to obtain sheet material；Sheet material is subjected to longitudinal stretching and cross directional stretch, makes part or complete
Portion's film forming solvent volatilization, to obtain film；Film is extracted in extractant, to obtain microporous barrier；And it will
Microporous barrier is coated with online, is dried and thermal finalization, to form coating on the surface of microporous barrier, and obtains lithium battery diaphragm.
The method according to an embodiment of the present invention for preparing lithium battery diaphragm is described in detail below with reference to Fig. 1.According to
The embodiment of the present invention, this method comprises:
S100: melting mixing
In the step, polyethylene and film forming solvent are subjected to melting mixing, to obtain squeezing out raw material.
According to an embodiment of the invention, the proportion of polyethylene and film forming solvent is not particularly restricted, those skilled in the art
Member can be selected according to actual needs, and according to a particular embodiment of the invention, the mass ratio of polyethylene and film forming solvent can
Think (15~40): (60~85), thus, it is possible to further increase the film forming for the lithium battery diaphragm being prepared.
According to an embodiment of the invention, the type of film forming solvent is not particularly restricted, those skilled in the art can root
It is selected according to actual needs, according to a particular embodiment of the invention, film forming solvent can be taken the photograph by least one boiling point lower than 200
Second solvent of the first solvent and/or at least one boiling point of family name's degree higher than 200 degrees Celsius forms.
According to a particular embodiment of the invention, above-mentioned first solvent is a kind of C10-14Hydrocarbon solvent or a variety of be selected from
C10-14Hydrocarbon solvent composition mixed solvent, above-mentioned second solvent can be for selected from paraffin oil, solid paraffin, soybean oil, flower
At least one in oil generation, olive oil, phthalic acid ester, dioctyl phthalate, dibutyl phthalate and glyceride
Kind.Thus, it is possible to further increase the film forming for the lithium battery diaphragm being prepared.
According to a particular embodiment of the invention, the proportion of above-mentioned first solvent and the second solvent depends on polyethylene used
The molecular weight and line speed of raw material.Specifically, polyethylene weight average molecular weight used is lower than 500,000, the first solvent and second
The volume ratio of solvent can be (90~100): (0~10)；The weight average molecular weight of polyethylene used is 50~1,000,000, and first is molten
The volume ratio of agent and the second solvent can be (50~70): (30~50)；The weight average molecular weight of polyethylene used is greater than 100
Ten thousand, the volume ratio of the first solvent and the second solvent can be (0~10): (90~100).Inventors have found that as polyethylene is flat
The increase of average molecular weight, the allocation ratio of the first solvent need to reduce, insufficient so as to avoid film forming solvent from melting occur
The phenomenon that.
A specific embodiment according to the present invention, it is molten by using mentioned kind and the first solvent matched and second
Agent can make kinematic viscosity 10~100cst of the film forming solvent at 40 degrees Celsius, to further increase the processing of material
Performance.
S200: mixing is squeezed out and is cooled and shaped
In the step, raw material will be squeezed out and carry out mixing extrusion and cooling and shaping, to obtain sheet material.
According to a particular embodiment of the invention, mixing is squeezed out and can be carried out according to the following steps: by polyethylene and accounting for film forming
The film forming solvent of solvent total weight 60~80% is first pre-mixed, and carries out melt blending extrusion in an extruder；Carry out
Remaining film forming solvent is injected extruder by the downstream during extrusion.In the upstream of double screw extruder, polyethylene powder
Only start to be swollen, viscosity increases slowly, if disposably filling all film forming solvents, is unfavorable for the kinetic energy of extruder is effective
The energy for being converted into melting and polyethylene dissolving powder, extruder is inefficient, be easy to cause the uneven of melting and mixing,
Influence final product quality.And if only filling part film forming solvent in upstream, it not only can guarantee the swelling of powder, but also logical
It crosses and increases the viscosity that solid content increases solution, the kinetic energy of extruder is made full use of to go melting, polyethylene dissolving and mix polyethylene
And film forming solvent.In the middle and lower reaches of extruder, when most of polyethylene is all molten and dissolution, the viscosity of solution will be big at this time
Amplitude increases, and residual solvent is added at this time suitably reduces viscosity, and extruder screw can be prevented to the excessive shear of strand, prevented
Major structure is crosslinked at strand, influences the stretching film forming pore-forming in downstream.
According to a particular embodiment of the invention, the temperature of extrusion can be 150~270 degrees Celsius, specifically, extrusion temperature
It can be according to the proportion of the first solvent and the second solvent in film forming solvent, when using low-boiling first solvent in film forming solvent
When, extrusion temperature should be controlled not higher than 180 degrees Celsius, when in film forming solvent only with high boiling second solvent, be squeezed out
Temperature should be controlled not higher than 270 degrees Celsius.It is suitably improved under the conditions of guaranteeing that film forming solvent is nonvolatile as a result, and squeezes out temperature
Degree, can effectively improve ability and speed that polyethylene is melted and dissolved in a solvent, while reducing the viscosity of solution.
According to a particular embodiment of the invention, cooling rate can be for not less than 15 degrees seconds Celsius, cooling velocity be lower than
15 degrees seconds Celsius, be easy to cause sheet material phase separation speed slow, and crystallinity is excessively high, and the head office for being unfavorable for next step stretches and cross
To stretching, the quality of product is directly influenced.
S300: it stretches
In the step, sheet material is subjected to longitudinal stretching and cross directional stretch, makes some or all of film forming solvent volatilization,
To obtain film.Specifically, above-mentioned longitudinal stretching can both have been drawn with cross directional stretch using asynchronous stretching or using synchronous
It stretches.
According to an embodiment of the invention, above-mentioned longitudinal stretching and draw ratio stretching in the transverse direction are not particularly restricted, ability
Field technique personnel can select according to actual needs, according to a particular embodiment of the invention, longitudinal stretching and cross directional stretch
Draw ratio can be all larger than 5 times, and total drawing ratio can control at 25~100 times, while longitudinal stretching and cross directional stretch
Can 90~125 degrees Celsius at a temperature of carry out, so as to so that the low boiling component preferential volatilization in film forming solvent finishes,
And after burning is handled, the heat of generation can be used for hot-rolling and baking oven of subsequent heat basement membrane production line etc., so as to
To substantially reduce production energy consumption, and avoid environmental pollution.
S400: extraction
In the step, film is extracted in extractant, to obtain microporous barrier.Specifically, if film forming is molten
High boiling second solvent is not used in agent, then it can be without extraction by the film that above-mentioned longitudinal stretching and cross directional stretch obtain
It takes, is directly entered subsequent coating station and is coated, it is possible thereby to greatly reduce production cost；If used in film forming solvent
High boiling second solvent then needs to extract film by extractant, extracts film forming solvent using extractant,
To obtain microporous barrier；Simultaneously as having part or most of film forming solvent in above-mentioned longitudinal stretching and cross directional stretch
Volatilization, extraction processing only need shorter extraction section, thus can both deform corrugation in too long extraction section to avoid film, may be used also
To use higher line speed to complete the extraction and separation to film forming solvent, so as to further increase production efficiency simultaneously
Reduce production cost.
According to an embodiment of the invention, extractant is not particularly restricted, those skilled in the art can be according to reality
Border is selected, and according to a particular embodiment of the invention, extractant can be for selected from methylene chloride, pentane, hexane, heptan
At least one of alkane, carbon tetrachloride, diethyl ether, dioxanes and methyl ethyl ketone.Thus, it is possible to further increase at extraction
The efficiency of reason.
S500: online coating, drying and thermal finalization
In the step, microporous barrier is coated with online, dried and thermal finalization, is applied to be formed on the surface of microporous barrier
Layer, and obtain lithium battery diaphragm.Specifically, method of the invention, which passes through, is directly applied the microporous barrier obtained after the completion of extraction
Cloth stretches secondary sizing in the prior art, and sizing and coating, drying are combined, so as to substantially reduce energy consumption,
The investment of the fixed assets such as relevant device is saved, while eliminating retractable volume step repeatedly in the prior art, to reduce
Yield loss caused by institute is effective before coating, improves the yield of final products.Microporous barrier is obtained through online coating, drying
Membrane surface coating layer has been formed simultaneously the support construction of stable basement membrane, makes basement membrane when carrying out thermal finalization, hot receipts will not occur
Contracting, and internal stress can be discharged, it is heat-shrinked finally obtained product and reduces, improve product quality.
According to an embodiment of the invention, coating method is not particularly restricted, those skilled in the art can be according to reality
It is selected, according to a particular embodiment of the invention, coating method can include but is not limited to: dip-coating formula, board-like, dimple
Board-like, roll-type, line roll-type, jet printing type etc..Application place can be the single side or two-sided of basement membrane.
According to a particular embodiment of the invention, it is wide can to export or extract the film web exported for longitudinal stretching for coating width
About 85~95%.A specific embodiment according to the present invention, coating breadth can be 1.2 meters.
According to a particular embodiment of the invention, filler, adhesive and solvent can be contained in slurry used by being coated with.
Wherein, filler can include but is not limited to all kinds of high molecular nanometer spheres, ceramics, such as aluminium oxide, boehmite, magnesia, oxidation
Calcium, silica, diatomite, titanium oxide, calcium sulfate, barium sulfate, calcium carbonate etc..Adhesive can include but is not limited to polypropylene
Acid, polyacrylate analog copolymer, polyvinyl alcohol and its copolymer, polyvinylpyrrolidone and its copolymer, carboxymethyl are fine
The fluorine resins such as dimension element and its derivative, Kynoar, polytetrafluoroethylene (PTFE), polyvinylidene fluoride copolymer；It may be polyamides
Polymer such as imines, polyamide, polysulfones, acrylonitrile polymers etc..Solvent can be common molten with water, ethyl alcohol, acetone, NMP etc.
One or more of agent mixing.A specific embodiment according to the present invention, the viscosity of coating sizing-agent can for 10~
500cps, the solid content in slurries can be 1~50wt%
According to a particular embodiment of the invention, drying and heat setting temperature can be 40~135 degrees Celsius.
A specific embodiment according to the present invention, lithium battery diaphragm may include basement membrane and be formed in basement membrane upper surface and
The coating of lower surface, and the thickness of signal layer coating can be 0.2~10 micron.
The method according to an embodiment of the present invention for preparing lithium battery diaphragm can effectively improve line speed as a result, increase
Add production capacity, reduce energy consumption and production costs, and by mutually tying secondary sizing drawing process in the prior art with coating, drying
It closes, retractable volume repeatedly in the prior art is eliminated, to significantly improve the yield of product.
In the second aspect of the present invention, the invention proposes a kind of lithium battery diaphragms.According to an embodiment of the invention, the lithium
Battery diaphragm is prepared by the method for preparing lithium battery diaphragm of above-described embodiment.
According to a particular embodiment of the invention, lithium battery diaphragm may include basement membrane and be formed in basement membrane upper surface and following table
The coating in face, and the thickness of signal layer coating can be 0.2~10 micron.
According to a particular embodiment of the invention, coating can be formed in upper surface and the following table of basement membrane by the mode being coated with
Face.According to an embodiment of the invention, coating method is not particularly restricted, those skilled in the art can according to actual needs into
Row selection, according to a particular embodiment of the invention, coating method can include but is not limited to: dip-coating formula, board-like, dimple is board-like,
Roll-type, line roll-type, jet printing type etc..Application place can be the single side or two-sided of basement membrane.
According to a particular embodiment of the invention, filler, adhesive and solvent can be contained in slurry used by being coated with.
Wherein, filler can include but is not limited to all kinds of high molecular nanometer spheres, metal oxide and metal hydroxides, such as aoxidize
Aluminium, boehmite, magnesia, calcium oxide, silica, diatomite, titanium oxide, calcium sulfate, barium sulfate, calcium carbonate etc..Adhesive
It can include but is not limited to polyacrylic acid, polyacrylate analog copolymer, polyvinyl alcohol and its copolymer, polyvinylpyrrolidine
Ketone and its copolymer, carboxymethyl cellulose and its derivative, Kynoar, polytetrafluoroethylene (PTFE), polyvinylidene fluoride copolymer etc.
Fluorine resin；Or polymer such as polyimides, polyamide, polysulfones, acrylonitrile polymers etc..Solvent can with water,
The mixing of one or more of common solvents such as ethyl alcohol, acetone, NMP.A specific embodiment according to the present invention, coating sizing-agent
Viscosity can be 10~500cps, the solid content in slurries can be 1~50wt%.
According to a particular embodiment of the invention, it is wide can to export or extract the film web exported for longitudinal stretching for coating width
About 85~95%, dry and heat setting temperature may range from 40~135 degrees Celsius.A specific implementation according to the present invention
Example, coating breadth are 1.2 meters, and drying temperature can be 60~90 degrees Celsius, and heat setting temperature is 90~130 degrees Celsius.
Lithium battery diaphragm according to an embodiment of the present invention has intensity high, and thickness and ventilative homogeneity are good, pore size point
Cloth is narrow, the good feature of thermal stability.
Below with reference to specific embodiment, present invention is described, it should be noted that these embodiments are only to describe
Property, without limiting the invention in any way.
Embodiment 1
Sheet material is extruded into according to the following steps implementation:
Polyethylene is mixed with film forming solvent, to obtain squeezing out raw material；
Wherein, the average molecular weight of polyethylene used, the volume ratio of the first solvent and the second solvent, poly- second in film forming solvent
The mass ratio and extrusion temperature of alkene and film forming solvent are specifically as shown in table 1, wherein the first solvent is C10-14Alkene, second is molten
Agent is Chinese wax oil.
Table 1
Embodiment 2
Lithium battery diaphragm is prepared according to the following steps:
In embodiment 1, the polyethylene that average molecular weight is 550,000 is mixed with film forming solvent, to be squeezed out
Raw material；
Raw material will be squeezed out and carry out mixing extrusion, obtain sheet material in 26 degrees Celsius of chillings；
By sheet material in 115 degrees Celsius of progress longitudinal stretchings, stretching ratio is 7 times；
By sheet material in 118 degrees Celsius of progress cross directional stretch, stretching ratio is 7 times, obtains film；
Film is extracted in extractant, extractant is methylene chloride, obtains microporous barrier；
Microporous barrier is coated, is dried and thermal finalization, to form coating on the surface of microporous barrier, and obtains the lithium
Battery diaphragm；Coating speed is consistent with linear velocity, is 40m/min, and coating width is 1.2 meters, and drying temperature is 60~90 Celsius
Degree, heat setting temperature are 90~130 degrees Celsius.
Wherein, as shown in table 2 using the specific nature of different coating, aluminum oxide coating layer electromicroscopic photograph is as shown in Fig. 2, vigorous nurse
Stone coating electromicroscopic photograph is as shown in figure 3, PVDF coating electromicroscopic photograph is as shown in Figure 4.
Table 2
In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", " specifically show
The description of example " or " some examples " etc. means specific features, structure, material or spy described in conjunction with this embodiment or example
Point is included at least one embodiment or example of the invention.In the present specification, schematic expression of the above terms are not
It must be directed to identical embodiment or example.Moreover, particular features, structures, materials, or characteristics described can be in office
It can be combined in any suitable manner in one or more embodiment or examples.In addition, without conflicting with each other, the skill of this field
Art personnel can tie the feature of different embodiments or examples described in this specification and different embodiments or examples
It closes and combines.
Although the embodiments of the present invention has been shown and described above, it is to be understood that above-described embodiment is example
Property, it is not considered as limiting the invention, those skilled in the art within the scope of the invention can be to above-mentioned
Embodiment is changed, modifies, replacement and variant.
Claims (10)
1. a kind of method for preparing lithium battery diaphragm characterized by comprising
Polyethylene and film forming solvent are subjected to melting mixing, to obtain squeezing out raw material；
The extrusion raw material is subjected to mixing extrusion and cooling and shaping, to obtain sheet material；
The sheet material is subjected to longitudinal stretching and cross directional stretch, makes some or all of film forming solvent volatilization, to obtain
Film；
The film is extracted in extractant, to obtain microporous barrier；And
The microporous barrier is coated with online, is dried and thermal finalization, to form coating on the surface of the microporous barrier, and is obtained
Obtain the lithium battery diaphragm.
2. the method according to claim 1 for preparing lithium battery diaphragm, which is characterized in that the polyethylene and the film forming
The mass ratio of solvent is (15~40): (60~85).
3. the method according to claim 2 for preparing lithium battery diaphragm, which is characterized in that the film forming solvent is by least one
The second solvent of first solvent of the kind boiling point lower than 200 degrees Celsius and/or at least one boiling point higher than 200 degrees Celsius forms,
Optionally, first solvent is a kind of C10-14Hydrocarbon solvent or it is a variety of be selected from C10-14Hydrocarbon solvent composition it is mixed
Bonding solvent, second solvent are selected from paraffin oil, solid paraffin, soybean oil, peanut oil, olive oil, phthalic acid ester, neighbour
At least one of dioctyl phthalate, dibutyl phthalate and glyceride.
4. the method according to claim 3 for preparing lithium battery diaphragm, which is characterized in that the polyethylene weight average molecular weight
Lower than 500,000, the volume ratio of first solvent and second solvent is (90~100): (0~10)；Or
The weight average molecular weight of the polyethylene is 50~1,000,000, and the volume ratio of first solvent and second solvent is (50
~70): (30~50)；Or
The weight average molecular weight of the polyethylene is greater than 1,000,000, and the volume ratio of first solvent and second solvent is (0
~10): (90~100).
5. the method according to claim 4 for preparing lithium battery diaphragm, which is characterized in that the mixing is squeezed out according to following
Step carries out:
Polyethylene is first pre-mixed with the film forming solvent for accounting for film forming solvent total weight 60~80%, and is carried out in an extruder
Melt blending squeezes out；
Remaining film forming solvent is injected the extruder by downstream during carrying out the melt blending extrusion.
6. the method according to claim 1 for preparing lithium battery diaphragm, which is characterized in that the temperature that the melt blending squeezes out
Degree is 150~270 degrees Celsius, and the rate of the cooling is not less than 15 degrees seconds Celsius,
Optionally, the temperature of the drying and thermal finalization is 40~135 degrees Celsius.
7. the method according to claim 1 for preparing lithium battery diaphragm, which is characterized in that the stretching of the longitudinal stretching and
The draw ratio stretching in the transverse direction is all larger than 5 times, and the longitudinal stretching and the cross directional stretch are the temperature at 90~125 degrees Celsius
The lower progress of degree.
8. the method according to claim 1 for preparing lithium battery diaphragm, which is characterized in that the extractant is selected from two
At least one of chloromethanes, pentane, hexane, heptane, carbon tetrachloride, diethyl ether, dioxanes and methyl ethyl ketone.
9. a kind of lithium battery diaphragm, which is characterized in that the lithium battery diaphragm is by preparation according to any one of claims 1 to 8
The method of lithium battery diaphragm is prepared.
10. lithium battery diaphragm according to claim 9, which is characterized in that the lithium battery diaphragm includes basement membrane and formation
In the coating of the basement membrane upper and lower surfaces, the coating with a thickness of 0.2~10 micron.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710596538.7A CN109285981A (en) | 2017-07-20 | 2017-07-20 | Lithium battery diaphragm and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710596538.7A CN109285981A (en) | 2017-07-20 | 2017-07-20 | Lithium battery diaphragm and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109285981A true CN109285981A (en) | 2019-01-29 |
Family
ID=65185049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710596538.7A Pending CN109285981A (en) | 2017-07-20 | 2017-07-20 | Lithium battery diaphragm and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109285981A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109970872A (en) * | 2017-12-28 | 2019-07-05 | 上海凯矜新材料科技有限公司 | Prepare cellulose nano-fibrous method |
| CN112072051A (en) * | 2020-09-18 | 2020-12-11 | 江苏厚生新能源科技有限公司 | Method for controlling residual oil content, porous film and method for producing same, and nonaqueous secondary battery |
| CN112864528A (en) * | 2021-04-26 | 2021-05-28 | 江苏厚生新能源科技有限公司 | Biaxial tension coating microporous diaphragm for lithium ion battery and preparation method thereof |
| CN112987818A (en) * | 2021-05-10 | 2021-06-18 | 南京力步机械有限公司 | Lithium battery diaphragm production line control method |
| CN113809470A (en) * | 2020-09-14 | 2021-12-17 | 上海恩捷新材料科技有限公司 | Battery membrane for energy storage device, preparation process and system thereof, and energy storage device |
| CN114300807A (en) * | 2021-12-19 | 2022-04-08 | 上海凯矜新材料科技有限公司 | Preparation method of lithium battery diaphragm |
| WO2022089065A1 (en) * | 2020-09-14 | 2022-05-05 | 上海恩捷新材料科技有限公司 | Battery separator and coating process and coating system therefor, and battery |
| CN114597587A (en) * | 2022-03-17 | 2022-06-07 | 中材锂膜有限公司 | Aramid fiber coated diaphragm and preparation method thereof |
| CN114851506A (en) * | 2022-07-07 | 2022-08-05 | 溧阳月泉电能源有限公司 | Manufacturing process of lithium battery polyolefin diaphragm |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1670989A (en) * | 2004-03-19 | 2005-09-21 | 株式会社巴川制纸所 | Electronic component separator and method for producing the same |
| CN101613544A (en) * | 2008-06-25 | 2009-12-30 | 新应材股份有限公司 | Ink-jet ink for color filter |
| CN101826606A (en) * | 2009-03-05 | 2010-09-08 | 丽水学院 | Polytetrafluoroethylene lithium-ion battery separator and preparation method thereof |
| CN102458622A (en) * | 2009-06-19 | 2012-05-16 | 东丽东燃机能膜合同会社 | Microporous membranes, methods for making such membranes, and the use of such membranes as battery separator film |
| CN103840113A (en) * | 2014-02-28 | 2014-06-04 | 苏州捷力新能源材料有限公司 | Preparation method of polyethylene isolation membrane for lithium batteries |
| CN105098129A (en) * | 2015-07-10 | 2015-11-25 | 长兴东方红包装有限公司 | Compound two-layer polyolefin diaphragm and preparation method thereof |
| CN105702899A (en) * | 2016-01-22 | 2016-06-22 | 深圳中兴创新材料技术有限公司 | Preparation method for battery diaphragm containing coating layer and on-line coating system |
| CN106554655A (en) * | 2016-11-04 | 2017-04-05 | 苏州星烁纳米科技有限公司 | Quantum dot ink and electroluminescent device |
-
2017
- 2017-07-20 CN CN201710596538.7A patent/CN109285981A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1670989A (en) * | 2004-03-19 | 2005-09-21 | 株式会社巴川制纸所 | Electronic component separator and method for producing the same |
| CN101613544A (en) * | 2008-06-25 | 2009-12-30 | 新应材股份有限公司 | Ink-jet ink for color filter |
| CN101826606A (en) * | 2009-03-05 | 2010-09-08 | 丽水学院 | Polytetrafluoroethylene lithium-ion battery separator and preparation method thereof |
| CN102458622A (en) * | 2009-06-19 | 2012-05-16 | 东丽东燃机能膜合同会社 | Microporous membranes, methods for making such membranes, and the use of such membranes as battery separator film |
| CN103840113A (en) * | 2014-02-28 | 2014-06-04 | 苏州捷力新能源材料有限公司 | Preparation method of polyethylene isolation membrane for lithium batteries |
| CN105098129A (en) * | 2015-07-10 | 2015-11-25 | 长兴东方红包装有限公司 | Compound two-layer polyolefin diaphragm and preparation method thereof |
| CN105702899A (en) * | 2016-01-22 | 2016-06-22 | 深圳中兴创新材料技术有限公司 | Preparation method for battery diaphragm containing coating layer and on-line coating system |
| CN106554655A (en) * | 2016-11-04 | 2017-04-05 | 苏州星烁纳米科技有限公司 | Quantum dot ink and electroluminescent device |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109970872A (en) * | 2017-12-28 | 2019-07-05 | 上海凯矜新材料科技有限公司 | Prepare cellulose nano-fibrous method |
| CN113809470A (en) * | 2020-09-14 | 2021-12-17 | 上海恩捷新材料科技有限公司 | Battery membrane for energy storage device, preparation process and system thereof, and energy storage device |
| WO2022089065A1 (en) * | 2020-09-14 | 2022-05-05 | 上海恩捷新材料科技有限公司 | Battery separator and coating process and coating system therefor, and battery |
| CN112072051A (en) * | 2020-09-18 | 2020-12-11 | 江苏厚生新能源科技有限公司 | Method for controlling residual oil content, porous film and method for producing same, and nonaqueous secondary battery |
| CN112864528A (en) * | 2021-04-26 | 2021-05-28 | 江苏厚生新能源科技有限公司 | Biaxial tension coating microporous diaphragm for lithium ion battery and preparation method thereof |
| CN112987818A (en) * | 2021-05-10 | 2021-06-18 | 南京力步机械有限公司 | Lithium battery diaphragm production line control method |
| CN112987818B (en) * | 2021-05-10 | 2021-07-16 | 南京力步机械有限公司 | Lithium battery diaphragm production line control method |
| CN114300807A (en) * | 2021-12-19 | 2022-04-08 | 上海凯矜新材料科技有限公司 | Preparation method of lithium battery diaphragm |
| CN114597587A (en) * | 2022-03-17 | 2022-06-07 | 中材锂膜有限公司 | Aramid fiber coated diaphragm and preparation method thereof |
| CN114851506A (en) * | 2022-07-07 | 2022-08-05 | 溧阳月泉电能源有限公司 | Manufacturing process of lithium battery polyolefin diaphragm |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109285981A (en) | Lithium battery diaphragm and preparation method thereof | |
| CN103618054B (en) | A kind of novel fire resistant lithium battery diaphragm and preparation technology thereof | |
| CN101590374B (en) | Polyvinylidene fluoride hollow fiber film and preparation method thereof | |
| CN103409837B (en) | The method of water-soluble polyvinyl alcohol fibers prepared by a kind of melt spinning | |
| CN106750205B (en) | A kind of preparation method of graphene modified poly ester film | |
| CN104993085B (en) | A kind of MULTILAYER COMPOSITE polyolefin diaphragm of lithium ion battery and preparation method thereof | |
| WO1997009167A9 (en) | Microporous membrane with a stratified pore structure created in situ and process | |
| CN101342465A (en) | Hollow fiber porous film and process for producing same | |
| CN104327351B (en) | A kind of microporous polyethylene film | |
| CN104262674A (en) | Preparation method of porous composite isolating membrane | |
| CN105017734A (en) | Polymeric material for 3D printing and preparation method of polymeric material | |
| CN109560235A (en) | A kind of new type lithium ion battery aramid fiber diaphragm preparation method | |
| CN111086181A (en) | Preparation method of lithium battery diaphragm | |
| Wen et al. | Microfluidic fabrication and thermal characteristics of core–shell phase change microfibers with high paraffin content | |
| CN108939947A (en) | Kynoar and ultra-high molecular weight polyethylene blending microporous membrane and preparation method thereof | |
| CN103496149B (en) | Polymer gradient functional material continuous production shaped device | |
| CN105315533A (en) | Manufacturing method of polyolefin-based multilayer composite porous film | |
| Zhang et al. | Microfluidic fabrication of core–sheath composite phase change microfibers with enhanced thermal conductive property | |
| CN110943194B (en) | Preparation method and coating application of lithium battery diaphragm with controllable surface structure | |
| CN104821382B (en) | A kind of method for improving polyethylene lithium battery diaphragm surface-active | |
| CN104617248A (en) | Method for preparing nanometer ceramic particle doped PE diaphragm | |
| CN104788792B (en) | A kind of method preparing the continuously extruded composite of high energy low temperature ball milling and the composite of the method preparation | |
| CN106366741B (en) | A kind of film anti-static liquid and its antistatic film preparation method | |
| CN106268356B (en) | Method for preparing ultrahigh molecular weight polyethylene composite hollow fiber by thermally induced phase separation | |
| CN108682773B (en) | A kind of preparation method of lithium battery diaphragm |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190129 |