JP6506369B2 - Method of manufacturing separator - Google Patents

Description

  The present invention relates to a separator, an electrochemical device, and a method of manufacturing the separator.

  Conventionally, a separator made of any of an olefin resin, a PDF resin, a PAN resin, a PMMA resin, and a urethane resin is known as a first generation separator. This separator is used for a secondary battery for a small portable device such as a mobile phone or a digital camera or an electric double layer capacitor (hereinafter abbreviated as EDLC). In addition, the external appearance of the secondary battery was small square.

  In addition, from the viewpoint of processability and cost, an olefin resin (in particular, ultrahigh molecular weight polypropylene (PP) or polyethylene (PE)) and fine particle alumina or silica are kneaded to obtain a uniaxial or biaxial stretching method. The separator produced using it has been commercialized (patent documents 1 and 2).

  7A, 7B, and 7C show the structure of a representative first generation separator. FIG. 7A shows a separator consisting of a single layer 101 of PP. FIG. 7B shows a separator consisting of a single layer 103 of PE. FIG. 7C shows the separator 111 in which the layer 105 of PP, the layer 107 of PE, and the layer 109 of PP are stacked.

  Second-generation separators are used in secondary batteries for personal computers (PCs), electric tools, robot power supplies, and the like. The secondary battery is a medium-sized rechargeable battery of 18650 type or 26650 type, or a square. A secondary battery using a second generation separator is required to have higher capacity and higher output than a secondary battery using a first generation. Moreover, shortening of charge time is required with high capacity-ization. Further, due to the enlargement of the secondary battery, further safety is required.

  In order to ensure the above-mentioned safety, a method of forming a ceramic layer on the separator has been proposed. For example, the structure shown in FIG. 8A comprises a separator 117, an anode 119, an anode current collector 121, a cathode 123, and a cathode current collector 125, and in the separator 117, an alumina insulating layer (HRL) is formed on the surface of the separator body 113. (Heat Resistance Layer) 115 is formed by coating. The HRL layer 115 has a heat resistant insulation function and a metal dendrite prevention function (Patent Documents 3 and 4). This structure has been developed and commercialized by Panasonic Corporation.

The structure shown in FIG. 8B comprises a separator 127, an anode 129, an anode current collector 131, a cathode 133, and a cathode current collector 135. In the separator 127, alumina or the like is formed on the anode side of the separator main body 137. A layer 139 coated with inorganic fine particles (specific surface area = 4 to ⁶ m ² / g) is provided, and a layer 141 coated with plate-like fine particles (7 to 10 m ² / g) is provided on the cathode side (Patent Document 5) 6). This structure is a structure developed and commercialized by Hitachi Maxell, Ltd.

Patent No. 4450442 JP, 1999-317212, A Patent No. 4654700 JP, 2009-32668, A JP, 2011-065849, A JP, 2011-065850, A

  However, in the separator 117 shown in FIG. 7A, when the HRL 115 is coated on one side and dried, there arises a problem that the separator 117 is warped. Further, in the separator 127 shown in FIG. 8B as well, the composition is different between the layer 139 and the layer 141, which causes a problem that the separator 127 is warped.

  This invention makes it the one side to provide the manufacturing method of the separator which can suppress curvature, the electrochemical element provided with the separator, and a separator.

  The separator of the present invention comprises a porous layer and one or more selected from the group consisting of porous silica, activated carbon, and zeolite, and a coated layer formed on one side or both sides of the porous layer. It is characterized by The separator of the present invention is unlikely to be warped.

  The method for producing a separator of the present invention comprises (A) at least one member selected from the group consisting of porous silica, activated carbon and zeolite, (B) a binder, (C) a slurry stabilizer, and (D) a coating aid The slurry is applied to one side or both sides of the porous layer to form a covering layer. According to the method of manufacturing a separator of the present invention, it is possible to easily manufacture a separator that is less likely to be warped.

It is a side sectional view showing the structure of a compound separator. It is a side sectional view showing the structure of a compound separator. It is explanatory drawing showing the manufacturing method of a separator. It is an explanatory view showing composition of coin type EDLC. It is an explanatory view showing composition of heteromorphic EDLC. It is an explanatory view showing composition of a lithium ion battery. FIG. 7A, FIG. 7B, and FIG. 7C are side sectional views showing the configuration of a first generation separator. 8A and 8B are side sectional views showing the configuration of a second generation separator.

  An embodiment of the present invention will be described. Examples of the porous layer in the present invention include those made of any of polyethylene resin, polypropylene resin, polyacrylonitrile resin, vinylidene fluoride resin, acrylic resin, and urethane resin. The olefin separators described in Patent Documents 1 and 2 may be used as the porous layer. Alternatively, a commercially available microporous separator may be used as the porous layer.

Further, as another porous layer, one obtained by adding alumina (Al ₂ O ₃ ) or silica (SiO ₂ ) to a polyolefin resin (for example, an ultrahigh molecular weight polyolefin resin) and obtained by a uniaxial or biaxial stretching method Can be mentioned.

The thickness of the porous layer is preferably in the range of 10 to 110 μm. In the case of the separator used for EDLC especially, in order to improve heat resistance, the film thickness of 40-110 micrometers is preferable. Moreover, in the case of the porous layer which consists of polyolefin resin, it is preferable that a film thickness is 8-20 micrometers and porosity is high. By doing this, the resistance can be reduced.

  The coating layer in the present invention contains one or more selected from the group consisting of porous silica, activated carbon, and zeolite. As porous silica, it is preferable that the crystal form is amorphous and porous in the practical temperature range of the electrochemical device.

  The covering layer can be impregnated with a large amount of electrolyte when the separator is applied to the electrochemical device. Therefore, the liquid injection time can be shortened and the concentration polarization can be reduced. Also, even if rapid charge and discharge are performed instantaneously, the growth of dendrite can be suppressed. Also, the mechanical strength of the separator is improved by providing the covering layer.

Also, by providing the covering layer, the dimensional contraction rate is improved (the dimensional stability is improved). As a result, internal shorts can be prevented, and the mechanical strength of the separator can be improved.
Moreover, the immersion property is improved by providing the covering layer. As a result, the electrolyte can be impregnated quickly, and the conveyor speed can be improved.

Also, the dendrite is improved by providing the covering layer. As a result, safety, reliability and yield are improved.
Moreover, liquid retentivity improves by providing a coating layer. As a result, efficient discharge is possible.

Moreover, heat resistance improves by providing a coating layer. As a result, the quick charge characteristics are improved.
The thickness of the coating layer is preferably in the range of 0.5 to 50 μm (preferably 3 to 15 μm). By being 0.5 micrometer or more, it becomes easy to form a coating layer uniformly. Moreover, by being 50 micrometers or less, it becomes difficult to produce a crack in a coating layer. When the separator is applied to a green electrochemical device, the film thickness is preferably 15 μm or less.

The covering layer may be formed on one side or both sides of the porous layer. Forming on both sides can further reduce the warp of the separator.
The physical properties of the porous silica are preferably, for example, in the following range.

Average particle size: 0.1 to 8 μm
Specific surface area: 250 to 800 m ² / g
Oil absorption: 50 to 350 ml / 100 g
When the physical properties are within the above range, in the electrochemical device to which the present separator is applied, high current charge / discharge and noncontact instantaneous charge become possible. In addition, when the average particle size is 0.1 μm or more, the amount of the slurry stabilizer in the slurry used to form the coating layer may be small. In addition, when the average particle size is 8 μm or less, the coating layer can be easily made uniform.

In addition, when the specific surface area is 250 m ² / g or more, when the present separator is applied to an electrochemical device, the electrolyte solution content can be increased. In addition, when the specific surface area of silica is 800 m ² / g or less, the mechanical strength of the agglomerated particles of silica can be enhanced. As a result, the destruction of the silica particles during charge and discharge can be suppressed.

  Moreover, when this oil absorption amount is 50 ml / 100 g or more, when this separator is applied to an electrochemical element, electrolyte solution liquid content can be increased. Moreover, the mechanical strength of a coating layer improves because oil absorption amount is 350 ml / 100 g or less.

In addition, the measurement of an average particle diameter, the measurement of a specific surface area, and the measurement of oil absorption amount are as follows, respectively.
Measurement of average particle size: measurement with a laser diffraction particle size distribution analyzer Measurement of specific surface area: measurement with a volumetric method (more specifically, method according to JIS K 1150 "silica gel test method") Measurement of oil absorption: JIS K 5101-13 The conductive layer in the present invention can be formed, for example, on the surface of the particles constituting the coating layer. For example, the particles constituting the covering layer are impregnated with a paint containing one or more selected from oxythiophene (EDOT), polyethylenedioxythiophenene (PEDOT), indium tin oxide (ITO), polypyrrole, and polyaniline, A conductive layer can be formed on the surface of the particles by sequentially performing air drying and heat drying (for example, drying at a temperature of about 150 ° C.). And a coating layer can be formed using particles provided with a conductive layer. Alternatively, after forming the covering layer, a conductive layer may be stacked thereon.

Examples of the material for forming the conductive layer include one or more selected from EDOT, PEDOT, ITO, polypyrrole, and polyaniline. The conductive layer can reduce electrostatic troubles of the separator by lowering the resistance of the covering layer by, for example, about 10 ⁻¹ to 10 ⁻² . In addition, as static electricity trouble, the trouble in which a separator extends or tears by static electricity is mentioned.

Examples of the electrochemical device of the present invention include a primary battery, a secondary battery, an electric double layer capacitor (EDLC), a simulated electric double layer capacitor, and the like.
The separator of the present invention contains, for example, (A) at least one selected from the group consisting of porous silica, activated carbon, and zeolite, (B) a binder, (C) a slurry stabilizer, and (D) a coating aid The slurry can be produced by applying the slurry on one side or both sides of the porous layer to form a coating layer.

  Examples of the binder include olefin binders, styrene-butadiene rubber binders (SBR binders), modified styrene-butadiene rubber binders (modified SBR binders), atarilate binders, cellulose binders, and fluorine binders (for example, , PTFE, PVDF and the like), aqueous binders and the like.

  In particular, a first binder which is an aqueous binder or an olefin binder, a styrene-butadiene rubber binder, a modified styrene-butadiene rubber binder (for example, acrylic dope type), an atalylate binder, a cellulose binder, vinyl pyrrolidone, Preferred is a mixed binder with a second binder which is at least one selected from the group consisting of fluorine-based binders. By using this mixed binder, the wettability of the slurry to the porous layer is improved, and the adhesive strength between the porous layer and the coating layer is improved.

  When a mixed binder is used, the blending amount of the first binder is preferably in the range of 0.5 to 2.0 parts by weight with respect to 100 parts by weight of the component (A), and the blending amount of the second binder is 2 to 2 A range of 5 parts by weight is preferred. By being in these ranges, the effect of the mixed binder mentioned above becomes more remarkable.

  Moreover, when using an atarilate type binder, the compounding quantity has the preferable range of 2 to 5 weight part with respect to 100 weight part of (A) component. By being 2 weight part or more, the bending strength of a coating layer improves. Moreover, the pouring impregnation property of a coating layer improves by being 5 parts weight or less.

As a slurry stabilizer, a water-soluble polymer, surfactant, etc. are mentioned, for example. The water-soluble polymer is preferably a block type polymer having a sulfonation rate of 5 to 30%. That is, sulfonic acid-based water-soluble polymers are preferred. As the surfactant, a fluorine-based nonionic surfactant is preferred. The incorporation of a slurry stabilizer into the slurry facilitates preparation of the slurry and extends the slurry life.

  As a coating adjuvant, Na neutralization CMC, or ammonia neutralization CMC etc. are mentioned, for example. By including a coating aid, the stability of the slurry and the uniformity of the coating layer are improved. In addition, when the separator is applied to a battery or EDLC, their lifetime is improved.

  The separator of the present invention can be applied to, for example, the composite separator 1 shown in FIG. The composite separator 1 is composed of a separator 3, an anode 5 and a cathode 7. The separator 3 includes a porous layer 9 and the cover layers 11 and 13 on both sides thereof. The composite separator 1 can be applied to various electrochemical devices (eg, primary battery, secondary battery, EDLC, etc.).

In addition, the separator of the present invention can be applied to, for example, the composite separator 21 shown in FIG. The composite separator 21 is composed of a separator 23, an anode 25 and a cathode 27. The separator 23 includes a porous layer 29, covering layers 31 and 33 on both sides thereof, and conductive layers 35 and 37 outside the porous layer 29. The composite separator 21 can be applied to various electrochemical devices (eg, primary battery, secondary battery, EDLC, etc.).
Example 1
1. Preparation of Slurry (1) Slurry S1
The manufacturing method of slurry S1 is demonstrated based on FIG. First, porous silica (SiO ₂ ) is dry mixed (P1), then water and CMC (coating aid) are added and wet mixed (P2) and kneaded (P3). Thereafter, an olefin-based binder (denoted as Binder 1 in FIG. 3), a modified SBR-based binder (denoted Binder 2 in FIG. 3), and a slurry stabilizer are added to obtain a slurry (P4).

Here, the above-mentioned compounding ingredients are specifically the following, respectively.
CMC: Daicel Fine Chem Co., Ltd. DN-800H
Olefin-based binder: manufactured by Mitsui Chemicals, Inc. Kemipearl S100
Modified SBR-based binder: SB latex manufactured by JSR Corporation Slurry stabilizer: Water-soluble polymer (surfactant manufactured by JSR Corporation)
The physical properties of the porous silica used are as follows.

Average particle size: 2.7 μm
Specific surface area: 300 m ² / g
Oil absorption: 330ml / 100g
In addition, the blending amounts (in parts by weight) of the respective components in the slurry S1 are shown in Table 1.
[Table 1]

(2) Slurry S2
First, a conductive layer consisting of EDOT was formed in advance on the particle surface of the same porous silica as that used in preparation of slurry S1, and thereafter, slurry S2 was prepared by the same process as in the case of slurry S1.

  The method of forming the conductive layer of EDOT on the surface of porous silica is as follows. That is, porous silica is impregnated with the EDOT conductive paint, air dried, and then dried at 150 ° C. to form a conductive layer of EDOT on the surface of the porous silica. By this conductive layer, the porous silica has a static elimination function.

The amount of EDOT present on the surface of the porous silica is 3 parts by weight with respect to 100 parts by weight of the porous silica.
(3) Slurry S3
Basically, the method is the same as in the case of slurry S1, but slurry S3 is prepared using the same amount of coconut shell activated carbon having a specific surface area of 700 m ² / g instead of porous silica.
(4) Slurry S4
The procedure is basically the same as in the case of slurry S1, but slurry S3 was prepared using the same amount of synthetic zeolite instead of porous silica.
2. Production of Separator A 15 μm thick film and a 25 μm thick film were produced from commercially available PP resin using a drawing method. This film is microporous. Using this film as a porous layer, the slurry was applied by blade coating method on both sides (P5) and dried to form a 3 μm thick coating layer (P6), and a separator was manufactured (P7) (see FIG. 3) ).

  In the above manufacturing method, six types of separators E1 to E6 shown in Table 2 were manufactured by changing the film thickness (15 μm or 25 μm) of the porous layer and the type (S1 to S4) of the slurry to be applied. The slurry S1 was used for E1 and E2, the slurry S2 was used for E3 and E4, the slurry S3 was used for E5, and the slurry S4 was used for E6.

In addition, a film with a thickness of 15 μm not coated with a slurry is referred to as a separator R1, and a film with a thickness of 25 μm not coated with a slurry is referred to as a separator R2.
[Table 2]

3. Evaluation of Separator (1) Gurley Value The Gurley value (air permeability) of each separator was measured in accordance with JIS P8117. The results are shown in Table 2 above. It was confirmed that the air permeability of the separators E1 to E6 was hardly reduced even when the coating layer was formed.
(2) Shrinkage at Hot Air Temperature Hot air was blown to each separator for 1 hour, and the shrinkage (%) with respect to the state was measured before treatment. The measurement was performed for each of the cases where the temperature of the hot air was 120 ° C. and 150 ° C. The measurement results are shown in Table 2 above. The contraction rates of the separators E1 to E6 were smaller than those of the separators R1 and R2. From this, it was confirmed that the separators E1 to E6 were hard to warp.
(3) 2 μm Impregnation Time of EMIBF 4 A high viscosity ionic liquid (EMIBF 4) was dropped 2 μm on each separator, and the time (sec) until the ionic liquid diffused to the separator surface was measured. The results are shown in Table 2 above. In the case of the separators E1 to E6, the ionic liquid diffused in a short time. From this, it has been confirmed that the separators E1 to E6 have high impregnation with a liquid (for example, an electrolytic solution).
(4) -65 ° C antistatic property In a dry room of dew point -65 ° C, an electrification test was conducted to evaluate the antistatic property. The evaluation criteria are as follows.

◎: no charging ○: slightly charging ×: with charging Evaluation results are shown in Table 2 above. It was confirmed that the separators E1 to E6 were less likely to generate static electricity. This characteristic is useful when the separator is applied to a mass-production machine. That is, in the process of manufacturing the separator and the electrochemical device including the same, the generation of static electricity can be prevented.
Example 2
1. Configuration of EDLC (1) Configuration of Coin Type EDLC 39 The configuration of the coin type EDLC 39 will be described based on FIG. The coin-shaped EDLC 39 has a coin shape having a diameter of 4.8 mm and a thickness of 1.4 mm. The coin-shaped EDLC 39 has a laminated structure including a separator 41, an anode 43 and a cathode 45. Furthermore, the separator 41 includes the porous layer 47 and the cover layers 49 and 51 on both sides thereof. The porous layer 47 is made of a microporous PP film of heat resistant specifications.

  The coating layers 49 and 51 were formed by applying and drying the slurry S1 on the surface of the porous layer 47. The anode 43 and the cathode 45 were formed by sheet-forming a composition consisting of activated carbon, acetylene black, a binder, and PTFE powder to a thickness of 500 μm and punching it into a predetermined shape. A 100% stock solution of EMIBF 4 was used as the electrolyte.

  Coin-shaped EDLCs 39 of E11 to E14 shown in Table 3 were manufactured by changing the film thickness of the porous layer 47 and the film thicknesses of the covering layers 49 and 51. The coin-shaped EDLC 39 of E11 to E14 is a 414 type surface mount capacitor.

Further, coin-shaped EDLCs of R11 and R12 were manufactured in the same manner as the coin-shaped EDLC 39 of E11 to E14 without forming the covering layers 49 and 51.
[Table 3]

(2) Configuration of Homomorphic EDLC 53 The configuration of the homomorphic EDLC 53 is shown in FIG. The homomorphic EDLC 53 is a capacitor having a cylindrical shape with a diameter of 18 mm and a length of 40 mm. The orthodontic EDLC 53 has a structure in which a sheet obtained by laminating two separators 55, an anode 57, and a cathode 59 is wound around. Furthermore, each separator 55 includes a porous layer 61 and covering layers 63 and 65 on both sides thereof. The porous layer 61 is made of a microporous PP film of heat resistant specifications.

  The coating layers 63 and 65 were formed by applying the slurry S1 on the surface of the porous layer 61 and drying it. Further, the anode 57 and the cathode 59 were formed by sheet-forming a composition comprising activated carbon, acetylene black, a binder, and PTFE powder to a thickness of 500 μm and punching it into a predetermined shape. A 100% stock solution of EMIBF 4 was used as the electrolyte.

  The film thickness of the porous layer 61 and the film thickness of the covering layers 63 and 65 were changed to manufacture a conformal EDLC 53 of E15 to E18 shown in Table 4. The homozygous EDLC 53 of E15 to E18 is of the 1840 type.

Further, without forming the covering layers 63 and 65, other points were produced in the same manner as the homomorphic EDLC 53 of E15 to E18 to produce homomorphic EDLCs of R13 and R14.
[Table 4]

2. Evaluation of EDLC For each EDLC, the ionic liquid impregnation, ESR, and liquid leakage were evaluated.
Here, the evaluation method of the ionic liquid impregnation property is a method of measuring the time until the electrolyte solution is dripped with 5 μL of the EMIBF 4 electrolyte and soaked in the separator. From the shortest time to soaking, it was evaluated as ◎, 、, △, x.

The ESR (equivalent series resistance) was evaluated by the impedance frequency characteristics of the battery sample.
In the case of coin-shaped EDLC, the method of evaluating the liquid leakage is a method of exposing 100 coin-shaped EDLCs to a temperature environment of 260 ° C. for 10 seconds and determining the number of leaked electrolytes. Further, in the case of the heteromorphic EDLC, the method is a method of holding 100 heteromorphic EDLCs under a temperature environment of 80 ° C. for 200 hours, and determining the number of leaks of the electrolyte or the number of blisters in the main body.

The evaluation results are shown in Table 3 above and Table 4 above. It has been confirmed that EDLCs of E11 to E18 are excellent in ionic liquid impregnation, ESR, and liquid leakage.
Example 3
1. Configuration of Lithium Ion Battery 67 The configuration of the lithium ion battery 67 is shown in FIG. The lithium ion battery 67 is a battery having a cylindrical shape with a diameter of 18 mm and a length of 65 mm.

  The lithium ion battery 67 has a structure in which a sheet in which two separators 69, an anode 71, and a cathode 73 are laminated is wound. Furthermore, each separator 69 includes a porous layer 75, cover layers 77 and 79 on both sides thereof, and conductive layers 81 and 83 outside thereof. The porous layer 75 is made of a microporous PP film of heat resistant specifications.

The coating layers 77 and 79 were formed by applying and drying the slurry S1 on the surface of the porous layer 75. The conductive layers 81 and 83 were formed by applying and drying a coating solution containing EDOT. The anode 71 is LiCoOx formed on the Al current collector by a known method. The cathode 73 is formed by applying and drying a cathode slurry composed of artificial graphite on a Cu foil current collector. As the electrolytic solution, LiPF ₆ (with a solvent of EMC) at a concentration of 1.2 mol / L was used.

The film thickness of the porous layer 75 and the film thickness of the covering layers 77 and 79 were changed, and lithium ion batteries 67 of E21 to E24 shown in Table 5 were manufactured. The lithium ion battery 67 is a 18650) cylindrical lithium ion battery.
[Table 5]

Further, R21 and R22 lithium ion batteries were manufactured in the same manner as the E21 to E24 lithium ion battery 67 without forming the covering layers 77 and 79.
2. Evaluation of Lithium Ion Battery For each lithium ion battery, the electrolyte impregnation property and the number of blister-short circuit were evaluated.

Here, the evaluation method of the electrolytic solution infiltration property is a method of measuring the time until 5 .mu.L of the EMIBF4 electrolytic solution is dropped to the separator and soaking. From the shortest time to soaking, it was evaluated as ◎, 、, △, x.

  The method for evaluating the number of blister-short circuits is a method of holding 100 lithium ion batteries under a temperature environment of 60 ° C. for 200 hours and determining the number of battery bodies that are swollen or can not be recharged.

The evaluation results are shown in Table 4 above. It has been confirmed that EDLCs E11 to E18 are excellent in electrolyte impregnation, and are less likely to cause swelling or short circuit.
The excellent electrolyte impregnation property facilitates the injection of the concentrated electrolyte in the manufacture of a lithium ion battery. Further, since the electrolytic solution can be impregnated abundantly in the vicinity of the electrode, the resistance of the lithium ion battery can be lowered, and the formation of dendrite can be prevented.

DESCRIPTION OF SYMBOLS 1, 21 ... Composite separator, 3, 23, 41, 55, 69 ... Separator, 5, 25, 43, 57, 71 ... Anode, 7, 27, 45, 59, 73 ... Cathode, 9, 29, 47, 61 , 75: porous layer, 11, 13, 31, 33, 49, 51, 63, 65, 77, 79: covering layer, 35, 37, 81, 83: conductive layer, 39: coin-shaped EDLC, 53: 捲Same type EDLC, 67 ... lithium ion battery

Claims (5)

It is a manufacturing method of a separator, and
Applying a slurry comprising (A) porous silica, (B) binder, (C) slurry stabilizer, and (D) coating aid on one side or both sides of the porous layer to form a covering layer,
Forming a conductive layer including ITO on the covering layer;
The physical property of the said porous silica is as follows, The manufacturing method of the separator characterized by the above-mentioned.
Average particle size: 0.1 to 8 μm
Specific surface area: 250 to 800 m ² / g
Oil absorption: 50 to 350 ml / 100 g It is a manufacturing method of a separator, and
Forming on the surface of porous silica a conductive layer comprising one or more selected from EDOT, PEDOT, ITO, polypyrrole, and polyaniline;
(A) The porous silica having the conductive layer formed on the surface, (B) a binder, (C) a slurry stabilizer, and (D) a coating aid is coated on one side or both sides of a porous layer Form a covering layer,
The physical property of the said porous silica is as follows, The manufacturing method of the separator characterized by the above-mentioned.
Average particle size: 0.1 to 8 μm
Specific surface area: 250 to 800 m ² / G
Oil absorption: 50 to 350 ml / 100 g   The binder comprises a first binder which is an aqueous binder or an olefin binder, a styrene-butadiene rubber binder, a modified styrene-butadiene rubber binder, an acrylate binder, a cellulose binder, vinyl pyrrolidone, and a fluorine binder. It is a mixed binder with the 2nd binder which is 1 or more types chosen from a group, The manufacturing method of the separator of Claim 1 or 2 characterized by the above-mentioned.   The method for producing a separator according to any one of claims 1 to 3, wherein the coating aid includes Na-neutralized CMC or ammonia-neutralized CMC.   The method for producing a separator according to any one of claims 1 to 4, wherein the slurry stabilizer comprises a surfactant or a sulfonic acid-based water-soluble polymer.

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