JP2013065477A - Method of manufacturing separator for secondary battery, nonaqueous electrolyte secondary battery, and apparatus of manufacturing separator for secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a separator for a secondary battery which suppresses deterioration of output performance of a battery, a nonaqueous electrolyte secondary battery, and an apparatus of manufacturing the separator for the secondary battery.SOLUTION: In a method of manufacturing a separator 63 for a secondary battery, the separator 63 is manufactured by an extrusion molding. And a magnetic field is formed in the surrounding of a die 71 by magnetic field formation parts 74, 75 connected to an AC power supply 80 during the extrusion molding of the separator 63. This magnetic field is formed such that a magnetic flux strides over a flow channel 712 of a resin material 630 in the die 71. The resin material 630 constituting the separator 63 passes through the magnetic field. Consequently, at least a portion of molecules of the resin material 630 is oriented in a constant direction.

Description

  The present invention relates to a method and apparatus for manufacturing a secondary battery separator. Furthermore, the present invention relates to a non-aqueous electrolyte secondary battery having a power generation element using the separator.

  In recent years, non-aqueous electrolyte secondary batteries represented by lithium ion secondary batteries have attracted attention as power sources not only for electronic devices such as portable PCs and mobile phones, but also for hybrid vehicles and electric vehicles. A lithium ion secondary battery generally includes a positive electrode plate having a positive electrode mixture layer containing a lithium metal oxide and a negative electrode plate having a negative electrode mixture layer containing a material capable of inserting and extracting lithium. It has a power generation element that is laminated with a separator in between.

  In the technical field of nonaqueous electrolyte secondary batteries, technical improvements are being made on a daily basis to improve output performance. For example, Patent Document 1 discloses a technique for improving performance by designing a porous separator. The separator disclosed in Patent Document 1 has high porosity and defines specific physical properties such as puncture strength in order to achieve both long-term reliability and high output.

JP 2009-242631 A

  However, the conventional porous separator described above has the following problems. That is, if the porosity of the porous separator is increased too much, the strength of the separator itself decreases. For this reason, it is difficult to maintain the shape, and there is a risk that the output performance of the battery will be lowered.

  The present invention has been made to solve the above-described problems of the prior art. That is, the problem is to provide a method for manufacturing a secondary battery separator, a non-aqueous electrolyte secondary battery, and a secondary battery separator manufacturing apparatus that suppress a decrease in the output performance of the battery.

  The method for manufacturing a separator for a secondary battery made for the purpose of solving this problem has an extrusion process for producing a long separator by extruding a resin material from a die. In the extrusion process, The magnetic flux forms a magnetic field across the flow path of the resin material in the die.

  In the method for producing a separator for a secondary battery of the present invention, the separator is produced by extrusion molding. A magnetic field is applied during the extrusion of the separator. This magnetic field is formed so that the magnetic flux straddles the flow path of the resin material (for example, polyolefin resin) constituting the separator of the die for extrusion molding. Then, as the resin material passes through the magnetic field, at least some of the molecules are oriented in a certain direction. And, when ions move in the separator, the resin molecules constituting the separator are oriented, so that it can be expected to reduce the influence of adsorption energy with the molecules. As a result, it can be expected to suppress a decrease in output performance.

  The magnetic field formed during the extrusion molding may be a magnetic field in the thickness direction of the separator. According to this configuration, it is considered that ions move more easily in the separator by orienting the resin molecules in the thickness direction of the separator. For this reason, it can be expected to further suppress the decrease in output performance.

  Further, the magnetic field formed at the time of extrusion molding may straddle at least a downstream portion of the flow path including the output port of the resin material of the die. As in this configuration, at least the output port of the die is covered with a magnetic field, so that the resin material is affected by the magnetic field until just before the resin material is pushed out of the die. Therefore, it can be expected that a molecularly oriented separator is stably produced.

  As another aspect, the present invention provides a non-aqueous electrolyte secondary battery having a power generation element in which electrode plates and separators are alternately sandwiched and laminated, and the separator is formed by extruding a resin material from a die. The resin material further includes a non-aqueous electrolyte secondary battery that has passed a magnetic field during the extrusion molding.

  In another aspect, the present invention provides an apparatus for manufacturing a separator for a secondary battery, in which an extrusion die serving as a mold for the separator and a magnetic field in which magnetic flux straddles a flow path of a resin material in the die. And a pair of magnetic field forming portions for forming a secondary battery separator.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the separator for secondary batteries which suppresses the fall of the output performance of a battery, the nonaqueous electrolyte secondary battery, and the manufacturing apparatus of the separator for secondary batteries are implement | achieved.

It is a perspective perspective view which shows the lithium ion secondary battery concerning embodiment. It is an expanded view which shows the laminated body which comprises the electric power generation element incorporated in a lithium ion secondary battery. It is a figure which shows the structure of the separator manufacturing system which concerns on embodiment. It is a figure which shows the extrusion location of the extrusion molding apparatus which concerns on embodiment. It is a figure which shows the evaluation result of a separator with a heat-resistant layer.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a nonaqueous electrolyte secondary battery according to the present invention will be described in detail with reference to the accompanying drawings. In the following embodiment, the present invention is applied to a lithium ion secondary battery for vehicle drive power source mounted on a hybrid vehicle.

[Configuration of lithium ion secondary battery]
As shown in FIG. 1, the lithium ion secondary battery 100 of this embodiment includes a power generation element 60 and an exterior portion 50 that houses the power generation element 60 and forms the outer shell of the lithium ion secondary battery 100. is there. FIG. 1 shows a state in which the exterior portion 50 is seen through.

  The exterior portion 50 includes a battery case 10 serving as a container and a sealing lid 20 that seals an opening of the battery case 10. The battery case 10 is made of a metal material such as aluminum, an aluminum alloy, a plated steel plate, or a stainless steel plate. The sealing lid 20 is made of a metal material such as aluminum, a plated steel plate, or a stainless steel plate. The metal material used for the battery case 10 and the sealing lid 20 may be any material that can be easily molded and has rigidity. An insulating film (not shown) is attached to the entire inner surface of the battery case 10.

  The battery case 10 is a bottomed rectangular box, that is, a rectangular parallelepiped having an upper surface opened. The battery case 10 houses the power generation element 60 and seals the power generation element 60 by closing the opening with a rectangular plate-shaped sealing lid 20. Specifically, in the exterior part 50, the battery case 10 and the sealing lid 20 are integrated by laser welding. The outer shape of the battery case 10 is an example and is not limited to a bottomed rectangular box. For example, it may be a bottomed cylindrical box.

  A positive electrode collector terminal 31 and a negative electrode collector terminal 32 are attached to the sealing lid 20 so as to penetrate the sealing lid 20 and protrude from the sealing lid 20 toward the outside of the exterior portion 50. An insulating member 33 made of resin is interposed at a position where the positive current collecting terminal 31 is attached to the sealing lid 20 to insulate the positive current collecting terminal 31 from the sealing lid 20. Similarly, an insulating member 34 made of resin is interposed at a location where the negative electrode current collecting terminal 32 is attached to the sealing lid 20 to insulate the negative electrode current collecting terminal 32 from the sealing lid 20. A rectangular plate-shaped safety valve 23 is also welded to the sealing lid 20. The safety valve 23 seals a liquid injection hole that penetrates the sealing lid 20, and an electrolytic solution is injected from the liquid injection hole.

The electrolytic solution injected into the battery case 10 is hexafluoride as a solute in a mixed organic solvent in which ethylene carbonate (EC) and dimethyl carbonate (DMC) are adjusted to a volume ratio of EC: DMC = 3: 7. It is an organic electrolytic solution in which lithium phosphate (LiPF ₆ ) is added to adjust the lithium ion concentration to 1.0 mol / l. In the lithium ion secondary battery 100, lithium ions in the electrolyte are responsible for electrical conduction.

  As shown in FIG. 2, the power generation element 60 is composed of a laminate in which a long positive electrode plate 61 and a similarly long negative electrode plate 62 are laminated with a separator 63 made of a polyolefin microporous film interposed therebetween. Is done. The positive electrode plate 61 carries a positive electrode mixture layer 612 on both surfaces of a positive electrode current collector foil 611 made of an aluminum foil. The positive electrode mixture layer 612 includes, for example, acetylene black, polyvinylidene fluoride (PVdF), etc., in addition to lithium nickel cobalt manganese oxide (NCM) as a positive electrode active material. The negative electrode plate 62 carries a negative electrode mixture layer 622 on both surfaces of a negative electrode current collector foil 621 made of copper foil. The negative electrode mixture layer 622 includes, for example, carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), etc. in addition to amorphous coated graphite as a negative electrode active material.

  The separator 63 is a known microporous resin (porosity 40 to 70%) made of polypropylene (PP) or polyethylene (PE). Further, heat resistant layers are provided on both surfaces of the separator 63. The heat-resistant layer includes, for example, SBR, polytetrafluoroethylene (PTFE), CMC, and MC in addition to an inorganic filler such as alumina.

  The positive electrode current collector foil 611, the positive electrode material mixture layer 612, the negative electrode current collector foil 621, the negative electrode material mixture layer 622, the separator 63, and the substances and ratios used for the electrolyte are examples, and are generally lithium ion secondary What is used for a battery may be appropriately selected.

  Further, the positive electrode mixture layer 612 is not formed at one end portion in the width direction (Y direction in FIG. 2) of the positive electrode plate 61, and the positive electrode current collector foil 611 is exposed. Also, the negative electrode mixture layer 622 is not formed at one end in the width direction of the negative electrode plate 62, and the negative electrode current collector foil 621 is exposed. Then, the portion where the positive electrode current collector foil 611 of the positive electrode plate 61 is exposed and the portion where the negative electrode current collector foil 621 of the negative electrode plate 62 is exposed are opposite to each other in the width direction. Laminated. Further, the positive electrode mixture layer 612 and the negative electrode mixture layer 622 are arranged so as to overlap each other when viewed from the thickness direction, that is, the positive electrode mixture layer 612 and the negative electrode mixture layer 622 are arranged to face each other with the separator 63 interposed therebetween. The

  Further, the separator 63 is one of the portions where the positive electrode current collector foil 611 of the positive electrode plate 61 is exposed (uncoated region) so as to cover the positive electrode mixture layer 612 and the negative electrode mixture layer 622 in the width direction. And the portion of the negative electrode plate 62 where the negative electrode current collector foil 621 is exposed (uncoated region) is disposed between the positive electrode plate 61 and the negative electrode plate 62 so as not to be covered.

  The power generation element 60 is obtained by winding and flattening the laminated body arranged as shown in FIG. 2 (see FIG. 1). Since one end of the positive electrode plate 61 in the width direction protrudes from the separator 63 with the positive electrode current collector foil 611 exposed, the power generation element 60 has a winding axis direction (Y direction in FIG. 2). The positive electrode plate 61 (positive electrode current collector foil 611) protrudes from one end portion after forming a spiral shape. On the other hand, one end portion in the width direction of the negative electrode plate 62 protrudes from the separator 63 with the negative electrode current collector foil 621 exposed, so that the power generation element 60 in the wound state has the other end in the winding axis direction. A negative electrode plate 62 (negative electrode current collector foil 621) protrudes in a spiral shape from the end of the electrode.

  Further, the portion of the power generation element 60 where the positive electrode plate 61 protrudes is electrically joined to the plate-shaped positive electrode current collecting terminal 31 bent in a crank shape as shown in FIG. On the other hand, the portion where the negative electrode plate 62 protrudes is electrically joined to the plate-shaped negative electrode current collecting terminal 32 which is also bent in a crank shape. Specifically, the positive electrode current collector terminal 31 is joined to the positive electrode current collector foil 611 exposed at one end in the width direction of the power generation element 60. On the other hand, the negative electrode current collector terminal 32 is joined to the negative electrode current collector foil 621 exposed at the other end in the width direction of the power generation element 60.

[Separator manufacturing system]
Then, the manufacturing system of the separator 63 which comprises the electric power generation element 60 mentioned above is demonstrated. The separator manufacturing system of this embodiment is a system for manufacturing a raw material of the separator 63, that is, a separator without a heat-resistant layer.

  In the separator manufacturing system 200 of the present embodiment, as shown in FIG. 3, an extruder 70 that produces a raw material 631 of the separator 63 by extrusion molding, an AC power supply 80 that supplies harmonic power, and a raw material of the separator 63. And a take-up roll 90 for collecting 631.

  The extruder 70 accommodates the resin material 630 of the separator 63 in a molten state, and as shown in FIG. 4, the raw fabric 631 of the long separator 63 is extruded. The original fabric 631 of the separator 63 is taken up by the take-up roll 90 after cooling, and an original fabric roll 632 that is a wound body of the original fabric 631 of the separator 63 is formed on the take-up roll 90. The end of the roll 632 wound up to a predetermined length is cut off.

  The heat-resistant layer may be applied in a process from when the raw fabric 631 of the separator 63 is extruded from the extrusion molding machine 70 until it is wound on the winding roll 90, or the raw fabric 631 is applied to the winding roll 90. After being wound up, the original fabric 631 may be unwound from the original fabric roll 632 and applied in another step.

  The extrusion molding machine 70 includes a container 72 that stores a molten resin material 630, a die 71 that is a mold having a flow path 712 and a passage section hole 710 of the resin material 630, and a resin material that is stored in the container 72. A screw 73 for pushing 630 to the die 71 and magnetic field forming portions 74 and 75 for forming a magnetic field are provided. The passage cross-sectional hole 710 of the die 71 has the same shape as the cross section of the separator 63. That is, the width of the passage cross-sectional hole 710 of the die 71 is equal to the width of the separator 63, and the height of the passage cross-sectional hole 710 of the die 71 is equal to the thickness of the separator 63.

  In the extrusion molding machine 70, the molten resin material 630 is put into the container 72, and the resin material 630 is pushed toward the die 71 by the screw 73. The resin material 630 pushed into the die 71 passes through the flow path 712 in the die 71. As the resin material 630 passes through the flow path 712 in the die 71, the temperature and pressure are stabilized. Thereafter, the resin material 630 is pushed out from the passage sectional hole 710 of the die 71. When the resin material 630 passes through the passage cross-sectional hole 710 of the die 71, a long original fabric 631 is formed.

  In the extrusion molding machine 70, a magnetic field forming unit 74 is disposed above the die 71 and a magnetic field forming unit 75 is disposed below the die 71. In other words, the pair of magnetic field forming portions 74 and 75 are arranged to face each other with the die 71 interposed therebetween. The opposing direction (magnetic flux direction) of the magnetic field forming portions 74 and 75 is equal to the thickness direction of the separator 63 pushed out from the die 71 (the height direction of the passage cross-sectional hole 710 of the die 71).

  Each of the magnetic field forming units 74 and 75 accommodates an exciting coil and a magnetic core. The exciting coil is electrically connected to an AC power source 80 and an AC bias is applied by the AC power source 80. By applying an AC bias to the excitation coils of the magnetic field forming units 74 and 75, the magnetic core is magnetized, and a magnetic field is formed between the magnetic field forming unit 74 and the magnetic field forming unit 75. That is, a magnetic field in the thickness direction of the separator 63 is formed around the die 71 by the magnetic field forming units 74 and 75 so that the magnetic flux straddles the flow path 710 of the die 71.

  In the separator manufacturing system 200 of this embodiment, the output of the AC power supply 80 is adjusted so that a 3T (Tesla) magnetic field is formed as a magnetic field forming condition. More specifically, an AC bias having a voltage of 1500 V to 4000 V and a frequency of 20 Hz to 80 Hz is applied to the magnetic field forming unit 74 and the magnetic field forming unit 75 by the AC power source 80. The magnetic field formation conditions are not limited to this, and may be selected as appropriate depending on the type and thickness of the separator material. In the material of this embodiment, a magnetic field of 1.5T to 5T is generally sufficient.

  Further, the magnetic field forming units 74 and 75 form a magnetic field in the entire flow path 712 of the resin material 630 in the die 71. Thereby, the original fabric 631 of the separator 63 pushed out from the die 71 is affected by the magnetic field in the width direction of the separator 63 without unevenness. Note that the magnetic field formed by the magnetic field forming units 74 and 75 is not necessarily formed in the entire flow path 712 of the die 71, and is formed in at least a part of the flow path 712 in the transport direction. The entire width direction is formed. As a result, the resin material 630 pushed into the die 71 is affected by the magnetic field to some extent before being pushed out from the passage cross section hole 710.

[Evaluation of lithium ion secondary battery]
Subsequently, evaluation of a lithium ion secondary battery using a porous separator with a heat-resistant layer will be described. In this evaluation, using the 18650 cell, the IV resistance at 10 seconds was measured in an environment of 25 ° C. (each measured value at 1 / 3C, 1C, 3C, and 5C was plotted).

  In this evaluation, a reference cell using a separator produced without forming a magnetic field at the time of extrusion molding and an evaluation cell using a separator produced by forming a magnetic field at the time of extrusion molding were produced. It was measured. Then, the relative value of the evaluation cell was obtained when the measured value of the reference cell was 100%.

  Specifically, in this evaluation, a reference cell using a PE single-layer separator (referred to as “reference cell 1”) and a reference cell using a PP / PE / PP three-layer separator (referred to as “reference cell 2”). Two reference cells were prepared. Similarly to the reference cell, the evaluation cell includes an evaluation cell using a PE single-layer separator (referred to as “evaluation cell 1”) and a cell using a PP / PE / PP three-layer separator. Produced. For the three-layer separator, an evaluation cell (referred to as “evaluation cell 2”) using a three-layer separator in which a magnetic field is applied only to PP and no magnetic field is applied to PE, and both PP and PE An evaluation cell (referred to as “evaluation cell 3”) using a three-layer separator to which a magnetic field was applied was produced.

The common specifications of each member used in this evaluation are as follows.
<Separator with heat-resistant layer>
Separator Polyolefin resin Thickness: 16 to 20 μm (Three layers total thickness for reference cell 2, evaluation cell 2, and evaluation cell 3)
Porosity: 45 to 70% (reference cell 1 and evaluation cell 1), 40 to 55% (reference cell 2, evaluation cell 2, and evaluation cell 3)
Heat resistant layer filler Inorganic filler Alumina (D50 = 0.2-1.2 μm, BET specific surface area = 1.3-18 m ² / g)
Boehmite (D50 = 0.4-1.8 μm, BET specific surface area = 2.8-27 m ² / g)
・ Heat resistant layer binder Acrylic binder, SBR, polyolefin binder, PTFE
・ Heat-resistant layer thickener CMC, MC
<Positive electrode plate>
・ Active material NCM111
・ Conductive material Acetylene black ・ Binder PVdF
・ Collector foil Aluminum foil (thickness: 15μm)
-Weight per unit area 9.8-15.2 mg / cm < ² >
・ Density 1.8-2.4g / cc
<Negative electrode plate>
-Active material Amorphous coated graphite-Binder SBR
・ Thickener CMC
・ Collector foil Copper foil (thickness: 10μm)
・ Weight per unit: 4.8 to 10.2 mg / cm ²
・ Density 0.8 ~ 1.4g / cc
<Electrolyte>
・ Salt LiPF ₆ (concentration: 1.0 mol / l)
Solvent EC: DEC = 3: 7

  The evaluation results are shown in FIG. FIG. 5A is a graph comparing the reference cell 1 and the evaluation cell 1. As shown in FIG. 5A, in the evaluation cell 1, the IV resistance was reduced by 16% compared to the reference cell 1. This result confirmed that the output performance was higher when using a separator that passed the magnetic field during extrusion molding than when using a separator that did not pass the magnetic field.

  FIG. 5B is a graph comparing the reference cell 2 with the evaluation cell 2 and the evaluation cell 3. As shown in FIG. 5B, in the evaluation cell 2, the IV resistance was reduced by 6% compared to the reference cell 2. From this result, it was confirmed that the output performance was higher when the separator that passed the magnetic field during extrusion molding was used in part than when only the separator that did not pass the magnetic field was used. Moreover, in the evaluation cell 3, the IV resistance was further reduced by 4% as compared with the evaluation cell 2. The results confirmed that the output performance was higher when only the separator that passed the magnetic field during extrusion molding was used than when the separator that passed the magnetic field was partially used. From these results, it can be seen that it is preferable to use more separators that form a magnetic field during extrusion to improve output performance.

  Although the exact mechanism for the resistance reduction effect due to magnetic field formation has not been clarified, the following factors are presumed. That is, when the separator 63 is considered at the molecular level, it is considered that the molecules are oriented in the thickness direction of the separator 63 by forming a magnetic field in the thickness direction of the separator 63 when the raw material 631 of the separator 63 is pushed out. . And when it uses as a secondary battery, when the ion moves in the separator 63, it is thought that the influence of the adsorption energy with a molecule | numerator is reduced because the molecule | numerator of polyolefin resin is orientated. As a result, it is presumed that the IV resistance was reduced.

  As described above in detail, in the method of manufacturing the separator 63 according to this embodiment, a magnetic field is applied to the die 71 when the material 631 of the separator 63 is extruded. This magnetic field is formed by the magnetic field forming units 74 and 75 so that the magnetic flux straddles the flow path 712 of the die 71. Then, it is considered that at least a part of the molecules are oriented in a certain direction by passing the resin material 630 constituting the separator 63 through the magnetic field. In addition, when the ions move in the separator 63, the molecules of the resin material 630 are oriented, so that it can be expected to reduce the influence of the adsorption energy with the molecules. Therefore, it can be expected to suppress a decrease in output performance of the lithium ion secondary battery 100 using the separator 63.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the lithium ion secondary battery is not limited to the vehicle driving power source, but may be used for home appliances and personal computers. Further, the nonaqueous electrolyte secondary battery is not limited to the lithium ion secondary battery, but can be applied to other nonaqueous electrolyte secondary batteries such as a nickel hydride secondary battery.

  In the embodiment, the separator 63 is a separator with a heat-resistant layer having heat-resistant layers on both sides, but the heat-resistant layer is not an essential component. That is, the present invention can be applied even to a separator having no heat-resistant layer.

  In the embodiment, the magnetic field forming units 74 and 75 are disposed outside the die 71, but the present invention is not limited to this. For example, the magnetic field forming units 74 and 75 may be embedded in the die 71. However, by arranging the magnetic field forming units 74 and 75 outside the die 71 as in the embodiment, the magnetic field forming units 74 and 75 are compared with the case where the magnetic field forming units 74 and 75 are embedded in the die 71. 75 is easy to maintain, and the degree of freedom of arrangement of the magnetic field forming units 74 and 75 is also increased.

  In the embodiment, the magnetic field forming units 74 and 75 form a magnetic field in the entire flow path 712 of the resin material 630 in the die 71. However, the present invention is not limited to this. That is, a part of the flow path 712 may be used. In this case, it is preferable that the magnetic flux straddles at least a downstream portion including the passage cross-sectional hole 710 of the die 71. Since at least the passage sectional hole 710 of the die 71 is in the magnetic field, the resin material 630 is affected by the magnetic field until immediately before the resin material 630 is pushed out of the die 71, and the separator 63 in a molecularly oriented state can be stably manufactured. Can be expected.

60 Electricity generating element 61 Positive electrode plate 62 Negative electrode plate 63 Separator 630 Resin material 70 Extruder 71 Die 710 Passing cross-sectional hole 712 Flow path 74, 75 Magnetic field forming unit 80 AC power supply 90 Winding roll 100 Lithium ion secondary battery

Claims (6)

In the method for manufacturing a secondary battery separator,
Extruding the resin material from the die to have an extrusion process for producing the long separator,
In the extrusion molding process, a magnetic field forms a magnetic field across the flow path of the resin material in the die. In the manufacturing method of the separator for secondary batteries of Claim 1,
The method of manufacturing a separator for a secondary battery, wherein the magnetic field is a magnetic field in a thickness direction of the separator. In the manufacturing method of the separator for secondary batteries of Claim 1 or Claim 2,
The method of manufacturing a separator for a secondary battery, wherein the magnetic field straddles at least a downstream portion including the output port of the resin material of the die in the flow path. In the manufacturing method of the separator for secondary batteries given in any 1 paragraph of Claims 1-3,
The method for producing a separator for a secondary battery, wherein the resin material is a polyolefin resin. In a non-aqueous electrolyte secondary battery having a power generation element formed by alternately laminating electrode plates and separators,
The non-aqueous electrolyte secondary battery, wherein the separator is manufactured by extrusion molding in which a resin material is extruded from a die, and the resin material has passed a magnetic field during the extrusion molding. In the secondary battery separator manufacturing equipment,
An extrusion die serving as the mold of the separator;
A pair of magnetic field forming portions for forming a magnetic field in which the magnetic flux straddles the flow path of the resin material in the die;
An apparatus for producing a separator for a secondary battery, comprising:

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