JP2017063004A - Lamination type battery manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamination type battery manufacturing method that can manufacture a positive electrode and/or negative electrode laminate wrapped by a separator without requiring accurate positioning of plural positive electrode and/or negative electrode laminates to the separator, thereby enhancing the productivity of the lamination type battery.SOLUTION: A lamination type battery manufacturing method comprises a step of clamping a first strip-shaped electrode laminate web having a plurality of notches from both the sides thereof by strip-shaped separator webs, a step of making at least parts of the opposed strip-shaped separator webs adhere to each other, a step of cutting out the first strip-shaped electrode laminate web, a step of making portions of the opposed strip-shaped separator webs corresponding to the portion from which the first strip-shaped electrode laminate web is cut out, adhere to the portions which correspond to the cut-out portion and do not adhere to each other, and a step of cutting the strip-shaped separator webs, and a step of alternately laminating a first electrode laminate wrapped with the separator and a second electrode laminate which is not wrapped with the separator.SELECTED DRAWING: None

Description

  The present invention relates to a method for manufacturing a stacked battery.

  In recent years, lithium ion secondary batteries have been put into practical use as batteries having high voltage and high energy density. Due to the widespread use of lithium ion secondary batteries and the demand for high performance, various studies have been conducted to further improve the performance of lithium ion secondary batteries.

  Examples of the form of the lithium ion secondary battery include a stacked lithium ion secondary battery and a wound lithium ion secondary battery. Among them, the laminated lithium ion secondary battery has advantages in that it is superior in energy volume efficiency, safety, quality, and durability as compared with a wound lithium ion secondary battery.

  Here, in one aspect of the laminated lithium ion secondary battery, a positive electrode laminate that is encased in a separator and has a positive electrode active material layer and a positive electrode current collector, and is not encased in a separator and is a negative electrode The active material layer and the negative electrode laminate having the negative electrode current collector are alternately laminated. In this aspect, in order to prevent a short circuit, it is common to use a positive electrode laminate that is completely encased in a separator, and means for efficiently producing the positive electrode laminate that is encased in this separator has been proposed. Yes.

  In Patent Document 1, a step of arranging and arranging a plurality of rectangular positive electrode laminates on a strip-shaped separator, a step of folding the separator at the bottom of the positive electrode laminate so as to sandwich the positive electrode laminate, A step of intermittently forming a welded portion on the separator along the side portion of the body, a step of cutting the separator along the welded portion to form a bag-like separator with a positive electrode laminate, and a bag-like separator with a positive electrode laminate And a step of laminating a rectangular negative electrode laminate, a method for producing a laminated secondary battery is disclosed. According to Patent Document 1, this leads to an improvement in productivity and a reduction in the amount of material used.

  Patent Document 2 discloses a method for manufacturing a lithium ion battery, in which a plurality of positive electrode or negative electrode laminates are sandwiched between upper and lower separator bands and cut at predetermined positions to form a bagged positive electrode or negative electrode laminate. Has been. According to Patent Document 2, this improves the productivity of the stacked battery.

JP 2009-289418 A JP 2007-242507 A

  In order to manufacture a laminated lithium ion secondary battery, it is necessary to laminate a plurality of positive electrode laminates and negative electrode laminates separated one by one in advance. The position must be accurately determined one by one. Further, in the production of the laminated lithium ion secondary battery, the area of the positive electrode laminate must be smaller than the area of the negative electrode laminate in order to prevent lithium deposition. Furthermore, the positive electrode laminate should not protrude beyond the negative electrode laminate (in the direction perpendicular to the laminate).

  As a means for laminating a large number of positive electrode laminates and negative electrode laminates in a short time while satisfying these conditions, the area of the negative electrode laminate and the area of the positive electrode laminate wrapped in the separator are made equal. Therefore, it is conceivable that the positional accuracy during lamination is relaxed and aligned after high-speed lamination.

  However, when an attempt is made to adjust the area of the positive electrode laminate wrapped in the separator using the methods of Patent Documents 1 and 2, each of the plurality of positive electrodes and / or negative electrode laminates is accurately positioned with respect to the separator. Therefore, the improvement in productivity is insufficient.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention is as follows:
A first electrode laminate that is encased in a separator and has a first active material layer and a first current collector; and a second active material layer and a second electrode that are not encased in the separator A method for producing a stacked battery, wherein the second electrode stack having two current collectors is alternately stacked,
A step of sandwiching a first strip electrode laminate original fabric having a plurality of notches on one side in the longitudinal direction from both sides with a strip separator original fabric,
The belt-shaped separator original fabric is fixed to the first electrode laminate original fabric by adhering at least a part of the portions corresponding to the cutout portions of the opposed strip-shaped separator original fabrics facing each other. The process of
Cutting the first strip-shaped electrode laminate original fabric from the cutout portion toward the longitudinal side not having the cutout portion to form the first electrode laminate;
Of the strip-shaped separator original fabric facing each other, the portion corresponding to the portion of the first strip-shaped electrode laminate original fabric cut away and the portion not bonded of the portions corresponding to the notch are bonded to each other The process of
The strip-shaped separator original fabric is cut at a region corresponding to the cutout portion and the portion of the first strip-shaped electrode laminate original fabric cut out to form a separator, and the first electrode laminate that is wrapped with the separator is A step of forming, and a step of alternately laminating the first electrode laminate that is encased in the separator and the second electrode laminate that is not encased in the separator. Method.

  According to the present invention, it is possible to manufacture a positive electrode and / or a negative electrode laminate that is wrapped in a separator without requiring that each of a plurality of positive and / or negative electrode laminates be accurately positioned with respect to the separator. Thus, the productivity of the stacked battery can be improved.

FIG. 1 is a top view of the first strip electrode laminate original. FIG. 2 is a top view of the strip separator original. FIG. 3A is a top perspective view of the strip separator original and the first strip electrode laminate original after the sandwiching step. FIG. 3B is a cross-sectional view taken along line III-III of the strip separator original and the first strip electrode laminate original at this stage. FIG. 4A is a top perspective view of the strip separator original and the first strip electrode laminate original after the first bonding step. FIG. 4B is a cross-sectional view taken along line IVb-IVb of the strip separator original and the first strip electrode laminate original at this stage. FIG. 4C is a cross-sectional view taken along line IVc-IVc of the strip separator original and the first strip electrode laminate original at this stage. FIG. 5A is a top perspective view of the strip separator original and the first strip electrode laminate original before the cutting process. FIG. 5B is a top perspective view of the strip separator original and the first electrode laminate in the stage after the cutting process. FIG. 6 is a top perspective view of the strip separator original and the first electrode laminate in the stage after the second bonding step. FIG. 7A is a top perspective view of the strip separator original and the first electrode laminate in a stage before the cutting step. FIG. 7B is a top perspective view of the separator and the first electrode laminate in the stage after the cutting process. FIG. 8A is a top view of the first electrode laminate that is wrapped with the separator and the second electrode laminate that is not wrapped with the separator. FIG. 8B is a schematic diagram of one aspect of the lamination process.

<< Production method of laminated battery >>
The method for manufacturing a laminated battery of the present invention is sandwiched between separators, and is not sandwiched between a first electrode laminate having a first active material layer and a first current collector, and a separator, And it is the manufacturing method of a laminated battery by which the 2nd electrode laminated body which has a 2nd active material layer and a 2nd electrical power collector is laminated | stacked alternately.

  In particular, the method for manufacturing a stacked battery of the present invention includes a sandwiching process, an adhesion process, a cutting process, a sealing process, a cutting process, and a stacking process.

  Below, each process of the manufacturing method of the laminated battery of this invention is demonstrated, referring drawings.

<Pinching process>
The sandwiching step means a step of sandwiching the first strip electrode laminate original fabric having a plurality of notches on one side in the longitudinal direction from both sides with the strip separator raw fabric.

  More specifically, first, a first strip electrode laminate original as shown in FIG. 1 is prepared. This first strip electrode stack original fabric (10) has a first active material layer (16) and a first current collector. In particular, in the method for manufacturing a laminated battery of the present invention, the first strip electrode laminate original fabric (10) has a plurality of notches (12) on one side in the longitudinal direction. Moreover, the 1st strip | belt-shaped electrode laminated body original fabric (10) may have an arbitrary tab part (14).

  Also, a strip separator raw fabric (20) as shown in FIG. 2 is prepared.

  Next, the strip-shaped separator original fabric (20) is disposed on the first strip-shaped electrode laminate original fabric (10). Then, by folding the strip separator raw fabric (20) along the planned folding line (22), as shown in FIGS. 3 (a) and (b), the first strip electrode stack original fabric (10) is formed. Insert from both sides.

  Although not shown, this sandwiching step can also be performed by sandwiching the first electrode stack with two separators having the same shape.

<Adhesion process>
The adhesion step means a step of adhering at least a part of the portions corresponding to the notches in the opposed strip-shaped separator originals. Thus, the strip separator raw is fixed to the first strip electrode laminate original.

  More specifically, as shown in FIGS. 4 (a) and 4 (b), the bonding process corresponds to the notch portion of the first strip electrode stack original fabric among the opposed strip separator original fabrics. This means that at least a part of the portion to be bonded is the bonding location (20a) and is bonded to each other at the bonding location (20a).

  This adhesion can be performed by, for example, heat welding, application of an adhesive to the strip separator original fabric, or the like.

  Moreover, as shown to FIG. 4 (a) and (c), at an adhesion | attachment process, the area | region pinched | interposed into the adhesion | attachment location (20a) of the 1st strip | belt-shaped electrode laminated body raw material is a strip | belt-shaped separator raw fabric. They may be sandwiched and glued together.

<Resection process>
The excision step means a step of excising the first strip electrode laminate original fabric from the notch portion toward the side not having the notch portion. As a result, the first strip-shaped electrode laminate original fabric becomes the first electrode laminate.

  More specifically, as shown in FIG. 5 (a), the first strip-shaped electrode laminate original fabric has an area from the notch to the side not having the notch as an excision site (18). The first strip electrode laminate original fabric is excised at the location (18). The excavation of the first strip electrode laminate original can be performed with a YAG laser, a cutting blade or the like. As a result, the first strip-shaped electrode laminate original fabric becomes the first electrode laminate (10a) as shown in FIG. 5B.

<Second bonding step>
In the second bonding step, of the opposing strip-shaped separator original fabric, the portion corresponding to the portion obtained by excising the first strip-shaped electrode laminate original fabric and the portion corresponding to the notch are not bonded. This is a step of bonding the parts together. Preferably, the first electrode stack is sealed through this step.

  More specifically, as shown in FIG. 6, the sealing step corresponds to a portion (20 b) corresponding to a portion of the opposed strip-shaped separator original fabric where the first strip-shaped electrode laminate original fabric has been excised. And the area | region including at least the part (20c) which is not adhere | attached among the parts corresponding to a notch part is made into an adhesion location, and it adheres mutually in this adhesion location (20b, 20c).

  Preferably, in the second bonding step, the first electrode stack (10a) is sealed by bonding the remaining portions (20d) of the opposed strip-shaped separator originals to each other.

<Cutting process>
The cutting step is a step of cutting the strip separator raw material in a region corresponding to a portion where the cutout portion and the first strip electrode stack original fabric are cut out. As a result, a first electrode laminate that is wrapped with the separator is formed.

  More specifically, as shown to Fig.7 (a), a strip | belt-shaped separator original fabric is cut | disconnected in the area | region corresponding to the part which excised the notch part and the 1st strip | belt-shaped electrode laminated body raw fabric. The cutting position can be, for example, the position indicated by the cutting line (30).

  Through this step, a first electrode laminate (10b) encased in a separator as shown in FIG. 7B is formed.

<Lamination process>
A lamination process is a process of laminating | stacking alternately the 1st electrode laminated body wrapped with the separator, and the 2nd electrode laminated body which is not wrapped with the separator.

  More specifically, as shown in FIG. 8A, the stacking process includes a first electrode stack (10b) wrapped in a separator and a second electrode stack (not sandwiched between separators) ( 40) can be laminated alternately.

  Here, as shown to Fig.8 (a), the 2nd electrode laminated body has a 2nd active material layer (42) and a 2nd electrical power collector. Further, the second electrode laminate may have an optional tab portion (44).

  Further, as shown in FIG. 8 (b), an outer diameter positioning jig (50), an actuator, or the like may be used as needed when stacking.

<Items used in each process>
Below, the thing used for said each process is demonstrated.

{First strip electrode laminate original}
The first strip electrode laminate original fabric has a first active material layer and a first current collector. Moreover, the 1st strip | belt-shaped electrode laminated body original fabric may have an arbitrary tab part. The first strip electrode laminate original fabric becomes the first electrode laminate through the above-described cutting step.

(First active material layer)
The first active material layer can contain, for example, a positive electrode active material. The positive electrode active material is not particularly limited as long as it is a material that can occlude ions such as lithium, sodium, and calcium during discharge and can optionally release ions during charge.

(First current collector)
The first current collector can be, for example, a positive electrode current collector. The material constituting the positive electrode current collector is not particularly limited as long as the material can collect current from the positive electrode active material.

(Tab part)
A plurality of tab portions may be present on the side surface of the first strip-shaped electrode laminate original fabric. Moreover, when manufacturing the laminated battery of the same shape, it is preferable that the space | interval of this some tab part is equal intervals, and is equal to the space | interval of a notch part.

(Notch)
A plurality of notches are formed on one side in the longitudinal direction of the first strip electrode laminate original fabric. In the case of manufacturing a laminated battery having the same shape, the intervals between the plurality of notches are preferably equal and equal to the interval between the tab portions.

{Strip-like separator stock}
The strip separator original fabric may be composed of only the base material, or the base material and the solid electrolyte layer on the base material. In particular, in the production of a liquid-type laminated battery, the strip separator raw material may be composed only of a base material. In the production of a laminated battery using a solid electrolyte, the strip separator raw material is a base material. And a solid electrolyte layer on the substrate.

  The strip separator raw material becomes a separator through the above cutting step.

  The base material may be made of, for example, polyethylene (PE), polypropylene (PP), or Teflon (registered trademark). In particular, the base material may be a microporous base material when the separator raw material is composed only of the base material, and the separator raw material is composed of the base material and the solid electrolyte layer on the base material. If it is, it may be a mesh substrate.

  When the substrate is a microporous substrate, the porosity of the substrate can be 60% or more, 65% or more, or 70% or more, and 95% or less, 90% or less, or 85%. Can be: Moreover, the size of the pores of the substrate may be, for example, 100 nm to 300 nm × 30 nm to 60 nm.

  When the substrate is a mesh substrate, the porosity of the substrate can be 60% or more, 65% or more, or 70% or more, and is 95% or less, 90% or less, or 85% or less. Can be. Moreover, the crosspiece width between holes can be 10 μm or more, 15 μm or more, or 20 μm or more, and can be 50 μm or less, 40 μm or less, or 30 μm or less.

  The thickness of the substrate can be 10 μm or more, 12 μm or more, or 15 μm or more, and can be 50 μm or less, 40 μm or less, or 30 μm or less.

  The material which comprises a solid electrolyte layer will not be specifically limited if it is a material which has the conductivity with respect to ions, such as lithium, sodium, and calcium, and is an insulating material.

{Second electrode laminate}
The second electrode stack includes a second active material layer and a second current collector. The second electrode laminate may have an optional tab portion.

(Second active material layer)
The second active material layer can contain, for example, a negative electrode active material. The negative electrode active material is not particularly limited as long as it is a material that can release ions such as lithium, sodium, and calcium during discharge and can optionally store ions during charge.

(Second current collector)
The second current collector can be, for example, a negative electrode current collector. The material constituting the negative electrode current collector is not particularly limited as long as the material can collect current from the negative electrode active material.

DESCRIPTION OF SYMBOLS 10 1st strip | belt-shaped electrode laminated body original fabric 10a 1st electrode laminated body 10b The 1st electrode laminated body wrapped by the separator 12 Notch part 14 Tab part of the 1st strip | belt-shaped electrode laminated body original fabric 16 1st Active material layer 18 Cut portion 20 Strip separator raw fabric 20a, 20b, 20c, 20d Bonded portion 22 Bending line 30 Cutting line 40 Second electrode laminate 42 Second active material layer 44 Tab of second electrode laminate 50 Outer diameter positioning jig

Claims (1)

A first electrode laminate that is encased in a separator and has a first active material layer and a first current collector; and a second active material layer and a first electrode that are not encased in the separator A method for producing a stacked battery, wherein the second electrode stack having two current collectors is alternately stacked,
A step of sandwiching a first strip electrode laminate original fabric having a plurality of notches on one side in the longitudinal direction from both sides with a strip separator original fabric,
The belt-shaped separator original fabric is fixed to the first electrode laminate original fabric by adhering at least a part of the portions corresponding to the notch portions of the opposed strip-shaped separator original fabrics facing each other. The process of
Cutting the first strip-shaped electrode laminate original fabric from the cutout portion toward the longitudinal side not having the cutout portion to form the first electrode laminate;
Of the strip-shaped separator original fabric facing each other, a portion corresponding to a portion of the first strip-shaped electrode laminate original fabric cut away and a non-bonded portion of the portions corresponding to the notch are bonded to each other The process of
The strip-shaped separator original fabric is cut in a region corresponding to the cutout portion and the portion of the first strip-shaped electrode laminate original fabric cut out to form a separator, and the first electrode laminate that is wrapped with the separator is A step of forming, and a step of alternately laminating the first electrode laminated body encased in the separator and the second electrode laminated body not encased in the separator. Method.

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