JP2019212437A - Lamination type battery - Google Patents

Abstract

To provide a manufacturing method of lamination type battery where an electrode plate and a tub are welded reliably.SOLUTION: A lamination type battery comprises multiple first electrode plates, multiple second electrode plates laminated in the lamination alternatively to the first electrode plates, first tubs connected with the first electrode plates, and second tubs connected with the second electrode plates. The first electrode plate has a first electrode collector including a first effective region and a first connection region. The first connection region is superposed on the first tub, and the first electrode collector separated most from the first tub in the lamination direction is longer than at least one other first electrode collector. The first electrode plate also has an insulation tape laminated on the first electrode collector, and the difference of length between the longest and shortest first electrode collectors is larger than the sum of the separation interval of the first effective regions of the longest and shortest first electrode collectors in the lamination direction, and the width of the insulation tape in the arrangement direction of the first effective regions and the first connection region.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a stacked battery.

  For example, as proposed in Patent Document 1, a stacked battery in which a positive electrode plate and a negative electrode plate are alternately stacked is widely used. As an example of the stacked battery, a lithium ion secondary battery can be exemplified. One feature of a lithium ion secondary battery is that it has a larger capacity than other types of stacked batteries. Lithium ion secondary batteries having such characteristics are now expected to be further spread in various applications such as in-vehicle applications and stationary housing applications.

  FIG. 10 is a schematic cross-sectional view showing a conventional laminated battery 1c. As illustrated in FIG. 10, the stacked battery 1 c includes a stacked body 5 c that includes positive electrode plates 10 X and negative electrode plates 20 Y that are alternately stacked, and an insulator 30 that is provided between the positive electrode plates 10 X and the negative electrode plate 20 Y. In addition, an exterior body 3 that accommodates the laminate 5c is provided. In general, the positive electrode plate 10X and the negative electrode plate 20Y include electrode regions b1 and b2 which are effective regions to which an active material is applied, and connection regions (end regions) a1 and a2 adjacent to the electrode regions b1 and b2. Then, the connection regions a1 and a2 of the positive electrode plate 10X and the negative electrode plate 20Y are overlapped on separate tabs 4 provided for the electrode plates 10X and 20Y, and the tabs corresponding to the positive electrode plate 10X and the negative electrode plate 20Y. 4X and 4Y are electrically connected.

  Usually, the plurality of positive plates 10X are sequentially stacked in the stacking direction dL, and then each connection region a1 of the plurality of positive plates 10X is on the tab 4X positioned on the plane including the first positive plate 10X. Stacked (bundled). Since the connection regions a1 of the respective positive electrode plates 10X have the same length, they are superimposed on the tab 4X in a cross section orthogonal to the stacking direction and along the arrangement direction of the electrode regions b1 and the connection regions a1. The end position of each connection region a1 shifts to the electrode region b1 side (left side in FIG. 10) as it is stacked.

  In general, the end regions a1 and a2 of the positive electrode plate 10X are joined by ultrasonic welding. In this case, in the positive electrode plate 10, only the region Z where the end regions a1 of all the positive electrode current collectors 11X overlap as seen from the stacking direction dL is welded. The dimension of this region Z depends on the end position of the end region a1 of the positive electrode plate 10X (the uppermost layer in FIG. 10) that is laminated last. For this reason, as the number of stacked positive electrode plates 10X increases, the area of the welded portion of the end region a1 of the positive electrode plate 10X decreases, and the electrical resistance may increase.

JP 2013-182715 A

  The present invention has been devised in view of the above points. That is, an object of the present invention is to provide a stacked battery in which an electrode plate and a tab are welded with reliability.

A stacked battery according to the present invention includes a plurality of first electrode plates,
A plurality of second electrode plates alternately stacked in the stacking direction with the first electrode plates;
A first tab electrically connected to the first electrode plate;
A second tab electrically connected to the second electrode plate,
The first electrode plate includes a first electrode current collector including a first effective region and a first connection region adjacent to the first effective region, and the first effective electrode on at least one surface of the first electrode plate. A first electrode active material layer laminated in the region,
The first connection regions of the plurality of first electrode plates are stacked on the first tab and electrically connected to each other;
Between the plurality of first electrode plates, the length of the first electrode current collector in a cross section that is parallel to the stacking direction and orthogonal to the arrangement direction of the first effective region and the first connection region is not constant. ,
The length of the first electrode current collector of the first electrode plate that is farthest from the first tab in the stacking direction is longer than the length of the first electrode current collector of at least one other first electrode plate. ,long,
The first electrode plate further includes an insulating tape laminated across the first connection region of the first electrode current collector and the first electrode active material layer,
The difference in length between the longest first electrode current collector and the shortest first electrode current collector included in the plurality of first electrode plates is the first effective region of the longest first electrode current collector and A separation distance along the stacking direction of the first effective region of the shortest first electrode current collector, and a width of the insulating tape along an arrangement direction of the first effective region and the first connection region, Greater than sum.

  The length of the first electrode current collector is the longest in the first electrode plate that is farthest from the first tab in the stacking direction, and the first electrode plate that is closest to the first tab in the stacking direction. It may be the shortest.

  The length of the first electrode current collector of one arbitrarily selected first electrode plate is other first electrode plate closer to the first tab in the stacking direction than the one first electrode plate It may be longer than the length of the first electrode current collector.

The plurality of first electrode plates include a first group of first electrode plates in which the first connection region of the first electrode current collector is overlaid on one surface of the first tab and electrically connected to each other. And a second group of first electrode plates, wherein the first connection region of the first electrode current collector is overlapped on the other surface of the first tab and electrically connected to each other,
Of the first electrode plates of the first group, the length of the first electrode current collector of the first electrode plate that is farthest from the one surface of the first tab in the stacking direction is the first electrode plate. Longer than the length of the first electrode current collector of at least one other first electrode plate of the group of first electrode plates;
Of the first electrode plates of the second group, the length of the first electrode current collector of the first electrode plate that is farthest from the other surface of the first tab in the stacking direction is the second electrode plate. It may be longer than the length of the first electrode current collector of at least one other first electrode plate of the group of first electrode plates.

The second electrode plate includes a second electrode current collector including a second effective region and a second connection region adjacent to the second effective region, and the second effective electrode on at least one surface of the second electrode plate. A second electrode active material layer laminated in the region,
The second connection regions of the plurality of second electrode plates are stacked on the second tab and electrically connected to each other;
Between the plurality of second electrode plates, the length of the second electrode current collector in a cross section that is parallel to the stacking direction and orthogonal to the arrangement direction of the second effective region and the second connection region is not constant. ,
The length of the second electrode current collector of the second electrode plate that is farthest from the second tab in the stacking direction is longer than the length of the second electrode current collector of at least one other second electrode plate. Long and good.

  The thicknesses of the first electrode plate and the second electrode plate that are alternately stacked in the stacking direction may be 4 mm or more.

  Further, the stacked battery described above may include 10 or more of the first electrode plate and the second electrode plate, respectively.

  According to the present invention, a stacked battery in which an electrode plate and a tab are welded with reliability can be provided.

1 is a schematic perspective view showing a stacked battery according to an embodiment of the present invention. FIG. 2 is a schematic plan view showing the stacked battery of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a figure for demonstrating an example of the manufacturing method of a laminated type battery. It is a figure for demonstrating an example of the manufacturing method of a laminated type battery. It is a figure for demonstrating an example of the manufacturing method of a laminated type battery. It is a figure for demonstrating an example of the manufacturing method of a laminated type battery. It is a figure for demonstrating an example of the manufacturing method of a laminated type battery. It is a figure for demonstrating an example of the manufacturing method of a laminated type battery. It is a figure for demonstrating the modification of a laminated battery. It is a schematic sectional drawing which shows the conventional laminated battery.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that, in the drawings attached to the present specification, for the sake of easy understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  FIG. 1 is a schematic perspective view showing a stacked battery 1 according to an embodiment of the present invention. 2 is a schematic plan view of FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III of FIG.

  In one embodiment described below, the stacked battery 1 includes an exterior body 3, a membrane electrode assembly 5 accommodated in the exterior body 3, and the interior of the exterior body 3 connected to the membrane electrode assembly 5. And a tab 4 extending from the outside to the outside. Among these, the membrane electrode assembly 5 has the 1st electrode plate 10 and the 2nd electrode plate 20 which were laminated | stacked alternately. Such a stacked battery 1 cannot perform its intended function unless electrical connection between the electrode plates 10 and 20 and the tab 4 is ensured. The laminated battery 1 according to the present embodiment is devised to stabilize the bonding between the plurality of electrode plates 10 and 20 and the tab 4 included in the laminated battery 1 as described below. Excellent in both performance and reliability. In addition, as described below, the method for manufacturing a stacked battery according to the present embodiment is devised to manufacture a stacked battery excellent in performance and reliability in a short time while maintaining a high yield. As a result, the productivity of the stacked battery 1 is improved.

  Hereinafter, an example in which the stacked battery 1 constitutes a lithium ion secondary battery will be described. In this example, the first electrode plate 10 constitutes the positive electrode plate 10X, and the second electrode plate 20 constitutes the negative electrode plate 20Y. However, as can be understood from the description of the operational effects described below, the embodiment described here is not limited to the lithium ion secondary battery, but the first electrode plate 10 and the second electrode plate. The present invention can be widely applied to a stacked battery 1 in which 20 are stacked alternately.

  The exterior body 3 is a packaging material for sealing the membrane electrode assembly 5. The exterior body 3 has a support base material and the contact bonding layer laminated | stacked on this support base material as an example. The supporting base material preferably has high gas barrier properties and molding processability. As such a supporting substrate, an aluminum foil or a stainless steel foil can be used. On the other hand, the adhesive layer functions as a seal layer for joining the supporting base materials. The adhesive layer preferably has insulating properties, chemical resistance, thermoplasticity and the like in addition to adhesiveness. As such an adhesive layer, polypropylene, modified polypropylene, low density polypropylene, ionomer, ethylene / vinyl acetate can be used.

  The tab 4 functions as a terminal in the stacked battery 1. The first tab 4X is electrically connected to the positive electrode plate 10X (first electrode plate 10) of the membrane electrode assembly 5, and the other second tab is connected to the negative electrode plate 20Y (second electrode plate 20) of the membrane electrode assembly 5. 4Y is electrically connected. The tab 4 can be formed using aluminum, nickel, nickel-plated copper, or the like. The pair of tabs 4 extends from the inside of the exterior body 3 to the outside of the exterior body 3. In addition, between the exterior body 3 and the tab 4 is sealed in a region where the tab 4 extends.

  Next, the membrane electrode assembly 5 will be described with reference mainly to the specific examples shown in FIGS. As shown in FIGS. 1 to 3, the membrane electrode assembly 5 includes a plurality of positive plates 10 </ b> X (first electrode plates 10) and negative plates 20 </ b> Y (second electrode plates 20). The positive plates 10X and the negative plates 20Y are alternately stacked along the stacking direction dL (see FIG. 3). The membrane electrode assembly 5 and the stacked battery 1 have a flat shape as a whole, have a small thickness in the stacking direction dL, and spread in directions d1 and d2 orthogonal to the stacking direction dL.

  In the illustrated non-limiting example, the positive electrode plate 10X and the negative electrode plate 20Y have a rectangular outer contour. The positive electrode plate 10X and the negative electrode plate 20Y have a longitudinal direction in a first direction d1 orthogonal to the stacking direction dL, and a short direction in a second direction d2 orthogonal to both the stacking direction dL and the first direction d1. The positive electrode plate 10X and the negative electrode plate 20Y are arranged so as to be shifted in the first direction d1. More specifically, the plurality of positive electrode plates 10X are arranged closer to one side (right side in FIG. 2) in the first direction d1, and the plurality of negative electrode plates 20Y are arranged on the other side (in FIG. 2). (Left side) The positive electrode plate 10X and the negative electrode plate 20Y overlap in the stacking direction dL at the center in the first direction d1.

  The positive electrode plate 10X (first electrode plate 10) has a sheet-like outer shape as illustrated. The positive electrode plate 10X (first electrode plate 10) includes a positive electrode current collector 11X (first electrode current collector 11) and a positive electrode active material layer 12X (first electrode active material layer) provided on the positive electrode current collector 11X. 12). In the lithium ion secondary battery, the positive electrode plate 10X releases lithium ions during discharging and occludes lithium ions during charging.

  The positive electrode current collector 11X has a first surface 11a and a second surface 11b facing each other as main surfaces. The positive electrode active material layer 12X is laminated on at least one of the first surface 11a and the second surface 11b of the positive electrode current collector 11X. Specifically, when the first surface 11a or the second surface 11b of the positive electrode current collector 11X forms the outermost surface in the stacking direction dL of the membrane electrode assembly 5, the positive electrode current collector 11X has a corresponding surface. Is not provided with the positive electrode active material layer 12X. Except for the configuration related to the arrangement of the positive electrode current collector 11X, the plurality of positive electrode plates 10X included in the stacked battery 1 have the positive electrode active material layers 12X on both sides of the positive electrode current collector 11X, and have the same configuration. Can be done.

  The positive electrode current collector 11X and the positive electrode active material layer 12X can be produced by various manufacturing methods using various materials that can be applied to the stacked battery 1 (lithium ion secondary battery). As an example, the positive electrode current collector 11X can be formed of an aluminum foil. The positive electrode active material layer 12X includes, for example, a positive electrode active material, a conductive additive, and a binder that serves as a binder. The positive electrode active material layer 12X is produced by applying and solidifying a positive electrode slurry in which a positive electrode active material, a conductive additive and a binder are dispersed in a solvent on a material forming the positive electrode current collector 11X. Can be done. As the positive electrode active material, for example, a metal acid lithium compound represented by the general formula LiMxOy (where M is a metal and x and y are composition ratios of the metal M and oxygen O) is used. Specific examples of the metal acid lithium compound include lithium cobaltate, lithium nickelate, and lithium manganate. As the conductive assistant, acetylene black or the like can be used. As the binder, polyvinylidene fluoride or the like can be used.

  As shown in FIG. 2, the positive electrode current collector 11X (first electrode current collector 11) has a first end region a1 (connection region) and a first electrode region b1 (effective region). The positive electrode active material layer 12X (first electrode active material layer 12) is disposed only in the first electrode region b1 of the positive electrode current collector 11X. The first end region a1 and the first electrode region b1 are arranged to be adjacent to each other along the first direction d1. The first end region a1 is located on the outer side (right side in FIG. 2) in the first direction d1 than the first electrode region b1. The plurality of positive electrode current collectors 11X are joined to one tab 4 by ultrasonic welding in the first end region a1. In the illustrated example, the first end regions a1 of the plurality of positive electrode plates 10X are overlapped on the first surface 4Xa of the first tab 4X and are electrically connected to each other. On the other hand, the first electrode region b1 extends in a region facing a negative electrode active material layer 22Y described later of the negative electrode plate 20Y. With such an arrangement of the first electrode region b1, it is possible to prevent lithium deposition from the positive electrode active material layer 12X.

  As shown in FIG. 3, the positive electrode plate 10X further includes an insulating tape 6X having a length L that is stacked across the first end region a1 of the positive electrode current collector 11X and the positive electrode active material layer 12X. ing. This insulating tape 6X is for reliably preventing the positive electrode plate 10X from undesirably contacting and short-circuiting with the adjacent negative electrode plate 20Y in the stacking direction dL. In the example shown in FIG. 3, the insulating tape 6X is provided with the same length L on each positive electrode current collector 11X. However, in other examples, the insulating tape 6X may have different lengths as long as the insulating function can be sufficiently exhibited. Although not shown, in another example, the insulating tape 6X may be provided only on one of the first surface (upper surface) and the second surface (lower surface) of each positive electrode current collector 11X.

  As shown in FIG. 3, the positive electrode plate 10X of the present embodiment has a cross section (that is, a cross section shown in FIG. 3) parallel to the stacking direction dL and orthogonal to the arrangement direction of the first electrode region b1 and the first end region a1. ), The end positions of the positive electrode current collectors 11X of the plurality of positive electrode plates 10X coincide with each other on the first tab 4X. In other words, the length of the positive electrode current collector 11X is the longest in the positive electrode plate 10X farthest from the first tab 4X in the stacking direction dL, and the positive electrode plate 10X closest to the first tab 4X in the stacking direction dL. The shortest. More specifically, the length of the positive electrode current collector 11X of one optional positive electrode plate 10X is closer to the first tab 4X in the stacking direction dL than the one positive electrode plate 10X (lower in FIG. 3). It is longer than the length of the positive electrode current collector 11X of the other positive electrode plate 10X.

  In order to realize the configuration as described above, the longest positive electrode current collector 11X and the shortest positive electrode current collector 11X included in the plurality of positive electrode plates 10X have the longest positive electrode current collector 11X. Of the first electrode region b1 and the shortest positive electrode current collector 11X along the stacking direction dL of the first electrode region b1 and the arrangement direction of the first electrode region b1 and the first end region a1 (first It is configured to be larger than the sum of the width L of the insulating tape 6X along the direction d1).

  Next, the negative electrode plate 20Y (second electrode plate 20) will be described. Similarly to the positive electrode plate 10X, the negative electrode plate 20Y also has a sheet-like outer shape. The negative electrode plate 20Y (second electrode plate 20) includes a negative electrode current collector 21Y (second electrode current collector 21) and a negative electrode active material layer 22Y (second electrode active material layer) provided on the negative electrode current collector 21Y. 22). In the lithium ion secondary battery, the negative electrode plate 20Y occludes lithium ions during discharging and releases lithium ions during charging.

  The second electrode region b2 of the negative electrode current collector 21Y has a first surface 21a and a second surface 21b facing each other as main surfaces. The negative electrode active material layer 22Y is laminated on at least one of the first surface 21a and the second surface 21b of the negative electrode current collector 21Y. The plurality of negative electrode plates 20Y included in the stacked battery 1 may be configured identically to each other as having a pair of negative electrode active material layers 22Y provided on both sides of the negative electrode current collector 21Y.

  The negative electrode current collector 21Y and the negative electrode active material layer 22Y can be manufactured by various manufacturing methods using various materials that can be applied to the stacked battery 1 (lithium ion secondary battery). As an example, the negative electrode current collector 21Y is formed of, for example, a copper foil. The negative electrode active material layer 22Y includes, for example, a negative electrode active material made of a carbon material and a binder functioning as a binder. For example, the negative electrode active material layer 22Y forms a negative electrode current collector 21Y using a negative electrode slurry in which a negative electrode active material made of carbon powder, graphite powder, or the like and a binder such as polyvinylidene fluoride are dispersed in a solvent. It can be produced by coating on a material and solidifying.

  As shown in FIG. 2, the negative electrode current collector 21Y (second electrode current collector 21) has a second end region a2 (connection region) and a second electrode region b2 (effective region). The negative electrode active material layer 22Y (second electrode active material layer 22) is disposed only in the second electrode region b2 of the negative electrode current collector 21Y. The second end region a2 and the second electrode region b2 are arranged adjacent to each other along the first direction d1. The second end region a2 is located outside the second electrode region b2 in the first direction d1 (left side in FIG. 2). The plurality of negative electrode current collectors 21Y are joined to one tab 4 by ultrasonic welding in the second end region a2. In the illustrated example, the second end regions a2 of the plurality of negative electrode plates 10Y are superimposed on the first surface 4Ya of the second tab 4Y and are electrically connected to each other. On the other hand, the second electrode region b2 extends to a region facing the positive electrode active material layer 12X of the positive electrode plate 10X.

  As shown in FIG. 3, the negative electrode plate 20Y includes an insulating tape 6Y having a length L that is stacked across the second end region a2 of the negative electrode current collector 21Y and the negative electrode active material layer 22Y. Yes. The insulating tape 6Y is for reliably preventing the negative electrode plate 20Y from undesirably contacting and short-circuiting with the adjacent positive electrode plate 10X in the stacking direction dL. In the example shown in FIG. 3, the insulating tape 6Y is provided with the same length L on each negative electrode current collector 21Y as the insulating tape 6X provided on the positive electrode plate 10X. However, in another example, the insulating tape 6Y may have different lengths as long as the insulating function can be sufficiently exhibited. Although not shown, in another example, the insulating tape 6Y may be provided only on one of the first surface (upper surface) and the second surface (lower surface) of each negative electrode current collector 21Y.

  As shown in FIG. 3, the negative electrode plate 20Y of the present embodiment has a cross section (parallel to the laminating direction dL and orthogonal to the arrangement direction of the first electrode region b1 and the first end region a1 (first direction d1)). That is, in the cross section shown in FIG. 3, the end positions of the negative electrode current collectors 21Y of the plurality of negative electrode plates 20Y coincide on the second tab 4Y. In other words, the length of the negative electrode current collector 2Y is the longest in the negative electrode plate 20Y farthest from the second tab 4Y in the stacking direction dL, and the negative electrode plate 20Y closest to the second tab 4Y in the stacking direction dL. The shortest. More specifically, the length of the negative electrode current collector 21Y of one arbitrarily selected negative electrode plate 20Y is closer to the second tab 4Y in the stacking direction dL than the one negative electrode plate 20Y (lower in FIG. 3). It is longer than the length of the negative electrode current collector 21Y of the other negative electrode plate 20Y.

  In order to realize the configuration as described above, the longest negative electrode current collector 21Y and the shortest negative electrode current collector 21Y included in the plurality of negative electrode plates 20Y have the longest negative electrode current collector 21Y. The separation distance D along the stacking direction of the second effective region and the second effective region of the shortest negative electrode current collector 21Y, and the arrangement direction of the second electrode region b2 and the second end region a2 (first direction d1) Is larger than the sum of the width L of the insulating tape 6Y.

  Incidentally, as shown in FIG. 3, at least one of the positive electrode plate 10 </ b> X (first electrode plate 10) and the negative electrode plate 20 </ b> Y (second electrode plate 20) may have an insulator (insulating layer) 30. The insulator 30 has a function of preventing a short circuit between the positive electrode plate 10X (first electrode plate 10) and the negative electrode plate 20Y (second electrode plate 20). In the illustrated example, the negative electrode plate 20 </ b> Y has an insulator 30. Specifically, the insulator 30 covers a pair of negative electrode active material layers 22Y included in each negative electrode plate 20Y. The negative electrode plate 20Y is covered with an insulator 30 on the surface facing the positive electrode active material layer 12X of the positive electrode plate 10X in the stacking direction dL. By providing the above-described insulating tapes 6X and 6Y and these insulators 30, the positive electrode plate 10X and the negative electrode plate 20Y are reliably prevented from being short-circuited undesirably. Instead of or in addition to the illustrated insulator 30, an insulator covering the pair of positive electrode active material layers 12X included in each positive electrode plate 10X may be provided.

  In the illustrated example, the insulator 30 also functions as the electrolyte layer 30A. The electrolyte layer 30A is a layer obtained by solidifying or gelling the electrolytic solution applied on the active material layers 22Y and 12X on the active material layers 22Y and 12X. Examples of the electrolytic solution include a polymer matrix and a non-aqueous electrolyte solution (that is, a non-aqueous solvent and an electrolyte salt) that are gelled to cause stickiness on the surface, or a polymer matrix and a non-aqueous solvent. A solid electrolyte can be used. Specific materials for producing the insulator 30 and the electrolyte layer 30A are not particularly limited, and various materials (for example, disclosed in JP 2012-190567 A) are used for constituting them. Material) can be used.

  The membrane electrode assembly 5 described above may include 10 or more of the positive electrode plate 10X and the negative electrode plate 20Y. For example, the membrane electrode assembly 5 may include 10 or more and 70 or less of the positive electrode plate 10X and the negative electrode plate 20Y, respectively. In this case, the total thickness of the positive plates 10X and the negative plates 20Y alternately stacked in the stacking direction dL may be 4 mm or more. Thus, by increasing the number of stacked positive electrode plates 10X and negative electrode plates 20Y, a large-capacity stacked battery can be configured.

  Next, with reference to FIG. 4A-FIG. 9, the manufacturing method of the laminated battery 1 which concerns on this Embodiment comprised as a lithium ion secondary battery is demonstrated. Each drawing is a diagram for explaining an example of a method for manufacturing a stacked battery.

  First, the positive electrode plate 10X (first electrode plate 10) and the negative electrode plate 20Y (second electrode plate 20) are respectively produced. At this time, the positive electrode plate 10X and the negative electrode plate 20Y may be produced at different timings by different processes. Further, the positive electrode plate 10X and the negative electrode plate 20Y are simultaneously produced in parallel, and the produced positive electrode plate 10X and negative electrode plate 20Y are sequentially supplied to the step of alternately laminating the positive electrode plates 10X and the negative electrode plates 20Y. It may be.

  For example, the positive electrode plate 10X is solidified by applying a composition (slurry) that constitutes the positive electrode active material layer 12X on a long aluminum foil that constitutes the positive electrode current collector 11X, Next, it can be produced by cutting to a desired size. Similarly, the negative electrode plate 20Y is formed by, for example, applying a composition (slurry) that forms the negative electrode active material layer 22Y on a long copper foil that forms the negative electrode current collector 21Y. It can be made by solidifying and then cutting to the desired size. In addition, when the insulator 30 that functions as the electrolyte layer 30A is applied to at least one of the positive electrode plate 10X and the negative electrode plate 20Y, it is formed on the long material before cutting or after the cutting that forms the electrode plates 10X and 20Y. The insulator 30 can be produced by applying an electrolytic solution on the sheet material and solidifying or gelling the electrolyte.

  Next, the first end region a1 (connection region) of the positive electrode current collector 11X (first electrode current collector 11) of the plurality of positive electrode plates 10X (first electrode plate 10) is arranged on the first tab 4X. To do. At this time, the second end region a2 (connection region) of the negative electrode current collector 21Y (second electrode current collector 21) of the plurality of negative electrode plates 20Y (second electrode plate 20) is placed on the second tab 4Y. Arrange them in layers. In this case, first, as shown in FIG. 4A, the first electrode plate is prepared. In the illustrated example, first, the negative electrode plate 20Y is prepared.

  Next, as shown in FIG. 4B, the positive electrode plate 10X is disposed on the negative electrode plate 20Y. At this time, the positive electrode plate 10X is disposed on the negative electrode plate 20Y so that the positive electrode active material layer 12X of the positive electrode plate 10X and the negative electrode active material layer 22Y of the negative electrode plate 20Y face each other.

  Next, as shown in FIG. 5, negative plates 20Y and positive plates 10X are alternately stacked. Also in this case, the positive electrode plate 10X and the negative electrode plate 20Y are laminated so that the positive electrode active material layer 12X of the positive electrode plate 10X and the negative electrode active material layer 22Y of the negative electrode plate 20Y face each other. Thus, the membrane electrode assembly 5 in which the plurality of positive plates 10X and the plurality of negative plates 20Y are alternately stacked is obtained.

  By the way, the first end region a1 of each positive electrode plate 10X has the same length. Therefore, the end position P (n) of the first end region a1 of the positive electrode plate 10X stacked nth (n is a natural number of 2 or more) is the first end of the positive electrode plate 10X stacked n−1. It is shifted to the first electrode region b1 side (left side in FIG. 5) from the end position P (n−1) of the partial region a1. In short, as described above, the end portions of the first end region a1 of the plurality of positive electrode plates 10X shift to the first electrode region b1 side as the stacking order proceeds from the first positive electrode plate 10X. Are stacked in a shape. As shown in FIG. 5, such a step-like stacking mode is the same in the end region a2 of the negative electrode plate 20Y.

  Next, as shown in FIG. 6, the first end regions a <b> 1 of the positive electrode plates 10 </ b> X stacked in a step shape are joined to each other. This joining is performed by the ultrasonic welding machine H, for example. In the first direction d1, the length of the first end region a1 bonded by ultrasonic bonding is a length in which all the first end regions a1 overlap in the stacking direction dL. Therefore, considering that the first end region a1 is stacked stepwise, the length is the length of the first end region a1 of the positive electrode plate 10X (the uppermost layer in FIG. 6) stacked last. It is determined by the end position Px. The first end region a1 located on the opposite side (right side in FIG. 6) from the position Px to the first electrode region b1 is not joined by the ultrasonic welding machine.

  Similarly, as shown in FIG. 6, the second end regions a <b> 2 of the negative electrode plates 20 </ b> Y stacked in a step shape are joined to each other. This joining can also be performed by the ultrasonic welder H. Also in this case, similarly to the joining of the first end region a1 of the positive electrode plate 10X, the length of the second end region a2 joined by ultrasonic joining in the first direction d1 is all the second end portions. This is the length in which the region a2 overlaps in the stacking direction dL. This length is determined by the end position Py of the second end region a2 of the negative electrode plate 20Y that is laminated last (the uppermost layer in FIG. 6). The second end region a2 located on the opposite side (left side in FIG. 6) to the second electrode region b2 from the position Py is not joined.

  Next, as shown in FIG. 7, the first end region a1 of the positive electrode plate 10X is cut at a position Px. Thereby, the first end region a1 of the positive electrode plate 10X is trimmed at the position Px described above. As can be understood from the joining process described above, the first joined portion C1 in which all the positive electrode current collectors 11X are joined is configured at the trimmed end portions. Further, the second end region a2 of the negative electrode plate 20Y is cut at the position Py described above. As a result, the second end region a2 of the negative electrode plate 20Y is trimmed at the position Py. At the trimmed end portion, a second bonding portion C2 is formed in which all the negative electrode current collectors 21Y are bonded.

  Then, as shown in FIG. 7, the obtained membrane electrode assembly 5 is placed on the tab 4. In this state, ultrasonic waves are emitted from the ultrasonic welding machine H again toward the first end region a1 and the second end region a2, and correspond to the joints C1, C2 of the end regions a1, a2. The tabs 4X and 4Y are joined to each other.

  As described above, the positive electrode plates 10X and the negative electrode plates 20Y are alternately stacked, and after the end regions a1 and a2 are trimmed, the plurality of positive electrode plates 10X are connected to the first end region of the positive electrode current collector 11X. At a1, they are joined to each other and become conductive. Then, the first tab 4X is electrically connected to the first end region a1 of the positive electrode current collector 11X. Similarly, the plurality of negative electrode plates 20Y are joined and conducted in the second end region a2 of the negative electrode current collector 21Y. The second tab 4Y is electrically connected to the second end region a2 of the negative electrode current collector 21Y. Thereafter, the membrane electrode assembly 5 is sealed in the outer package 3 so that the tabs 4X and 4Y extend from the outer package 3, whereby the multilayer battery 1 is obtained.

  According to the present embodiment as described above, a plurality of cross sections are parallel to the stacking direction of the positive electrode plate 10X and orthogonal to the arrangement direction (first direction d1) of the first electrode region b1 and the first end region a1. The end position Px of the positive electrode current collector 11X of the positive electrode plate 10X coincides on the first tab 4X. Thus, in the stacked battery 1, the positive electrode plate 10X and the first tab 4X can be reliably bonded, and a short circuit between the outer package and the positive electrode plate 10X can be reliably prevented. Furthermore, since the same structure is also adopted in the negative electrode plate 20Y, the negative electrode plate 20Y and the second tab 4Y can be bonded with reliability, and a short circuit between the outer package and the negative electrode plate 20Y can be ensured. Can be prevented.

  In addition, as described above, the positive electrode plate 10X includes the insulating tape 6X that is stacked over the first end region a1 of the positive electrode current collector 11X and the positive electrode active material layer 12X. The lengths of the longest positive electrode current collector 11X (located at the uppermost position in FIG. 3) and the shortest positive electrode current collector 11X (located at the lowermost position in FIG. 3) included in the plurality of positive electrode plates 10X. The difference between the first electrode region b1 of the longest positive electrode current collector 11X and the separation distance D along the stacking direction dL of the first electrode region b1 of the shortest positive electrode current collector 11X, and the eleventh electrode region b1 and the first electrode region b1 It is larger than the sum of the width L of the insulating tape 6X along the arrangement direction d1 of the one end region a1. For this reason, in the stacked battery 1, the positive electrode plate 10X and the first tab 4X can be reliably bonded while aligning the end position of the end region a1 of the positive electrode current collector 11X. Similarly, since the same configuration is adopted in the negative electrode plate 20Y, the negative electrode plate 20Y and the second tab 4Y are bonded with reliability while aligning the end position of the end region a2 of the negative electrode current collector 21Y. can do.

  Further, when the stacked battery 1 described above is manufactured, the positive electrode current collector 11X of the positive electrode plate 10X is cut at a position opposite to the first electrode region b1 side of the joint C1. The step of aligning the end position of the positive electrode current collector 11X of the positive electrode plate 10X is provided. Thus, the end position of the positive electrode current collector 11X is reliably aligned, and the positive electrode plate 10X and the first tab 4X can be bonded with reliability. Similarly, the above process is also adopted when aligning the end position of the negative electrode current collector 21X of the negative electrode plate 20Y. For this reason, the edge part position of the negative electrode collector 21Y is also aligned reliably, and the negative electrode plate 20Y and the 2nd tab 4Y can be joined reliably.

  In particular, when the multilayer battery 1 according to the present invention is manufactured, after the step of joining the first end region a1 of the positive electrode plate 10X, the above-described cutting step (step of trimming the first end region a1) is performed. After that, the first end region a1 is joined to the first tab 4X. According to the present invention, since the tab 4X is electrically connected to the positive electrode plate 10X in this order, the bonding of the first end regions a1 and the bonding of the positive electrode plate 10X and the tab 4X are highly reliable. Can be provided with sex.

  Next, a modification of the multilayer battery 1 according to the present invention will be described.

  FIG. 9 is a schematic cross-sectional view showing a stacked battery 1A according to a modification of the present invention. As illustrated in FIG. 9, the stacked battery 1A includes a plurality of positive electrode plates 10X (first electrode plates 10) as first end regions a1 (connections) of a positive electrode current collector 11X (first electrode current collector 11). A first group of positive electrode plates 10Xa (first electrode plate 10a) which are overlapped and electrically connected to each other on the first surface 4Xa of the first tab 4X, and a first end region of the positive electrode current collector 11X A material including a second group of positive electrode plates 10Xb (first electrode plates 10b) in which a1 is superimposed on the second surface 4Xb of the first tab 4X and electrically connected to each other is used. As shown in FIG. 9, the positive electrode current collector 11X of the first group of positive electrode plates 10Xa has the end portion aligned on the first surface 4Xa of the first tab 4X, and the second group of positive electrodes. The positions of the ends of the positive electrode current collector 11X of the plate 10Xb are aligned on the second surface 4Xb of the first tab 4X.

  Similarly to the positive electrode plate 10X, the second end region a2 (connection region) of the negative electrode current collector 21Y (second electrode current collector 21) is the second tab as the negative electrode plate 20Y (second electrode plate 20). The first group of negative electrode plates 20Ya (second electrode plate 20a) which are stacked on the first surface 4Ya of 4Y and electrically connected to each other, and the second end region a2 of the negative electrode current collector 21Y are the second tab 4Y. And a second group of negative electrode plates 20Yb (second electrode plates 20b) which are stacked on the second surface 4Yb and electrically connected to each other. As shown in FIG. 9, the negative electrode current collector 21Y of the first group of negative electrode plates 20Ya has an end portion aligned on the first surface 4Ya of the second tab 4Y, and the second group of negative electrodes The negative electrode current collector 21Y of the plate 20Yb has an end portion aligned on the second surface 4Yb of the second tab 4Y.

  In short, in the multilayer battery 1A according to this modification, the positive electrode plate 10X and the negative electrode plate 20Y of the multilayer battery 1 described above are also provided on the other surface of the tab 4 (the lower surface in FIG. 9). In particular, in the illustrated example, the configuration of the positive electrode plate 10X and the negative electrode plate 20Y provided on one surface (the upper surface in FIG. 9) of the tab 4 and the positive electrode plate 10X provided on the other surface of the tab 4 are illustrated. The configuration of the negative electrode plate 20 </ b> Y is symmetric with respect to the tab 4.

  When the stacked battery 1 shown in FIG. 9 is manufactured, first, the positive plates 10X and the negative plates 20Y are alternately stacked as described with reference to FIGS. 4A and 4B. Then, the first end region a1 of the positive electrode current collector 11X of the positive electrode plate 10X is stacked (bundled) with each other and joined by, for example, the ultrasonic welding machine H. Thereafter, the first end regions a1 are trimmed so as to be at the same end position. Similarly, the second end region a2 of the negative electrode current collector 21Y of the negative electrode plate 20Y is laminated (bundled) with each other and joined by, for example, the ultrasonic welding machine H. Thereafter, the second end regions a2 are trimmed so as to be at the same end position. Through these steps, the membrane electrode assembly 5 is produced.

  In this modification, two sets of the above membrane electrode assemblies 5 are produced. One membrane electrode assembly 5 is disposed on one surface of the tab 4, and the other membrane electrode assembly 5 is disposed on the other surface of the tab 4. Here, for convenience of explanation, the positive electrode plate 10X and the negative electrode plate 20Y of one membrane electrode assembly 5 are referred to as the first group of positive electrode plates 10Xa and the first group of negative electrode plates 20Ya, respectively, and the other membrane electrode assembly 5 is used. The positive electrode plate 10X and the negative electrode plate 20Y are referred to as a second group of positive electrode plates 10Xb and a second group of negative electrode plates 20Yb, respectively. The manufacturing method of the two sets of membrane electrode assemblies 5 is the same as the manufacturing method of the membrane electrode assembly 5 in the laminated battery 1 described above, and therefore detailed description thereof is omitted here (see FIGS. 5 to 7). ).

  The first end region a1 of the first group of positive electrode plates 10Xa and the second end region a2 of the first group of negative electrode plates 20Ya are positioned with respect to the tab 4 on one side of the tab 4, and each end The partial areas a1 and a2 are joined to the corresponding tabs 4a and 4b by the ultrasonic welding machine H. This joining step is the same as the joining step described with reference to FIG. Furthermore, in the present modification, the first end region a1 of the second group of positive electrode plates 10Xb and the second end region a2 of the second group of negative electrode plates 20Yb are in relation to the tab 4 on the other side of the tab 4. Each end region a1, a2 is positioned and joined to the corresponding tab 4a, 4b by the ultrasonic welder H.

  As described above, the first group of positive electrode plates 10Xa and the second group of positive electrode plates 10Xb are joined and electrically connected to each other in the first end region a1 of each positive electrode current collector 11X. Further, the first tab 4X is electrically connected to the first end region a2 of the positive electrode current collector 11X. Similarly, the first group of negative electrode plates 20Ya and the second group of negative electrode plates 20Yb are joined to and conductive with each other in the second end region a2 of each negative electrode current collector 21Y. Further, the second tab 4Y is electrically connected to the second end region a2 of the negative electrode current collector 21Y. Thereafter, the membrane electrode assembly 5 is sealed in the outer package 3 so that the tabs 4X and 4Y extend from the outer package 3, whereby the laminated battery 1A shown in FIG. 9 is obtained.

  Also with the laminated battery 1 </ b> A according to the modified example as described above, the same operational effects as those of the laminated battery 1 described above can be obtained.

  In the above-described embodiment and modification, a plurality of positive plates 10X and negative plates 20Y having the same length are prepared, and the plurality of positive plates 10X and negative plates 20Y are alternately stacked to form each end region. A process of cutting and aligning the end regions a1 and a2 after welding a1 and a2 respectively is employed. However, the method of aligning the end positions of the current collectors 11X and 21Y of the positive electrode plate 10X and the negative electrode plate 20Y is not limited to such an example. For example, in another embodiment, the end positions of the positive electrode current collector 11X and / or the negative electrode current collector 21Y are changed by making the lengths of the plurality of positive electrode plates 10X and / or the plurality of negative electrode plates 20Y different. It is also possible to produce an aligned stacked battery.

  That is, the length of the positive electrode current collector 11X is constant between the plurality of positive electrode plates 10X in a cross section parallel to the stacking direction dL and perpendicular to the arrangement direction d1 of the first electrode region b1 and the first end region a1. Instead, the length of the positive electrode current collector 11X of the positive electrode plate 10X farthest from the first tab 4X in the stacking direction dL is longer than the length of the positive electrode current collector 11X of at least one other positive electrode plate 10X. It is good. Specifically, the length of the positive electrode current collector 11X is the longest in the positive electrode plate 10X farthest from the first tab 4X in the stacking direction dL, and the positive electrode plate 10X closest to the first tab 4X in the stacking direction dL. It may be the shortest. More specifically, the length of the positive electrode current collector 11X of one positive electrode plate 10X that is arbitrarily selected is the other positive electrode plate 10X that is closer to the first tab 4X in the stacking direction dL than the one positive electrode plate 10X. It may be longer than the length of the positive electrode current collector 11X.

  In this case, the end region a1 of the positive electrode current collectors 11X of the plurality of positive electrode plates 10X is stacked on the first tab 4X by appropriately setting the length of the positive electrode current collector 11X of each positive electrode plate 10X. Only, that is, without the step of cutting the end region a1 of the positive electrode current collector 11X, the end position of each positive electrode current collector 11X can be aligned. Of course, if the same technique is adopted for the plurality of negative electrode plates 20Y, the end positions of the respective negative electrode current collectors 21Y can be aligned without the step of cutting the end region b1 of the negative electrode current collector 21Y. .

  Or in the above embodiment and modification, there may be some dispersion | variation in the at least one edge part position of the positive electrode collector 11X and the negative electrode collector 21Y. Specifically, in the cross section parallel to the stacking direction dL and perpendicular to the arrangement direction d1 of the first electrode region b1 and the first end region a1, the end position of the positive electrode current collector 11X of the plurality of positive electrode plates 10X, And / or the 1st tab 4X and / or 2nd tab in which the edge part position of the negative electrode collector 21Y of the some negative electrode plate 20Y had the length of 30% or less of the length of each junction part C, for example You may be located in the area | region on 4Y. The multilayer battery produced in this way can also exhibit the same effects as the multilayer battery 1 according to the above-described embodiment.

  In addition, although the some modification with respect to embodiment mentioned above was demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

1 laminated battery 4X first tab 4Xa first surface 4Xb second surface 4Y second tab 5 membrane electrode assembly 6X insulating tape 6Y insulating tape 10 first electrode plate 10a first electrode plate 10X positive electrode plate 10Xa positive electrode plate 11 first Electrode current collector 11X Positive electrode current collector 11a First surface 11b Second surface 11c End surface 11d End surface 12 First electrode active material layer 12X Positive electrode active material layer 20 Second electrode plate 20Y Negative electrode plate 21 Second electrode current collector 21Y Negative electrode Current collector 21a First surface 21b Second surface 22 Second electrode active material layer 22Y Negative electrode active material layer a1 First end region a2 Second end region b1 First electrode region b2 Second electrode region

Claims (7)

A plurality of first electrode plates;
A plurality of second electrode plates alternately stacked in the stacking direction with the first electrode plates;
A first tab electrically connected to the first electrode plate;
A second tab electrically connected to the second electrode plate,
The first electrode plate includes a first electrode current collector including a first effective region and a first connection region adjacent to the first effective region, and the first effective electrode on at least one surface of the first electrode plate. A first electrode active material layer laminated in the region,
The first connection regions of the plurality of first electrode plates are stacked on the first tab and electrically connected to each other;
Between the plurality of first electrode plates, the length of the first electrode current collector in a cross section that is parallel to the stacking direction and orthogonal to the arrangement direction of the first effective region and the first connection region is not constant. ,
The length of the first electrode current collector of the first electrode plate that is farthest from the first tab in the stacking direction is longer than the length of the first electrode current collector of at least one other first electrode plate. ,long,
The first electrode plate further includes an insulating tape laminated across the first connection region of the first electrode current collector and the first electrode active material layer,
The difference in length between the longest first electrode current collector and the shortest first electrode current collector included in the plurality of first electrode plates is the first effective region of the longest first electrode current collector and A separation distance along the stacking direction of the first effective region of the shortest first electrode current collector, and a width of the insulating tape along an arrangement direction of the first effective region and the first connection region, A stacked battery larger than the sum.   The length of the first electrode current collector is the longest in the first electrode plate that is farthest from the first tab in the stacking direction, and the first electrode plate that is closest to the first tab in the stacking direction. The stacked battery according to claim 1, wherein the stacked battery becomes the shortest.   The length of the first electrode current collector of one arbitrarily selected first electrode plate is other first electrode plate closer to the first tab in the stacking direction than the one first electrode plate The stacked battery according to claim 1 or 2, wherein the length of the first electrode current collector is not less than the length of the first electrode current collector. The plurality of first electrode plates include a first group of first electrode plates in which the first connection region of the first electrode current collector is overlaid on one surface of the first tab and electrically connected to each other. And a second group of first electrode plates in which the first connection region of the first electrode current collector is overlapped on the other surface of the first tab and electrically connected to each other,
Of the first electrode plates of the first group, the length of the first electrode current collector of the first electrode plate that is farthest from the one surface of the first tab in the stacking direction is the first electrode plate. Longer than the length of the first electrode current collector of at least one other first electrode plate of the group of first electrode plates;
Of the first electrode plates of the second group, the length of the first electrode current collector of the first electrode plate that is farthest from the other surface of the first tab in the stacking direction is the second electrode plate. The stacked battery according to any one of claims 1 to 3, which is longer than a length of the first electrode current collector of at least one other first electrode plate in the group of first electrode plates. . The second electrode plate includes a second electrode current collector including a second effective region and a second connection region adjacent to the second effective region, and the second effective electrode on at least one surface of the second electrode plate. A second electrode active material layer laminated in the region,
The second connection regions of the plurality of second electrode plates are stacked on the second tab and electrically connected to each other;
Between the plurality of second electrode plates, the length of the second electrode current collector in a cross section that is parallel to the stacking direction and orthogonal to the arrangement direction of the second effective region and the second connection region is not constant. ,
The length of the second electrode current collector of the second electrode plate that is farthest from the second tab in the stacking direction is longer than the length of the second electrode current collector of at least one other second electrode plate. The stacked battery according to claim 1, which is long.   The stacked battery according to any one of claims 1 to 5, wherein a thickness of the first electrode plate and the second electrode plate alternately stacked in the stacking direction is 4 mm or more.   The stacked battery according to any one of claims 1 to 6, comprising 10 or more of the first electrode plate and the second electrode plate, respectively.

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