JP2012209072A - Electrode laminate of electrode laminated battery and manufacturing method of the electrode laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent displacement between an electrode and a separator and short circuit between electrodes in an electrode laminate structure of laminating electrodes and separators.SOLUTION: The present invention relates to an electrode laminate 1 of an electrode laminated battery which is made by laminating a plurality of electrodes 2, 3 and separators 4 arranged between thereof. A protrusion protruding in a lamination direction of the electrodes 2, 3 is provided on at least one side face of each separator 4. The protrusion regulates movement of each of electrodes 2, 3 with respect to a direction perpendicular to the lamination direction of the electrodes. A junction 5 is formed resulted from jointing each protrusion of adjacent separators 4 with each other.

Description

  The present invention relates to an electrochemical device having laminated electrode pairs, and more particularly to an electrode laminate constituting an electrode laminate battery and a method for producing the electrode laminate.

  With the spread of portable electronic devices, there is a demand for electrochemical devices such as lithium secondary batteries that are small, light, thin, and capable of continuous operation for a long time. A conventional secondary battery uses a metal outer can. Recently, however, it has become possible to reduce the battery weight and increase the degree of freedom in electronic device design by using a thin and light film outer package instead of a metal outer can. The exterior body used for such a battery is a film in which a plurality of resins are mainly laminated on an aluminum foil, and by using this aluminum laminate film, it is thinner than a battery using a conventional metal exterior can, Can be lightened.

  As a method for producing an electrode group housed in an exterior body, there are a method of winding a strip-shaped electrode and a method of laminating a large number of electrodes.

  In the former winding method, the equipment can be used as it is as an advanced type of a cylindrical battery, but the shape of the battery is limited, and it is difficult to make a battery other than a cube, a rectangular parallelepiped or a column. In addition, when trying to make a thin battery, there is a possibility that the electrode may crack or break during winding, so a thick and dense electrode cannot be used, which is disadvantageous in terms of energy density. is there.

  In the latter lamination method, the shape of the battery can be made relatively free, and since there is no need for winding, a thick and high-density electrode can be used, and a battery having a thinner and higher energy density can be produced. Further, the lamination method has an advantage that the area ratio between the positive electrode and the negative electrode can be made constant. However, since the laminated structure itself does not have a mechanism for fixing the positions of the electrode and the separator, it has been a cause of misalignment and short circuit. Such misalignment or short circuit of the electrodes can cause deterioration of battery characteristics or failure. Therefore, at the time of stacking the electrodes, for example, a method is adopted in which a tape is attached to the electrodes to prevent displacement.

  In addition, many proposals have been made to design a battery that is less prone to misalignment and short-circuiting by the lamination method. One of them is the bag method. As disclosed in JP-A-6-36801, JP-A-9-213377 and JP-A-10-55795, generally, an electrode is sandwiched between two separators, A bag-shaped electrode is produced by heat-sealing the peripheral portions of both separators. Next, this bag-packed electrode is laminated and stored in a metal can or an exterior body to form a battery.

JP-A-6-36801 JP-A-9-213377 JP-A-10-55795

  However, the conventional method has the following problems.

  The problem is that, in the conventional method of alternately laminating electrodes and separators, battery characteristics are deteriorated and short circuits are likely to occur. This is because there is no mechanism for fixing the relative position of the electrode and the separator in the step of laminating each layer. The reason is that the electrode and the separator are misaligned and the battery characteristics are deteriorated due to the decrease in the facing area between the positive electrode and the negative electrode, or the electrodes are contacted and short-circuited by the misalignment.

  In order to solve the above problems, conventionally, a method has been devised in which one electrode (for example, positive electrode) is covered with a separator in a bag shape and alternately stacked with the other electrode (for example, negative electrode). However, even in this method, the occurrence of misalignment and short circuit is not completely solved. The cause is that in the step of stacking the electrodes covered in a bag shape, there is no mechanism for fixing the relative position between the electrode covered in a bag shape with the separator and the separator.

  In view of the above problems, an object of the present invention is to prevent misalignment of an electrode and a separator and occurrence of a short circuit between electrodes in an electrode laminated structure in which an electrode and a separator are laminated.

  The present invention relates to the electrode stack of an electrode stack type battery including an electrode stack formed by stacking a plurality of electrodes with separators disposed between the electrodes. In one aspect thereof, a convex portion protruding in the electrode stacking direction is provided on at least one side surface of each separator, and the convex portion regulates movement of the electrode in a direction perpendicular to the electrode stacking direction. ing.

  According to the present invention, in an electrode laminate of an electrode laminate type battery in which a plurality of electrodes are laminated with separators disposed between the electrodes, the movement of the electrodes is caused by the protrusions provided on the separator. Since the direction perpendicular to the stacking direction of the electrodes is regulated, it is possible to prevent the deterioration of characteristics and the occurrence of a short circuit due to the displacement of the electrodes.

The perspective view which shows an example of the electrode laminated body of this invention used for an electrode laminated battery. The exploded view which showed the component of the electrode laminated body of FIG. The figure which showed the cross section of the electrode laminated body of the state which laminated | stacked the positive electrode, the negative electrode, and the separator, and joined the peripheral part of the adjacent separator. The top view which shows the structural example of the peripheral part of each separator joined. The figure which shows the assembly flow of the electrode laminated body which comprises the battery of a present Example. The figure which showed the aspect which supplies a positive electrode, a negative electrode, and a separator to this position when the electrode laminated body by a present Example is assembled in a predetermined position. The figure which shows the cross-section of the separator provided with the separator molding part of a present Example. The figure which shows the production method and production apparatus of the separator molding part in a present Example. The figure which shows the manufacturing method of an electrode laminated body using the some separator provided with the separator molding part in this Example, a some positive electrode, and a some negative electrode, and the manufacturing apparatus of an electrode laminated body. The figure for demonstrating another example (electrode laminated body using the electrode structure packed in a bag) of the manufacturing method and manufacturing apparatus of the electrode laminated body used for the battery of this invention. The figure for demonstrating another example (electrode laminated body using the electrode structure packed in a bag) of the manufacturing method and manufacturing apparatus of the electrode laminated body used for the battery of this invention. The figure for demonstrating another example (electrode laminated body using the electrode structure packed in a bag) of the manufacturing method and manufacturing apparatus of the electrode laminated body used for the battery of this invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an example of an electrode laminate in the electrode laminate battery of the present invention. FIG. 2 is an exploded view showing components of the electrode laminate of FIG.

  As shown in FIG. 2, the electrode laminate 1 of FIG. 1 constituting the battery of this example is formed by laminating a rectangular flat plate-like positive electrode 2, a negative electrode 3, and a separator 4. The separator 4 is arranged so as to partition the positive electrode 2 and the negative electrode 3, and in FIG. Are stacked vertically. In order to prevent a short circuit between the positive electrode 2 and the negative electrode 3, the separator 4 generally has a larger outer shape than the positive electrode 2 and the negative electrode 4. The separator 4 is made of a thermoplastic resin.

  FIG. 3 shows a cross section of the electrode laminate 1 in a state where the positive electrode 2, the negative electrode 3, and the separator 4 are laminated as described above and the peripheral portions of the adjacent separators 4 are joined. In this figure, the positive electrode 2 and the negative electrode 3 face each other in a state of being partitioned by a separator 4. All the separators 4 are joined to each other at the peripheral portion of each separator 4, and the joined part 5 thus formed makes the aspect after joining of all the separators 4 look like a ladder as seen in the cross section as shown in FIG. 3. It is made up.

  FIG. 4 shows a configuration example of a peripheral portion in joining of the separators 4. As shown in this figure, a separator molding portion 9 formed by molding the separator 4 itself is provided in a part of the peripheral portion of each separator 4 to be the joint portion 5. Separator molding portion 9 has a shape that regulates movement of positive electrode 2 (or negative electrode 3) in a direction perpendicular to the electrode stacking direction. The separator molding part 9 of the present example is an L-shaped ridge in plan view along two sides forming the corners of the four corners of the rectangular positive electrode 2 (or negative electrode 3). In addition, about the shape of the separator shaping | molding part 9, it is possible to set a point, a line, and others arbitrarily, and it is also possible to set arbitrarily also about the position.

  In this invention, the electrode covered by the bag shape is produced by joining the peripheral part of each separator 4 in which the separator molding part 9 was provided.

  Next, the manufacturing method of the electrode laminated body 1 by this invention is explained in full detail.

  FIG. 5 is a diagram showing an assembly flow of the electrode laminate 1. As shown in this figure, the negative electrode 3 is mounted on the separator 4 already mounted on the positive electrode 2, the separator 4 is mounted thereon, and the positive electrode 2 is mounted thereon. A set of electrode pairs is obtained. The structure of the electrode stack 1 is obtained by repeating such stacking to form a plurality of pairs of electrodes.

  FIG. 6 shows a mode in which the electrodes (the positive electrode 2 and the negative electrode 3) and the separator 4 are supplied to the positions when the electrode laminate 1 is assembled at a predetermined position. As shown in this figure, the positive electrode 2, the negative electrode 3, and the separator 4 include a positive electrode raw material 10 formed by winding the positive electrode 2 continuous in a strip shape, a negative electrode raw material 11 formed by winding the negative electrode 3 continuous in a band shape, and It is cut out and supplied from a separator raw 12 formed by winding a separator 4 continuous in a strip shape. The supplied positive electrode 2, negative electrode 3, and separator 4 are made into the electrode laminate 1 shown in FIG. 1 through the process flow of FIG. 5.

  FIG. 7 shows a cross-sectional structure of the separator 4 provided with the separator molding portion 9 described above. A separator molding portion 9 (FIG. 4) is provided in a part of the peripheral portion of the separator 4. The separator molding portion 9 is formed by molding a part of the peripheral portion of the separator 4 cut out from the separator raw fabric 12 by a thermocompression bonding method.

  As illustrated in FIG. 4, the separator molding portion 9 is formed in an L shape along two sides forming the corners of the square positive electrode 2 (or the negative electrode 3). The movement in the direction perpendicular to the electrode stacking direction can be restricted. The thickness of the separator molding portion 9 in the electrode stacking direction is preferably equal to the thickness of the positive electrode 1 and the negative electrode 2.

  FIG. 8 shows a manufacturing method and a manufacturing apparatus for the separator molding unit 9.

  When producing the separator molding part 9, first, the separator 4 is mounted on the upper surface of the lamination stage 8, as shown in FIG. Then, as shown in FIG. 8B, the separator 4 is pressed against the upper surface of the stacking stage 8 by the separator pressing member 13 in a direction perpendicular to the upper surface of the stacking stage 8.

  Subsequently, as shown in FIG. 8C, the separator molding mechanism 14 is driven. The separator molding mechanism 14 is provided so as to be movable along the upper surface of the stacking stage 8. The separator molding mechanism 14 is formed between the inner surface of the separator molding mechanism 14 itself and the outer peripheral end surface of the separator pressing member 13. A space for forming the portion 9 can be secured. And the peripheral part of the separator 4 located between the driven separator shaping | molding mechanism 14 and the separator pressing member 13 is shape | molded by a thermocompression-bonding means, and the separator shaping | molding part 9 is formed. This thermocompression bonding means is preferably provided in the separator molding mechanism 14 and is, for example, a metal block in which a heater is disposed.

  Finally, the separator pressing member 13 and the separator molding mechanism 14 are retracted, whereby the separator 4 provided with the separator molding portion 9 is completed.

  The separator pressing member 13 and the separator molding mechanism 14 are shaped so that the separator molding unit 9 regulates the movement of the positive electrode 2 (or the negative electrode 3) in the direction perpendicular to the electrode stacking direction (see FIG. 4). It is desirable that it is set.

  Further, a method for manufacturing the electrode laminate 1 using the plurality of separators 4 provided with the separator molding section 9, the plurality of positive electrodes 2, and the plurality of negative electrodes 3, and the apparatus for manufacturing the electrode laminate 1 are shown in FIG. In the following.

  First, the separator 4 provided with the separator molding unit 9 is transported using the suction transport mechanism 16 and mounted on the upper surface of the stage 7. Then, on the separator 4, as shown in FIG. 9A, the negative electrode 3 is mounted using the suction conveyance mechanism 16. At this time, the movement of the negative electrode 3 in the direction along the separator 4 is restricted by the separator molding part 9. Thereafter, the other separator 4 provided with the separator molding part 9 is mounted on the negative electrode 3 laminated on the separator 4 by using the suction conveyance mechanism 16 (FIG. 9B). At this time, the surface of the other separator 4 on the side where the separator molding portion 9 is not provided is brought into contact with the negative electrode 3. Then, by using the bonding mechanism 17 provided in the suction conveyance mechanism 16, the stacked separator molding portions 9 are heated and bonded to each other to form the bonding portion 5 as shown in FIG. 9C. . Using the suction conveyance mechanism 16 again, the positive electrode 2 is mounted on the other separator 4 as shown in FIGS. The joining mechanism 17 includes a thermocompression bonding means for joining the separators with heat. In addition, when the other separators 4 are stacked on one separator 4, the separator molding portions 9 located above and below may be fitted to each other so that the separators can be easily aligned. desirable. For example, a concave portion is formed on the upper surface of the separator molding portion 9, and a convex portion that fits into the concave portion is formed on the lower surface of the separator molding portion 9.

  By alternately repeating the above operations for the positive electrode 2 and the negative electrode 3, a separator structure having a ladder-like cross-sectional shape as shown in FIG. 3 is obtained. That is, in the structure of FIG. 3, a plurality of separators 4 in which the positive electrode 1 or the negative electrode is arranged inside the separator molding portion 9 on one side surface are laminated while the separator molding portions 9 are joined to each other to form the joint portion 12. Is formed.

  Moreover, it may replace with the manufacturing method and manufacturing apparatus of the above-mentioned electrode laminated body 1, and an aspect as shown in FIGS. 10-12 may be sufficient. That is, the present invention can be applied to the case where the electrode laminate 1 is manufactured by covering one electrode (for example, positive electrode) in a bag shape with a separator and alternately stacking the electrode with the other electrode (for example, negative electrode).

  FIG. 10 shows a structure in which the electrode is packaged with a separator. This structure is a structure in which the negative electrode 3 (or the positive electrode 2) is covered with the separator 4 and the separator molding portion 9 and packed into a bag. It is desirable that the separators 4 facing each other with the electrodes sandwiched are joined at a separator molding portion 9 having the same thickness in the electrode stacking direction as the electrodes. Moreover, it is desirable that the separator molding portion 9 has a shape (see FIG. 4) that restricts the movement of the positive electrode 2 (or the negative electrode 3) in a direction perpendicular to the electrode stacking direction.

  FIG. 11 shows a manufacturing method and a manufacturing apparatus for manufacturing the bag-packed electrode structure of FIG. First, the separator 4 provided with the separator molding part 9 is produced as shown in FIG. Thereafter, in the stage 8, the negative electrode 3 is mounted on the separator 4 as shown in FIG. At this time, the movement of the negative electrode 3 in the direction along the separator 4 is restricted by the separator molding part 9. Next, the other separator 4 is mounted on the negative electrode 3 whose movement is restricted by the separator molding unit 9 by using the suction conveyance mechanism 15 (FIG. 11B). Thereafter, as shown in FIG. 11 (c), the separators 4 sandwiching the negative electrode 3 are joined together using a thermocompression bonding means (not shown) of the separator molding mechanism 14. Finally, when the separator molding mechanism 14 and the suction conveyance mechanism 15 are retracted, a bag-shaped electrode structure as shown in FIG. 10 is formed (FIG. 11D).

  Furthermore, FIG. 12 shows an electrode structure formed by packing positive electrode 2 or negative electrode 3, a method of manufacturing electrode laminate 1 using a plurality of positive electrodes 2, and a plurality of negative electrodes 3, and an apparatus for manufacturing electrode laminate 1. Let's talk about it.

  First, the packed negative electrode 3 is mounted on the upper surface of the stage 7. Then, the positive electrode 2 is mounted on the negative electrode 3 packed in the bag. Subsequently, another bag-packed negative electrode 3 is laminated on the positive electrode 2 by using the suction conveyance mechanism 16 as shown in FIGS. At that time, by using the joining mechanism 17 provided in the suction conveyance mechanism 16, the stacked separator molding parts 9 are heated and joined to form the joined part 5 as shown in FIG. Is done.

  In the state where the two negative electrodes 3 packed in a bag are stacked via the positive electrode 2, the separator molding portions 9 do not contact each other by the thickness of the positive electrode 2, and a gap is generated. However, by sufficiently increasing the thickness of the separator molding part 9 in the electrode stacking direction, the separator molding part 9 is softened or melted when heated by the joining mechanism 17, and the gap between the separator molding parts 9 is increased. It is possible to fill and form the joint portion 5.

  By repeating the above operation alternately for the positive electrode 2 and the negative electrode 3, a separator ladder molding structure is formed.

  As mentioned above, although embodiment of this invention was shown and demonstrated with the figure, this invention is not limited to the form shown in the figure, Other forms are also included in the range which does not deviate from the technical idea of this invention. is there.

  Therefore, the positive electrode 2 and the negative electrode 3 may be stacked so as to alternately face each other with the separator 4 interposed therebetween, and the stacking order may be changed.

  The joining mechanism 17 for joining the separator molding unit 9 may be connected to the suction conveyance mechanism 16 or to the stage 7 or may be driven independently of them.

  The joining mechanism 17 does not include the thermocompression bonding means, and may include other means such as applying an adhesive to join the members together.

  The joining mechanism 17 may function as a presser that fixes the positive electrode 2, the negative electrode 3, and the separator 4 being stacked to the stage 7.

  Either the positive electrode 1 or the negative electrode 2 may be used as the electrode packed in the separator 4 in the bag-shaped electrode structure.

  When forming the bag-shaped electrode structure (see FIG. 11), the other separator 4 mounted on the separator 4 including the separator molding portion 9 via the electrode may include the separator molding portion 9.

  According to the embodiment of the present invention as described above, the following effects are obtained.

  As a first effect, it is possible to prevent the deterioration of characteristics and the occurrence of short circuit due to the displacement of the electrodes. By the separator molding part 9 provided in the separator 4, it is made into the electrode laminated structure (refer FIG. 3, 4) which controls the movement to the direction perpendicular | vertical to the lamination direction of this electrode of the positive electrode 2 or the negative electrode 3. Because.

  As a second effect, it is possible to reduce the electrode fixing process such as tape application, which has been performed for the purpose of preventing the positional deviation between the electrode and the separator after the lamination of the electrode and the separator is completed. This is because the movement of the positive electrode 2 or the negative electrode 3 inside the electrode laminate is already restricted by the separator molding portion 9 of the separator 4.

  As a third effect, one electrode and one separator can be obtained by producing an electrode laminate using the separator 4 including the separator molding portion 9 or an electrode packed in two separators 4. It becomes possible to fix the relative position of an electrode and a separator whenever it laminates | stacks. Therefore, it is possible to reliably prevent the positional deviation of the electrodes and the occurrence of a short circuit.

  As a fourth effect, the separator 4 is transported to the stage 7, and the adsorption transport mechanism 16 is equipped with the joining mechanism 17 for joining the separator molding portions 9 of the stacked separators 4. The separator molding part 9 can be joined simultaneously with the lamination of the four. Therefore, it is possible to shorten the production time of the electrode laminate.

DESCRIPTION OF SYMBOLS 1 Electrode laminated body 2 Positive electrode 3 Negative electrode 4 Separator 5 Joint part 7, 8 Stage 9 Separator shaping | molding part 10 Positive electrode raw material 11 Negative electrode raw material 12 Separator raw material 13 Separator pressing member 14 Separator molding mechanism 15, 16 Adsorption conveyance mechanism 17 Joining mechanism

Claims (10)

The electrode laminate of an electrode laminate type battery including an electrode laminate formed by laminating a plurality of electrodes between separators,
A convex portion protruding in the electrode stacking direction is provided on at least one side surface of each separator, and the convex portion regulates movement of the electrode in a direction perpendicular to the electrode stacking direction. The electrode laminated body characterized by the above-mentioned. The electrode laminate according to claim 1,
The electrode laminate, wherein the portions of the separator provided with the convex portions are in a shape that fits together when the separator is laminated. The electrode laminate according to claim 1 or 2,
The electrode stack, wherein the separators adjacent to each other in the stacking direction of the electrodes are joined to each other at the positions of the protrusions in a state where movement of the electrodes is restricted by the protrusions of the separators. The electrode laminate according to any one of claims 1 to 3,
The electrode laminate, wherein the convex portion is formed using a part of the separator. The electrode laminate according to any one of claims 1 to 4, wherein
The electrode laminate, wherein a thickness of the convex portion in the electrode stacking direction is equal to a thickness of the electrode. A method for producing the electrode laminate of an electrode laminate battery comprising an electrode laminate formed by laminating a plurality of electrodes between separators,
Forming a part of each separator, and forming a convex portion on one side surface of each separator for restricting the movement of the electrode in a direction perpendicular to the stacking direction of the electrodes;
A step of restricting movement of the electrode with respect to a direction perpendicular to the stacking direction of the electrodes by mounting the electrode on one side surface of the one separator;
Mounting the other separator on the electrode mounted on one of the separators;
A step of joining the one separator and the other separator to each other at the position of the convex portion. It is a manufacturing method of the electrode layered product according to claim 6,
Performing the step of joining the one separator and the other separator at the position of the convex portion simultaneously with the step of mounting the other separator on the electrode mounted on the one separator. The manufacturing method of the electrode laminated body. A method for producing the electrode laminate of an electrode laminate battery comprising an electrode laminate formed by laminating a plurality of electrodes between separators,
Forming a part of one of the separators and forming a convex portion on one side surface of the one separator to restrict the movement of the electrode in a direction perpendicular to the stacking direction of the electrodes;
While mounting the electrode on one side surface of the one separator, the movement of the electrode is restricted by the convex portion in a direction perpendicular to the stacking direction of the electrode, and then the other separator is mounted on the electrode. And a step of producing a plurality of bag-packed electrodes by joining with the convex portions of the one separator,
Mounting the other packaged electrode on the one packaged electrode via the unpackaged electrode;
Joining the separator constituting the one bag-packed electrode and the separator constituting the other bag-packed electrode to each other at the position of the convex portion. Body manufacturing method. It is a manufacturing method of the electrode layered product according to claim 8,
Concurrently with the step of mounting the other packaged electrode on the one packaged electrode via the unpackaged electrode,
Performing the step of joining the separator constituting the one bag-packed electrode and the separator constituting the other bag-packed electrode to each other at the position of the convex portion. The manufacturing method of an electrode laminated body. It is a manufacturing method of the electrode layered product according to any one of claims 6 to 9,
The method for producing an electrode laminate, wherein the separators are joined by thermocompression bonding or application of an adhesive.

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