JPH09120823A - Electrode group, electrode group manufacturing device, and electrode group manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize space for mounting a spiral electrode group in a battery provided with it. SOLUTION: An electrode group 1 is provided with a core rod body 2 of a square cross sectional surface, a negative electrode collector 4, and a separator 5 disposed between both collectors 3, 4 to insulate the collectors 3, 4 from each other. The negative electrode collector 3, the positive electrode collector 4, and the separator 5 are sprially wound around the core rod body to have a square cross sectional surface around the core rod body 2, thereby the electrode group 1 is formed in a square rod form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode group, and more particularly to a spiral type electrode group.

[0002]

2. Description of the Related Art In the field of lithium batteries and the like, those equipped with a spiral electrode group are known. Here, the spiral electrode group generally means that one electrode plate (for example, a positive electrode plate) in a belt shape and the other electrode plate (for example, a negative electrode plate) in a belt shape are separators with a cylindrical core rod as a center. It refers to an electrode group that is spirally wound while being superposed in an insulating state with a pinch in between.

Since the spiral electrode group as described above is generally formed in a columnar shape, a battery including it is also usually formed in a columnar shape. Such a columnar battery is not good in volumetric efficiency and often hinders efficient use of space for mounting the battery.

An object of the present invention is to enable a battery provided with a spiral electrode group to efficiently use a space for mounting the same.

[0005]

The electrode group according to the present invention comprises:
A core rod having a quadrangular cross section and one strip-shaped pole fixed to the core rod at one end and spirally wound around the core rod so that the cross section has a quadrangular cross section. While maintaining insulation between the plate, the core rod and one of the pole plates, the other strip-shaped pole spirally wound around the core rod so as to have a rectangular cross section while being overlapped with the one pole plate. And a board.

In such an electrode group of the present invention, a core rod having a quadrangular cross section is used, and one strip electrode plate and the other strip electrode plate are quadrangular in cross section. Since it is spirally wound into the core rod body, it is formed into a prismatic shape as a whole. According to such a prismatic electrode group, a battery employing it can be formed into a prismatic shape. The prismatic battery can efficiently use the space for mounting the battery.

In the electrode group manufacturing apparatus according to the present invention, one lateral strip electrode plate and the other lateral strip electrode plate are superposed in an insulating state around a core rod having a quadrangular cross section as a center, It is a manufacturing apparatus for manufacturing an electrode group that is spirally wound into a rectangular shape. This manufacturing equipment
Rotating the core rod about its axis, and winding means for winding the one pole plate in the form of a strip and the other pole plate in the form of the other pole while winding the pole plate and the other pole, and the core rod rotated by the winding means. Rotation angle detecting means for detecting the rotation angle of the body, and the shortest distance from the shaft center to the outer peripheral surface of the core rod body and the outer peripheral surface according to the rotation angle of the core rod body detected by the rotation angle detecting means. For guiding one strip-shaped electrode plate and the other strip-shaped electrode plate that is wound around the core rod by reciprocating in the direction of approaching and separating from the core rod within the range of the difference from the longest distance to And the guide means of.

According to the above-described electrode group manufacturing apparatus of the present invention, the one strip-shaped electrode plate and the other strip-shaped electrode plate are superposed on the core rod body rotated by the winding means. Get involved. At this time, the guide means reciprocates in the contacting / separating direction with respect to the core rod body in accordance with the rotation angle of the core rod body detected by the rotation angle detecting means.
For this reason, one strip-shaped electrode plate and the other strip-shaped electrode plate can be guided by the guide means and can be wound according to the outer peripheral surface shape of the core rod body. In this way, the one strip-shaped electrode plate and the other strip-shaped electrode plate wound around the core rod body as a whole can form a prismatic electrode group corresponding to the shape of the core rod body.

The electrode group manufacturing apparatus according to the present invention is
For example, an urging means for urging the guide means in the core rod direction may be further provided. In this case, the one strip-shaped electrode plate and the other strip-shaped electrode plate wound around the core rod are
Since it is guided by the guide means and is biased by the biasing means in the direction of the core rod body, it can be more reliably rolled up according to the outer peripheral surface shape of the core rod body.

In another electrode group manufacturing apparatus according to the present invention, a strip-shaped one electrode plate and another strip-shaped electrode plate are traversed while being superposed in an insulating state around a core rod having a rectangular cross section. It is a manufacturing apparatus for manufacturing an electrode group that is spirally wound so that its surface has a rectangular shape. This manufacturing apparatus is configured to rotate the core rod around its axis, and to wind the core rod body while overlapping one strip-shaped electrode plate and the other strip-shaped electrode plate by the winding means and the winding means. And a biasing means for biasing one strip-shaped electrode plate and the other strip-shaped electrode plate that are wound around the core rod body toward the core rod body.

According to such a manufacturing apparatus, one strip-shaped electrode plate and the other strip-shaped electrode plate are wound while being superposed on each other on the core rod body rotated by the winding means. At this time, the one strip-shaped electrode plate and the other strip-shaped electrode plate that are wound around the core rod body are biased toward the core rod body by the biasing means. Therefore, the bipolar plate can be wound according to the outer peripheral surface shape of the core rod body. The bipolar plates thus wound around the core rod body can form a prismatic electrode group corresponding to the shape of the core rod body as a whole.

In the method of manufacturing an electrode group according to the present invention, the cross section is formed while the strip-shaped one electrode plate and the strip-shaped other electrode plate are superposed in an insulating state around the core rod whose cross section is square. This is a method of manufacturing an electrode group that is spirally wound into a rectangular shape. In this manufacturing method, the core rod is rotated about its axis, and while one strip-shaped electrode plate and the other strip-shaped electrode plate are superposed on each other, one strip-shaped one is formed along the outer peripheral surface shape of the core rod. The method includes the step of spirally winding it around the core rod body while guiding the electrode plate and the other strip-shaped electrode plate.

According to such a method of manufacturing an electrode group, one strip-shaped electrode plate and the other strip-shaped electrode plate are wound on the core rod while being superposed on each other. At this time, one strip-shaped electrode plate and the other strip-shaped electrode plate can be wound while being guided along the outer peripheral surface shape of the core rod body. Therefore, the one strip-shaped electrode plate and the other strip-shaped electrode plate wound around the core rod body can form a prismatic electrode group corresponding to the shape of the core rod body as a whole.

[0014]

EXAMPLE FIG. 1 shows an electrode group according to an example of the present invention. Note that FIG. 1 is a cross-sectional view of the electrode group. In the figure, the electrode group 1 mainly includes a core rod body 2, and a cathode current collector 3, an anode current collector 4, and a separator 5 which are wound around the core rod body 2.

The core rod body 2 is made of a member capable of functioning as a cathode current collector rod, and is formed in a square tube shape having a square cross section with an opening in the central portion 2a.

The cathode current collector 3 is made of, for example, a copper foil on which a cathode active material layer is arranged, and is formed in a strip shape. The cathode active material layer contains a cathode active material such as carbon. Such a cathode current collector 3
Has one end 3a spot-welded to the core rod body 2 and is wound in a spiral in a clockwise direction.

The anode current collector 4 is made of, for example, an aluminum foil on which an active material layer for an anode is arranged, and is formed in a strip shape. The anode active material layer may be, for example, LiC.
An active material for an anode such as oO ₂ or LiNiO ₂ is included. One end 4a of such an anode current collector 4 is disposed in the vicinity of the core rod body 2, and the anode current collector 4 is spirally wound in a clockwise direction parallel to the cathode current collector 3.

The separator 5 is formed in the shape of a strip made of an electrically insulating material usually used for batteries. Such a separator 5 is folded in two, and the folded-back portion 5 a is arranged so as to contact the core rod body 2. Further, the folded separator 5 is arranged between the cathode current collector 3 and the anode current collector 4, and both the current collectors 3,
While being insulated from each other, it is spirally wound in a clockwise direction in parallel with the cathode current collector 3 and the anode current collector 4. It should be noted that one end 4 a of the anode current collector 4 is kept insulated from the core rod body 2 by such a separator 5.

In the electrode group 1 described above, the cathode current collector 3, the anode current collector 4 and the separator 5 wound around the core rod body 2 are all corners corresponding to the outer peripheral surface shape of the core rod body 2. Is caught in a shape. Therefore, the electrode group 1
Is formed into a prismatic shape as a whole.

Such an electrode group 1 can be housed in, for example, a battery case to form a battery. At this time, since the electrode group 1 is formed in a prismatic shape, it is possible to use a rectangular battery case. As a result, the battery including the electrode group 1 of the present embodiment can be configured as a prismatic shape as a whole, so that it is difficult to form a useless space in the space for mounting the battery, and the space can be efficiently used. Can be used.

Next, a manufacturing apparatus for manufacturing the above electrode group 1 will be described. FIG. 2 is a diagram showing a schematic configuration of the manufacturing apparatus 10. In the figure, the manufacturing apparatus 10 is mainly composed of a winding device 11 and a pair of guide devices 12, 12.

The winding device 11 includes a motor 13, a gear 14 rotatably attached to the motor 13, a reduction gear 15 meshed with the gear 14, and a reduction gear 15.
The rotary shaft 16 is mainly provided with a rotating shaft 16 which is rotated by the above and extends between the pair of guide devices 12, 12. The rotation shaft 16
Is formed in a prismatic shape so that it can be inserted into the central portion 2a of the core rod body 2 described above. Such a winding device 11 transmits the rotational force of the motor 13 to the rotary shaft 16 via the gear 14 and the reduction gear 15, and rotates the rotary shaft 16 in the counterclockwise direction of FIG. 3 (III-III cross-sectional view of FIG. 2). It can rotate (in the direction of the arrow in the figure).

In the winding device 11 described above, the reduction gear 15 is equipped with an encoder 17 for detecting the rotation angle θ (FIG. 3) of the rotation shaft 16. The encoder 17 is connected to the calculator 19 via the amplifier 18, and can transmit the rotation angle θ of the rotary shaft 16 to the calculator 19.

The pair of guide devices 12, 12 includes a rotary shaft 16
They are placed one above the other with a pinch in between. Each guide device 12 supports a roller 20 extending in parallel with the rotating shaft 16, an air cylinder 21, a roller 20 rotatably supported, and the urging force of the air cylinder 21 causes the roller 20 to rotate the roller 20.
Support 22 for urging in six directions.

The air cylinder 21 is connected to the servo 23. The servo 23 is connected to the calculator 19, and can move the entire air cylinder 21 in the vertical direction of FIG. 2 according to the calculation result of the calculator 19.

Next, the contents of calculation in the calculator 19 will be described. The rotation angle θ of the rotary shaft 16 detected by the encoder 17 is input to the calculator 19. The rotation angle θ of the rotating shaft 16 referred to here means a rotating angle in the case where the rotating shaft 16 rotates counterclockwise in the figure around the axis c of the rotating shaft 16 as shown in FIG. Calculator 19
Calculates the movement amount (X) of the entire air cylinder 21 according to the rotation angle θ of the rotation shaft 16 as described above. The movement amount of the entire air cylinder 21 calculated here is, as shown in FIG. 3, the distance r from the axis c of the rotating shaft 16 to the outer peripheral surface of the core rod body 2 mounted on the rotating shaft 16 and the rotation. It is the difference (r-ra) from the shortest distance ra from the axis c of the shaft 16 to the outer peripheral surface of the core rod 2. The distance r is the shortest distance ra from the shaft center c of the rotating shaft 16 to the outer peripheral surface of the core rod body 2 and the longest distance from the shaft center c to the outer peripheral surface of the core rod body 2 (from the shaft center c to the core rod). Within the range of the difference between the distance to the corner of the body 2) rb,
It is calculated by the following formula.

R = ra / cos θ

The movement amount (X) of the entire air cylinder 21 calculated in this way is specifically 0 (rotation axis 1
From the case where the rotation angle θ of 6 is 0 °) to rb-ra
The range is (when the rotation angle θ of the rotation shaft 16 is 45 °, for example). FIG. 4 shows the relationship between the rotation angle θ of the rotating shaft 16 and the movement amount (X). As shown in the figure, the movement amount (X) makes four reciprocations in the range of 0 to rb-ra while the rotating shaft 16 makes one rotation.

The amount of movement (X) calculated by the arithmetic unit 19 in this manner is transmitted to the servo 23. Servo 2
3 shows the entire air cylinder 21 according to this information.
Reciprocate vertically. Specifically, when the rotating shaft 16 starts to rotate counterclockwise in the drawing from the case where the rotating angle θ of the rotating shaft 16 as shown in FIG.
Moves the air cylinder 21 in the direction away from the rotary shaft 16 by the movement amount (X) calculated by the calculator 19. Then, when the rotation angle θ reaches 45 °, the movement amount (X) begins to decrease as shown in FIG. 4, so the servo 23 moves the air cylinder 21 in the direction of the rotation axis 16. In this way, the air cylinder 21
It moves according to the cycle shown in FIG. 4, and makes four reciprocations within the range of the movement amount (X) while the rotating shaft 16 makes one rotation.

Next, a method of manufacturing the electrode group 1 using the above-described manufacturing apparatus 10 will be described. First, as shown in FIG. 5, one end 3 a of the cathode current collector 3 is spot-welded to the core rod 2. Then, as shown in FIGS. 2 and 3, the core rod body 2 to which the cathode current collector 3 is welded is manufactured by the manufacturing apparatus 1 as shown in FIG.
It is attached to the rotary shaft 16 of 0.

As shown in FIG. 6, the separator 5 is arranged on the core rod body 2 thus mounted on the rotary shaft 16. Here, one end side 51 of the strip-shaped separator 5
So that they can overlap the cathode current collector 3 welded to the core rod body 2, the separator 5 is attached to the core rod body 2 and the upper guide device 12.
Between the rollers 20 and. Then, the other end side of the separator 5 is made to extend from the left side surface of the core rod body 2 in the figure to the lower side surface, and is folded back at the lower side surface. One end 4a of the anode current collector 4 is sandwiched between the folded-back portions 5a of the separator 5 thus formed. As described above, in the state in which the cathode current collector 3, the anode current collector 4, and the separator 5 are arranged with respect to the manufacturing apparatus 10, the roller 20 of each guiding device 12 causes the separator 5 to be the core rod by the urging force of the air cylinder 21. Body 2
Biased in the direction.

Next, the manufacturing apparatus 10 is operated to rotate the rotary shaft 1
6 is started to rotate counterclockwise in FIG. 6 (in the direction of the arrow in the figure). As a result, the cathode current collector 3 and the anode current collector 4 are
While being sandwiched between the separators 5, it is gradually wound around the core rod body 2 as shown in FIGS. 7 and 8.

In such a winding process of the cathode current collector 3, the anode current collector 4 and the separator 5 with respect to the core rod 2, the encoder 17 constantly detects the rotation angle θ of the rotary shaft 16, and the information is detected by the amplifier 18. Via the computing unit 19
To communicate. The calculator 19 calculates the movement amount (X) of the air cylinder 21 based on the above-described calculation formula. Based on the calculation result, the servo 23 reciprocates the air cylinder 21 up and down. For example, when the rotating shaft 16 rotates by 45 ° as shown in FIG. 7, the air cylinder 21 has X (here, X = rb-ra) more than that in the case shown in FIG. 6 (when the rotation angle θ = 0 °). ) Is moved to a position away from the rotary shaft 16. Further, as shown in FIG.
When rotated by 5 ° (when the rotation angle θ = 90 °), the air cylinder 21 moves from the position in the case of FIG. 7 to X (here,
X = rb−ra) to move to a position closer to the rotary shaft 16.

As described above, in the manufacturing apparatus 10 of this embodiment, the air cylinder 21 is moved according to the rotation angle of the rotary shaft 16.
Move back and forth, and the support 22 is the air cylinder 21.
The roller 20 supported by the support 22 is always in close contact with the separator 5 and freely rotates in the direction indicated by the arrow in FIGS. Therefore, the cathode current collector 3, the anode current collector 4 and the separator 5 that are wound around the core rod body 2 are
While being guided by 0, the rod-shaped electrode group 1 can be surely wound into a prismatic shape along the outer peripheral surface of the core rod body 2, and finally the prismatic electrode group 1 can be formed.

Incidentally, in such a winding step, each support 22 resists the urging force of the air cylinder 21,
The cathode collector 3, the anode collector 4, and the separator 5 wound around the core rod 2 are gradually moved in a direction away from the rotating shaft 16 by the thickness of the separator 5.

[Other Embodiments] (1) In the above embodiment, the insulation between the cathode current collector 3 and the anode current collector 4 and the insulation between the core rod 2 and the anode current collector 4 are ensured. Although the separator 5 is used for this purpose, the present invention is not limited to this. For example, the cathode current collector 3 and the anode current collector 4
When the solid electrolyte layer is formed on each of the active material layers, the solid electrolyte layer can function as a separator, and thus the electrode group according to the present invention can be configured without using a separate separator. When the cathode current collector 3 and the anode current collector 4 are provided with such a solid electrolyte layer, the battery can be constructed without injecting the electrolytic solution into the battery case.

(2) In the above embodiment, the cathode current collector 3 was spot-welded to the core rod body 2 and the anode current collector 4 was insulated from the core rod body 2, but the present invention is not limited to this. That is,
The present invention can be implemented in the same manner when the anode current collector 4 is spot-welded to the core rod body 2 and the cathode current collector 3 is insulated from the core rod body 2. However, in this case, as the core rod body 2,
It is necessary to use one that functions as an anode current collector.

(3) In the manufacturing apparatus 10 described above, the entire air cylinder 21 is configured to reciprocate according to the rotation angle of the rotary shaft 16, but the electrode group 1 can be manufactured without such a configuration. That is, in the above-described manufacturing apparatus 10, if the roller 20 is configured to be biased in the direction of the rotating shaft 16 by the air cylinder 21,
The cathode current collector 3, the anode current collector 4 and the separator 5 are
Because of the urging force of the urging device, the roller 20 is always pressed while being pressed in the direction of the core rod 2 by the roller 20, so that the roller 20 is reliably wound into the prismatic shape along the outer peripheral surface of the core rod 2 Specifically, the prismatic electrode group 1 can be formed.

(4) In the manufacturing apparatus 10 described above, the roller 2
Although the air cylinder 21 is used as a means for urging 0 in the direction of the rotation axis 16, the present invention can be similarly implemented when a spring is used instead of the air cylinder 21.

[0040]

The electrode group according to the present invention is formed into a prismatic shape as a whole. Therefore, by using such a prismatic electrode group, the battery can be formed into a prismatic shape, so that the space for mounting the battery can be efficiently used.

In the electrode assembly manufacturing apparatus according to the present invention, one strip-shaped electrode plate and the other strip-shaped electrode plate can be wound according to the outer peripheral surface shape of the core rod body while being guided by the guide means. A prismatic electrode group corresponding to the shape of the rod can be formed.

In another electrode group manufacturing apparatus according to the present invention, a biasing means for biasing one strip-shaped electrode plate and the other strip-shaped electrode plate wound around the core rod body toward the core rod body is provided. Since it is provided, the bipolar plate can be wound according to the outer peripheral surface shape of the core rod body. Therefore, this manufacturing apparatus can form a prismatic electrode group corresponding to the shape of the core rod body.

In the method of manufacturing the electrode group according to the present invention, one strip-shaped electrode plate and the other strip-shaped electrode plate are wound while being guided along the outer peripheral surface shape of the core rod body. A prismatic electrode group corresponding to the shape can be formed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electrode group according to an embodiment of the present invention.

FIG. 2 is a schematic view of an electrode group manufacturing apparatus according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a diagram showing a relationship between a rotation angle (θ) of a rotary shaft and a movement amount (X) of a support in the manufacturing apparatus.

FIG. 5 is a diagram showing a step in the case of manufacturing the electrode group by the manufacturing apparatus.

FIG. 6 is a diagram showing another step of manufacturing the electrode group by the manufacturing apparatus.

FIG. 7 is a diagram showing still another step of manufacturing the electrode group by the manufacturing apparatus.

FIG. 8 is a diagram showing still another step of manufacturing the electrode group by the manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode group 2 Core rod 3 Cathode current collector 4 Anode current collector 5 Separator 10 Manufacturing device 11 Entrainment device 12 Guide device 16 Rotating shaft 17 Encoder 21 Air cylinder 23 Servo

Claims (5)

[Claims] 1. A core rod body having a quadrangular cross section, and one end of which is fixed to the core rod body and which is spirally wound around the core rod body so that the cross section becomes quadrangular. One of the pole plates wound up, and while maintaining an insulating state with the core rod body and the one pole plate, to the core rod body so that the cross section becomes a quadrangular shape while being overlapped with the one pole plate An electrode group including the other strip-shaped electrode plate wound in a spiral shape. 2. A core rod having a rectangular cross section as a center,
A manufacturing device for manufacturing an electrode group in which one strip-shaped electrode plate and the other strip-shaped electrode plate are wound in a spiral shape so as to have a rectangular cross section while being superposed in an insulating state, wherein the core rod A body is rotated about its axis, and a winding means for winding the one pole plate and the other pole plate of the belt into the core rod body while superposing the pole plate and the winding means, and is rotated by the winding means. A rotation angle detecting means for detecting the rotation angle of the core rod body, and the shortest distance from the axial center of the core rod body to the outer peripheral surface according to the rotation angle of the core rod body detected by the rotation angle detecting means. And one of the strip-shaped polar plates that is wound around the core rod body by reciprocating in the contacting and separating directions with respect to the core rod body within a range of a difference between the axial center and the longest distance from the outer peripheral surface. And said strip Square electrode group production apparatus provided with a guide means for guiding the electrode plate. 3. The apparatus for manufacturing an electrode group according to claim 2, further comprising an urging means for urging the guiding means toward the core rod body. 4. A core rod having a rectangular cross section,
A manufacturing device for manufacturing an electrode group in which one strip-shaped electrode plate and the other strip-shaped electrode plate are wound in a spiral shape so as to have a rectangular cross section while being superposed in an insulating state, wherein the core rod Rotating the body about its axis, and winding means for winding the one pole plate and the other pole plate of the belt into the core rod body while superposing them, and the core rod by the winding means. An apparatus for manufacturing an electrode group, comprising: one strip-shaped electrode plate that is wound around the body; and a biasing unit that biases the other strip-shaped electrode plate toward the core rod body. 5. A core rod having a rectangular cross section,
A method for manufacturing an electrode group in which one strip-shaped electrode plate and the other strip-shaped electrode plate are wound in a spiral shape so that a cross section thereof has a quadrangular shape while being superposed in an insulating state, wherein the core rod body has its axis While rotating about the center, one of the strip-shaped polar plate and the other strip-shaped polar plate are overlapped and along the outer peripheral surface shape of the core rod body, the strip-shaped one polar plate and the strip-shaped polar plate. A method for manufacturing an electrode group, which includes a step of winding the electrode group in a spiral shape while guiding the other electrode plate.