JP2019102140A - Manufacturing method for battery - Google Patents

Abstract

To provide a manufacturing method for a battery capable of manufacturing not only an electrode body but also a battery at a low cost by preventing an electrode laminate from being damaged or partially considerably deformed even while preventing positional displacement.SOLUTION: According to a manufacturing method for a battery 1, a laminating step S9 of forming an electrode 20 includes an adhering step S11 of pressing a pressed part 30p(n+1) of a new electrode laminate 30(n+1) from an outside in a lamination direction GH and adhering the new electrode laminate 30(n+1) to an electrode laminate group 30z. In the adhering step S11, the new electrode laminate 30(n+1)is pressed while defining a portion which is not at least partially overlapped in the lamination direction GH with a pressed part 30p(n) in an electrode laminate 30(n) at a destination in contact with the new electrode laminate 30(n+1) in the electrode laminate group 30z as the pressed part 30p(n+1) of the new electrode laminate 30(n+1).SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method of manufacturing a battery including a stacked electrode assembly in which a plurality of first electrode plates and second electrode plates are alternately stacked via a separator.

  As an electrode body of batteries, such as a lithium ion secondary battery, the laminated-type electrode body which laminated | stacked multiple positive electrode plates and negative electrode plates which make rectangular shape etc. alternately via the separator is known. Such a stacked electrode assembly is manufactured, for example, by the following method. That is, the first separator and the second separator are brought into close contact with both main surfaces of the negative electrode plate to form a composite of these. Thereafter, the composite and the positive electrode plate are brought into close contact with each other to form an integrated electrode laminate in which the first separator, the negative electrode plate, the second separator, and the positive electrode plate are laminated in this order.

  Thereafter, a plurality of the electrode stacks are stacked to form an electrode body. At that time, in the electrode stack group in which a plurality of electrode stacks are already stacked, in order to prevent positional deviation between the electrode stacks, pressing near the four corners of the electrode stack group from above with claws The method of stacking the following new electrode laminated body is known (refer FIG. 6, FIG. 9, FIG. 18-FIG. 23 grade | etc., Of patent document 1).

  Specifically, a new electrode stack is stacked on the electrode stack group while holding the electrode stack group with a claw. Then, since the electrode stacks also overlap on the claws, the claws are sandwiched between the electrode stacks (between the electrode stack group and the electrode stack newly stacked) (Patent Document 1). See Figure 19 of Thereafter, the claws are pulled out from between the electrode stacks, moved upward, and the electrode stack group including the newly stacked electrode stack is pressed from above (see, for example, FIGS. ). This is repeated to form an electrode body.

JP 2012-227130 A

  However, in the method of Patent Document 1, as described above, after the new electrode stack is stacked, the claw is moved out of the space between the electrode stacks. The laminate may be damaged.

  As a method of solving this problem, after stacking a new electrode stack on an electrode stack group, the entire electrode stack is pressed in the stacking direction to bring the new electrode stack into close contact with the electrode stack group. It is conceivable to repeat stacking of electrode stacks while preventing occurrence of positional deviation between the electrode stacks in the electrode stack group. However, this method requires a large-sized pressing device to fully press the electrode stack group at a sufficient pressure, and the speed of pressing tends to be slow, and the production cost of the electrode body and battery It is not preferable because it becomes high.

  Therefore, after stacking a new electrode stack, the present inventor brings the new electrode stack into close contact with the electrode stack group by pressing only a part of the new electrode stack in the stacking direction. We considered that. However, when manufactured by this method, since the electrode laminate group is repeatedly pressed in the laminating direction at the same portion in the spreading direction of the electrode laminate, the electrode laminate is formed at the boundary between the pressed portion and the surrounding portion. The electrode plates and separators that make up the As a result, there is a possibility that the battery performance may be deteriorated due to the change of the permeability of the conductive ion at the deformed portion.

  The present invention has been made in view of the present situation, and in forming the electrode body, the electrodes are prevented from causing positional displacement between the electrode stacks in the stacked electrode stack group. Provided is a method of manufacturing a battery capable of manufacturing an electrode body at a low cost and, consequently, a battery by suppressing the damage of the laminate and a large deformation of a part of the electrode laminate (each electrode plate and the separators forming the electrode laminate). The purpose is

  One aspect of the present invention for solving the above problems is that a plurality of electrode stacks in which a first separator, a first electrode plate, a second separator, and a second electrode plate are stacked and integrated in this order are stacked. The first separator of the new electrode stack is located in the uppermost layer of the electrode stack group in which a plurality of the electrode stacks are already stacked. The step of stacking the new electrode stack on the group of electrode stacks is repeated so as to be in close contact with the second electrode plate to form the electrode body, and the step of stacking includes the step of stacking the new electrode stack. After stacking the body on the group of electrode stacks, pressing the pressed portion which is a part of the new electrode stack from the outside in the stacking direction, before stacking the next new electrode stack, New electrode laminate The method further includes an adhesion step of closely adhering to the electrode stack group, wherein the adhesion step is performed in the electrode stack of the plurality of electrode stacks forming the electrode stack group in a portion in contact with the new electrode stack, The method for manufacturing a battery, in which a portion to which at least a portion does not overlap in the stacking direction is the portion to which at least a part does not overlap with the pressed portion as the pressed portion of the new electrode stack. It is.

  In the above-described battery manufacturing method, in the stacking step of stacking a plurality of electrode stacks to form an electrode body, a new electrode stack is stacked on an electrode stack group and then the next new electrode stack is not stacked. Then, a part of the new electrode stack (pressed portion) is pressed to bring the new electrode stack into close contact with the electrode stack group. By doing this, while preventing the occurrence of positional deviation between the electrode stacks in the stacked electrode stack group, the electrode stack is scratched with claws as in the method of Patent Document 1 Can be prevented. In addition, since only a part of the new electrode laminate is pressed instead of pressing the new electrode laminate on the entire surface, the pressing device can be miniaturized or the production speed can be increased, and the electrode assembly can be manufactured at low cost. As a result, the battery can be manufactured.

  Furthermore, in the above-described manufacturing method, a portion to which at least a portion does not overlap in the stacking direction is a portion to which the pressed portion already pressed in the previous electrode stack of the electrode stack group belongs. And press the new electrode stack. Thereby, in the electrode laminate group, the same portion in the spreading direction of the electrode laminate can be suppressed from being repeatedly pressed in the laminating direction, and a part of the electrode laminate (each electrode plate and separators forming the electrode laminate is largely deformed) You can suppress it.

"A new electrode laminate is used as a portion to be pressed of a new electrode laminate, in a portion where at least a portion does not overlap with the pressed portion in the previous electrode laminate of the electrode laminate group in the stacking direction. As a specific method of “pressing”, for example, a new electrode such that the pressed portion of the previous electrode stack laminated immediately before and the pressed portion of the new electrode stack do not overlap at all in the stacking direction. The method of changing the to-be-pressed part of a laminated body is mentioned. In this case, the positions of the pressed portions may be changed so that the pressed portions of all the electrode stacks until the electrode body is not overlapped at all in the stacking direction, or partially overlap in the stacking direction ( For example, the pressed portion of the second electrode stack and the pressed portion of the fourth electrode stack may partially or entirely overlap in the stacking direction.
Alternatively, the pressed portion of the new electrode stack is changed so that the pressed portion of the previous electrode stack stacked immediately before and the pressed portion of the new electrode stack do not partially overlap in the stacking direction. There is also a way to In this case, there is a method of shifting the pressed portion of the new electrode stack little by little from the pressed portion of the previous electrode stack stacked immediately before.
In addition, "a pressed portion" may be singular or plural. That is, only one part of the electrode laminate may be used as the pressed part, or a plurality of parts of the electrode laminate may be used as the pressed part.

It is a perspective view of the battery concerning an embodiment. It is a sectional view of a battery concerning an embodiment. It is a sectional view of an electrode body concerning an embodiment. It is a sectional view of an electrode layered product concerning an embodiment. It is a flowchart of the manufacturing method of the battery which concerns on embodiment. It is explanatory drawing which shows a mode that it concerns on embodiment and forms an electrode body. It is the top view which looked at a mode that a part of new electrode laminated body was pressed in the stacking | stacking process concerning an embodiment from upper direction. FIG. 8 is a partial cross-sectional view taken along line A-A in FIG. 7 according to the embodiment. It is the top view which looked at a mode which concerns on a comparison form and presses a part of new electrode laminated body by the stacking process from upper direction. FIG. 10 is a partial cross-sectional view taken along line B-B in FIG. 9 according to a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a perspective view and a cross-sectional view of a battery 1 according to the present embodiment. Further, FIG. 3 shows a cross-sectional view of the electrode assembly 20 accommodated in the battery 1, and FIG. 4 shows a cross-sectional view of the electrode stack 30 constituting the electrode assembly 20. Hereinafter, the battery longitudinal direction BH, the battery lateral direction CH, and the battery thickness direction DH of the battery 1 will be described as the directions shown in FIGS. 1 and 2. The longitudinal direction EH, the lateral direction FH, and the stacking direction GH of the electrode body 20 will be described as the directions shown in FIGS. 3 and 2.

  The battery 1 is a rectangular and sealed lithium ion secondary battery mounted on a vehicle such as a hybrid car, a plug-in hybrid car, and an electric car. The battery 1 includes a battery case 10 made of metal in a rectangular box shape, an electrode body 20 housed inside the battery case 10, and a positive electrode terminal member 70 and a negative electrode terminal member 80 supported by the battery case 10. In the battery case 10, an electrolytic solution 17 is accommodated, and a part thereof is impregnated in the electrode body 20.

  The positive electrode terminal member 70 is electrically connected to the positive electrode exposed portion 31m of each positive electrode plate (second electrode plate) 31 of the electrode body 20 in the battery case 10 and penetrates the case lid member 13 of the battery case 10 It extends to the outside of the battery. Further, the negative electrode terminal member 80 is connected to the negative electrode exposed portion 41m of each negative electrode plate (first electrode plate) 41 of the electrode body 20 in the battery case 10 so as to be conductive, while penetrating the case lid member 13 It extends up to Further, a bag-like insulating film enclosure 19 made of an insulating film is disposed between the electrode body 20 and the battery case 10.

  The electrode body 20 (see FIG. 3) has a substantially rectangular parallelepiped shape, and the rectangular positive electrode plate 31 and the rectangular negative electrode plate 41 are alternately interposed via the rectangular separators (first separator 51 and second separator 61). It is a stacked electrode assembly in which a plurality of layers are stacked. As described later, the electrode assembly 20 is integrally formed by laminating a plurality of electrode stacks 30 (see FIG. 4) in which the first separator 51, the negative electrode plate 41, the second separator 61, and the positive electrode plate 31 are stacked in this order. It is

Among them, the positive electrode plate 31 is formed by providing the positive electrode active material layers 33 and 33 including the positive electrode active material in a rectangular shape on both main surfaces of the positive electrode current collector foil 32 made of rectangular aluminum foil. In the positive electrode plate 31, the end on the left side in FIGS. 3 and 4 has no positive electrode active material layer 33 in the thickness direction (vertical direction in FIGS. 3 and 4), and the positive electrode current collector foil 32 has a thickness The positive electrode exposed portion 31m is exposed in the direction.
The negative electrode plate 41 is formed by providing negative electrode active material layers 43 and 43 including a negative electrode active material in a rectangular shape on both main surfaces of a negative electrode current collector foil 42 made of rectangular copper foil. Of the negative electrode plate 41, the end on the right side in FIGS. 3 and 4 has no negative electrode active material layer 43 in the thickness direction (vertical direction in FIGS. 3 and 4), and the negative electrode current collector foil 42 has a thickness The negative electrode exposed portion 41m is exposed in the direction.

  The first separator 51 is interposed between the positive electrode plate 31 and the negative electrode plate 41 in a state of being in close contact with the positive electrode plate 31 and the negative electrode plate 41 disposed thereon. The first separator 51 is composed of a rectangular plate-shaped separator main body 52 made of a porous film of polyethylene, and porous adhesion layers 53 and 53 formed on both main surfaces of the separator main body 52, respectively. The adhesion layer 53 is made of polyethylene particles and a binder for binding the polyethylene particles to each other and the polyethylene particles and the separator main body 52.

  The second separator 61 is interposed between the negative electrode plate 41 and the positive electrode plate 31 in a state in which the second separator 61 is in close contact with the negative electrode plate 41 and the positive electrode plate 31 disposed thereon. The second separator 61 is also composed of a separator main body 62 formed of a porous film of polyethylene in a rectangular plate shape, and porous adhesion layers 63 and 63 formed on both main surfaces of the separator main body 62 respectively. The adhesion layer 63 also comprises polyethylene particles and a binder.

  Then, the manufacturing method of the said battery 1 is demonstrated (refer FIGS. 5-8). First, in the “strip-shaped positive electrode plate forming step S1”, a strip-shaped positive electrode plate 31x to be a rectangular positive electrode plate 31 is formed by cutting. That is, a positive electrode current collector foil 32 made of a strip-like aluminum foil is prepared, and a positive electrode paste containing a positive electrode active material is applied to one main surface thereof, and dried by heating to form a positive electrode active material layer 33. Further, the above-mentioned positive electrode paste is similarly applied to the main surface on the opposite side of the positive electrode current collector foil 32 and dried by heating to form a positive electrode active material layer 33. Thereafter, the positive electrode plate is pressed by a roll press to increase the density of the positive electrode active material layers 33, 33. Thus, the strip-shaped positive electrode plate 31x is formed.

  In addition, separately, “strip-shaped negative electrode plate forming step S2” is performed to form a strip-shaped negative electrode plate 41x that is to be a rectangular negative electrode plate 41 by cutting. That is, a negative electrode current collector foil 42 made of a strip-shaped copper foil is prepared, and a negative electrode paste containing a negative electrode active material is coated on one main surface thereof, and dried by heating to form a negative electrode active material layer 43. Further, the above-mentioned negative electrode paste is similarly applied to the main surface on the opposite side of the negative electrode current collector foil 42 and dried by heating to form the negative electrode active material layer 43. Thereafter, the negative electrode plate is pressed by a roll press to increase the density of the negative electrode active material layers 43, 43. Thus, the strip-shaped negative electrode plate 41x is formed.

  In addition, separately, “strip-shaped first separator forming step S3” is performed to form a strip-shaped first separator 51x that is to be a rectangular first separator 51 by cutting. That is, a strip-shaped separator main body 52 made of a porous film of polyethylene is prepared, and a dispersion liquid containing polyethylene particles and a binder as a dispersion medium is applied to one main surface of the separator main body 52, and dried by heating. The adhesion layer 53 is formed. Further, the above-mentioned dispersion is similarly applied to the main surface on the opposite side of the separator main body 52, and dried by heating to form the adhesion layer 53. Thereby, the strip-shaped first separator 51x is formed.

  Further, separately, the “strip second separator forming step S4” is performed to form a second strip separator 61x which is to be a rectangular second separator 61 by cutting. That is, as in the strip-like first separator formation step S3, a dispersion containing the above-described polyethylene particles and the like is applied to one main surface of the separator main body 62 and dried by heating to form the adhesion layer 63. Also, the above-mentioned dispersion is similarly applied to the main surface on the opposite side of the separator main body 52, and dried by heating to form the adhesion layer 63. Thereby, the strip-shaped second separator 61x is formed.

Next, an electrode assembly 20 is formed by the electrode assembly manufacturing apparatus 100 using the strip positive electrode plate 31x, the strip negative electrode plate 41x, the strip first separator 51x, and the strip second separator 61x.
First, the electrode body manufacturing apparatus 100 will be described (see FIG. 6). This electrode assembly manufacturing apparatus 100 includes a negative electrode plate supply unit 110, a first separator supply unit 120, a second separator supply unit 130, a positive electrode plate supply unit 140, a positive electrode plate cutting unit 150, and a first roll press unit. And 160, a second roll press unit 170, a laminated body cutting unit 180, and a laminated unit 190.

Among them, a strip-like negative electrode plate 41x wound around the unwinding roll 111 is attached to the negative electrode plate feeding portion 110, and the strip-like negative electrode plate 41x extends in the longitudinal direction EX from the negative electrode plate feeding portion 110 (in FIG. Are sent out).
Below the negative electrode plate supply unit 110, a first separator supply unit 120 is disposed. A strip-shaped first separator 51x wound around the unwinding roll 121 is attached to the first separator feeding portion 120, and the strip-shaped first separator 51x is fed out from the first separator feeding portion 120 in the longitudinal direction EX. It has become.
Further, the second separator supply unit 130 is disposed above the negative electrode plate supply unit 110. A strip-shaped second separator 61x wound around the unwinding roll 131 is attached to the second separator feeding portion 130, and the strip-shaped second separator 61x is fed from the second separator feeding portion 130 in the longitudinal direction EX. It has become.

A strip-like positive electrode plate 31x wound around an unwinding roll 141 is attached to the positive electrode plate feeding portion 140, and the strip-like positive electrode plate 31x is fed from the positive electrode plate feeding portion 140 in the longitudinal direction EX.
The positive electrode plate cutting unit 150 is disposed downstream of the positive electrode plate supply unit 140. The positive electrode plate cutting portion 150 is a portion for cutting the strip-shaped positive electrode plate 31 x at predetermined intervals in the longitudinal direction EX to form the rectangular positive electrode plate 31.

  The first roll press unit 160 is a portion where the strip-shaped first separator 51 x, the strip-shaped negative electrode plate 41 x and the strip-shaped second separator 61 x are pressed by a roll press to be integrated. Specifically, the first roll press unit 160 includes a first press roll 161 and a second press roll 163 disposed in parallel to the first press roll 161 with a gap therebetween. In the gap between the first press roll 161 and the second press roll 163, the strip-shaped first separator 51x, the strip-shaped negative electrode plate 41x and the strip-shaped second separator 61x are continuously pressurized in the longitudinal direction EX and integrated Form the body 25x.

  The second roll press unit 170 is disposed downstream of the first roll press unit 160. The second roll press portion 170 is a portion where the strip composite 25x and the positive electrode plate 31 cut into a rectangular shape are integrated by pressing. Specifically, the second roll press unit 170 has a third press roll 171 and a fourth press roll 173 disposed parallel to the third press roll 171 with a gap therebetween. In the gap between the third press roll 171 and the fourth press roll 173, the strip composite 25x and the positive electrode plate 31 are continuously pressed and integrated to form a strip electrode laminate 30x.

  The laminate cutting unit 180 is disposed downstream of the second roll pressing unit 170. The laminate cutting portion 180 is a portion where the strip electrode laminate 30 x is cut at predetermined intervals in the longitudinal direction EX to form the rectangular electrode laminate 30.

  The stacked portion 190 is a portion where the plurality of electrode stacked bodies 30 are stacked to form the electrode body 20, and has a flat mounting table 191 on which the electrode stacked body 30 is mounted. The stacking unit 190 also includes a pressing device 200 that presses the pressed portion 30p, which is a part of the stacked electrode stack 30, from above in the stacking direction GH (see FIGS. 6 to 8). The pressing device 200 has two cylindrical pressure parts 210, a support part 220 for supporting the pressure parts 210, a central axis 230 fixed at the center of the support part 220, and a central axis 230. And a movable mechanism 240 capable of moving the central shaft 230 up and down.

Among these, each of the two pressing parts 210 has a cylindrical shape in which the tip end part 210s has a hemispherical shape, and the pressing parts 210 are arranged so that the pressing parts 210 become parallel to the stacking direction GH. It is attached to the support part 220 in the state which spaced apart predetermined intervals.
The moving mechanism 240 is configured to be able to pivot the central axis 230 and to move the central axis 230 up and down (in the stacking direction GH). When the central shaft 230 is rotated by the moving mechanism 240, the support portion 220 fixed to the central shaft 230 and the pressing portions 210 fixed to the support portion 220 extend in the expansion direction IH of the electrode stack 30 (longitudinal direction EH and Rotate in the lateral direction FH). Thereby, the part (pressed portion 30p) for pressing the electrode stack 30 by the pressing unit 210 can be changed to the spreading direction IH. In addition, when the central shaft 230 moves up and down (in the stacking direction GH) by the moving mechanism 240, the support portions 220 and the pressing units 210 also move up and down (in the stacking direction GH). As a result, a part (the pressed portion 30p) of the stacked electrode stack 30 can be pressed from above in the stacking direction GH at the tip end portion 210s of the pressing portion 210.

  In forming the electrode assembly 20 using the electrode assembly manufacturing apparatus 100, first, in the “strip-shaped complex formation step S5” (see FIG. 5), the strip-shaped first separator 51x, the strip-shaped negative electrode plate 41x and the strip-shaped second separator 61x The strip-shaped composite 25x which is laminated in this order and integrated is formed. Specifically, the strip-shaped negative electrode plate 41x transported from the negative electrode plate supply unit 110, the strip-shaped first separator 51x transported from the first separator supply unit 120, and the strip-shaped second separator transported from the second separator supply unit 130 Each 61 x is directed to the first roll press unit 160.

  Then, in a state in which the strip-shaped negative electrode plate 41x is overlapped between the strip-shaped first separator 51x and the strip-shaped second separator 61x in the gap KG1 between the first press roll 161 and the second press roll 163 of the first roll press unit 160. , These are continuously pressurized in the longitudinal direction EX to be integrated. As a result, a strip-shaped complex 25x in which the strip-shaped first separator 51x, the strip-shaped negative electrode plate 41x and the strip-shaped second separator 61x are in close contact with each other is formed.

  At the same time, the "strip-like positive electrode plate cutting step S6" is performed. That is, the strip-like positive electrode plate 31 x is cut at predetermined intervals W 1 in the longitudinal direction EX by the positive electrode plate cutting portion 150 to obtain the rectangular positive electrode plate 31.

  Next, in the “strip electrode stack forming step S7”, a strip electrode stack 30x in which the strip composite 25x and the rectangular positive electrode plate 31 are integrated is obtained. Specifically, the positive electrode plate 31 cut in a rectangular shape is superimposed on the strip-shaped second separator 61x of the strip-shaped complex 25x. Then, the band-shaped composite 25x and the positive electrode plate 31 are integrated by applying pressure by the gap KG2 between the third press roll 171 and the fourth press roll 173 of the second roll press unit 170. Thus, a strip electrode laminate 30x in which the strip composite 25x and the positive electrode plate 31 are in close contact with each other is formed.

  Thereafter, in the “strip electrode stack cutting step S8”, the strip electrode stack 30x is cut by the stack cutting portion 180 in the longitudinal direction EX at predetermined intervals W2 (W2> W1) to form a rectangular electrode stack Get thirty. In the electrode stack 30, as shown in FIG. 4, the first separator 51, the negative electrode plate 41, the second separator 61, and the positive electrode plate 31 are laminated in this order and integrated.

Next, in “stacking step S9”, an electrode stack in which the first separator 51 of the new electrode stack 30 (n + 1) has already been stacked with a plurality (n pieces) of electrode stacks 30 (1 to n). The electrode stack 20 is formed by repeatedly stacking new electrode stacks 30 (n + 1) on the electrode stack group 30z so as to be in close contact with the positive electrode plate 31 positioned in the uppermost layer of the group 30z (FIG. 7). And Figure 8).
Specifically, first, on the electrode stack group 30z consisting of n electrode stacks 30 (1 to n), that is, of the electrode stack group 30z, the n-th electrode stack stacked immediately before that A new (n + 1) -th electrode laminate 30 (n + 1) is aligned and placed on the body 30 (n) (placement step S10).

  Thereafter, the pressed portion 30p (n + 1), which is a part of the new (n + 1) th electrode laminate 30 (n + 1), is pressed in the stacking direction GH, and the new (n + 1) th electrode The electrode stack 30 (n + 1) is brought into close contact with the nth electrode stack 30 (n) at the top of the electrode stack group 30z (adhesion step S11). Specifically, by lowering the central shaft 230 with the moving mechanism 240 of the pressing device 200, the support portion 220 fixed to the central shaft 230 and the pressure portions 210 are lowered to move the hemispheres of the pressure portions 210. The two pressed portions 30p (n + 1), which are a part of the electrode stack 30 (n + 1), are pressed in the stacking direction GH by the tip portion 210s of the shape. Then, the new (n + 1) th electrode stack 30 (n + 1) is brought into close contact with the nth electrode stack 30 (n) of the electrode stack group 30z.

  At this time, in the n-th electrode stack 30 (n) of the uppermost layer in the electrode stack 30f, a portion does not partially overlap with the pressed portion 30p (n) that has already been pressed. The portion is a pressed portion 30p (n + 1) of a new (n + 1) -th electrode stack 30 (n + 1). In FIGS. 7 and 8, in the new (n + 1) -th electrode laminate 30 (n + 1), a state in which the pressing portion 210 presses the pressed portion 30p (n + 1) is indicated by a solid line. It is shown.

  Specifically, by rotating the central shaft 230 clockwise in FIG. 7 by the moving mechanism 240 of the pressing device 200, the support portion 220 and the pressure portions 210 fixed to the central shaft 230 are stacked. The body 30 is rotated clockwise in FIG. 7 in the spreading direction IH. Thereby, the position of the spreading direction IH of each pressing unit 210 is changed. Thereafter, as described above, each pressing portion 210 is lowered to stack the pressed portion 30p (n + 1) which is a part of the (n + 1) th electrode stack 30 (n + 1). Press to GH. As a result, the pressed portion 30p (n + 1) of the (n + 1) -th electrode laminate 30 (n + 1) is compared with the pressed portion 30p (n) of the n-th electrode laminate 30 (n). The (n + 1) -th electrode stack 30 (n + 1) can be pressed while being slightly shifted.

  Thereafter, the mounting step S10 and the adhesion step S11 described above are repeated to form the electrode assembly 20. Thereafter, the electrode assembly 20 is flat-pressed to form the electrode assembly 20 in which the electrode stacks 30 are in close contact with each other over the entire surface.

  Next, the battery 1 is assembled in "assembly step S12". Specifically, the case lid member 13 is prepared, and the positive electrode terminal member 70 and the negative electrode terminal member 80 are fixed thereto (see FIGS. 1 and 2). Thereafter, the positive electrode exposed portions 31m of the plurality of positive electrode plates 31 of the electrode body 20 are overlapped with each other, and the positive electrode terminal member 70 is welded thereto. The negative electrode exposed portions 41m of the plurality of negative electrode plates 41 of the electrode body 20 Are mutually stacked, and the negative electrode terminal member 80 is welded to this. Next, the insulating film enclosure 19 is put on the electrode body 20, and these are inserted into the case body member 11, and the opening of the case body member 11 is closed by the case lid member 13. Then, the case body member 11 and the case lid member 13 are welded to form the battery case 10. Thereafter, the electrolyte solution 17 is injected into the battery case 10 through the injection hole 13 h and impregnated in the electrode body 20. Thereafter, the liquid injection hole 13 h is sealed by the sealing member 15. Thereafter, various tests are performed on the battery 1. Thus, the battery 1 is completed.

  As described above, in the method of manufacturing the battery 1, in the stacking step S <b> 9 of stacking the plurality of electrode stacks 30 to form the electrode body 20, the new electrode stack 30 (n + 1) After stacking at 30z, the pressed portion 30p (n + 1), which is a part of the new electrode stack 30 (n + 1), is stacked before stacking the next new electrode stack 30 (n + 2). By pressing, a new electrode stack 30 (n + 1) is brought into close contact with the electrode stack 30z. In this way, it is possible to prevent the electrode stack 30 from being damaged while preventing the occurrence of positional deviation between the electrode stacks 30 (1 to n) in the stacked electrode stack group 30z. it can. Further, instead of pressing the new electrode stack 30 (n + 1) over the entire surface, only a part (pressed portion 30p (n + 1)) of the new electrode stack 30 (n + 1) is pressed. Therefore, the pressing device 200 can be downsized, and the production speed can be increased, and the electrode body 20 can be manufactured at low cost as a result.

  Here, as a comparative embodiment in FIGS. 9 and 10, in the stacking step S9, the same portion (pressed portion 30p) in the spreading direction IH (longitudinal direction EH and horizontal direction FH) of the electrode stack 30 is repeated in the stacking direction GH. The case where it is pressed is shown. In this comparative embodiment, the predetermined positions (four pressed portions 30p) in the vicinity of the four corners of the electrode stack 30 are each set in the stacking direction GH by the four pressing portions 210 in which the position in the spreading direction IH is fixed. Press with the same pressure as. Thus, when the pressed portion 30p of the electrode stack 30 overlaps the stacking direction GH, the positive electrode plate 31 and the second separator 61 that form the electrode stack 30 at the boundary 30r between the pressed portion 30p and the surrounding portion. The negative electrode plate 41 and the first separator 51 are largely deformed. Then, in the battery 1 using the electrode assembly 20 formed in this manner, the battery performance may be degraded due to, for example, a change in lithium ion permeability at the deformed portion (boundary portion 30r).

  On the other hand, in the method of manufacturing the battery 1 of the present embodiment, the pressed portion 30p (n) already pressed in the electrode stack 30 (n) at the top of the electrode stack group 30z is the stacking direction GH. A new electrode stack 30 is pressed as a portion to be pressed 30p (n + 1) of the new electrode stack 30 (n + 1) (see FIGS. 7 and 8). As a result, the electrode stack group 30z can suppress repeated pressing of the same portion in the spreading direction IH (longitudinal direction EH and horizontal direction FH) of the electrode stack 30 in the stacking direction GH. It is possible to suppress large deformation of part of the positive electrode plate 31, the second separator 61, the negative electrode plate 41 and the first separator 51).

Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be appropriately modified and applied without departing from the scope of the invention.
For example, in the embodiment, the first electrode plate in the present invention is described as the negative electrode plate 41, and the second electrode plate is described as the positive electrode plate 31, but the present invention is not limited thereto. For example, the first electrode plate may be the positive electrode plate 31 and the second electrode plate may be the negative electrode plate 41.

  In the embodiment, the pressed portion 30p (n) of the previous electrode stack 30 (n) stacked immediately before and the pressed portion 30p (n + 1) of the new electrode stack 30 (n + 1). In this example, the method of shifting the pressed portions 30p (n + 1) of the new electrode stack 30 (n + 1) little by little so that the portions do not partially overlap the stacking direction GH is exemplified. It is not limited. For example, the pressed portion 30p (n) of the previous electrode stack 30 (n) stacked immediately before and the pressed portion 30p (n + 1) of the new electrode stack 30 (n + 1) are stacked in the stacking direction. The pressed portion 30p (n + 1) of the new electrode stack 30 (n + 1) may be changed so as not to overlap with GH at all. In this case, the positions of the pressed portions 30p may be changed so that the pressed portions 30p of all the electrode stacks 30 until the electrode body 20 is formed do not overlap at all in the stacking direction GH. It may be made to overlap in the stacking direction GH.

  Further, in the embodiment, the case where the part (the pressed portion 30p) of the electrode stack 30 is pressed using the two pressing portions 210 (the pressed portion 30p has two parts) is exemplified. It is not restricted to this. For example, one pressing portion 210 may be used to press a part (the pressed portion 30p) of the electrode stack 30 (in this case, the pressed portion 30p is formed of only one portion), or three You may press a part (to-be-pressed part 30p) of the electrode laminated body 30 using the above pressurizing part 210 (In this case, the to-be-pressed part 30p consists of three or more site | parts).

  For example, even when pressing the electrode stack 30 with one pressing unit 210, as in the embodiment, the pressed portion 30p (n) of the previous electrode stack 30 (n) and the new electrode stack 30 ( The pressed portion 30p (n + 1) of the new electrode stack 30 (n + 1) is set so that the pressed portion 30p (n + 1) of n + 1) does not partially overlap in the stacking direction GH. It is possible to adopt a method of gradually shifting. In addition, the pressed portion 30p (n) of the previous electrode stack 30 (n) and the pressed portion 30p (n + 1) of the new electrode stack 30 (n + 1) do not overlap at all in the stacking direction GH. As described above, a method may be adopted in which the pressed portion 30p (n + 1) of the new electrode stack 30 (n + 1) is changed.

  Further, in the embodiment, a part (the pressed part 30p) of the electrode stack 30 is pressed using the pressing part 210 in which the tip part 210s has a hemispherical shape, but the form of the pressing part It is not limited. For example, it is possible to press a part (the pressed portion 30p) of the electrode stack 30 by using a pressing portion having a semicylindrical shape (a cross section orthogonal to the longitudinal direction is a semicircle).

  Further, in the embodiment, as the first separator 51 and the second separator 61, separators in which adhesion layers 53 and 63 made of polyethylene particles and a binder are respectively provided on both main surfaces of the separator bodies 52 and 62 are illustrated. The adhesion layers 53 and 63 are not limited to those made of polyethylene particles and a binder. For example, the adhesion layers 53 and 63 can be formed of only the binder. In this case, in a state where the electrode assembly 20 is configured (see FIG. 3), the negative electrode plate 41 and the first separator 51 are adhered by the adhesion layer 53, and the negative electrode plate 41 and the second separator 61 are adhered by the adhesion layer 63. Do. Further, the positive electrode plate 31 and the first separator 51 are adhered by the adhesion layer 53, and the positive electrode plate 31 and the second separator 61 are adhered by the adhesion layer 63.

DESCRIPTION OF SYMBOLS 1 Battery 20 Electrode body 30, 30 (n) Electrode laminated body 30p, 30p (n) Pressed part 30z Electrode laminated body group 31 Positive electrode plate (2nd electrode plate)
41 Negative plate (first electrode plate)
51 first separator 61 second separator 100 electrode body manufacturing device 190 stacked portion 200 pressing device 210 pressing portion EH longitudinal direction FH horizontal direction GH stacking direction IH spreading direction KG1, KG2 gap W1, W2 predetermined interval S1 strip-shaped positive electrode plate forming step S2 Strip negative electrode plate forming step S3 Strip first separator forming step S4 Strip second separator forming step S5 Strip composite forming step S6 Strip positive electrode plate cutting step S7 Strip electrode laminate forming step S8 Strip electrode laminate cutting step S9 Stacking step S10 Mounting step S11 Adhesion step S12 Assembly step

Claims (1)

A manufacturing method of a battery including a laminated electrode body in which a plurality of electrode laminates in which a first separator, a first electrode plate, a second separator, and a second electrode plate are laminated and integrated in this order are stacked. ,
The new electrode laminate such that the first separator of the new electrode laminate is in close contact with the second electrode plate positioned in the uppermost layer of the electrode laminate group in which a plurality of the electrode laminates are already stacked. Repeatedly stacking the electrode stacks on the electrode stack group to form the electrode body,
The above stacking process is
After stacking the new electrode stack on the electrode stack group and before stacking the next new electrode stack, the pressed portion which is a part of the new electrode stack is externally applied in the stacking direction A pressing step of pressing the new electrode laminate into contact with the electrode laminate group by pressing;
The above adhesion process is
Among the plurality of electrode laminates forming the electrode laminate group, in the electrode laminate at a point in contact with the new electrode laminate, at least a portion of the pressed portion already pressed in the lamination direction is The manufacturing method of the battery which presses the said new electrode laminated body as a to-be-pressed part of the said new electrode laminated body the site | part which does not overlap.

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