JP5994668B2 - Electrode storage separator manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing an electrode storage separator that stores an electrode of a power storage device, and an apparatus for manufacturing an electrode storage separator.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. This type of secondary battery is disclosed in Patent Document 1, for example. The secondary battery includes a positive electrode and a negative electrode, an electrode assembly in which both electrodes are insulated by a separator and laminated to form a layer. And in patent document 1, the separator which insulates both electrodes is made into a bag shape, and either one electrode is accommodated in the bag-shaped separator. Such a bag-shaped separator is manufactured by a method in which the end portions of the separator folded in two are bonded or welded to each other, or a method in which two separators are overlapped and the end portions are bonded or welded to be bonded.

JP 59-56352 A

  When the separator is welded, the heated welded portion is pressed while applying a load. However, when the separators are overlapped with each other in a state where the separators are overlapped, or when the thicknesses are not uniform, the welded portions come into contact with each other, which causes poor welding.

  This invention was made paying attention to the problem which exists in such a prior art, The objective is providing the manufacturing method and manufacturing apparatus of the electrode storage separator which can perform the welding of a separator favorably. There is.

The manufacturing method of the electrode storage separator which solves the said subject has a 1st separator, the 2nd separator facing the said 1st separator, and the storage part which stores an electrode, The said storage part and the said 1st separator And an electrode housing separator formed by welding the first separator and the second separator between the edges of the second separator, wherein the first separator and one side of the second separator Along with this, the plurality of welded portions arranged in parallel are pressed in a heated state, and the welded portions are independently controlled and welded by an actuator so as to equalize the load applied to each welded portion . According to this, it is possible to suppress welding defects caused by the contact of the welded portion as a factor by performing the welding by uniformly controlling the applied load of each welded portion. Therefore, the separator can be favorably welded.

  In the above manufacturing method, the electrode has a tab extending from an edge of the electrode, and the tab of the electrode stored in the storage portion has a surface facing the first separator and the second separator. And the first separator, the second separator, and the second separator; The welding portion can be pressed and welded to the position where the overlapping portion overlaps in a heated state. According to this, even when the thickness differs between the position where the first separator, the second separator and the tab overlap and the position where the first separator, the second separator and the tab do not overlap, the applied load of each welded portion is controlled evenly. By doing so, it is possible to suppress poor welding due to the contact of the welded part. Therefore, the separator can be favorably welded.

  In the above manufacturing method, the electrode has a tab extending from an edge of the electrode, and the tab of the electrode stored in the storage portion has a surface facing the first separator and the second separator. And the first separator and the second separator are pressed and welded in a heated state at a position where the first separator and the second separator overlap, and the first separator, the second separator, and the It is also possible to press the welding portion in a non-heated state at a position where the overlapping portion overlaps, so that the first separator, the second separator, and the tab are not welded. According to this, when the positions where the first separator, the second separator, and the tab do not overlap are welded by uniformly controlling the load applied to each welded portion, the first separator and the second separator that are thicker than the positions. And welding can be performed without being influenced by the position where the tabs overlap. Therefore, the separator can be favorably welded.

  In the above manufacturing method, it is preferable that a plurality of welding portions are arranged in parallel on each of two opposing sides of the first separator and the second separator, and the two sides are welded simultaneously. According to this, the work efficiency of welding can be improved.

An apparatus for manufacturing an electrode storage separator that solves the above-described problem includes a first separator, a second separator that faces the first separator, and a storage unit that stores an electrode, and the storage unit and the first separator. And an electrode storage separator manufacturing apparatus in which the first separator and the second separator are welded between edges of the second separator, and on one side of the first separator and the second separator. A plurality of welds arranged in parallel to each other, a heating part that heats each weld part, a pressing part that presses each weld part, and each weld by the actuator so as to equalize the load applied to each weld part. A control unit that controls the units independently . According to this, it is possible to suppress welding defects caused by the contact of the welded portion as a factor by performing the welding by uniformly controlling the applied load of each welded portion. Therefore, the separator can be favorably welded.

  In the manufacturing apparatus, the first welding device having a plurality of welding portions arranged in parallel along one side of the two opposing sides of the first separator and the second separator, and along the other side. It is preferable to include a second welding device having a plurality of welding portions arranged in parallel. According to this, the work efficiency of welding can be improved.

  According to the present invention, the separator can be favorably welded.

The perspective view which shows the external appearance of a secondary battery. The perspective view which shows the positive electrode and negative electrode which comprise an electrode assembly. The schematic diagram of a welding apparatus. The schematic diagram which shows the mode of welding. The schematic diagram which shows the mode of welding. The schematic diagram which shows the mode of welding.

Hereinafter, an embodiment embodying a manufacturing method and a manufacturing apparatus of an electrode storage separator will be described with reference to FIGS.
As shown in FIG. 1, a secondary battery 10 as a power storage device includes an electrode assembly 12 and an electrolytic solution housed in a case 11. The case 11 includes a bottomed square cylindrical case main body 13 and a rectangular flat plate-shaped lid 14 that closes an opening of the case main body 13. A positive electrode terminal 16 and a negative electrode terminal 17 are electrically connected to the electrode assembly 12. A ring-shaped insulating ring 18 for insulating from the case 11 is attached to each of the positive terminal 16 and the negative terminal 17. The positive terminal 16 and the negative terminal 17 are exposed outside the case 11 from the lid 14.

  As shown in FIG. 2, the electrode assembly 12 has a bag shape and an electrode storage separator 20 in which a positive electrode 19 is stored as an electrode, and a negative electrode 21 having a polarity different from that of the positive electrode 19. . The electrode assembly 12 has a layered structure in which a plurality of electrode storage separators 20 and a plurality of negative electrodes 21 are alternately stacked.

  The positive electrode 19 has a square sheet-like positive electrode metal foil (aluminum foil in the embodiment) 22 and a positive electrode active material layer 23 containing a positive electrode active material on both surfaces of the positive electrode metal foil 22. A positive electrode current collecting tab 24 as a tab extends from the edge 19 a of the positive electrode 19. The positive electrode current collecting tab 24 of each positive electrode 19 is electrically connected to the positive electrode terminal 16. The negative electrode 21 has a square sheet-like negative electrode metal foil (copper foil in the embodiment) 25 and a negative electrode active material layer 26 containing a negative electrode active material on both surfaces of the negative electrode metal foil 25. A negative electrode current collecting tab 27 extends from the edge 21 a of the negative electrode 21. The negative electrode current collecting tab 27 of each negative electrode 21 is electrically connected to the negative electrode terminal 17.

  As shown in FIG. 2, the electrode storage separator 20 is composed of a square sheet-shaped first separator 20a and a square sheet-shaped second separator 20b facing each other. Both the first separator 20a and the second separator 20b are made of a microporous film. The first separator 20 a and the second separator 20 b have the same size and are slightly larger than the positive electrode 19. Thus, the first separator 20a and the second separator 20b have the protruding portions 28a, 28b, 28c, and 28d that protrude from the respective edges 19a, 19b, 19c, and 19d of the positive electrode 19 in a state where the positive electrode 19 is overlapped. . The protruding portion 28 a protrudes from the edge 19 a where the positive electrode current collecting tab 24 extends in the positive electrode 19. The protruding portion 28 b protrudes from the edge 19 b on the opposite side of the side along the edge 19 a of the positive electrode 19. The protruding portion 28c protrudes from the side edge 19c orthogonal to the side along the edge 19a. The protruding portion 28d protrudes from the edge 19d on the opposite side of the side along the edge 19c.

  In the electrode storage separator 20, the protruding portions 28a to 28d facing each other of the first separator 20a and the second separator 20b are joined by a joining portion 29 formed by welding. The first separator 20a and the second separator 20b are joined all around. Further, the positive electrode current collecting tab 24 of the positive electrode 19 is located between the surfaces of the protruding portions 28a, which are the opposed surfaces of the first separator 20a and the second separator 20b, and passes between the surfaces to form the first separator 20a. And it protrudes from each edge of the 2nd separator 20b. Thereby, the positive electrode current collection tab 24 has the overlap part 24a which overlaps with the surface which the 1st separator 20a and the 2nd separator 20b oppose. And the positive electrode current collection tab 24 is joined by the junction part 29 in the overlap part 24a which is a position which overlaps with the 1st separator 20a and the 2nd separator 20b. The electrode storage separator 20 is formed by joining the first separator 20a and the second separator 20b, so that the inside of the joint portion 29 becomes the electrode storage portion S, and ends of the storage portion S, the first separator 20a, and the second separator 20b. It is welded between the edges.

Next, an apparatus for manufacturing the electrode storage separator 20 will be described.
As shown in FIG. 3, the manufacturing apparatus includes a mounting table 30 on which the electrode storage separator 20 is mounted during welding work, and a plurality of welding mechanisms 32 supported by the support portion 31. The welding mechanism 32 includes a block-shaped welding portion 33 that is pressed against an object to be welded during a welding operation, a rod 34 that is connected to the welding portion 33 and expands and contracts, and an actuator 35 that expands and contracts the rod 34. The actuator 35 is, for example, a device that expands and contracts the rod 34 by hydraulic pressure or pneumatic pressure, or a device that expands and contracts the rod 34 by a motor. Each welding portion 33 moves toward and away from the object to be welded by the actuator 35 extending and contracting the rod 34. In this embodiment, the actuator 35 and the rod 34 constitute a pressing portion. The actuator 35 has a pressure detection mechanism such as a pressure sensor.

  The plurality of welding mechanisms 32 are supported by the support portion 31 in a state where the respective welding portions 33 are arranged in a straight line. Thereby, at the time of welding work, the some welding part 33 is arrange | positioned so that the one side of the 1st separator 20a and the 2nd separator 20b may be followed, and the one side can be welded at a time. And the manufacturing apparatus of this embodiment has the 1st welding apparatus 36 which supported the some welding mechanism 32 in the support part 31, and the 2nd welding apparatus 37 of the same structure as the 1st welding apparatus 36, These Two opposing sides of the first separator 20a and the second separator 20b can be welded simultaneously by two sets of welding devices.

  In addition, the manufacturing apparatus includes a control unit 38 that controls the operation of the actuator 35, a moving mechanism 39 that moves the first welding device 36 and the second welding device 37 to predetermined welding positions, and a welding portion 33 of each welding mechanism 32. And a heating unit 40 for heating.

Next, the operation of the manufacturing apparatus will be described together with a method for manufacturing the electrode storage separator 20.
As shown in FIG. 4, at the time of welding operation, a first welding device 36 and a second welding device 37 are disposed at the welding positions of the first separator 20a and the second separator 20b. FIG. 4 shows a state in which the first welding device 36 and the second welding device 37 are respectively arranged on the edge 19a side of the positive electrode 19 and the edge 19b facing the edge 19a.

  In this arrangement, each welding part 33 is heated to a temperature required for welding by the heating part 40. And each welding part 33 of the heated state is pressed by the operation | movement of each actuator 35 by making the 1st separator 20a and the 2nd separator 20b into a welding target object. At this time, the control part 38 monitors the detection result of the pressure detection mechanism of each actuator 35, and controls each welding mechanism 32 independently. Specifically, the control unit 38 stops the operation of the actuator 35 of the welded portion 33 when the applied load when the welded portion 33 is pressed reaches a predetermined load. By this control, the control unit 38 adjusts the operation of the actuator 35 of each welding part 33 so that the applied load of each welding part 33 is equalized. Thereby, the 1st separator 20a and the 2nd separator 20b are welded in the state in which the applied load of each welding part 33 was equalized. In the manufacturing apparatus of this embodiment, when the welding on the edge 19a side and the edge 19b side is completed, the first welding device 36 and the second welding device 37 are on the edge 19c side and the end facing the edge 19c. Each moves to the edge 19d, and welding is performed.

  As shown in FIG. 5, when the first separator 20a and the second separator 20b are overlapped with each other, the portion where the overlapping portion 24a of the positive current collecting tab 24 is located between the surfaces is located at the positive current collecting tab 24. The thickness is thicker than the portion where the first separator 20a and the second separator 20b overlap each other. As described above, in the manufacturing apparatus of this embodiment, even when there are portions having different thicknesses when the first separator 20a and the second separator 20b are overlapped as described above, the load applied to each welded portion 33 is equalized as described above. Welding is controlled. Thereby, the imbalance of the applied load of the welding part 33 is avoided, and the applied load does not increase or decrease locally.

  Further, as shown in FIG. 6, for example, when wrinkles are generated on the first separator 20a side, the thickness when the first separator 20a and the second separator 20b are overlapped varies. Even in such a case, in the manufacturing apparatus of this embodiment, welding is performed by equally controlling the applied load of each welding portion 33 as described above.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) By controlling the applied load of each welded portion 33 evenly, it is possible to suppress poor welding caused by the contact of the welded portion 33 as a factor. Therefore, the electrode storage separator 20 can be favorably welded.

  (2) For example, when a load is locally applied at the time of welding, it may melt excessively or may transmit heat more than necessary. In such a case, an electrode having a desired size may not be obtained due to the shrinkage of the separator, and the separator may be clogged (shut down). In addition, when sufficient heat cannot be applied due to contact with one piece or the like, the separator does not melt and cannot be welded. However, according to the configuration of the embodiment, since the applied load of each welding portion 33 is controlled uniformly, the occurrence of the above situation can be avoided.

(3) By welding one side at a time, it is difficult to be affected by the shrinkage of the separator during welding, and good welding can be performed.
(4) The welding work efficiency can be improved by welding two opposing sides simultaneously.

  (5) Even if the thickness is different between the position where the first separator 20a, the second separator 20b and the positive electrode current collecting tab 24 overlap and the position where the first separator 20a, the second separator 20b and the positive electrode current collecting tab 24 do not overlap, By uniformly controlling the applied load of each welded portion 33, it is possible to suppress welding defects caused by the contact of the welded portion 33 as a factor. Therefore, the electrode storage separator 20 can be favorably welded.

In addition, you may change this embodiment as follows.
The position where the first separator 20a, the second separator 20b, and the positive electrode current collecting tab 24 overlap does not need to be welded. In this case, in the manufacturing apparatus of the above embodiment, the welding mechanism 32 can be controlled independently, so that the welding portion 33 is pressed against the welding mechanism 32 at a position overlapping the positive electrode current collecting tab 24 in an unheated state. The positive electrode current collecting tab 24 may not be welded to either the first separator 20a or the second separator 20b. According to this configuration, when the positions where the first separator 20a, the second separator 20b, and the positive electrode current collecting tab 24 do not overlap each other are welded by uniformly controlling the load applied to each welding portion 33, the thickness is thicker than that position. The first separator 20a, the second separator 20b, and the positive electrode current collecting tab 24 can be welded without being affected by the overlapping position. Therefore, the electrode storage separator 20 can be favorably welded. Moreover, the structure of the welding apparatus for welding the edge | side with and without the positive electrode current collection tab 24 can be made into the same structure. Note that “non-heated” is not limited to a state in which no thermal energy is applied, and is heated in a state lower than the melting temperature of the first separator 20a and the second separator 20b, It includes a state where the first separator 20a and the second separator 20b are heated at a temperature at which they are not welded even when pressed.

(Circle) at the time of welding, you may press the welding part 33 from whichever side of the 1st separator 20a and the 2nd separator 20b.
The electrode storage separator 20 may be configured by folding one separator in half. In this case, welding locations can be reduced.

The electrode stored in the electrode storage separator 20 may be changed to the negative electrode 21.
In the manufacturing apparatus, the number of welding mechanisms 32 supported by one set of support portions 31 can be arbitrarily set. The number of welding mechanisms 32 can be set according to the bonding strength between the first separator 20a and the second separator 20b, but the larger the number, the easier it is to suppress poor welding due to piece contact.

  The support part 31 may be an annular support part, and a plurality of welds 33 may be arranged along the four sides of the positive electrode 19 so that the four sides are welded simultaneously. If comprised in this way, while shortening welding time, it is hard to receive to the influence of the shrinkage | contraction of the separator at the time of welding, and favorable welding can be performed.

In addition, only one set of welding apparatuses may be provided in the manufacturing apparatus, and the welding operation may be performed on each side.
The secondary battery 10 may be a lithium ion secondary battery or another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer and the negative electrode active material layer and transfer charge. Further, a capacitor may be used as the power storage device.

  (Circle) the secondary battery 10 of embodiment may be mounted in a motor vehicle as a vehicle power supply device, and may be mounted in an industrial vehicle. Further, the present invention may be applied to a stationary power storage device.

  S: storage part, 19: positive electrode, 19a: edge, 20 ... electrode storage separator, 20a ... first separator, 20b ... second separator, 24 ... positive current collecting tab, 24a ... overlapping part, 33 ... welding part, 36 ... 1st welding apparatus, 37 ... 2nd welding apparatus, 38 ... Control part, 40 ... Heating part.

Claims (6)

A first separator; a second separator that faces the first separator; and a storage portion that stores an electrode; and between the storage portion and an edge of the first separator and the second separator, A method of manufacturing an electrode storage separator formed by welding a first separator and the second separator,
The welding is performed by an actuator so as to press the plurality of welded portions arranged in parallel along one side of the first separator and the second separator in a heated state, and to equalize the load applied to each welded portion. A method of manufacturing an electrode storage separator that is controlled and welded independently . The electrode has a tab extending from an edge of the electrode;
The tab of the electrode housed in the housing portion has an overlapping portion that overlaps the opposing surfaces of the first separator and the second separator,
The first separator and the second separator are pressed and welded in a state where the welding portion is heated;
The manufacturing method of the electrode storage separator of Claim 1 which presses and welds in the state which the said welding part heated at the position where the said 1st separator, the said 2nd separator, and the said overlap part overlap. The electrode has a tab extending from an edge of the electrode;
The tab of the electrode housed in the housing portion has an overlapping portion that overlaps the opposing surfaces of the first separator and the second separator,
At the position where the first separator and the second separator overlap, the welding part is pressed and welded in a heated state,
The welding portion is pressed in a non-heated state at a position where the first separator, the second separator, and the overlapping portion overlap, and the first separator, the second separator, and the tab are welded. The manufacturing method of the electrode storage separator of Claim 1.   The electrode according to any one of claims 1 to 3, wherein a plurality of welded portions are arranged in parallel on each of two opposing sides of the first separator and the second separator, and the two sides are welded simultaneously. A method for manufacturing a storage separator. A first separator; a second separator that faces the first separator; and a storage portion that stores an electrode; and between the storage portion and an edge of the first separator and the second separator, An apparatus for manufacturing an electrode storage separator formed by welding a first separator and the second separator,
A plurality of welds arranged in parallel along one side of the first separator and the second separator;
A heating part for heating each welded part;
A pressing portion that presses each welded portion;
An apparatus for manufacturing an electrode storage separator, comprising: a control unit that controls each welding part independently by an actuator so as to equalize the load applied to each welding part . A first welding device having a plurality of welding portions arranged in parallel along one side of the first separator and the two opposing sides of the second separator;
The manufacturing apparatus of the electrode storage separator of Claim 5 provided with the 2nd welding apparatus which has a some welding part paralleled along the other side.