JP2021002428A - Device for manufacturing power storage device - Google Patents

Abstract

To provide a device for manufacturing a power storage device, capable of suppressing a deterioration in performance of a power storage device due to welding.SOLUTION: A device for manufacturing a power storage device that includes a cell stack held by a pair of restraint plates and a pair of end plates includes: a base on which the cell stack, the pair of restraint plates and the pair of end plates can be placed; a restraint unit which restrains the cell stack and the pair of end plates placed on the base; and a welding unit which welds one of the pair of end plates placed on the base to the pair of restraint plates placed on the base. The restraint unit includes: a pressing part which is brought into contact with the one of the pair of end plates placed on the base; and a heat dissipation structure provided to the pressing part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a manufacturing device for a power storage device.

As a kind of power storage device, there is an assembled battery (cell stack) configured by holding a plurality of arranged battery cells (cells). Patent Document 1 below discloses an embodiment in which a plurality of cells arranged in a row are held by a pair of end plates and bolts and nuts.

JP-A-2015-79564

From the viewpoint of reducing the number of parts, the use of a cell stack held by a plurality of welded restraint plates is being studied. In this case, the heat diffused in the cell stack due to the welding of the restraint plates may adversely affect the storage cells in the cell stack. As a result, the performance of the power storage device may deteriorate.

An object of the present invention is to provide a power storage device manufacturing device capable of suppressing performance deterioration of the power storage device due to welding.

The power storage device manufacturing device according to one aspect of the present invention is a power storage device manufacturing device including a cell stack held by a pair of restraint plates and a pair of end plates. The manufacturing apparatus includes a cell stack, a base on which a pair of restraint plates and a pair of end plates can be arranged, a restraint unit for restraining the cell stack and a pair of end plates arranged on the base, and a base on the base. A welding unit for welding one of a pair of arranged end plates to a pair of restraint plates arranged on a base is provided. The restraint unit has a pressing portion that contacts one of the pair of end plates arranged on the base, and a heat radiating structure provided on the pressing portion.

The restraint unit of the manufacturing apparatus is provided with a heat dissipation structure at a pressing portion in contact with end plates welded to a pair of restraint plates. As a result, the heat conducted to the end plates during welding of the end plates and the pair of restraint plates is satisfactorily diffused to the outside through the pressing portion. Therefore, it is possible to suppress the temperature rise of the storage cell in the cell stack. Therefore, by using the above-mentioned manufacturing apparatus, it is possible to suppress the deterioration of the performance of the power storage device due to welding.

The heat radiating structure may have a convex portion provided on the surface of the pressing portion. Further, the heat dissipation structure may be provided inside the pressing portion and may have a passage through which the refrigerant passes. In these cases, since the pressing portion is easily cooled by the heat dissipation structure, the temperature rise of the storage cell in the cell stack can be satisfactorily suppressed.

The thermal conductivity of the pressing portion may be 100 W / mK or more. In this case, since the heat conducted to the end plate during welding is easily conducted to the pressing portion, the temperature rise of the storage cell in the cell stack can be satisfactorily suppressed.

According to one aspect of the present invention, it is possible to provide a power storage device manufacturing device capable of suppressing performance deterioration of the power storage device due to welding.

FIG. 1 is a schematic plan view showing a manufacturing apparatus for a power storage device according to the first embodiment. FIG. 2A is a schematic perspective view of the power storage device, and FIG. 2B is an enlarged cross-sectional view of a region surrounded by the alternate long and short dash line shown in FIG. 2A. FIG. 3 is a schematic perspective view of the storage cell. FIG. 4 is a schematic plan view showing a manufacturing apparatus for the power storage device according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate description is omitted.

(First Embodiment)
FIG. 1 is a schematic plan view showing a manufacturing apparatus for a power storage device according to the first embodiment. The manufacturing apparatus 1 shown in FIG. 1 is an apparatus used for manufacturing the power storage device 100. In the following, the outline of the power storage device 100 will be described first with reference to FIGS. 2 (a) and 2 (b) and FIG. FIG. 2A is a schematic perspective view of the power storage device, and FIG. 2B is an enlarged cross-sectional view of a region surrounded by the alternate long and short dash line shown in FIG. 2A. FIG. 3 is a schematic perspective view of the storage cell.

The power storage device 100 shown in FIG. 2A includes a cell stack 101 composed of a plurality of power storage cells 200 arranged along a predetermined direction, and a restraint member 102 that restrains the cell stack 101. In the following, the predetermined direction is referred to as a direction X, a direction intersecting or orthogonal to the direction X is referred to as a direction Y, and a direction intersecting or orthogonal to the direction X and the direction Y is referred to as a direction Z. In the first embodiment, the directions X, Y, Z are orthogonal to each other. Further, "viewing from the direction Z" corresponds to a plan view.

The cell stack 101 includes a plurality of storage cells 200 constrained by the restraint member 102. Each storage cell 200 in the cell stack 101 is connected in series or in parallel to each other via a bus bar or the like (not shown). The cell stack 101 may appropriately include members (elastic members, metal plates, etc.) other than the storage cell 200. In the first embodiment, each of the storage cells 200 included in the cell stack 101 is held by a cell holder (not shown).

As shown in FIG. 3, the storage cell 200 is a secondary battery such as a lithium ion battery or a nickel hydrogen storage battery. The power storage cell 200 includes a main body 201 having a substantially rectangular parallelepiped shape, and terminals 202 and 203 located on one surface 201a of the main body 201. The inside of the main body 201 is filled with a positive electrode, a negative electrode, a separator, and an electrolyte.

The restraint member 102 is a frame-shaped member that surrounds the cell stack 101 in a plan view, and includes a pair of end plates 111 and 112 and a pair of restraint plates 121 and 122. Therefore, in a plan view, the cell stack 101 is surrounded and held by a pair of end plates 111 and 112 and a pair of restraint plates 121 and 122.

The end plates 111 and 112 are plate-shaped members that restrain the cell stack 101 along the direction X. Therefore, the end plates 111 and 112 can be said to be restraint plates. The end plate 111 abuts on one end of the cell stack 101 in direction X, and the end plate 112 abuts on the other end of the cell stack 101 in direction X. Each of the end plates 111 and 112 is a metal plate or an alloy plate, and has a substantially rectangular shape when viewed from the direction X.

The restraint plates 121 and 122 are plate-shaped members that restrain the cell stack 101 along the direction Y. The restraint plate 121 abuts on one end of the cell stack 101 in the direction Y, and the restraint plate 122 abuts on the other end of the cell stack 101 in the direction Y. Each of the restraint plates 121 and 122 is a metal plate or an alloy plate, and has a substantially rectangular shape when viewed from the direction Y. Further, the restraint plate 121 has a substantially C shape when viewed from the direction X. That is, protrusions 121a extending toward the center of the cell stack 101 in the direction Y are provided at both ends of the restraint plate 121 along the direction Z. Similar to the restraint plate 121, protrusions 122a extending toward the center of the cell stack 101 in the direction Y are provided at both ends of the restraint plate 122 along the direction Z. The protruding portions 121a and 122a are portions that are hooked on the power storage cell 200 (or the cell holder of the power storage cell 200).

The end plate 111 and the restraint plates 121 and 122 are integrated via welded portions 131 and 132. The welded portion 131 is a fillet welded portion provided on one end portion 111a of the end plate 111 in the direction Y and the restraint plate 121. The welded portion 132 is a fillet welded portion provided on the other end of the end plate 111 in the direction Y and the restraint plate 122, similarly to the welded portion 131. Each of the one end 111a and the other end is a portion that is located outward in the direction X and has rounded corners extending along the direction Z. The one end 111a and the other end may be, for example, a notch. The end plates 112 and the restraint plates 121 and 122 are also integrated via the same welded portions as the welded portions 131 and 132. Therefore, it can be said that the restraint member 102 is a member formed by integrating the pair of end plates 111 and 112 and the pair of restraint plates 121 and 122.

Next, returning to FIG. 1, the configuration of the manufacturing apparatus 1 will be described in detail. In the first embodiment, the manufacturing apparatus 1 is an apparatus for forming a restraint member 102 for holding the cell stack 101. More specifically, the manufacturing apparatus 1 is an apparatus for welding the end plates 111 and 112 included in the restraint member 102 and the restraint plates 121 and 122. The manufacturing apparatus 1 includes a base 2, welding units 3 and 4, a first restraint unit 5, and a second restraint unit 6.

The base 2 is a table on which the cell stack 101, the pair of end plates 111, 112, and the pair of restraint plates 121, 122 can be arranged. The base 2 has a substantially rectangular shape in a plan view, for example. The surface of the base 2 may be provided with a structure (marker, protrusion, etc.) for aligning the cell stack 101 or the like.

The welding unit 3 is a device that welds the end plate 111 arranged on the base 2 and the pair of restraint plates 121, 122, and can perform, for example, spot welding, arc welding, and the like. The welding unit 3 is located on one side of the base 2 in the direction X in a plan view, and is separated from the base 2. That is, the base 2 and the welding unit 3 are provided independently of each other. The welding unit 3 includes a power supply 21, a robot arm 22 connected to the power supply 21, and an end effector 23 attached to the tip of the robot arm 22. The power supply 21 is a power supply source and a control unit having a controller for driving the robot arm 22 and the end effector 23. The robot arm 22 has one or more joints and a motor, and is a component that moves the mounted end effector 23 in the directions X, Y, and Z. The end effector 23 is a component that executes welding by supplying electric power from the power source 21.

The welding unit 4 is the same device as the welding unit 3, and is a device for welding the end plate 112 arranged on the base 2 and the pair of restraint plates 121 and 122. The welding unit 4 is located on the other side in the direction X from the base 2 in a plan view, and is separated from the base 2. That is, the base 2 and the welding unit 4 are provided independently of each other, and the welding unit 4 is located on the opposite side of the welding unit 3 with the base 2 sandwiched in the direction X. The welding unit 4 includes a power supply 24, a robot arm 25 connected to the power supply 24, and an end effector 26 attached to the tip of the robot arm 25. The power supply 24, the robot arm 25, and the end effector 26 exhibit the same functions as the power supply 21, the robot arm 22, and the end effector 23, respectively.

The first restraint unit 5 is a device that restrains the cell stack 101 and the pair of end plates 111 and 112 arranged on the base 2 along the direction X. The first restraint unit 5 presses the first pressing device 31 that presses one of the end plates 111 and 112 arranged on the base 2 and the other of the end plates 111 and 112 arranged on the base 2. It has a second pressing device 32.

The first pressing device 31 is a device that presses the cell stack 101 along the direction X via one of the end plates 111 and 112, and is separated from the base 2. That is, the first pressing device 31 and the base 2 are provided independently of each other. The first pressing device 31 includes a main body 33 and a cylinder 34 that is attached to the main body 33 and can move forward and backward along the direction X. The main body 33 is a portion that controls the advance / retreat of the cylinder 34, and is located between the base 2 and the power supply 21 of the welding unit 3 in the direction X. A fluid (gas, liquid) may be supplied to the main body 33. The cylinder 34 has a main body portion 34a having a substantially rod shape, and a pressing portion 34b located at the tip of the main body portion 34a and capable of contacting one of the end plates 111 and 112. The cylinder 34 moves forward and backward due to, for example, an electronic signal from the main body 33 and a fluid supplied to or discharged from the main body 33. The first pressing device 31 is, for example, an actuator, a hydraulic cylinder, a gas cylinder (gas spring), or the like.

A convex portion 34c that functions as a heat radiating structure is provided on a part of the surface of the pressing portion 34b. The convex portion 34c is a portion provided to increase the surface area of the pressing portion 34b. The convex portion 34c may be provided on a surface other than the tip surface 34d that can abut on one of the end plates 111 and 112 in the pressing portion 34b. In the first embodiment, a plurality of convex portions 34c are provided on the surface of the pressing portion 34b. The dimension of the tip surface 34d along the direction Y is shorter than the dimension of the end plates 111 and 112 along the direction Y. Therefore, for example, when the tip surface 34d comes into contact with the end plate 111, one end 111a and the other end of the end plate 111 are exposed.

The pressing portion 34b may be formed of the same material as the main body portion 34a, or may be formed of a different material. From the viewpoint of improving the heat dissipation performance of the pressing portion 34b, the thermal conductivity of the pressing portion 34b is higher than the thermal conductivity of stainless steel, for example, 100 W / mK or more. Therefore, the metal constituting the pressing portion 34b is, for example, aluminum, copper, tungsten, molybdenum, or the like. From the viewpoint of cost and the like, the metal may be aluminum or copper. The alloy constituting the pressing portion 34b is, for example, brass or the like. The stainless steel is, for example, an alloy in accordance with the provisions of JIS G 4305: 2012.

The second pressing device 32 is a device that presses the cell stack 101 along the direction X via the other of the end plates 111 and 112, and is separated from the base 2. That is, the second pressing device 32 and the base 2 are provided independently of each other. The second pressing device 32 includes a main body 35 and a cylinder 36 that is attached to the main body 35 and can move forward and backward along the direction X. The main body 35 is a portion that controls the advance / retreat of the cylinder 36, and is located on the opposite side of the first pressing device 31 with the base 2 sandwiched in the direction X. Therefore, the second pressing device 32 is located on the other side in the direction X from the base 2 in a plan view. Further, the second pressing device 32 is located between the base 2 and the power supply 24 of the welding unit 4 in the direction X. The cylinder 36 has a main body portion 36a having a substantially rod shape, and a pressing portion 36b located at the tip of the main body portion 36a and capable of contacting the other of the end plates 111 and 112. The cylinder 36 advances and retreats due to, for example, an electronic signal from the main body 35 and a fluid supplied to or discharged from the main body 35. The second pressing device 32 is, for example, an actuator, a hydraulic cylinder, a gas cylinder (gas spring), or the like, like the first pressing device 31.

The pressing portion 36b is formed of the same material as the pressing portion 34b. Further, similarly to the pressing portion 34b, a convex portion 36c is provided on a part of the surface of the pressing portion 36b. The convex portion 36c may be provided on a surface other than the tip surface 36d that can abut the other of the end plates 111 and 112 in the pressing portion 36b. In the first embodiment, a plurality of convex portions 36c are provided on the surface of the pressing portion 36b. The dimension of the tip surface 36d along the direction Y is shorter than the dimension of the end plates 111 and 112 along the direction Y. Therefore, for example, when the tip surface 36d comes into contact with the end plate 112, both ends of the end plate 112 along the direction Y are exposed.

The pressing force of the first pressing device 31 (that is, the thrust of the cylinder 34) and the pressing force of the second pressing device 32 (that is, the thrust of the cylinder 36) may be the same or different from each other. When the pressing force of the first pressing device 31 and the pressing force of the second pressing device 32 are different from each other, the lower pressing force corresponds to the binding force of the cell stack 101, for example, 1 kN or more and 20 kN or less.

The second restraint unit 6 is a device that restrains the cell stack 101 and the pair of restraint plates 121 and 122 arranged on the base 2 along the direction Y. The second restraint unit 6 presses the third pressing device 41 that presses one of the restraint plates 121 and 122 arranged on the base 2 and the other of the restraint plates 121 and 122 arranged on the base 2. It has a fourth pressing device 42.

The third pressing device 41 is a device that presses the cell stack 101 along the direction Y via one of the restraint plates 121 and 122, and is separated from the base 2. That is, the third pressing device 41 and the base 2 are provided independently of each other. The third pressing device 41 includes a main body 43 and a cylinder 44 that is attached to the main body 43 and can move forward and backward along the direction Y. The main body 43 is a portion that controls the advance / retreat of the cylinder 44, and is located on one side in the direction Y with respect to the base 2 in a plan view. The cylinder 44 has a main body portion 44a having a substantially rod shape, and a pressing portion 44b located at the tip of the main body portion 44a and capable of contacting one of the restraint plates 121 and 122. The cylinder 44 moves forward and backward due to, for example, an electronic signal from the main body 43 and a fluid supplied to or discharged from the main body 43. The third pressing device 41 is, for example, an actuator, a hydraulic cylinder, a gas cylinder (gas spring), or the like.

The pressing portion 44b may be formed of the same material as the main body portion 44a, or may be formed of a different material. Further, the dimensions of the pressing portion 44b along the direction X may be the same as or different from the dimensions of the restraint plates 121 and 122 along the direction X.

The fourth pressing device 42 is a device that presses the cell stack 101 along the direction Y via the other of the restraint plates 121 and 122, and is separated from the base 2. That is, the fourth pressing device 42 and the base 2 are provided independently of each other. The fourth pressing device 42 includes a main body 45 and a cylinder 46 that is attached to the main body 45 and can move forward and backward along the direction Y. The main body 45 is a portion that controls the advance / retreat of the cylinder 46, and is located on the opposite side of the third pressing device 41 with the base 2 sandwiched in the direction Y. That is, the main body 45 is located on the other side in the direction Y from the base 2 in a plan view. The cylinder 46 has a main body portion 46a having a substantially rod shape, and a pressing portion 46b located at the tip of the main body portion 46a and capable of contacting the other of the restraint plates 121 and 122. The cylinder 46 advances and retreats due to, for example, an electronic signal from the main body 45 and a fluid supplied to or discharged from the main body 45. The fourth pressing device 42 is, for example, an actuator, a hydraulic cylinder, a gas cylinder (gas spring), or the like.

The pressing portion 46b may be formed of the same material as the main body portion 46a, or may be formed of a different material. Further, the dimensions of the pressing portion 46b along the direction X may be the same as or different from the dimensions of the restraint plates 121 and 122 along the direction X.

In the first embodiment, the pressing force of the third pressing device 41 (that is, the thrust of the cylinder 44) and the pressing force of the fourth pressing device 42 (that is, the thrust of the cylinder 46) are the same as each other. For example, the pressing force of the third pressing device 41 corresponds to the binding force of the cell stack 101, and is, for example, 50 N or more and 500 N or less.

According to the manufacturing apparatus 1 according to the first embodiment described above, the pressing portion 34b included in the first pressing device 31 of the first restraint unit 5 and in contact with the end plates 111 welded to the restraint plates 121 and 122. Is provided with a convex portion 34c which is a heat dissipation structure. As a result, the heat conducted to the end plate 111 during welding of the end plate 111 and the pair of restraint plates 121 and 122 is satisfactorily diffused to the outside via the pressing portion 34b. Further, the pressing portion 36b included in the second pressing device 32 of the first restraining unit 5 and in contact with the end plate 112 welded to the restraining plates 121 and 122 is also provided with a convex portion 36c having a heat dissipation structure. .. As a result, the heat conducted to the end plate 112 during welding of the end plate 112 and the pair of restraint plates 121 and 122 is satisfactorily diffused to the outside via the pressing portion 36b. Therefore, it is possible to suppress a temperature rise of the storage cell 200 in the cell stack 101, particularly the storage cell 200 adjacent to the end plates 111 and 112. Therefore, by using the manufacturing apparatus 1, it is possible to suppress the deterioration of the performance of the power storage device 100 due to welding.

In the first embodiment, the thermal conductivity of the pressing portion 34b may be 100 W / mK or more. In this case, since the heat conducted to the end plate 111 at the time of welding is easily conducted to the pressing portion 34b, the temperature rise of the storage cell 200 in the cell stack 101 can be satisfactorily suppressed. Similarly, the thermal conductivity of the pressing portion 36b may be 100 W / mK or more.

(Second Embodiment)
Hereinafter, the manufacturing apparatus of the power storage device according to the second embodiment will be described. In the description of the second embodiment, the description overlapping with the first embodiment will be omitted, and the part different from the first embodiment will be described. That is, the description of the first embodiment may be appropriately used for the second embodiment to the extent technically possible.

FIG. 4 is a schematic plan view showing a manufacturing apparatus for the power storage device according to the second embodiment. As shown in FIG. 4, the manufacturing apparatus 1A according to the second embodiment has a different pressing portion from the manufacturing apparatus 1 according to the first embodiment. Specifically, the cylinder 34A included in the first restraint unit 5A of the manufacturing apparatus 1A includes a pressing portion 34e. The pressing portion 34e is provided inside the pressing portion 34e and has a passage 34f through which the refrigerant passes. The passage 34f corresponds to the heat dissipation structure of the pressing portion 34e, and is connected to the refrigerant supply device 51 via the pipes 52 and 53. The refrigerant supply device 51 is a device for supplying the refrigerant into the passage 34f, and has, for example, a pump or the like. The refrigerant supply device 51 supplies the refrigerant to the passage 34f via the pipe 52. Further, the refrigerant supply device 51 recovers the refrigerant that has received heat from the pressing portion 34e via the pipe 53. The recovered refrigerant is cooled again by, for example, the refrigerant supply device 51. The refrigerant is a fluid (gas or liquid). From the viewpoint of cost and the like, for example, water is used as the refrigerant.

The cylinder 36A included in the manufacturing apparatus 1A includes a pressing portion 36e. The pressing portion 36e has a passage 36f through which the refrigerant passes, similarly to the pressing portion 34e. The passage 36f corresponds to the heat dissipation structure of the pressing portion 36e, and is connected to the refrigerant supply device 54 via the pipes 55 and 56. The refrigerant supply device 54 is the same device as the refrigerant supply device 51.

Even when the manufacturing apparatus 1A according to the second embodiment is used, the same effects as those of the first embodiment can be obtained.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment. For example, the first embodiment and the second embodiment may be combined. In this case, since the pressing portion has both a convex portion and a passage, the heat dissipation performance of the pressing portion can be further improved. Further, from the viewpoint of increasing the surface area of the pressing portion, the pressing portion may be provided with not only a convex portion but also a concave portion.

In the above embodiment, the cylinder included in the first restraint unit may also have a heat dissipation structure. For example, a passage through which the refrigerant passes may be provided inside the cylinder.

In the above embodiment, the pressing portion of each cylinder included in the second restraint unit may have at least one of the above heat dissipation structures. In this case, the heat conducted to the restraint plate during welding of the end plate and the restraint plate is satisfactorily diffused to the outside through the pressing portion. Therefore, the temperature rise of the storage cell in the cell stack can be better suppressed. Further, the cylinder included in the second restraint unit may also have a heat dissipation structure.

In the above embodiment, the welding unit or the like may be provided with a sensor for detecting the position of the cell stack or the like. In this case, the welding quality can be improved.

In the second embodiment, the refrigerant supply device does not necessarily have to be provided. For example, when the refrigerant is a gas such as air, the refrigerant supply device and piping may not be provided.

1,1A ... Manufacturing equipment, 2 ... Base, 3,4 ... Welding unit, 5 ... First restraint unit, 6 ... Second restraint unit, 31 ... First pressing device, 32 ... Second pressing device, 34,34A , 36, 36A, 44, 46 ... Cylinder, 34a, 36a, 44a, 46a ... Main body, 34b, 34e, 36b, 36e, 44b, 46b ... Pressing part, 34f, 36f ... Passage, 41 ... Third pressing device, 42 ... 4th pressing device, 100 ... power storage device, 101 ... cell stack, 102 ... restraint member, 111, 112 ... end plate, 121, 122 ... restraint plate, 131, 132 ... welded portion.

Claims (4)

A device for manufacturing a power storage device including a cell stack held by a pair of restraint plates and a pair of end plates.
A base on which the cell stack, the pair of restraint plates, and the pair of end plates can be arranged,
A restraint unit that restrains the cell stack and the pair of end plates arranged on the base, and
A welding unit that welds one of the pair of end plates arranged on the base to the pair of restraint plates arranged on the base.
With
The restraint unit has a pressing portion that contacts one of the pair of end plates arranged on the base, and a heat radiating structure provided on the pressing portion.
Manufacturing equipment. The manufacturing apparatus according to claim 1, wherein the heat radiating structure has a convex portion provided on the surface of the pressing portion. The manufacturing apparatus according to claim 1 or 2, wherein the heat radiating structure is provided inside the pressing portion and has a passage through which a refrigerant passes. The manufacturing apparatus according to any one of claims 1 to 3, wherein the heat conductivity of the pressing portion is 100 W / mK or more.

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