JP2016031848A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure good sealability without requiring high clearance accuracy between a case body and a lid in a joining process of joining the case body and the lid.SOLUTION: In a power storage device (secondary battery 10), an electrode assembly 12 is housed in a case body 13 having an opening, and the opening is blocked by a lid 14. The case body 13 and the lid 14 are joined in the state where a three dimensional carbon fiber-reinforced thermoplastic resin 18 is interposed between the case body 13 and the lid 14, and the lid 14 is plastically deformed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power storage device, and more particularly, to a power storage device characterized by a joint structure between a case main body in which an electrode assembly is accommodated and a lid.

  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. In this type of secondary battery, the electrode assembly is housed in the case body, and the case is kept airtight by closing the opening of the case body with a lid. When the opening of the case body is closed with a lid, the case body and the lid are joined by welding.

  As a method for welding the case main body and the lid, as shown in FIG. 9, when the opening of the case main body 51 that houses the electrode assembly is closed with the lid 52, the joined portion between the case main body 51 and the lid 52 is used. A metal plate 54 having the same melting point as that of the case main body 51 and the lid body 52 is disposed at 53. And at the time of welding, the to-be-joined part 53 is welded by laser welding (keyhole type welding) by melting the to-be-joined part 53 together with the metal plate 54 by the laser beam 56 emitted from the laser beam irradiation head 55. Has been proposed (see Patent Document 1).

JP 2014-50876 A

  There is no problem as long as the case body 51, the lid body 52, and the metal plate 54 are formed with high accuracy. However, due to manufacturing variations of the case body 51, the lid body 52, and the metal plate 54, when laser welding is performed, the gap between the case body 51 and the lid body 52 as shown in FIGS. When the gap 57 is generated or the metal plate 54 is floated, heat is not easily transmitted to the three members, and welding defects such as blow holes and cracks are likely to occur. Further, a jig for pressing and fixing the metal plate 54 is required, and the process becomes complicated.

  The present invention has been made in view of the above problems, and its object is to require high clearance accuracy between the case main body and the lid body in the joining step of joining the case main body and the lid body. It is an object of the present invention to provide a power storage device that can ensure good sealing performance.

  A power storage device that solves the above problems is a power storage device in which an electrode assembly is housed in a case body having an opening, and the opening is closed by a lid, and the case body and the lid are both A three-dimensional carbon fiber reinforced thermoplastic resin is interposed therebetween, and the lid is joined in a plastically deformed state. Here, the “three-dimensional carbon fiber” means a three-dimensional woven fabric, a three-dimensional braid (three-dimensional braiding), or a laminated fiber layer having at least biaxial orientation in which fiber layers made of continuous fibers are laminated. A structure in which a plurality of carbon yarns or carbon fiber bundles are three-dimensionally organized in a state where the carbon fiber bundles or carbon fiber bundles intersect with each other, such as those joined by thickness direction yarns that intersect with each other.

  According to this configuration, in the joining step of joining the case main body and the lid body, the periphery of the lid body is a heating roller in a state where the three-dimensional carbon fiber reinforced thermoplastic resin exists between the case main body and the lid body. After the resin part of the three-dimensional carbon fiber reinforced thermoplastic resin is melted by being sequentially heated in a pressed state, the case body and the lid body are replaced with the three-dimensional carbon fiber reinforced thermoplastic resin by returning to the solid state. Are joined together. Even if there is a gap between the case body and the lid body with the lid body in contact with the opening end of the case body due to variations in the manufacture of the case body and the lid body, the periphery of the lid body is the heating roller. Since the resin portion of the three-dimensional carbon fiber reinforced thermoplastic resin is melted by sequentially heating in a pressed state, the case body and the lid are well bonded to the three-dimensional carbon fiber reinforced thermoplastic resin. . Since the three-dimensional carbon fiber reinforced thermoplastic resin is excellent in strength, the joint portion between the case main body and the lid that becomes the maximum stress generation portion is reinforced when the case internal pressure of the power storage device increases. Therefore, the power storage device can ensure good sealing performance without requiring high clearance accuracy between the case main body and the lid body in the joining step of joining the case main body and the lid body. In addition, the three-dimensional carbon fiber constituting the three-dimensional carbon fiber reinforced thermoplastic resin has a higher thermal conductivity than the thermoplastic resin and is larger by two digits or more depending on the type of carbon fiber. When the body is heated, the entire three-dimensional carbon fiber reinforced thermoplastic resin is efficiently heated.

  The lid body is preferably plastically deformed by roller rolling hemming with a heating roller in a state where a three-dimensional carbon fiber reinforced thermoplastic resin exists between the case body and the lid body. Here, “roller rolling hemming” means that a workpiece is heated and pressed by a roller having a concave arc surface over the entire circumference at the tip of a substantially cylindrical roller so that the corner becomes a convex arc surface. This means the process of plastic deformation.

According to this configuration, since the corner portion of the lid body is processed into a convex arc surface in the joining step of joining the case body and the lid body, it is not necessary to chamfer the lid body in a separate process.
The three-dimensional carbon fiber reinforced thermoplastic resin includes thickness direction carbon fibers arranged in a thickness direction, and the thickness direction carbon fibers are the three-dimensional carbon fiber reinforced thermoplastics of the lid body and the case body. It is preferable to intervene so as to be in a direction orthogonal to the joint surface with the resin. Here, the “orthogonal direction” is not limited to a direction that is exactly orthogonal, but also includes a direction slightly inclined from the orthogonal direction.

  According to this configuration, in the joining step of joining the case main body and the lid body, the lid body heats in the thickness direction carbon while the peripheral edge of the lid body is sequentially pressed by the heating roller and the lid body is heated. Since it is transmitted well in the thickness direction via the fibers, the entire three-dimensional carbon fiber reinforced thermoplastic resin efficiently rises to a predetermined temperature. As a result, the joining operation can be performed efficiently and in a short time.

  It is preferable that at least one of the case main body and the lid body has a protrusion formed on a joint surface with the three-dimensional carbon fiber reinforced thermoplastic resin. According to this configuration, the strength of the joint between the three-dimensional carbon fiber reinforced thermoplastic resin, the case main body, and the lid is increased by the caulking action of the protrusions, as compared with the case where there are no protrusions.

  ADVANTAGE OF THE INVENTION According to this invention, in the joining process which joins a case main body and a cover body, favorable sealing performance can be ensured, without request | requiring a high clearance precision between a case main body and a cover body.

The schematic perspective view of a secondary battery. The partial schematic cross section of a junction part. The schematic perspective view of a carbon fiber reinforced thermoplastic resin. (A) is a schematic plan view of the frame which arranges carbon fiber, (b) is a side view of a frame. The schematic perspective view which shows the state of joining work. The partially broken side view which shows the state of joining work typically. (A), (b) is a schematic cross-sectional view showing the bonding action when the edge of the lid is thinner toward the outer periphery, and (c), (d) are the outer edges of the lid. FIG. 4 is a schematic cross-sectional view showing the bonding action when the thickness is so thick. The schematic cross section of another embodiment. The schematic perspective view which shows the state of the welding operation of a prior art. (A), (b) is a schematic cross section which shows the state of the welding part of a prior art.

Hereinafter, an embodiment in which the present invention is embodied in a secondary battery as a power storage device will be described with reference to FIGS.
As shown in FIG. 1, a secondary battery 10 as a power storage device has an electrode assembly 12 housed in a case 11. An electrolyte (not shown) is also accommodated in the case 11. The case 11 includes a bottomed rectangular tube-shaped metal case main body 13 and a square plate-shaped metal lid 14 that closes the opening 13a (shown in FIG. 2 and the like). In the present embodiment, for example, 1000 series aluminum (industrial pure aluminum) is used as the material of the case main body 13 and the lid body 14. The secondary battery 10 is embodied as a lithium ion secondary battery.

  A positive electrode terminal 15 and a negative electrode terminal 16 are electrically connected to the electrode assembly 12 accommodated in the case 11. The positive electrode terminal 15 and the negative electrode terminal 16 are respectively attached with ring-shaped insulating rings 17 for insulating from the case 11. Further, the positive electrode terminal 15 and the negative electrode terminal 16 are exposed outside the case 11 from the lid body 14.

  As shown in FIGS. 1 and 2, in the secondary battery 10, the lid body 14 is joined so as to close the opening 13 a of the case body 13. The case body 13 and the lid body 14 are joined together with a three-dimensional carbon fiber reinforced thermoplastic resin 18 interposed therebetween and the lid body 14 is plastically deformed. The lid 14 is formed by roller rolling hemming with a heating roller 19 (shown in FIGS. 5 and 6) in a state in which the three-dimensional carbon fiber reinforced thermoplastic resin 18 exists between the case body 13 and the lid 14. The peripheral edge of the surface opposite to the surface facing the case main body 13 is formed as a convex arc surface 20 by being plastically deformed.

  More specifically, as shown in FIG. 2, a stepped portion 14 a is formed on the periphery of the surface of the lid body 14 facing the case body 13, and the joint between the lid body 14 and the case body 13 is an opening of the case 11. The case main body 13 and the lid body 14 are interposed via the three-dimensional carbon fiber reinforced thermoplastic resin 18 in a state where the tip end portion of the convex portion 14b of the lid body 14 is loosely fitted to the case main body 13 so as to be the end face on the side 13a. It is joined.

  The three-dimensional carbon fiber constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 is a thickness direction yarn in which a laminated fiber layer having at least biaxial orientation in which fiber layers made of continuous fibers are laminated intersects with each fiber layer. It is comprised by the three-dimensional fiber structure (three-dimensional textile fabric) couple | bonded by. As shown in FIG. 3, the three-dimensional fiber structure 21 is formed in a rectangular frame shape corresponding to the end surface shape of the case body 13 on the opening 13 a side. For example, 6 nylon (nylon 6) is used as the thermoplastic resin.

  When the three-dimensional fiber structure 21 is manufactured, as shown in FIGS. 4A and 4B, a jig 24 including a support base 22 and a frame body 23 placed on the support base 22. Is used. The frame body 23 is formed in a square frame shape corresponding to the outer shape of the laminated fiber layer to be manufactured. In the frame 23, pins 25 are detachably arranged at a predetermined pitch in an area corresponding to the insertion area of the thickness direction thread. The pin 25 is detachably fixed to the support base 22 while penetrating the frame body 23.

  Then, as shown in FIG. 4A, the carbon fiber bundles 26 are arranged on the frame body 23 so as to be engaged with the pins 25 and folded back with the pins 25 attached. FIG. 4A shows an intermediate stage in which the carbon fiber bundles 26 are arranged in the vertical direction (y direction) in the drawing. After the carbon fiber bundles 26 are arranged on the entire surface of the frame body 23 in the vertical direction, the carbon fiber bundles 26 are arranged on the entire surface of the frame body 23 in the horizontal direction (x direction) in the figure. Then, after the arrangement of the carbon fiber bundles 26 in the x direction and the y direction is finished so as to have a predetermined number of layers, the pins 25 are removed from the support base 22, and the laminated carbon fiber bundles 26 are inserted into the frame body 23. The three-dimensional fiber structure 21 is manufactured by inserting the thickness direction yarn (thickness direction carbon fiber) in a folded shape in the stacking direction by the thickness direction yarn inserting device while being supported by the pin 25. The insertion of the thread in the thickness direction is performed by, for example, a device similar to the device disclosed in Japanese Patent No. 2878259, and the pins 25 are sequentially removed while the stacked carbon fiber bundles 26 are supported by a jig. At the same time, the thread in the thickness direction is inserted after the pin 25 is removed.

  The thickness of one layer can be reduced (0.2 mm or less / layer) by reducing the thickness of the in-plane arrangement yarn or by opening (expanding) the fiber bundle. As a result, anisotropy can be controlled even with a thin plate. Further, the heat conduction of the three-dimensional carbon fiber reinforced thermoplastic resin 18 depends on the fiber volume content (Vf) of the three-dimensional fiber structure 21 constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 and the value of the thermal conductivity of the carbon fiber. The rate changes. Carbon fibers having a thermal conductivity of 600 W / m · K or more are preferable. The fiber volume content (Vf) is preferably such that the in-plane yarn Vf is around 20% and the thickness direction yarn Vf is around 20%.

Next, a method for joining the case body 13 and the lid body 14 will be described.
As shown in FIGS. 5 and 6, the case body 13 and the lid body 14 are joined by placing the lid body 14 on the opening 13 a side end portion of the case body 13 with a three-dimensional carbon fiber reinforced thermoplastic resin 18 interposed therebetween. In this state, the heating roller 19 of the hemming device 27 is moved along the corner portion 14 c of the lid body 14. Since the lid body 14 has the step portion 14a, the convex portion 14b is inserted into the opening portion 13a of the case body 13 with the step portion 14a in contact with one surface of the three-dimensional carbon fiber reinforced thermoplastic resin 18. By placing the lid body 14 in this manner, the lid body 14 is positioned so as not to move along the surface direction.

  As shown in FIG. 6, the hemming processing device 27 has a shaft 28 that is rotationally driven, and a heating roller 19 is coaxially connected to the distal end of the shaft 28 so as to be integrally rotatable at the base end portion. A concave arc portion 19 a having a concave arc shape (concave round shape) is provided at the tip of the heating roller 19 along the circumferential direction of the heating roller 19 and over the entire circumference. For example, the hemming device 27 supports the heating roller 19 and the shaft 28 on a movable robot arm.

  Then, as shown in FIG. 5, with the concave arc portion 19a of the heating roller 19 in contact with the corner portion 14c of the lid body 14, the pressure is applied in the vertical direction D1, and the heating roller 19 is rotated about the axis. However, it is moved along the step part 14a of the lid body 14 over the entire circumference of the lid body 14 (indicated by an arrow Y1).

  As a result, the corner portion 14 c of the lid body 14 is plastically deformed into a convex round shape following the concave arc portion 19 a of the heating roller 19. At the same time, the three-dimensional carbon fiber reinforced thermoplastic resin 18 is heated above the melting temperature of the thermoplastic resin by the heating roller 19 through the lid body 14. And the level | step-difference part 14a of the cover body 14 and the opening part 13a side end surface of the case main body 13 are closely_contact | adhered to a molten thermoplastic resin in a press state. When the pressure heating by the heating roller 19 is finished and the thermoplastic resin is solidified, the lid body 14 and the case main body 13 are joined via the three-dimensional carbon fiber reinforced thermoplastic resin 18.

  Here, as shown in FIG. 2, when the case main body 13 and the lid body 14 are manufactured with appropriate accuracy, the end surface of the case main body 13 and the stepped portion 14 a of the lid body 14 are in a parallel state. . Therefore, in a state where the three-dimensional carbon fiber reinforced thermoplastic resin 18 is disposed between the case main body 13 and the lid body 14, the gap between the case main body 13 and the three-dimensional carbon fiber reinforced thermoplastic resin 18 and the stepped portion 14 a is already present. There is almost no clearance between the three-dimensional carbon fiber reinforced thermoplastic resin 18. In such a state, when the lid body 14 is pressurized and heated by the heating roller 19 and the case body 13 and the lid body 14 are joined, of course, the joining via the three-dimensional carbon fiber reinforced thermoplastic resin 18 is good. To be done.

  On the other hand, as shown in FIG. 7A, when the thickness of the edge of the lid 14 is thinner toward the outer peripheral side, the three-dimensional carbon disposed on the end surface of the case body 13 on the opening 13a side. A gap 29 is formed between the upper surface of the fiber reinforced thermoplastic resin 18 and the stepped portion 14a of the lid 14 so as to increase toward the outer peripheral side of the lid 14. However, even in this case, when the lid body 14 is pressurized and heated by the heating roller 19 and the case body 13 and the lid body 14 are joined, the lid body 14 is plastically deformed as shown in FIG. At the same time, the thermoplastic resin of the three-dimensional carbon fiber reinforced thermoplastic resin 18 is melted, and the case main body 13 and the lid body 14 are favorably joined via the three-dimensional carbon fiber reinforced thermoplastic resin 18.

  Moreover, as shown in FIG.7 (c), when the thickness of the edge part of the cover body 14 is thicker as the outer peripheral side, the three-dimensional carbon fiber reinforced heat arrange | positioned on the opening part 13a side end surface of the case main body 13 is shown. A gap 29 is formed between the upper surface of the plastic resin 18 and the stepped portion 14 a of the lid body 14, which becomes smaller toward the outer peripheral side of the lid body 14. However, even in this case, when the lid body 14 is pressurized and heated by the heating roller 19 and the case body 13 and the lid body 14 are joined, the lid body 14 is plastically deformed as shown in FIG. At the same time, the thermoplastic resin of the three-dimensional carbon fiber reinforced thermoplastic resin 18 is melted, and the case main body 13 and the lid body 14 are favorably joined via the three-dimensional carbon fiber reinforced thermoplastic resin 18.

  That is, due to manufacturing variations of the case body 13 and the lid body 14, there is a gap between the case body 13 and the lid body 14 in a state where the lid body 14 is in contact with the opening 13 a side end portion of the case body 13. Even if it occurs, the resin portion of the three-dimensional carbon fiber reinforced thermoplastic resin 18 is melted by the peripheral edge of the lid body 14 being sequentially heated by the heating roller 19 in a pressed state. Therefore, the case main body 13 and the lid body 14 are favorably bonded to the three-dimensional carbon fiber reinforced thermoplastic resin 18. Since the three-dimensional carbon fiber reinforced thermoplastic resin 18 is excellent in strength, the case body 13 and the lid body 14 that become the maximum stress generation site when the internal pressure of the case 11 of the power storage device (secondary battery 10) increases are joined. Department is strengthened.

According to this embodiment, the following effects can be obtained.
(1) The power storage device (secondary battery 10) is a power storage device in which the electrode assembly 12 is accommodated in a case main body 13 having an opening 13a and the opening 13a is closed by a lid 14, and the case main body 13 And the lid body 14 are joined in a state where the three-dimensional carbon fiber reinforced thermoplastic resin 18 is interposed therebetween and the lid body 14 is plastically deformed. Therefore, the power storage device ensures a good sealing property without requiring high clearance accuracy between the case body 13 and the lid body 14 in the joining process of joining the case body 13 and the lid body 14. Can do. Further, the three-dimensional carbon fiber constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 has a higher thermal conductivity than the thermoplastic resin and is two or more orders of magnitude larger depending on the type of carbon fiber. Thus, when the lid body 14 is heated, the entire three-dimensional carbon fiber reinforced thermoplastic resin 18 is efficiently heated.

  (2) The lid 14 is plastically deformed by roller rolling hemming with a heating roller 19 in a state in which the three-dimensional carbon fiber reinforced thermoplastic resin 18 exists between the case body 13 and the lid 14. According to this configuration, since the corner portion 14c of the lid body 14 is processed into the convex arcuate surface 20 in the joining process of joining the case body 13 and the lid body 14, it is necessary to chamfer the lid body 14 in a separate process. Disappears.

  (3) The three-dimensional carbon fiber reinforced thermoplastic resin 18 includes thickness direction carbon fibers arranged in the thickness direction, and the thickness direction carbon fibers are the three-dimensional carbon fiber reinforced heat of the lid body 14 and the case body 13. It is interposed so as to be in a direction orthogonal to the joint surface with the plastic resin 18. The orthogonal direction is not limited to the exactly orthogonal direction, but includes a direction slightly inclined from the orthogonal direction.

  According to this configuration, in the joining process of joining the case body 13 and the lid body 14, the lid body 14 is heated while the peripheral edge of the lid body 14 is sequentially pressed by the heating roller 19, and the lid body 14 is heated. However, since it is transmitted well in the thickness direction via the carbon fiber in the thickness direction, the entire three-dimensional carbon fiber reinforced thermoplastic resin 18 efficiently rises to a predetermined temperature. As a result, the joining operation can be performed efficiently and in a short time.

  (4) The three-dimensional fiber structure 21 constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 has a carbon fiber bundle 26 x so that it has a rectangular frame shape corresponding to the opening 13a side end of the case body 13. Thickness direction yarns (thickness direction carbon fibers) are inserted in a folded shape into a carbon fiber layer having a predetermined number of layers arranged in a folded shape in the direction and the y direction. Therefore, the strength is higher than that obtained by cutting a planar three-dimensional fiber structure larger than the outer shape of the end portion of the case body 13 into a square frame shape.

  (5) The secondary battery 10 as a power storage device contains an electrolyte solution (not shown) in the case 11 in addition to the electrode assembly 12. The case body 13 and the lid body 14 are joined together with a three-dimensional carbon fiber reinforced thermoplastic resin 18 interposed therebetween.

  In this configuration, the three-dimensional carbon fiber reinforced thermoplastic resin 18 is locally softened to be softened, so that the case body 13 and the lid body that have been joined are not affected by heat on the electrode assembly 12. 14 can be separated and the power storage device can be opened.

  In the power storage device, the electrolytic solution is decomposed and reduced by repeated charging and discharging, and the characteristics thereof deteriorate. In this case, the deteriorated power storage device is opened, the electrolyte solution is replenished or replaced, and then resealed, so that the characteristics can be recovered, and the product can be remanufactured (Refabricate). For example, a power storage device used for a mobile object such as a vehicle can be reused as a mobile phone base station or a stationary power storage device for home use.

The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIG. 8, at least one of the case main body 13 and the lid body 14 is formed with a protrusion 30 on the joint surface with the three-dimensional carbon fiber reinforced thermoplastic resin 18. According to this configuration, the strength of the joint between the three-dimensional carbon fiber reinforced thermoplastic resin 18, the case main body 13, and the lid body 14 is increased due to the caulking action of the protrusions 30 as compared with the case where the protrusions 30 are not provided.

  ○ The three-dimensional carbon fiber constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 has a thickness direction in which a laminated fiber layer having at least biaxial orientation in which fiber layers made of continuous fibers are laminated intersects each fiber layer. It is not limited to a three-dimensional woven fabric connected with yarn. For example, a laminated fiber layer in which plain weaves are laminated may be bonded with a thickness direction thread.

  The three-dimensional carbon fiber constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 does not necessarily include a thickness direction yarn, and may be, for example, a three-dimensional braid (three-dimensional braiding).

  The three-dimensional carbon fiber constituting the three-dimensional carbon fiber reinforced thermoplastic resin 18 is not necessarily limited to being integrally formed in an annular shape corresponding to the shape at the opening 13a side end of the case body 13. For example, when the opening is rectangular, a band-shaped three-dimensional carbon fiber having a length corresponding to each side of the rectangle may be used to form a ring as a whole.

  The lid 14 is not necessarily limited to a configuration in which the lid 14 is joined to the case body 13 via the three-dimensional carbon fiber reinforced thermoplastic resin 18 in a state where the corner 14c is plastically deformed so as to be the convex arcuate surface 20. The three-dimensional carbon fiber reinforced thermoplastic resin 18 may be plastically deformed to such an extent that the three-dimensional carbon fiber reinforced thermoplastic resin 18 can be reliably pressed and urged toward the case body 13 side. In this case, the heating roller 19 does not have the concave arc portion 19a on the tip side, and may be a simple column.

In the case where the protrusion 30 is formed on the lid body 14, for example, it is formed by pressing with a punch or a die from the side opposite to the position where the protrusion 30 of the lid body 14 is formed.
In the case where the protrusion is formed on the case body 13, for example, it is formed by cutting a portion other than the portion where the protrusion 30 is to be formed.

The protrusion 30 is not limited to a conical shape or a pyramid shape, and may be, for example, a ridge having a triangular cross section, or an annular shape along the circumference of the case body 13 or the lid body 14.
○ Instead of forming the protrusions 30, the joint surfaces of the case main body 13 and the lid body 14 with the three-dimensional carbon fiber reinforced thermoplastic resin 18 may be roughened by sandblasting or the like.

  The shape of the case 11 may be changed as appropriate in accordance with the shape of the electrode assembly 12 to be accommodated. For example, the case 11 may be cylindrical. In this case, a bottomed cylindrical case body 13 and a disk-shaped lid body 14 may be used.

The secondary battery 10 is not limited to a lithium ion secondary battery, and may be another secondary battery such as a nickel hydrogen secondary battery or a nickel cadmium secondary battery.
The power storage device is not limited to the secondary battery 10 and may be a capacitor such as an electric double layer capacitor or a lithium ion capacitor.

The following technical idea (invention) can be understood from the embodiment.
(1) A method of manufacturing a power storage device in which an electrode assembly is housed in a case body having an opening, and the opening is closed with a lid, in the joining step of joining the case body and the lid In a state in which a three-dimensional carbon fiber reinforced thermoplastic resin is disposed between the case body and the lid body, the peripheral edge of the lid body is heated while being sequentially pressed by a heating roller, whereby the lid body is interposed. Then, the resin part of the three-dimensional carbon fiber reinforced thermoplastic resin is melted, and the case main body and the lid are joined via the three-dimensional carbon fiber reinforced thermoplastic resin.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as a power storage device, 12 ... Electrode assembly, 13 ... Case body, 13a ... Opening, 14 ... Lid, 18 ... Three-dimensional carbon fiber reinforced thermoplastic resin, 19 ... Heating roller, 30 ... Projection .

Claims (4)

An electrode assembly is housed in a case body having an opening, and the opening is closed by a lid,
A power storage device, wherein the case body and the lid are joined together with a three-dimensional carbon fiber reinforced thermoplastic resin interposed therebetween and the lid is plastically deformed.   The said cover body is plastically deformed by the roller rolling type hemming process by a heating roller in the state in which a three-dimensional carbon fiber reinforced thermoplastic resin exists between the said case main body and the said cover body. Power storage device.   The three-dimensional carbon fiber reinforced thermoplastic resin includes thickness direction carbon fibers arranged in a thickness direction, and the arrangement direction of the thickness direction carbon fibers is the three-dimensional carbon fiber of the lid and the case body. The power storage device according to claim 1 or 2, wherein the power storage device is interposed so as to be in a direction orthogonal to a joint surface with the reinforced thermoplastic resin.   4. The power storage device according to claim 1, wherein at least one of the case main body and the lid body has a protrusion formed on a joint surface with the three-dimensional carbon fiber reinforced thermoplastic resin. 5. .