JP5206242B2 - Power storage device and method for manufacturing power storage device - Google Patents

Description

  The present invention relates to a power storage device having a structure in which a positive electrode element and a negative electrode element are wound with a separator (electrolyte layer) interposed therebetween.

  The secondary battery has a power generation element for charging and discharging and a battery case for housing the power generation element. Here, the power generation element has a positive electrode element, a negative electrode element, and a separator. For example, a power generation element can be configured by winding a core member with a separator disposed between a positive electrode element and a negative electrode element (see, for example, Patent Documents 1-3).

In addition, the battery case is provided with electrode terminals (a positive electrode terminal and a negative electrode terminal) used for taking out the electric power stored in the power generation element and storing the electric power in the power generation element. In the secondary battery described in Patent Document 1, the positive electrode terminal is fixed to one end surface of the battery case, and is electrically and mechanically connected to the positive electrode element of the power generation element via a lead wire. The negative electrode terminal is fixed to the other end surface of the battery case, and is electrically and mechanically connected to the negative electrode element of the power generation element via a lead wire.
JP 2001-256950 A (paragraph 0026, FIG. 1) Japanese Patent Laid-Open No. 11-329398 (FIG. 1) Japanese Patent Laying-Open No. 2001-15169 (FIGS. 8 and 11)

  In the configuration in which the power generation element is connected to the electrode terminal via the lead wire, the cost of the secondary battery is increased by the amount of use of the lead wire. In addition, since a region for connecting the lead wire to the electrode terminal and the power generation element must be provided or a space for arranging the lead wire in the secondary battery must be secured, the secondary battery is large. It may become.

  Accordingly, an object of the present invention is to provide a power storage device that can be reduced in size without using a lead wire.

The power storage device according to the first invention of the present application includes an electrode element wound around a predetermined axis, and an electrode terminal electrically connected to the electrode element. The electrode terminal has a contact surface that is an end portion of the current collector plate in the direction of the predetermined axis and is in contact with an end portion on which the electrode layer is not formed and extends around the predetermined axis . Further, the contact surface faces a direction away from the predetermined axis, and the distance from the predetermined axis to the contact surface increases continuously or stepwise in a direction away from the end of the current collector plate along the predetermined axis . .

As a contact surface, it can form in the shape along the conical surface centering on the predetermined axis. Thereby, the edge part of a current collecting plate can be made easy to wind around a contact surface.

The area | region in which the electrode layer is not formed among current collector plates can be made to contact a contact surface in the state bent along the contact surface. Thereby, the contact area in a current collecting plate and a contact surface is securable.

The end of the current collector plate can be welded to the contact surface. By welding the current collector plate and the contact surface, it is possible to reduce the electrical resistance between the electrode terminal and the current collector plate. Moreover, a notch part can be formed in the edge part of a current collecting plate . Thus, it is possible to suppress the time of winding the end of the current collector plate to the contact surface of the electrode terminal, an excessive load to the end portion of the current collector plate from being applied.

  Note that at least one of the positive electrode terminal and the negative electrode terminal provided in the power storage device can be used as an electrode terminal in the present invention.

Second aspect of the invention, Ru manufacturing method der power storage device having electrodes elements wrapped around a predetermined axis, and an electrode terminal connected to electrode elements electrically. The electrode element has a current collector plate and an electrode layer formed in a partial region of the current collector plate. The electrode terminal is in an end portion in the direction of the predetermined axis of the current collector plate, and has a contact surface that is in contact with an end portion where the electrode layer is not formed and extends around the predetermined axis. In addition, the contact surface of the electrode terminal faces away from the predetermined axis, and the distance from the predetermined axis to the contact surface increases continuously or stepwise in the direction away from the end of the current collector plate along the predetermined axis. Is doing. Here, while winding the electrode elements around the predetermined axis, Ru contacting the end of the current collector plate to the contact surface.

Here, the end of the current collector plate can be welded to the contact surface while winding the electrode element. Specifically, welding can be performed by irradiating a portion of the current collector plate that contacts the contact surface with laser light. Thereby, the electrical resistance between a current collecting plate and an electrode terminal can be reduced.

Further, it is possible before contacting the current collector plate to the contact surface, previously bent into a shape along the contact surface end of the current collector plate. Thereby, an electrode element (current collector plate) can be smoothly wound around an electrode terminal.

In the first invention of the present application, since the electrode element (current collector plate) is brought into contact with the electrode terminal without using a lead wire or the like, the power storage device can be reduced in size. In addition, by configuring the contact surface of the electrode terminal as in the present invention, the end of the current collector plate can be easily brought into contact with the electrode terminal when the electrode element is wound around the predetermined axis.

According to the second aspect of the present invention, the electrode element (current collector plate) can be easily brought into contact with the contact surface of the electrode terminal. In other words, when the electrode element is wound around the predetermined axis, the electrode element (current collector plate) can be easily wound around the contact surface of the electrode terminal. Thereby, an electrical storage apparatus can be manufactured easily.

  Examples of the present invention will be described below.

  A structure of a secondary battery (power storage device) that is Embodiment 1 of the present invention will be described with reference to FIGS. Here, FIG. 1 is a cross-sectional view showing the internal structure of the secondary battery, and FIG. 2 is an external view of the secondary battery when viewed from the direction indicated by arrow A in FIG. In addition, as a secondary battery, things, such as a nickel metal hydride battery and a lithium ion battery, are mentioned, for example. In this embodiment, a case where a secondary battery is used will be described. However, the present invention can also be applied to an electric double layer capacitor (capacitor) as a power storage device.

  The secondary battery 1 of the present embodiment can be used as a power source for a vehicle, for example. Examples of this vehicle include a hybrid vehicle and an electric vehicle. A hybrid vehicle is a vehicle provided with other power sources such as an internal combustion engine and a fuel cell in addition to a secondary battery as a power source. An electric vehicle is a vehicle that travels using only the output of the secondary battery 1. When the secondary battery 1 of the present embodiment is mounted on a vehicle, it is necessary to use a plurality of secondary batteries in order to extract energy necessary for traveling of the vehicle. Specifically, it is necessary to secure electric power necessary for traveling of the vehicle by electrically connecting a plurality of secondary batteries in series.

  The secondary battery 1 includes a wound power generation element 10 and a battery case 20 that houses the power generation element 10. The battery case 20 has a cylindrical portion 21 formed in a cylindrical shape, and flat plate portions 22 and 23 fixed to both ends of the cylindrical portion 21. The battery case 20 is preferably formed of a material excellent in durability and corrosion resistance. Specifically, a metal such as aluminum can be used as this material. It is also possible to form the battery case 20 from a resin.

  The flat plate portions 22 and 23 can be fixed to the cylindrical portion 21 by welding, for example. The flat plate portions 22 and 23 are formed with holes 22a and 23a for allowing a positive electrode terminal 40 and a negative electrode terminal 50 described later to pass therethrough.

  The power generation element 10 is an element that can be charged and discharged, and includes a positive electrode element 11 and a negative electrode element 12 as electrode elements, and a separator 13. The separator 13 is disposed so as to be positioned between the positive electrode element 11 and the negative electrode element 12. That is, the power generation element 10 is configured by laminating the positive electrode element 11, the separator 13, and the negative electrode element 12 in this order. Here, the electrolytic solution is impregnated in the separator 13 by, for example, a liquid injection process in a vacuum state.

  The positive electrode element 11, the negative electrode element 12, and the separator 13 are wound around the core member 30 in a state where they are overlapped with each other. A positive electrode terminal 40 and a negative electrode terminal 50 as electrode terminals are disposed on both ends of the core member 30, in other words, on both end surfaces of the battery case 20.

  As shown in FIG. 3A, the positive electrode element 11 has a current collector plate 11a for a positive electrode and an active material layer (electrode layer) 11b formed on both surfaces of the current collector plate 11a. Although FIG. 3A shows only one surface of the current collector plate 11a, the other surface has the same configuration. Here, the region R1 is a region of the current collector plate 11a where the active material layer 11b is not formed, and is a region in contact with the positive electrode terminal 40 (contact surface 42b) as shown in FIG. The region R2 is a region where the active material layer 11b is formed in the current collector plate 11a.

  When a lithium ion battery is used as the secondary battery 1, for example, the current collector plate 11a can be formed of aluminum. The active material layer 11b has an active material corresponding to the positive electrode, and includes a binder and a conductive agent as necessary. As the positive electrode active material, nickel oxide can be used in the case of a nickel metal hydride battery, and lithium-transition metal composite oxide can be used in the case of a lithium ion battery.

  As shown in FIG. 3B, the negative electrode element 12 includes a current collector plate 12a for a negative electrode and an active material layer (electrode layer) 12b formed on both surfaces of the current collector plate 12a. 3B shows only one surface of the current collector plate 12a, the other surface has the same configuration. Here, the region R2 is a region of the current collector plate 12a where the active material layer 12b is formed. Further, the region R3 is a region where the active material layer 12b is not formed, and is a region in contact with the negative electrode terminal 50 (contact surface 52b) as shown in FIG.

When a lithium ion battery is used as the secondary battery 1, for example, the current collector plate 12a can be made of copper. The active material layer 12b has an active material corresponding to the negative electrode, and includes a binder and a conductive agent as necessary. As the negative electrode active _{material, MmNi (5-x-y} -z) Al x Mn y Co z in the case of the nickel hydrogen battery: using (Mm misch metal) hydrogen absorbing alloy such as, in the case of the lithium ion battery Carbon can be used.

  The region R <b> 2 in the positive electrode element 11 and the negative electrode element 12 is a region used for charging / discharging and overlaps with each other in the longitudinal direction of the core member 30. Here, the separator 13 should just be located on area | region R2.

  In this embodiment, the positive electrode active material layer 11b is formed on both surfaces of the current collector plate 11a, and the negative electrode active material layer 12b is formed on both surfaces of the current collector plate 12a. is not. Specifically, the active material layer for the positive electrode can be formed on one surface of the current collector plate, and the active material layer for the negative electrode can be formed on the other surface of the current collector plate. This is a so-called bipolar electrode.

  The positive electrode terminal 40 includes a shaft portion 41 extending along the core member 30 and a flange portion 42 extending in a direction orthogonal to the longitudinal direction of the core member 30 (left-right direction in FIG. 1). A screw portion that engages with the screw portion of the nut 70 is formed on the outer peripheral surface of the shaft portion 41. A seal member 60 made of an insulating material is disposed between the shaft portion 41 and the hole portion 22a of the flat plate portion 22. Thereby, the inside of the battery case 20 can be sealed, and the battery case 20 and the positive electrode terminal 40 can be insulated. Here, the seal member 60 is sandwiched between the positive electrode terminal 40 (flange portion 42) and the washer 61. The washer 61 is fixed by engaging the nut 70 with the shaft portion 41.

  The flange portion 42 includes a flat surface 42 a that faces the flat plate portion 22 of the battery case 20, and a contact surface 42 b that is electrically and mechanically connected to the power generation element 10. The flat surface 42 a is in contact with the seal member 60. The contact surface 42b is in contact with the positive electrode element 11 (current collector plate 11a) of the power generation element 10. Further, the contact surface 42 b is configured as a conical surface with the core member 30 as the center. More specifically, the contact surface 42b is formed in a shape along a conical surface with the core member 30 as the center, and has a shape that protrudes toward the power generation element 10 (negative electrode terminal 50). ing. Here, the distance between the contact surface 42 b and the flat surface 42 a in the longitudinal direction of the core member 30 (left and right direction in FIG. 1) is the longest on the side in contact with the core member 30, and decreases as the distance from the core member 30 increases.

  The negative electrode terminal 50 includes a shaft portion 51 that extends along the core member 30 and a flange portion 52 that extends in a direction orthogonal to the longitudinal direction of the core member 30. On the outer peripheral surface of the shaft portion 51, a screw portion that engages with the screw portion of the nut 90 is formed. Further, a seal member 80 formed of an insulating material is disposed between the shaft portion 51 and the hole portion 23a of the flat plate portion 23. Accordingly, the inside of the battery case 20 can be sealed, and the battery case 20 and the negative electrode terminal 50 can be insulated. Here, the seal member 80 is sandwiched between the negative electrode terminal 50 (flange portion 52) and the washer 81. The washer 81 is fixed by engaging the nut 90 with the shaft portion 51.

  The flange portion 52 includes a flat surface 52 a that faces the flat plate portion 23 of the battery case 20, and a contact surface 52 b that is electrically and mechanically connected to the power generation element 10. The flat surface 52 a is in contact with the seal member 80. The contact surface 52b is in contact with the negative electrode element 12 (current collector plate 12a) of the power generation element 10. Further, the contact surface 52 b is configured as a conical surface with the core member 30 as the center. More specifically, the contact surface 52b is formed in a shape along a conical surface with the core member 30 as the center, and has a shape that protrudes toward the power generation element 10 (positive electrode terminal 40). ing. Here, the distance between the contact surface 52 b and the flat surface 52 a in the longitudinal direction of the core member 30 (the left-right direction in FIG. 1) is the longest on the side in contact with the core member 30 and decreases as the distance from the core member 30 increases.

  Here, when the battery case 20 is formed of a metal, the inner wall surface of the cylindrical portion 21 is provided with a layer formed of an insulating material. That is, by using the insulating layer, the flange portion 42 of the positive electrode terminal 40 and the flange portion 52 of the negative electrode terminal 50 are prevented from directly contacting the inner wall surface of the cylindrical portion 21.

  Next, the process of manufacturing the secondary battery 1 of the present embodiment will be described with reference to FIG. Here, FIG. 4 is a diagram illustrating a process of winding the power generation element 10 around the core member 30.

  Before winding the power generation element 10 around the core member 30, first, the positive electrode element 11, the negative electrode element 12, and the separator 13 are prepared. Then, the power generation element 10 configured by laminating the positive electrode element 11, the separator 13, and the negative electrode element 12 in this order is wound around the core member 30. Specifically, by rotating the positive electrode terminal 40 and the negative electrode terminal 50 fixed to the core member 30 in the direction indicated by the arrow X, the power generation element 10 moves in the direction indicated by the arrow Y with respect to the core member 30. The core member 30 is wound around.

  At this time, the region R1 of the current collector plate 11a contacts the contact surface 42b of the flange portion 42, and the region R3 of the current collector plate 12a contacts the contact surface 52b of the flange portion 52. Here, in the present embodiment, as shown in FIG. 1, the current collector plates 11 a and 12 a are wound up to the front end sides of the flange portions 42 and 52. For this reason, when the current collecting plates 11a and 12a are wound along the outer peripheral surface of the core member 30, as shown in FIGS. 5 and 6, a part of the region R1 in the current collecting plate 11a is a contact surface of the flange portion 42. It deforms along 42b.

  As shown in FIG. 1, the distance between the end of the region R <b> 2 and the contact surfaces 42 b and 52 b (the distance in the left-right direction in FIG. 1) becomes longer as the distance from the core member 30 increases. Here, of the regions R1 and R3, the regions R1 and R3 located near the core member 30 have the largest contact areas with the contact surfaces 42b and 52b. And as it leaves | separates from the core member 30, the contact area with each contact surface 42b, 52b in each area | region R1, R3 becomes small.

  5 and 6 show a state in which a part of the region R1 is bent along the contact surface 42b, but the entire region R1 may be bent along the contact surface 42b. In particular, on the side close to the core member 30, the entire region R1 may be bent along the contact surface 42b. 5 and 6 show the contact state between the current collector plate 11a and the flange portion 42, the contact state between the current collector plate 12a and the flange portion 52 is also the same.

  And the current collection plate 11a can be welded to the contact surface 42b by irradiating the laser beam from the laser irradiation apparatus 100 with respect to the contact part with the contact surface 42b among the current collection plates 11a. That is, it is possible to irradiate the contact portions of the current collector plate 11 a and the contact surface 42 b with the laser light while winding the power generation element 10 around the core member 30. The current collector plate 12a and the flange portion 52 can also be welded by the same method. Here, the laser irradiation apparatus 100 includes, for example, an oscillator that generates laser light, and an optical system that directs the laser light generated by the oscillator toward an object (the current collector plate 11a and the contact surface 42b) in a focused state. And can be configured.

  In the present embodiment, a part (end) of the current collector plate 11a is brought into contact with the contact surface 42b in a bent state. That is, the contact area of the current collector plate 11a and the contact surface 42b is ensured. Thereby, the current collecting plate 11a and the contact surface 42b can be easily welded using a laser beam.

  Here, FIG. 7 is a schematic diagram showing a configuration as a comparative example of the present embodiment, and corresponds to FIG. In FIG. 7, the same reference numerals are used for members having the same functions as those described in this embodiment.

  In the configuration shown in FIG. 7, the surface 42 c of the flange portion 42 that contacts the current collector plate 11 a is configured by a plane orthogonal to the longitudinal direction of the core member 30. In this configuration, since only the end portion of the current collector plate 11a is brought into contact with the flat surface 42c, the current collector plate 11a and the flat surface 42c are in point contact. In this case, it may be difficult to irradiate the laser beam of the laser irradiation apparatus 100 to the contact portion between the current collector plate 11a and the flat surface 42c and to weld the current collector plate 11a and the flat surface 42c.

  In the configuration shown in FIG. 7 as well, it is possible to easily irradiate the laser beam by contacting the flat surface 42c with a part of the current collector plate 11a bent as in the present embodiment. However, in this case, it may be difficult to wind the current collector plate 11 a around the core member 30.

  In the present embodiment, the inclination angle (taper angle) θ (see FIG. 6) of the contact surface 42b only needs to be smaller than 90 [deg] and larger than 0 [deg]. Here, if the inclination angle θ is close to 90 [deg], the secondary battery 1 can be miniaturized in the longitudinal direction of the core member 30. Further, if the inclination angle θ is brought close to 0 [deg], the end portion (region R1) of the current collector plate 11a can be easily deformed along the contact surface 42b, or the contact area between the current collector plate 11a and the contact surface 42b. Can be increased. Based on the viewpoint described above, the inclination angle θ of the contact surface 42b can be set as appropriate. The same applies to the contact surface 52b.

  Here, in the present embodiment, the inclination angles θ of the contact surfaces 42b and 52b are equal to each other, but the present invention is not limited to this. That is, the inclination angles θ of the contact surfaces 42b and 52b can be different from each other.

  On the other hand, when the current collector plate 11a is welded to the contact surface 42b, the laser beam irradiation method by the laser irradiation device 100 can be set as appropriate. For example, it is possible to always irradiate the laser beam to the contact portions of the current collector plate 11a and the contact surface 42b, or to intermittently irradiate the laser beam. If the laser beam is always irradiated, the entire region R1 of the current collector plate 11a can be welded to the contact surface 42b. Thus, the electrical resistance between the current collector plate 11a and the contact surface 42b can be reduced as the welded portions of the current collector plate 11a and the contact surface 42b are increased. And the output performance of the secondary battery 1 can be improved by making an electrical resistance small.

  Further, in the case of intermittently irradiating laser light, the timing of irradiating the laser light and the time for continuously irradiating the laser light can be set as appropriate. Specifically, if the welded portions of the current collector plate 11a and the contact surface 42b are determined in advance, the welded portions may be irradiated with laser light. In this case, the rotational speed of the core member 30 (the speed at which the power generation element 10 is wound), the laser light irradiation timing, and the irradiation time are controlled.

  According to the present embodiment, while the power generation element 10 is wound around the core member 30, the power generation element 10 is connected to the positive electrode terminal 40 and the current collecting plates 11a, 12a and the contact surfaces 42b, 52b by irradiating the laser light. It can be easily connected to the negative electrode terminal 50. Further, unlike Patent Document 1, it is not necessary to connect the power generation element 10 and the electrode terminals 40 and 50 using lead wires. Then, the cost of the secondary battery 1 can be reduced or the secondary battery 1 can be downsized by the amount not using the lead wire.

  If the region R1 of the current collector plate 11a is bent along the slope of the contact surface 42b as in this embodiment, an excessive load (bending stress) may act on a part of the region R1. Therefore, as shown in FIG. 8, if the notch portion 11a1 is formed in advance with respect to the region R1 of the current collector plate 11a, the region R1 of the current collector plate 11a can be wound around the contact surface 42b. An excessive load on R1 can be suppressed. Here, the shape of the notch 11a1 and the position and number of the notch 11a1 can be set as appropriate. That is, the position and number of the notches 11a1 may be determined so that excessive bending stress is not applied to the region R1 of the current collector plate 11a. Similarly to the current collector plate 11a, the current collector plate 12a can be formed with a notch.

  Further, the region R1 of the current collector plate 11a can be bent in advance so that the current collector plate 11a can be easily wound along the contact surface 42b. Specifically, as shown in FIG. 9, by using the guide member 101, the region R1 of the current collector plate 11a and the region R3 of the current collector plate 12a are bent in a predetermined direction before being wound around the core member 30. be able to. Here, the predetermined direction is a direction along the contact surfaces 42b and 52b. The guide member 101 has a bent portion 101a for giving a curvature to the region R1 of the current collector plate 11a and a bent portion 101b for giving a curvature to the region R3 of the current collector plate 12a.

  The shape of the guide member 101 is not limited to the shape shown in FIG. That is, any shape may be used as long as the region R1 of the current collector plate 11a can be bent or the region R3 of the current collector plate 12a can be bent. In the configuration shown in FIG. 9, one guide member 101 is used, but the regions R1 and R3 of the current collector plates 11a and 12a can be bent using a plurality of guide members, respectively.

  In this embodiment, the current collector plates 11a and 12a are welded using laser light, but the present invention is not limited to this. That is, any method may be used as long as the current collector plates 11a and 12a can be fixed to the contact surfaces 42b and 52b. For example, welding using ultrasonic waves may be performed, or thermal spraying or brazing may be performed.

  In the present embodiment, the contact surfaces 42b and 52b are formed of continuous inclined surfaces, but the present invention is not limited to this. That is, the contact surfaces 42b and 52b can be formed stepwise. In other words, the stepped portion can be provided by changing the diameters of the contact surfaces 42b and 52b stepwise. Further, the contact surfaces 42b and 52b can be configured by combining the inclined surface and the stepped portion.

  Furthermore, in the present embodiment, the power generation element 10 is wound around the core member 30, but the present invention is not limited to this. For example, if the positive electrode terminal 40 and the negative electrode terminal 50 are supported in a state where a predetermined interval is maintained, the power generating element 10 is wound around the positive electrode terminal 40 and the negative electrode terminal 50 without using the core member 30. Can do. In the present embodiment, the contact surface 42b of the positive electrode terminal 40 and the contact surface 52b of the negative electrode terminal 50 are configured as tapered surfaces, but only one of the contact surfaces 42b and 52b can be configured as a tapered surface. .

It is sectional drawing which shows the internal structure of the secondary battery which is Example 1 of this invention. FIG. 2 is an external view of a secondary battery when viewed from a direction indicated by an arrow A in FIG. 1. It is a front view which shows the structure of a positive electrode element. It is a front view which shows the structure of a negative electrode element. In Example 1, it is a figure explaining the process which makes an electric power generation element contact an electrode terminal. In Example 1, it is an enlarged view which shows the contact part of an electric power generation element and an electrode terminal. In Example 1, it is an enlarged view which shows the contact part of an electric power generation element and an electrode terminal. In the comparative example of Example 1, it is an enlarged view which shows the contact part of an electric power generation element and an electrode terminal. In the modification of Example 1, it is the schematic which shows the structure of a current collecting plate. In the modification of Example 1, it is the schematic which shows the structure for bending the edge part of a current collecting plate.

Explanation of symbols

1: Secondary battery (power storage device) 10: Power generation element 11: Positive electrode element (electrode element) 11a, 12a: Current collector plate 11b, 12b: Active material layer (electrode layer) 12: Negative electrode element (electrode element)
13: Separator (electrolyte layer) 20: Battery case 30: Core member 40: Positive electrode terminal (electrode terminal)
41, 51: Shaft part 42, 52: Flange part 42b, 52b: Contact surface 50: Negative electrode terminal (electrode terminal)
60, 80: Seal member 70, 90: Nut 100: Laser irradiation device 101: Guide member

Claims (10)

An electrode element having a current collector plate and an electrode layer formed in a part of the current collector plate, and wound around a predetermined axis;
An electrode terminal electrically connected to the electrode element,
The electrode terminal is an end of the current collector plate in the direction of the predetermined axis, and is in contact with an end where the electrode layer is not formed, and has a contact surface extending around the predetermined axis. And
The contact surface faces a direction away from the predetermined axis, and a distance from the predetermined axis to the contact surface is continuous or stepwise in a direction away from the end portion of the current collector plate along the predetermined axis. power storage device, characterized in that has increased.   The power storage device according to claim 1, wherein the contact surface is formed in a shape along a conical surface with the predetermined axis as a center. Region not formed of the electrode layer of the previous SL collector plate of claim 1 or 2, characterized in that in contact with the contact surface when the bent along said contact surface Power storage device. The power storage device according to claim 1, wherein the end portion of the current collector plate is welded to the contact surface. The power storage device according to any one of claims 1 to 4, wherein the current collector plate has a notch at the end.   The power storage device according to claim 1, wherein the electrode terminal is at least one of a positive electrode terminal and a negative electrode terminal. A method of manufacturing a power storage device having an electrode element wound around a predetermined axis and an electrode terminal electrically connected to the electrode element,
The electrode element has a current collector plate, and an electrode layer formed in a partial region of the current collector plate,
The electrode terminal is an end portion in the direction of the predetermined axis of the current collector plate, is in contact with an end portion on which the electrode layer is not formed, and has a contact surface extending around the predetermined axis,
Continuous the contact surface of the electrode terminals, with faces away from the predetermined axis, in the direction away from the end portion of the collector plate along the predetermined axis, the distance from the predetermined axis to the contact surface Increase gradually or stepwise,
A method for manufacturing a power storage device, wherein the end of the current collector plate is brought into contact with the contact surface while the electrode element is wound around the predetermined axis. The method for manufacturing a power storage device according to claim 7, wherein the end of the current collector plate is welded to the contact surface while winding the electrode element. The method for manufacturing a power storage device according to claim 8, wherein welding is performed by irradiating a laser beam to a contact portion of the current collector plate with the contact surface. Prior to contacting the end portion of the collector plate to the contact surface, either the end portion of the collector plate of claims 7, characterized in that bent shape along the contact surface 9 1 The manufacturing method of the electrical storage apparatus as described in one.

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