JP2012169064A - Rectangular secondary battery, and method of manufacturing the same - Google Patents

Abstract

When ultrasonically welding a positive / negative electrode current collector plate to positive / negative electrode metal foils of an electrode group, the metal foils are prevented from being rubbed and damaged by vibration.
A protruding piece is formed on a joining piece of a positive current collector plate. The joining piece pressing surface 81 a of the joining piece supporting jig 80 is in contact with the joining piece 23, and the protruding piece abutting surface 82 a is in contact with the abutting surface 24 a of the protruding piece 24. At the same time, the positive electrode mixture untreated portion 41 c is pressed against the bonded piece pressing surface 81 a by the metal foil pressing surface 91 a of the metal foil pressing jig 90. Even if the horn 95 and the anvil 96 vibrate in the AA ′ direction, the vibration of the joining piece 23 of the positive electrode current collector plate 21 is suppressed, and the positive electrode mixture untreated portions 41 c can be prevented from rubbing with each other.
[Selection] Figure 14

Description

  The present invention relates to a prismatic secondary battery and a manufacturing method thereof, and more particularly to a structure and a manufacturing method for favorably welding an electrode group and a current collector plate.

Some rectangular secondary batteries have a structure in which a flat electrode group in which positive and negative electrodes are wound through a separator is accommodated in a battery container, and an electrolytic solution is injected.
The battery container is composed of a battery lid having a positive electrode / negative electrode terminal and a battery can. A positive electrode / negative electrode current collector plate is attached to the battery cover in a cantilever shape, and the free end side is the positive electrode of the electrode group. -It is welded to the negative electrode.
The positive electrode current collector plate is formed on the positive electrode metal foil exposed along one side edge in the width direction of the electrode group, in other words, the direction orthogonal to the winding direction. It welds to the negative electrode metal foil exposed along the other side edge of the direction orthogonal to a rotation direction.

Both the positive electrode / negative electrode current collector plate and the positive electrode / negative electrode metal foil are welded by the same method. The following description is given by taking the positive electrode side as an example.
In a direction perpendicular to the winding direction of the positive electrode metal foil, the portion protruding from the side surface of the separator is gathered to the axial center side of the winding body. The positive electrode current collector plate is pressed from one side of the collected positive electrode metal foil toward the other side. A horn and an anvil are respectively disposed on the outer surface of the positive electrode metal foil and the other surface of the collected positive electrode metal foil, and joined by ultrasonic welding with the positive electrode current collector plate and the wound positive electrode metal foil interposed therebetween (for example, , See Patent Document 1).

Japanese Patent No. 4061938

In the method according to Patent Document 1, the positive and negative current collector plates are ultrasonically welded in a state where only one end is fixed to the battery lid and the other end is in a cantilever shape in a free state.
For this reason, the positive and negative current collectors sandwiched between the horn and the anvil, and the wound positive and negative electrode metal foils are arranged such that the horn that is the amplitude side metal fitting and the anvil that is the receiving side metal fitting are arranged. Vibrates along a plane perpendicular to the direction.
As a result, the position of the electrode group welded to the current collector plate is shifted, or the metal foils rub against each other, so that the metal foil is cracked or broken, and the performance and safety of the prismatic secondary battery are reduced. descend.

  The prismatic secondary battery according to the present invention has a positive electrode mixture having a positive electrode mixture formed on both sides and a positive electrode metal foil having one side edge along the longitudinal direction exposed to the outside, and a negative electrode mixture formed on both sides. A flat electrode group in which a negative electrode having a negative electrode metal foil with the other side edge exposed opposite to one side edge of the metal foil is wound through a separator, and one exposed to the outside of the positive electrode metal foil A positive current collector having a joint joined to the side edge, a negative current collector having a joint joined to the other side edge exposed to the outside of the negative metal foil, one end of the positive current collector and the negative electrode And a battery container for supporting one end of the current collector plate in a cantilever shape, and at least one of the positive electrode current collector plate and the negative electrode current collector plate is opposite to the one end supported by the battery container. A protrusion having a contact surface at an angle different from the joint surface of the joint at the other end of the And features.

  In addition, the method for manufacturing a prismatic secondary battery according to the present invention includes a positive electrode mixture in which a positive electrode metal foil is exposed from a positive electrode mixture, a positive electrode mixture untreated portion formed along one side edge, and a negative electrode metal foil. The negative electrode mixture untreated portion exposed from the negative electrode mixture forms an electrode group in which a negative electrode formed along the other side edge facing the one side edge is wound through a separator, and a battery container The positive electrode current collector plate with one end supported in a cantilever shape is ultrasonically welded to the positive electrode mixture untreated portion, and the negative electrode current collector plate with one end supported in a cantilever shape is superposed on the negative electrode mixture untreated portion. A method of manufacturing a rectangular secondary battery for sonic welding, comprising: forming a protrusion having a surface formed at an angle different from a welding surface on at least one of a positive electrode current collector plate and a negative electrode current collector plate; The welding surface of the current collector plate and the negative electrode current collector plate is brought into contact with the untreated portion of the corresponding polarity mixture, and the positive electrode current collector Alternatively, a current collector plate supporting step of supporting a protrusion provided on one side of the negative electrode current collector plate with a jig to restrain the displacement of the protrusion, and then a positive current collector plate or a negative current collector plate And a step of ultrasonic welding to the untreated portion of the polar mixture.

  According to the prismatic secondary battery and the method for manufacturing the prismatic secondary battery of the present invention, the displacement and vibration of the current collector plate during welding can be reduced by supporting the protrusion provided on the current collector plate. The positional deviation between the current collector plate and the electrode group can be reduced, and the occurrence of cracks and breaks in the metal foil can be reduced.

Sectional drawing of one Embodiment of the square secondary battery which concerns on this invention. FIG. 2 is an exploded perspective view of the cylindrical secondary battery shown in FIG. 1. The external appearance perspective view of the state which showed the detail of the electrode group illustrated in FIG. 1, and expanded one part. FIG. 4 is an enlarged cross-sectional view of the electrode group illustrated in FIG. 3. FIG. 2 is an enlarged perspective view of the battery lid unit illustrated in FIG. 1. FIG. 6 is a plan view of the battery lid unit illustrated in FIG. 5. FIG. 7 is a sectional view taken along line VII-VII of the battery lid unit illustrated in FIG. 6. FIG. 8 is an enlarged cross-sectional view in the vicinity of a positive electrode connection terminal illustrated in FIG. 7. FIG. 6 is an enlarged perspective view of the other end side of the current collector illustrated in FIG. 5. FIG. 2 is a process flow diagram illustrating an embodiment of a method for manufacturing the rectangular secondary battery illustrated in FIG. 1. The perspective view which shows the state before installing the collector plate support jig | tool in an electrode group. FIG. 12 is a perspective view showing a state where a current collector plate supporting jig is installed in the electrode group in relation to the process following FIG. 11. The perspective view which shows the state before mounting | wearing the electrode group 40 with the metal foil pressing jig 90 regarding the process following FIG. The expanded sectional view which shows one Embodiment of the state which carries out ultrasonic welding of a current collection plate and an electrode group regarding the process following FIG. The side view of the state in which the battery cover unit and electrode group in FIG. 2 were joined. The expanded sectional view cut | disconnected by the XVI-XVI line | wire in FIG. The expanded sectional view of the state corresponding to Drawing 16 showing the modification of Embodiment 1 of the present invention. FIG. 18 is a cross-sectional view illustrating a state where ultrasonic welding is performed in the state illustrated in FIG. 17. An exploded perspective view of a prismatic secondary battery according to the second embodiment of the present invention. FIG. 20 is an enlarged perspective view of the other end side of the current collector illustrated in FIG. 19. The expanded sectional view which shows the state which installed the current collector plate support jig in the electrode group. The perspective view which shows the relationship between the electrode group in the state of FIG. 21, the collector plate support jig | tool, and a metal foil holding jig.

(Embodiment 1)
-Structure of prismatic secondary battery-
Hereinafter, a prismatic secondary battery according to the present invention will be described with reference to the drawings, using a lithium ion prismatic secondary battery as an embodiment.
FIG. 1 is an external perspective view showing an embodiment of a prismatic secondary battery according to the present invention, and FIG. 2 is an exploded perspective view of the prismatic secondary battery shown in FIG.
In the rectangular secondary battery 1, an electrode group 40 is accommodated in a thin, substantially rectangular parallelepiped battery container 2 composed of a battery lid 3 and a battery can 4, and a non-aqueous electrolyte is injected although not shown. Configured. The battery lid 3 and the battery can 4 are made of aluminum, for example.

A positive electrode current collector plate 21, a negative electrode current collector plate 31, and the like are integrally assembled to the battery lid 3 to constitute a battery lid unit 10. The positive electrode current collector plate 21 and the negative electrode current collector plate 31 of the battery cover unit 10 are respectively joined to the positive electrode metal foil or the negative electrode current collector foil of the electrode group 40 by, for example, ultrasonic welding, so that the battery cover / power generation The unit 50 is accommodated from the opening at the upper end of the battery can 4.
In FIG. 2, the battery lid / power generation unit 50 is directly accommodated in the battery can 4, but the battery lid / power generation unit 50 once has the same shape as the battery can 4 and has a small size. Alternatively, the battery can be accommodated in the battery can 4 after being accommodated in a small insulating bag.

3 is an external perspective view of the electrode group 40 in a state where the winding end side is unfolded, and FIG. 4 is an enlarged cross-sectional view of the electrode group illustrated in FIG.
The electrode group 40 is formed by winding a positive electrode 41 and a negative electrode 42 in a flat shape around a shaft core (not shown) with first and second separators 43 and 44 interposed therebetween. Reference numeral 40a denotes a hollow portion having a width corresponding to the thickness of the axial center of the electrode group 40, and reference numeral 40b denotes a wide surface.
The positive electrode 41 has a positive electrode mixture layer 41b formed on both front and back surfaces of a positive electrode metal foil 41a made of, for example, aluminum foil. The positive electrode mixture layer 41b is formed by applying the positive electrode mixture to the positive electrode metal foil 41a so that the positive electrode mixture untreated portion 41c where the positive electrode metal foil 41a is exposed is formed on one side edge.
The negative electrode 42 is obtained by, for example, coating a negative electrode mixture layer 42b on both front and back surfaces of a negative electrode metal foil 42a made of copper foil or the like. In the negative electrode mixture layer 42b, a negative electrode mixture untreated portion 42c in which the negative electrode metal foil 42a is exposed is formed on the other side edge that is a side edge opposite to the side edge where the positive electrode mixture untreated portion 41c is disposed. In this way, the negative electrode metal foil 42a is formed by coating the positive electrode mixture.

The positive electrode mixture layer 41b adds 10 parts by weight of flaky graphite as a conductive material and 10 parts by weight of PVDF as a binder with respect to 100 parts by weight of lithium manganate (chemical formula LiMn ₂ O ₄ ) as a positive electrode active material. Then, NMP is added as a dispersion solvent and kneaded. This positive electrode mixture is applied to both surfaces of an aluminum foil having a thickness of 20 μm, leaving the positive electrode mixture untreated portions 41c. Thereafter, drying, pressing, and cutting are performed to obtain a positive electrode 41 having a thickness of 90 μm (total of both front and back surfaces) of the positive electrode active material application portion not including the aluminum foil.

  In the negative electrode mixture layer 42b, 10 parts by weight of polyvinylidene fluoride (hereinafter referred to as PVDF) is added as a binder to 100 parts by weight of amorphous carbon powder as a negative electrode active material, and a dispersion solvent is added thereto. N-methyl pyrrolidone (hereinafter referred to as NMP) is added and kneaded. This negative electrode mixture is applied to both sides of a 10 μm thick copper foil leaving the negative electrode mixture untreated portions 42c. Thereafter, drying, pressing, and cutting are performed to obtain a negative electrode 42 having a thickness of 70 μm (total on both front and back surfaces) of the negative electrode active material coating portion not including the copper foil.

  In order to form the electrode group 40, the winding start side end portion of the negative electrode 42 is respectively connected to the positive electrode 41 between the first and second separators 43, 44 whose tip portions are welded to a shaft core (not shown). It is arranged and wound so as to be located inside the winding start side end. In this case, the positive electrode mixture untreated portion 41c and the negative electrode mixture untreated portion 42c are arranged so as to be located on the side edges on the opposite side in the width direction (direction orthogonal to the winding direction). The width of the negative electrode mixture layer 42b, in other words, the length in the direction orthogonal to the winding direction is formed wider than the width of the positive electrode mixture layer 41b. Moreover, the width | variety of the 1st separator 43 is set as the dimension which exposes the positive mix untreated part 41c of the positive electrode 41 to the exterior in the one side edge side. The width of the second separator 44 is such that the negative electrode mixture untreated portion 42c of the negative electrode 42 is exposed to the outside on the other side edge side.

A hollow portion 40a (see FIGS. 2 and 3) is formed on the winding start side of the electrode group 40, in other words, on the axial core side. Further, on the winding end side of the electrode group 40, the outermost periphery is the second separator 44, and the inner side is the negative electrode 42. Therefore, the positive electrode mixture layer 41b covers the entire length from the winding start side to the winding end side, and all portions thereof are covered with the negative electrode mixture layer 42b also in the width direction.
The reason for this structure is that in the case of a lithium ion secondary battery, lithium as the positive electrode active material is ionized and penetrates the separator, but the negative electrode active material is not formed on the negative electrode side and the negative electrode metal foil 42a is formed. This is because if it is exposed, lithium is deposited on the negative electrode metal foil 42a, causing an internal short circuit.

  Thus, in the electrode group 40, the positive electrode mixture untreated portion 41 c of the positive electrode metal foil 41 a is exposed to the outside in the positive electrode 41, and the negative electrode mixture of the negative electrode metal foil 42 a is not exposed in the negative electrode 42. The processing unit 42c is exposed to the outside.

FIG. 5 is an enlarged perspective view of the battery lid unit shown in FIG.
The battery cover 3 is made of aluminum. The battery lid 3 is provided with a liquid injection port 11 for injecting a non-aqueous electrolyte. Further, the battery lid 3 is provided with a cleavage valve 12 for releasing the pressure when the internal pressure exceeds a reference value due to overcharge or the like. The cleavage valve 12 has a cleavage groove 12a.

In the non-aqueous electrolyte, lithium hexafluorophosphate (LiPF ₆ ) is dissolved at a concentration of 1 mol / liter in a mixed solution in which ethylene carbonate and dimethyl carbonate are mixed at a volume ratio of 1: 2. Can be used.

The liquid injection port 11 is closed by laser welding after the electrolyte injection.
The battery lid 3 is welded to the battery can 4 formed of aluminum by laser welding, thereby sealing from the outside.

6 is a plan view of the battery lid unit shown in FIG. 5, FIG. 7 is a sectional view taken along line VII-VII of the battery lid unit shown in FIG. 6, and FIG. It is an expanded sectional view near the illustrated positive electrode connection terminal.
The battery lid unit 10 includes a battery lid 3, a positive electrode side terminal component 60, and a negative electrode terminal component 70.
The positive electrode side terminal component 60 includes an external positive electrode terminal 61, a positive electrode connection terminal 62, a positive electrode terminal plate 63, an insulating plate 64, a gasket 65 (see FIG. 7), and a positive electrode current collector plate 21.
The external positive electrode terminal 61, the positive electrode terminal plate 63, the positive electrode connection terminal 62, and the positive electrode current collector plate 21 are fixed integrally and attached to the battery lid 3.

The positive electrode side terminal component 60 is produced as follows.
In advance, the positive electrode current collecting plate 21 is caulked to the positive electrode connection terminal 62. A gasket 65 is inserted into the through hole of the battery lid 3. An insulating plate 64 is disposed on the battery lid 3 such that the through hole of the battery lid 3 and the through hole of the insulating plate 64 are aligned.

Next, the external positive terminal 61 is fitted into a through hole provided in the positive terminal plate 63 and fixed to the positive terminal plate 63 on the insulating plate 64. The external positive terminal 61 and the positive terminal plate 63 may be caulked. Further, the positive electrode connection terminal 62 with the positive electrode current collector plate 21 crimped is inserted into the through hole of the gasket 65 from the back side of the battery lid 3, and the tip end side of the positive electrode connection terminal 62 is penetrated by the insulating plate 64 and the positive electrode terminal plate 63. Insert through the hole. The tip end side of the positive electrode connection terminal 62 has a cylindrical shape that is slightly smaller than the through hole of the positive electrode terminal plate 63. By caulking the tip portion of the positive electrode connection terminal 62, the positive electrode side terminal component 60 is The battery cover 3 is assembled integrally.
In this state, the positive electrode current collector plate 21, the positive electrode connection terminal 62, the positive electrode terminal plate 63, and the external positive electrode terminal 61 are electrically connected. Further, the positive electrode current collector plate 21, the positive electrode connection terminal 62, the positive electrode terminal plate 63, and the external positive electrode terminal 61 are insulated from the battery lid 3 by the insulating plate 64 and the gasket 65.

The negative electrode side terminal constituting unit 70 includes an external negative electrode terminal 71, a negative electrode connection terminal 72, a negative electrode terminal plate 73, an insulating plate 74, a gasket 75, and a negative electrode current collector plate 31.
Although there is no figure corresponding to FIG. 8 which is an enlarged sectional view of the positive electrode side terminal component 60 regarding the negative electrode side terminal component 70, it is structurally similar to FIG. 8, and therefore is necessary in the following description. Refer to FIG. 8 accordingly.
The external negative electrode terminal 71, the negative electrode terminal plate 73, the negative electrode connection terminal 72, and the negative electrode current collector plate 31 are integrally assembled to the battery lid 3.

The negative electrode side terminal component 70 is produced as follows.
The negative electrode current collecting plate 31 is caulked to the negative electrode connection terminal 72 in advance. A gasket 75 is inserted into the through hole of the battery lid 3. An insulating plate 74 is disposed on the battery lid 3 such that the through hole of the battery lid 3 and the through hole of the insulating plate 74 are aligned.

Next, the external negative electrode terminal 71 is fitted into a through hole provided in the negative electrode terminal plate 73 and fixed to the negative electrode terminal plate 73 on the insulating plate 74. Further, the negative electrode connection terminal 72 with the negative electrode current collecting plate 31 crimped is inserted into the through hole of the gasket 75 from the back side of the battery lid 3, and the tip end side of the negative electrode connection terminal 72 is penetrated through the insulating plate 74 and the negative electrode terminal plate 73. Insert through the hole. The tip end side of the negative electrode connection terminal 72 has a cylindrical shape that is slightly smaller than the through hole of the negative electrode terminal plate 73. By caulking the tip portion of the negative electrode connection terminal 72, the negative electrode side terminal component 70 is The battery cover 3 is assembled integrally.
In this state, the negative electrode current collector plate 31, the negative electrode connection terminal 72, the negative electrode terminal plate 73, and the external negative electrode terminal 7 are electrically connected. The negative electrode current collector plate 31, the negative electrode connection terminal 72, the negative electrode terminal plate 73, and the external negative electrode terminal 71 are insulated from the battery lid 3 by an insulating plate 74 and a gasket 75.

  By joining the positive and negative current collecting plates 21, 31 to the electrode group 40, the prismatic secondary battery 1 can charge and discharge external electronic devices connected to the external positive terminal 61 and the external negative terminal 71. It becomes possible.

  The positive electrode current collector plate 21 is made of aluminum. The positive electrode current collector plate 21 has a support portion 22a in which a main body portion 22 attached to the battery lid 3 is bent at approximately 90 °. The bent support portion 22a is bifurcated at the end portion, and a flat joining piece 23 is formed. Each joining piece 23 is ultrasonically welded to the electrode group 40 as will be described in detail later. Each of the joining pieces 23 is bent at an angle inclined with respect to the support portion 22a. The inclination directions of the pair of joining pieces 23 are opposite to each other, but are the same angle with respect to the center plane and are line symmetric. A protruding piece (protruding portion) 24 that is bent in a direction substantially parallel to the support portion 22 a is formed at the end of each joining piece 23.

FIG. 9 shows an enlarged perspective view on the free end side of the positive electrode current collector plate 21.
The protruding piece 24 is bent with respect to the joining piece 23 and has a contact surface 24 a perpendicular to the wide surface 40 b of the electrode group 40.
That is, the positive electrode current collector plate 21 is supported by the battery lid 3 in a cantilever shape with one end fixed and the other end free. A protruding piece 24 having a contact surface 24a is formed on the free end. Has been.

The negative electrode current collecting plate 31 is made of copper, but has the same structure as the positive electrode current collecting plate 21.
The negative electrode current collector plate 31 has a support portion 32a in which a main body portion 32 attached to the battery lid 3 is bent at approximately 90 °. The bent support portions 32a are bifurcated at the end portions, and the joining pieces 33 are formed respectively. Each joining piece 33 is ultrasonically welded to the electrode group 40 as described in detail later. The inclination directions of the pair of joining pieces 33 are opposite to each other, but are at the same angle with respect to the center plane and are line symmetric. A protruding piece 34 that is inclined in a direction substantially parallel to the main body 32 is formed at the end of each joining piece 33. A protruding piece (protruding portion) 24 that is bent in a direction substantially parallel to the support portion 32 a is formed at the end of each joining piece 33.

The protruding piece 44 is bent with respect to the joining piece 33 and has a contact surface 24 a perpendicular to the wide surface 40 b of the electrode group 40.
That is, the negative electrode current collecting plate 31 is supported by the battery lid 3 in a cantilever shape with one end fixed and the other end free. A protruding piece (protruding portion) having an abutment surface 34a on the free end side. ) 34 is formed.

Since the positive electrode current collector plate 21 and the negative electrode current collector plate 31 are supported by the battery lid 3 in a cantilever shape, ultrasonic waves are applied to the positive electrode mixture untreated portion 41c or the negative electrode mixture untreated portion 42c of the electrode group 40. When welding, vibration is likely to occur with the vibration of the horn and anvil. That is, the positive / negative current collectors 21 and 31 and the positive / negative metal foil sandwiched between the horn and the anvil vibrate along a plane perpendicular to the direction in which the horn and the anvil are arranged.
For this reason, the position of the electrode group 40 welded to the current collector plates 21 and 31 of the positive and negative electrodes is shifted, or the metal foils 41a and 42a of the positive and negative electrodes are rubbed with each other, so that the metal foil is cracked, If it breaks, the performance and safety of the prismatic secondary battery deteriorate.
Although details will be described later, the protruding piece 24 provided on the positive electrode current collector plate 21 and the protruding piece 34 provided on the negative electrode current collector plate 31 are pressed during ultrasonic welding by pressing the protruding pieces 24 and 34 with a jig. It is formed in order to suppress vibrations.
Hereinafter, the operation of the prismatic secondary battery 1 and its operation will be described.

FIG. 10 is a process flow diagram showing an embodiment of a method for manufacturing the rectangular secondary battery 1 shown in FIG.
First, in step S1, the electrode group 40 is produced.
As described above, the negative electrode 42 and the positive electrode 41 are disposed between the first and second separators 43 and 44, respectively, and are wound. In this case, the one side edges in the longitudinal direction of the positive electrode mixture untreated portion 41c and the negative electrode mixture untreated portion 42c protrude from the side edges of the first and second separators 43 and 44, respectively, and are exposed to the outside. Turn around. One side edges of the positive electrode mixture untreated portion 41 c and the negative electrode mixture untreated portion 42 c are respectively positioned on opposite sides in the width direction of the electrode group 40. Moreover, the electrode group 40 is formed in a flat wound body in which the upper and lower surfaces are wide surfaces 40b.

Separately from step S1, the battery lid unit 10 is produced in step S2.
The method for producing the battery lid unit 10 is as described above.

Next, in step S <b> 3, the electrode group 40 is attached to the battery lid unit 10.
That is, in FIG. 2, to move the electrode group 40 in the X ₁ direction, the positive electrode mixture of the electrode group 40 untreated portion 41c and the negative electrode mixture non-processing unit 42c, respectively, a pair of joining pieces of the positive electrode current collector plate 21 23 and between the pair of joining pieces 33 of the negative electrode current collector 31.
When the electrode group 40 is inserted, the positive electrode mixture untreated portion 41 c and the negative electrode mixture untreated portion 42 c are respectively connected to the pair of joined pieces 23 of the positive electrode current collector plate 21 and the pair of joined pieces 33 of the negative electrode current collector plate 31. Is gathered to the shaft core side. Thereafter, the cavity 40a of the electrode group 40 is pushed open by an unillustrated expansion jig. By this operation, the wound positive and negative electrode mixture processing untreated portions 41c and 42c are divided into two. This facilitates mounting of the metal foil pressing jig 90 described later to the electrode group 40.

Next, in step S <b> 4, a current collecting plate support jig is installed on the electrode group 40 attached to the battery lid unit 10.
FIG. 11 is a perspective view showing a state before the current collector plate supporting jig 80 is installed in the electrode group 40, and FIG. 12 shows a state in which the current collector plate supporting jig 80 is installed in the electrode group 40. It is a perspective view shown.
As illustrated in FIG. 11, current collector plate supporting jigs 80 are respectively disposed facing the upper and lower wide surfaces 40 b of the electrode group 40 mounted on the battery lid unit 10. The current collector plate support jigs 80 arranged above and below have the same structure. The current collector plate support jig 80 is made of, for example, polyacetal resin or PEEK (PolyEtherEtherKetone) resin.
A pair of joining piece pressing portions 81 and a protruding piece pressing portion 82 are formed on both sides of the current collector plate supporting jig 80, respectively.

A pair of joining piece presser portions 81 of each current collecting plate supporting jig 80 has a positive or negative current collecting plate 31 at two locations of the pair of joining pieces 23 and 33, that is, at the free end side and the fixed end side. , 33 and a joined piece pressing surface 81a for pressing the positive or negative electrode mixture untreated portions 41c and 42c. The joining piece pressing surface 81a is an inclined surface that is inclined in a direction to open from the axial center side toward the wide surface 40b side of the electrode group 40.
The protruding piece pressing portion 82 of the current collecting plate supporting jig 80 has a protruding piece contact that abuts against the abutting faces 24a, 34a of the protruding pieces 24, 34 formed on the positive or negative current collecting plates 31, 33 on the inner surface side. A contact surface 82a is provided. The protruding piece contact surface 82 a is perpendicular to the wide surface 40 b of the electrode group 40.

The current collector plate support jig 80 disposed on the upper side of the electrode group 40 is moved in the X ₂ direction, the current collector plate support jig 80 disposed on the lower side of the electrode group 40 X 'in _two directions FIG. 12 shows a state in which the current collector plate supporting jig 80 is moved and installed on the electrode group 40.

When step S4 is completed, in step S5, the positive and negative current collecting plates 31 and 41 are positioned by the pair of current collecting plate supporting jigs 80, and the outer surfaces of the joining pieces 23 and 33 are supported.
Although FIG. 12 shows only the positive electrode side terminal component 60 side, the same applies to the negative electrode terminal component 70 side. The following description will be made on the positive electrode terminal component 60 side as a representative of both.
After the pair of current collecting plate supporting jigs 80 is installed in the electrode group 40, the position of the current collecting plate supporting jig 80 is adjusted, and the pair of joining piece pressing surfaces 81a of the current collecting plate supporting jig 80 are adjusted. Are brought into contact with the joining piece 23 of the positive electrode current collector plate 21, respectively. Further, the projecting piece contact surface 82 a of the current collector plate support jig 80 is brought into contact with the abutting surface 24 a of the projecting piece 24 of the positive current collector plate 21.
As a result, the outer surface of the joining piece 23 of the positive electrode current collector plate 21 and the abutting surface 24 a of the protruding piece 24 are supported by the current collector plate support jig 80.

When step S5 is completed, in step S6, the metal foil holding jig 90 is installed in the electrode group 40, and the positive electrode current collector plate 21 joining piece 23 is fixed so as not to be displaced.
FIG. 13 is a perspective view showing a state before the metal foil pressing jig 90 is attached to the electrode group 40.
A pair of metal foil holding jigs 90 are respectively arranged on the sides of the electrode group 40. Each metal foil pressing jig 90 has a metal foil pressing portion 91 in which a pair of metal foil pressing surfaces 91a is formed. The pair of metal foil pressing surfaces 91a are symmetrical with respect to a plane including the winding axis of the electrode group 40 and parallel to the wide surface 40b, and have an inclined surface that becomes wider toward the tip side. The inclination angle of the metal foil pressing surface 91 a is the same as the inclination angle of the joining piece 23 of the positive electrode current collector plate 21.

The tip end side of the metal foil pressing surface 91a is inserted into the hollow portion 40a of the electrode group 40 that has been pushed open so as to be divided into two in step S3 described above, and the positive electrode mixture untreated portion 41c is expanded in the y direction while expanding. Moving.
By moving the metal foil holding jig 90 in the y direction, the positive electrode mixture untreated portion 41c divided into two parts is further spread and gathered in a direction parallel to the metal foil holding surface 91a. And the joining piece 23 of the positive electrode current collector plate 21 and the positive electrode mixture untreated portion 41c gathered in two parts are respectively collected by the current collector plate supporting jig 80 and the metal foil holding jig 90. It is pinched and fixed.

When step S6 is completed, in step S7, the positive and negative electrode metal foils and the positive and negative electrode current collector plates are joined by ultrasonic welding.
FIG. 14 is an enlarged cross-sectional view of a state in which the current collector plate and the electrode group are ultrasonically welded.
In this state, the joined piece 23 of the positive electrode current collector plate 21 and the positive electrode mixture untreated portion 41c divided and gathered into two pieces are joined to the joined piece retainer surface of the joined piece retainer 81 in the current collector plate supporting jig 80. 81a and the metal foil holding surface 91a of the metal foil holding part 91 in the metal foil holding jig 90 are sandwiched and held while the displacement is restricted. Further, the projecting piece abutment surface 82a of the projecting piece pressing portion 82 of the current collector plate support jig 80 is brought into contact with the abutting surface 24a of the projecting piece 24 provided on the positive electrode current collecting plate 21, whereby the joining piece 23 is held with its displacement restrained over the entire length including the free end side.

In this state, the end face of the horn 95 that is an ultrasonic amplitude side metal fitting is brought into contact with one of the innermost peripheral surfaces of the positive electrode mixture untreated portion 41c gathered in two, and the anvil 96 is collected in the positive electrode. Ultrasonic welding is performed by contacting the outer surface side of the joining piece 23 of the electric plate 21. That is, ultrasonic welding is performed by sandwiching one of the positive electrode mixture untreated portions 41c collected in two divided pieces with the joining piece 23 between the horn 05 and the anvil 96.
When performing ultrasonic welding, the horn 95 and the anvil 96 vibrate in the AA ′ direction orthogonal to the pressing direction. In the case of a conventional cantilever structure in which the positive current collector 21 is supported on the battery lid 3 only at one end and the other end is a free end, the positive current collector 21 and the wound positive mix are not used. The processing unit 41 c vibrates in the AA ′ direction together with the horn 95 and the anvil 96. For this reason, when the position of the electrode group 40 welded to the positive electrode current collector plate 21 is shifted, or the positive electrode mixture untreated portions 41c are rubbed with each other, the positive electrode mixture untreated portions 41c are cracked or broken. As a result, the performance and safety of the prismatic secondary battery are lowered.

On the other hand, in the above-described embodiment, the protruding piece 24 is formed on the free end side of the positive electrode current collecting plate 21, and the collecting plate supporting jig 80 is provided on the abutting surface 24 a of the protruding piece 24. The protruding piece contact surface 82a contacts. Further, the joining piece 23 is pressed against the joining piece pressing surface 81a together with the positive electrode mixture untreated portion 41c by the metal foil holding surface 91a of the metal foil holding jig 90. Thereby, the joining piece 23 is hold | maintained so that a displacement may be restrained over the full length also including the free end side.
For this reason, also when performing ultrasonic welding, the vibration of the joining piece 23 is suppressed and the vibration of the positive electrode mixture untreated part 41c is also suppressed accordingly.
As a result, it is possible to prevent the position of the electrode group 40 from being displaced or being damaged by rubbing the positive electrode mixture untreated portions 41c with each other. Therefore, it is possible to prevent the positional deviation of the electrode group 40 and the crack and breakage of the positive electrode mixture untreated portion 41c, and to prevent the performance and safety of the prismatic secondary battery from being lowered.

15 is a side view of the battery lid unit and the electrode group in FIG. 2 joined to each other, and FIG. 16 is an enlarged cross-sectional view taken along line XVI-XVI in FIG.
In FIG. 16, the angle between the wide surface 40 b of the electrode group 40 and the abutting surface 24 a of the protruding piece 24 of the positive current collector plate 21 is θ _1, and the joining piece 23 between the wide surface 40 b of the electrode group 40 and the positive current collector plate 21. Is the angle θ ₂ .
As shown in FIG. 14, the current collector plate support jig 80 is installed from the directions of X ₂ and X ′ ₂ perpendicular to the wide surface 40 _b of the electrode group 40. Therefore, when the angle θ ₁ is 90 ° or more, the current collector plate is simply moved by moving the current collector plate support jig 80 in the direction of X ₂ or X ′ ₂ that is one axial direction, in other words, linearly. The protruding piece abutting surface 82 a of the supporting jig 80 can be brought into contact with the abutting surface 24 a of the protruding piece 24 of the positive electrode current collector plate 21. However, when the angle θ ₁ is less than 90 °, in order to bring the protruding piece abutting surface 82a of the current collector plate support jig 80 into contact with the abutting surface 24a of the protruding piece 24 of the positive electrode current collector plate 21, After the current collector plate support jig 80 is moved in the X ₂ or X ′ ₂ direction, it must also be moved in a direction parallel to the wide surface 40 _b of the electrode group 40.

Therefore, when the angle θ ₁ between the wide surface 40b of the electrode group 40 and the abutting surface 24a of the protruding piece 24 of the positive electrode current collector plate 21 is 90 ° or more, the positive electrode current collector of the electrode group 40 is collected by the current collector plate supporting jig 80. The process of supporting the electric plate 21 becomes efficient.
In this case, the angle θ ₂ between the wide surface 40 _b of the electrode group 40 and the joining piece 23 of the positive current collector plate 21 is such that the wide surface 40 _b of the electrode group 40 and the abutting surface 24 a of the protruding piece 24 of the positive current collector plate 21. At the same angle as the angle θ ₁ , the vibration at the time of ultrasonic welding cannot be suppressed by bringing the protruding piece abutting surface 82a of the current collector plate support jig 80 into contact with the abutting surface 24a of the protruding piece 24. Further, in the positive electrode current collector plate 21 shown in FIG. 9, the protruding piece 24 is formed to protrude to one surface side of the joining piece 23, and in this structure, the angle θ ₂ is larger than the angle θ _1. large.
Therefore, the relationship of 0 ° ≦ θ ₁ <θ ₂ is desirable from the viewpoint of efficiently performing the step of supporting the positive electrode current collector plate 21 of the electrode group 40 by the current collector plate support jig 80.

(Modification)
FIG. 17 is a modified example of the first embodiment, and is an enlarged cross-sectional view in a state corresponding to FIG.
In Embodiment 1 illustrated in FIG. 16, the angle θ ₁ between the wide surface 40 b of the electrode group 40 and the abutting surface 24 a of the projecting piece 24 of the positive electrode current collector plate 21 is approximately 90 °.
On the other hand, in FIG. 17, the angle θ ₁ between the wide surface 40b of the electrode group 40 and the abutting surface 24a of the projecting piece 24 of the positive electrode current collector plate 21 is formed to be larger than 90 °. In this structure, the protruding piece 24 ′ formed on the joining piece 23 of the positive electrode current collector plate 21 is bent toward the joining piece 23 side at an angle larger than perpendicular to the wide surface 40 b of the electrode group 40. Can be produced.

FIG. 18 is a cross-sectional view showing a state in which the positive electrode current collector plate 21 and the electrode group 40 shown as a modification in FIG. 17 are ultrasonically welded.
When the angle θ ₁ between the wide surface 40 b of the electrode group 40 and the abutting surface 24 a ′ of the projecting piece 24 ′ of the positive current collector plate 21 is larger than 90 °, the projecting piece presser 82 of the current collector plate support jig 80. The protruding piece abutment surface 82a 'formed on the surface has an inclination angle corresponding to the inclination angle of the abutting surface 24a' of the protruding piece 24 'of the positive electrode current collector plate 21.
Therefore, also in the modified example, the protruding piece abutting surface 82a ′ of the current collecting plate supporting jig 80 is made to move to the protruding piece 24 of the positive current collecting plate 21 only by moving the current collecting plate supporting jig 80 in one axial direction. It can be brought into contact with the 'abutting surface 24a'.
The other members in the modification are the same as those in the first embodiment, and the same members are assigned the same drawing numbers and the description thereof is omitted.

  As shown in FIGS. 11 and 12, the current collector plate support jig 80 has a joining piece pressing portion 81 and a protruding piece pressing portion 82 on both sides. Therefore, the step of ultrasonically welding the negative electrode current collecting plate 31 to the negative electrode mixture untreated portion 42c of the electrode group 40 may be performed simultaneously with the step of ultrasonicating the positive electrode current collecting plate 21 to the positive electrode mixture untreated portion 41c. Is possible.

According to the above-described embodiment, the protruding pieces 24 and 34 provided on the positive and negative current collecting plates 21 and 31 are pressed by the current collecting plate supporting jig 80 and the metal foil holding jig 90 to restrain the displacement. For this reason, it is possible to suppress the vibrations of the positive and negative current collecting plates 21 and 31 during ultrasonic welding.
This makes it possible to reduce misalignment between the positive and negative current collectors 21 and 31 and the electrode group 40, and to reduce the occurrence of cracks and breaks in the positive and negative metal foils 41a and 42a.

In the above embodiment, the angle θ ₁ between the wide surface 40 b of the electrode group 40 and the abutting surface 24 a of the protruding piece 24 of the positive current collector plate 21, and the wide surface 40 b of the electrode group 40 and the positive current collector plate 21. The angle θ ₂ with the joining piece 23 was set to 0 ° ≦ θ ₁ <θ ₂ .
As a result, the current collector plate supporting jig 80 is simply moved linearly, so that the joining piece 23 of the positive current collector plate 21 and the protruding piece 24 of the positive current collector plate 21 are connected to the current collector plate supporting jig 80. It can be installed at a position pressed by 80. For this reason, the process of supporting the positive electrode current collector plate 21 of the electrode group 40 by the current collector plate support jig 80 becomes efficient.

(Embodiment 2)
FIG. 19 is an exploded perspective view of a prismatic secondary battery as Embodiment 2 of the present invention.
The difference between the second embodiment and the first embodiment is that the positive electrode current collector plate 25 and the negative electrode current collector plate 35 are not divided into two portions.
Each of the positive electrode current collector plates 25 and 35 has a shape in which one end side is bent in a vertical direction from a support portion supported by the battery lid 3. In the middle portion of the portion extending in the vertical direction, inclined portions 25 a and 35 a that are inclined toward the axial center side of the electrode group 40 are formed.
Flat joining pieces 26 and 36 joined to the electrode group 40 are formed below the inclined portions 25a and 35a.

FIG. 20 is an enlarged perspective view of the joining end 26 of the positive electrode current collector plate 25 on the free end side.
Projecting pieces 27 and 37 (see FIG. 19) bent in a direction perpendicular to the joining pieces 26 and 36 are formed at the distal end portions which are free ends of the joining pieces 26 and 36.
The inner side surfaces of the projecting pieces 27 and 37 are abutting surfaces 27a and 37a described later.

As shown by the two-dot chain line, the positive and negative current collecting plates 25 and 35 are joined by ultrasonic welding to the positive and negative electrode mixture untreated portions 41 c and 42 c gathered to the shaft core side.
Hereinafter, a method of joining the positive and negative current collectors 25 and 35 and the electrode group 40 in the prismatic secondary battery 1A shown in the second embodiment will be described. However, since the positive electrode side and the negative electrode side are the same, the first embodiment is the same. As in the case of, the positive electrode side will be described as a representative.

FIG. 21 is an enlarged cross-sectional view showing a state where the current collector plate supporting jig 80A and the metal foil holding jig 90A are installed on the electrode group 40 mounted on the battery lid unit 10A. FIG. It is a perspective view which shows the relationship between the electrode group 40 in the state, the collector plate support jig | tool 80A, and the metal foil holding jig | tool 90A.
In the second embodiment, unlike the first embodiment, the positive electrode current collector plate 25 and the electrode group 40 are held by using one collector plate supporting jig 80A and one metal foil holding jig 90A.

The current collector plate support jig 80 </ b> A has a pair of joining piece pressing portions 83 and one protruding piece pressing portion 85. A groove 84 that is the same as or deeper than the thickness of the bonding piece 26 of the positive electrode current collector plate 25 is provided on the upper surface of the bonding piece pressing portion 83. The groove 84 has a side surface 84 a that contacts the outer side surface 26 a (see FIG. 19) of the bonding piece 26, and a bonding piece pressing surface 84 b that is parallel to the wide carrier surface 40 b of the electrode group 40. The joining piece pressing surface 84 b is the bottom surface of the groove 84.
The protruding piece pressing portion 85 has a protruding piece contact surface 85a perpendicular to the wide surface 40b of the electrode group 40.

  The metal foil holding jig 90A has a pair of metal foil holding portions 91. The metal foil pressing portions 91 are respectively formed at positions corresponding to the pair of joining piece pressing portions 83 of the current collector plate supporting jig 80A. Each metal foil pressing portion 91 has a metal foil pressing surface 91 a parallel to the wide surface 40 b of the electrode group 40.

The positive electrode current collector plate 25 of the battery lid unit 10 is placed on the current collector plate supporting jig 80A so that the joining piece 26 is disposed in the groove 84 of the current collector plate holding jig 80A. Further, the abutting surface 27a of the projecting piece 27 formed on the positive electrode current collector plate 25 is brought into contact with the projecting piece abutting surface 85a of the current collector plate supporting jig 80A. In this state, the joining piece 26 is sandwiched between the side surface 84a of the groove 84 and the projecting piece abutting surface 85a of the projecting piece pressing portion 85, and cannot move in the direction parallel to the wide surface 40b of the electrode group 40. It has become.

The metal foil holding jig 90 </ b> A is arranged on the upper side and moved downward while pressing the positive electrode mixture untreated portion 41 c on the joining piece 26 of the positive electrode current collector plate 25 with the metal foil holding surface 91 a of the metal foil holding portion 91. .
This state is illustrated in FIG. 21 and FIG.

In the ultrasonic welding, as shown by a two-dot chain line in FIG. 21, the end face of the horn 95 is brought into contact with the outermost periphery of the wound positive electrode mixture untreated portion 41c, and the anvil 96 is joined to the positive electrode current collector plate 25. It is made to contact the outer surface side of 26.
As described above, in this state, the joining piece 26 of the positive electrode current collector plate 25 is sandwiched between the side surface 84a of the groove 84 and the projecting piece abutting surface 85a of the projecting piece pressing portion 85, and the wide surface 40b of the electrode group 40 is obtained. It is impossible to move in the parallel direction.

Therefore, even when the horn 95 and the anvil 96 vibrate in the direction BB ′ during ultrasonic welding, the vibration of the joining piece 26 is suppressed, and accordingly, the vibration of the positive electrode mixture untreated portion 41 c is also suppressed. Is done.
For this reason, it can prevent that the position of the electrode group 40 shifts | deviates or it damages because the positive mix untreated part 41c mutually rubs. As a result, it is possible to prevent the displacement of the electrode group 40 and the occurrence of cracks and breakage of the positive electrode mixture untreated portion 41c, and to prevent the performance and safety of the prismatic secondary battery from being lowered.

Thus, the second embodiment also has the same effect as the first embodiment.
In addition, the positive and negative electrode mixture untreated portions 41c and 42c of the electrode group 40 have a simple structure that is simply gathered to the axial center side, and therefore a current collector plate support jig 80A to which the electrode group 40 is mounted is provided. In addition, the structure of the metal foil holding jig 90A is simplified.

  In the above embodiment, the case of a lithium ion prismatic secondary battery has been described. However, the present invention can also be applied to a prismatic secondary battery using a water-soluble electrolyte such as a nickel metal hydride battery, a nickel cadmium battery, or a lead storage battery.

  In the above embodiment, the joining piece pressing portion 81 and the protruding piece pressing portion 82 are fixed to the current collector plate supporting jig 80. However, both or one of the joining piece pressing portion 81 and the protruding piece pressing portion 82 may be movably provided on the current collector plate support jig 80.

In each of the above embodiments, the battery container 2 is configured by the battery lid 3 and the battery can 4 having the battery lid 3 opened, and the positive electrode current collector plates 21 and 25 and the negative electrode current collector plates 31 and 35 are attached to the battery lid 3. Explained as a structure.
However, it has a frame shape in which both side surfaces facing the wide surface 40b of the electrode group 40 are opened, and a portion corresponding to the battery lid 3, in other words, a portion where the positive electrode terminal component and the negative electrode terminal component are formed. The present invention can also be applied to a prismatic secondary battery in which a battery container is configured by a battery can having a side surface and a pair of battery lids that close openings on both sides of the battery can.

  Further, the battery lid 3 and the battery can 4 are not limited to aluminum, and iron or other materials can be used. In addition, the prismatic secondary battery of the present invention can be applied with various modifications within the scope of the gist of the invention. In short, a positive electrode mixture is formed on both surfaces, and one side along the longitudinal direction A positive electrode having a positive electrode metal foil having an edge exposed to the outside; a negative electrode having a negative electrode metal foil having a negative electrode mixture formed on both sides and having the other side edge exposed to one side edge of the positive electrode metal foil; A positive electrode current collector plate having a flat electrode group in which the upper and lower outer surfaces are flat surfaces and a bonding portion bonded to one side edge exposed to the outside of the positive electrode metal foil And a negative electrode current collector plate having a joint bonded to the other side edge exposed to the outside of the negative electrode metal foil, and one end of the positive electrode current collector plate and one end of the negative electrode current collector plate, each in a cantilever shape A battery container to support, at least one of the positive electrode current collector plate and the negative electrode current collector plate The other end portion opposite to the supported end to the battery container, as long as it has a protruding portion having a butting face of a different angle from the bonding surface of the joint.

  In addition, the method for manufacturing a prismatic secondary battery according to the present invention includes a positive electrode mixture in which a positive electrode metal foil is exposed from a positive electrode mixture, a positive electrode mixture untreated portion formed along one side edge, and a negative electrode metal foil. The negative electrode mixture untreated portion exposed from the negative electrode mixture forms an electrode group in which a negative electrode formed along the other side edge facing the one side edge is wound through a separator, and a battery container The positive electrode current collector plate with one end supported in a cantilever shape is ultrasonically welded to the positive electrode mixture untreated portion, and the negative electrode current collector plate with one end supported in a cantilever shape is superposed on the negative electrode mixture untreated portion. A method of manufacturing a rectangular secondary battery for sonic welding, comprising: forming a protrusion having a surface formed at an angle different from a welding surface on at least one of a positive electrode current collector plate and a negative electrode current collector plate; The welding surface of the current collector plate and the negative electrode current collector plate is brought into contact with the untreated portion of the corresponding polarity mixture, and the positive electrode current collector Alternatively, a current collector plate supporting step of supporting a protrusion provided on one side of the negative electrode current collector plate with a jig to restrain the displacement of the protrusion, and then a positive current collector plate or a negative current collector plate What is necessary is just to be equipped with the process of ultrasonically welding to a polar unmixed part.

DESCRIPTION OF SYMBOLS 1, 1A Square secondary battery 2 Battery container 3 Battery cover 4 Battery can 10 Battery cover unit 21, 25 Positive electrode current collecting plate 23, 26, 33, 36 Joint piece 24, 27, 34, 37 Projection piece 24a, 27a Joint piece Abutting surface 31, 35 Negative electrode current collector plate 40 Electrode group 41 Positive electrode 41c Positive electrode mixture untreated portion 42 Negative electrode 42c Negative electrode mixture untreated portion 43, 44 Separator 80, 80A Current collecting plate support jig 81, 83 Joining One-side holding part 81a, 83a Joint piece-holding surface 82, 85 Projecting piece-holding part 82a, 85a Projecting piece-contacting surface 84 Groove 90, 90A Metal foil holding jig 91 Metal-foil holding part 91a Metal-foil holding surface

Claims (9)

A positive electrode having a positive electrode metal foil with a positive electrode mixture formed on both sides and having one side edge along the longitudinal direction exposed to the outside, and a negative electrode mixture formed on both sides opposite to one side edge of the positive electrode metal foil A flat electrode group in which a negative electrode having a negative electrode metal foil with the other side edge exposed is wound through a separator;
A positive electrode current collector having a bonding portion bonded to the one side edge exposed to the outside of the positive electrode metal foil;
A negative electrode current collector having a bonding portion bonded to the other side edge exposed to the outside of the negative electrode metal foil;
A battery container for supporting one end of the positive electrode current collector plate and one end of the negative electrode current collector plate in a cantilever shape,
At least one of the positive electrode current collector plate and the negative electrode current collector plate has a projecting surface having an abutting surface at an angle different from the joint surface of the joint portion at the other end portion opposite to the one end supported by the battery container. A prismatic secondary battery comprising a portion. 2. The prismatic secondary battery according to claim 1, wherein one side edge of the positive electrode metal foil and the other side edge of the negative electrode metal foil are inclined with respect to the wide surface of the electrode group in a direction orthogonal to the longitudinal direction. The abutting surface of the projecting portion is inclined at an angle θ ₁ with respect to the wide surface of the electrode group, and the positive current collector plate and the negative current collector plate are relative to the wide surface of the electrode group. A prismatic secondary battery having a bonding surface bonded to the positive or negative electrode metal foil at an angle θ ₂ and a relationship of 90 ° ≦ θ ₁ <θ ₂ .   3. The prismatic secondary battery according to claim 1, wherein an abutment surface of the projecting portion has a plane of approximately 90 ° with respect to a wide surface of the electrode group.   2. The prismatic secondary battery according to claim 1, wherein the projecting portion is bent perpendicularly to a joint surface joined to the metal foil of the positive electrode or the negative electrode. The positive electrode mixture untreated portion where the positive electrode metal foil is exposed from the positive electrode mixture is a positive electrode formed along one side edge, and the negative electrode mixture untreated portion where the negative electrode metal foil is exposed from the negative electrode mixture And a negative electrode formed along the other side edge facing the one side edge to form an electrode group wound through a separator, and a positive electrode collector whose one end is supported in a cantilevered manner in the battery container A method for manufacturing a prismatic secondary battery, wherein an electrode plate is ultrasonically welded to the positive electrode mixture untreated portion, and a negative electrode current collector plate having one end supported in a cantilever shape is ultrasonically welded to the negative electrode mixture untreated portion. There,
Forming a protrusion having a surface formed at an angle different from a weld surface on at least one of the positive electrode current collector plate and the negative electrode current collector plate;
The welding surface of the positive electrode current collector plate and the negative electrode current collector plate is brought into contact with a corresponding unmixed portion of the mixture, and the protrusion provided on one of the positive electrode current collector plate or the negative electrode current collector plate A current collector plate supporting step of supporting by a jig and restraining the displacement of the protruding portion;
And a step of ultrasonically welding the positive electrode current collector plate or the negative electrode current collector plate to a corresponding unmixed portion of the mixed material. 6. The method of manufacturing a prismatic secondary battery according to claim 5, wherein the current collector plate supporting step includes:
The positive electrode current collector plate or the negative electrode current collector plate formed with the protrusions in a state where one of the positive electrode current collector plate or the negative electrode current collector plate formed with the protrusions is in contact with the corresponding unmixed portion of the mixture. A step of supporting one outer surface of the jig with a holding part of the jig,
Contacting the abutting portion of the jig with the protruding portion;
A step of pressing and holding the untreated portion of the positive electrode or the negative electrode against the holding portion of the jig from a surface opposite to the holding portion of the jig. Production method. 7. The method of manufacturing a prismatic secondary battery according to claim 6, wherein the electrode group has a flat shape in which both upper and lower outer surfaces are wide surfaces, and the positive electrode and negative electrode mixture untreated portions are The contact portion of the jig is wound on the flat surface of the electrode group on the projecting portion provided on the positive or negative current collector plate. has a surface contacting with the angle theta ₁ against, pressing portion of the jig, it has a surface in contact with the current collector plate of the positive or negative electrode at an angle theta ₂ with respect to the wide surface of the electrode group, A method for producing a prismatic secondary battery, characterized by having a relationship of 90 ° ≦ θ ₁ <θ ₂ .   The method for manufacturing a prismatic secondary battery according to claim 6 or 7, wherein the step of contacting the contact portion of the jig with the protruding portion provided on one of the positive electrode current collector plate or the negative electrode current collector plate, A method for producing a prismatic secondary battery, wherein the jig having the contact portion is moved linearly. 9. The method for manufacturing a rectangular secondary battery according to claim 6, wherein the pressing portion and the contact portion are provided in one jig. 10. Production method.

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