JP2003059487A - Welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a yield in welding. SOLUTION: Laser beams L2 are applied on an outer peripheral part 10C of a positive current collecting plate 10 to melt it with heat, a melted part Y2 is made to flow to the top surface 23A of a ring 23 from the positive current collecting plate 10, an outside air contacting slope YG2 is substantially widened, the whole melted part Y2 is efficiently cooled and solidified by the heat radiation of the slope YG2 to prevent a problem that the root part of a positive lead 9 acts as a radiator plate. Thereby, the root part of the positive lead 9 and the positive current collecting plate 10 are surely electrically mechanically joined and welded, and a yield in welding can be increased.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a welding method, and is suitable for application to, for example, a welding method used when manufacturing a non-aqueous electrolyte secondary battery.

[0002]

2. Description of the Related Art Conventionally, in non-aqueous electrolyte secondary batteries,
A lithium composite oxide such as a lithium cobalt composite oxide is used as the positive electrode active material, and a lithium or lithium ion alloy such as a lithium ion alloy or a lithium ion doping or dedoping material such as a carbon material is used as the negative electrode active material. Possible substances are used.

In the non-aqueous electrolyte secondary battery,
The positive electrode active material and the negative electrode active material are reacted to function as a battery. A relatively high battery voltage is obtained, and the battery has a relatively high energy density and excellent charge / discharge cycle characteristics. In recent years, it has been widely used in portable electronic devices and the like because it has many advantages.

By the way, as a non-aqueous electrolyte secondary battery,
Although a relatively high battery voltage is originally obtained, there is a so-called high output type in which the battery voltage is further increased.

In such a high power type non-aqueous electrolyte secondary battery, a positive electrode material having a film-shaped positive electrode active material inside a bottomed cylindrical negative electrode can and a negative electrode having a film-shaped negative electrode active material The wound electrode body (described later) formed by using the material is inserted and filled with the non-aqueous electrolyte, and in this state, the can lid having the positive electrode pin is fitted into the opening of the negative electrode can. Is configured.

As a result, in the high output type non-aqueous electrolyte secondary battery, the battery voltage generated by the discharge reaction of the negative electrode active material and the positive electrode active material can be output from the negative electrode can and the positive electrode pin to the outside. Has been done.

[0007]

By the way, the spirally wound electrode body used in the high-power type non-aqueous electrolyte secondary battery having such a structure can be formed according to the following procedure shown in FIGS. 8 to 13. .

That is, as shown in FIG. 8, in the first step, one end portion in the width direction of the positive electrode current collector 101 is formed on both surfaces of the positive electrode current collector 101 made of strip-shaped aluminum foil or the like. The positive electrode active material 102 is applied in a film form while avoiding (hereinafter, referred to as side edge).

The positive electrode current collector 101 is not coated on the side edge portion of the positive electrode current collector 101 not coated with the positive electrode active material 102 (hereinafter referred to as uncoated side edge portion). The positive electrode material 100 is formed by providing a plurality of strip-shaped positive electrode leads 103, which are part of the side edges, in a comb shape along the longitudinal direction of the positive electrode current collector 101.

Regarding the negative electrode material 200, the positive electrode material 1
In the same manner as 00, a negative electrode current collector 2 made of strip-shaped copper foil or the like
01 is coated on both surfaces of the negative electrode current collector 201 so as to avoid the side edge portion of the negative electrode current collector 201, and is a strip shape that is a part of the uncoated side edge portion of the negative electrode current collector 201. The plurality of negative electrode leads 203 are formed in a comb shape along the longitudinal direction of the negative electrode current collector 201.

Then, as shown in FIGS. 9 and 10, in the second step, two sheets of the first and second separators 104 made of a strip-shaped microporous polypropylene film are used as the positive electrode material 100 and the negative electrode material 200. And the cylindrical winding body 1 by winding in an insulated state from each other.
06 is formed.

At this time, as shown in FIG.
Each positive electrode lead 103 projects from one end of the winding body 106, and each negative electrode lead 20 projects from the other end of the wound body 106.
3 is protruding.

Then, as shown in FIG.
In the step (1), one end of the winding body 106 in one direction is inserted into the ring 107 made of aluminum, so that the positive electrode leads 103 are once aggregated so as not to disperse in the ring 107.

Subsequently, as shown in FIG. 11 (B), the tips of the collected positive electrode leads 103 are connected to the ring 107.
Of the positive electrode current collector 108 made of aluminum and formed in a disk shape on each of the positive electrode leads 103 radially expanded to the upper surface 107A of the ring 107 (see FIG. )) And the lower surface of the positive electrode current collector plate 108, the positive electrode leads 103 are sandwiched therebetween.

Then, as shown in FIG. 11C, a predetermined position inside the outer peripheral edge (edge portion between the upper surface and the side surface) of the upper surface 108A of the positive electrode current collector plate 108 (hereinafter, referred to as an inner predetermined position). The positive electrode lead 103 is welded to the positive electrode current collector plate 108 by irradiating the positive electrode current collector plate 108 with the laser beam L1.

In practice, as shown in FIG. 12, the positive electrode current collector plate 108 is provided with a thin stepped portion on the outer peripheral portion of the lower surface corresponding to the ring 107, and the stepped portion and the ring 1 are provided.
Each of the positive electrode leads 103 is sandwiched between them.

Therefore, when the laser beam L1 is applied to a predetermined position on the upper surface of the positive electrode current collector plate 108, the heat generated as a result is transferred from the thin outer peripheral portion to the positive electrode lead 10.
3 and the ring 107 can be sequentially conducted.

As a result, as shown in FIG. 13, when the laser light L1 is irradiated to a predetermined position inside the upper surface 108A of the positive electrode current collector plate 108, the positive electrode lead 103 and the ring 107 are integrally heated together with the predetermined inside position. It can be melted, and after being heated and melted in this way, it is naturally cooled to solidify the positive electrode current collector plate 108, the positive electrode lead 103, and the ring 107 in an integrated state, and thus, the positive electrode current collector. The plate 108, the positive electrode lead 103, and the ring 107 can be electrically and mechanically connected to each other.

Next, in the fourth step, the positive electrode lead 10 protruding outward from the outer periphery of the positive electrode current collector plate 108.
The tip part of 3 is cut with an ultrasonic cutter.

The negative electrode lead is also shown in FIGS.
In the same manner as in the case of the positive electrode lead described above in No. 3, by irradiating laser light from the upper surface of the negative electrode current collector plate with the negative electrode lead sandwiched between the ring and the negative electrode current collector plate, The negative electrode current collector plate, the negative electrode lead, and the ring are electrically and mechanically connected, and then the tip portion of the negative electrode lead protruding outward from the outer periphery of the negative electrode current collector plate is cut with an ultrasonic cutter.

Thus, the wound electrode body can be formed by the first to fourth steps. Incidentally, in the spirally wound electrode body, each positive electrode lead 103 is electrically and mechanically connected to the positive electrode pin of the can lid through the positive electrode current collector plate 108, and each negative electrode lead passes through the negative electrode current collector plate. It is designed to be electrically connected to the bottom of the negative electrode can.

By the way, the positive electrode lead 103, the positive electrode current collector plate 108, and the ring 107 are generally made of aluminum foil or the like having a relatively high linear expansion coefficient as described above, and their volume expands when heated and melted. However, when cooled in this state, it has the property of shrinking the volume during solidification.

Therefore, as shown in FIG. 14, when the positive electrode current collector plate 108 is heated by the irradiation of the laser beam L1, the positive electrode current collector plate 108, the positive electrode lead 103 and the ring 1 are heated.
The volume of the molten portion Y1 of 07 expands.

Here, as shown in FIG. 15A, when the molten portion Y1 expands by heat, the positive electrode lead 103 also expands and is pressed at the boundary portion YK1 with the positive electrode lead 103. , The positive electrode lead 10
It is integrated with 3 and joined.

Then, when the irradiation of the laser beam L1 is finished, the molten portion Y1 is naturally cooled and contracts and solidifies.

However, at this time, in the molten portion Y1, the periphery is the positive electrode current collector plate 108 and the positive electrode lead 103.
Since the ring 107 is surrounded by the aluminum material of the ring 107 and only a small part of the one surface of the positive electrode current collector plate 108 is exposed to the outside air, the portion exposed to the outside air (hereinafter, referred to as an outside air contact portion). Called) YG1
Heat is not efficiently radiated only from (FIG. 14), and as a result, the positive electrode lead 103 also functions as a heat radiating plate and radiates heat.

Therefore, as shown in FIG. 15 (B), in the molten portion Y1, the positive electrode lead 10 contracts in the center direction during cooling and is joined to the boundary portion YK1.
The positive electrode lead 103 is extended by contracting 3 in a direction away from the melted portion Y1.

Then, as shown in FIG. 15 (C), the positive electrode lead 103 is due to the relatively low elastic coefficient of aluminum, in the molten portion Y1 and the boundary portion YK1 when it is stretched by contraction due to its cooling. May be disconnected.

Therefore, as shown in FIG. 16, in such a welding method, the positive electrode current collector plate 108 and the positive electrode lead 103 are used.
It is difficult to surely weld the steel and the steel, and thus it is difficult to improve the yield at the time of welding.

The present invention has been made in consideration of the above points, and an object thereof is to propose a welding method capable of improving the yield during welding.

[0031]

In order to solve the above problems, in the present invention, a positive electrode is formed in a strip shape, and a plurality of positive electrode conductors are provided in one side edge portion in the width direction in a comb shape. Winding formed by winding a negative electrode formed in a strip shape and having a plurality of negative electrode conductors formed on one side edge portion in the width direction in a comb shape so as to overlap each other in the width direction. In the welding method of welding the current collector to the body, each positive electrode conductor at one end along the longitudinal direction of the winding body and each negative electrode conductor at the other end along the longitudinal direction of the winding body, The positive electrode conductor or the negative electrode conductor at one end or the other end along the longitudinal direction of the revolving body is radially expanded by bending the positive electrode conductor or the negative electrode conductor, and a current collecting member is provided on the radially expanded positive electrode conductor or the negative electrode conductor. The outer peripheral end of the current collecting member is placed on the current collecting member by heating and melting by heating and melting means. A pole conductor or each negative electrode conductor so as to heat and melt together.

Therefore, in the present invention, by forming a wide slope in contact with the outside air in the melted portion, the melted portion is efficiently cooled through the slope, and as a result, the positive electrode conductor or the negative electrode conductor is radiated. Without functioning as a board,
The current collecting member and the positive electrode conductor or the negative electrode conductor can be solidified and reliably welded in a joined state.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a high-power type non-aqueous electrolyte secondary battery as a whole, and a safety valve 3 and a positive electrode lid 4 are integrally fitted into an opening of a bottomed cylindrical negative electrode can 2. Inside the negative electrode can 2, a cylindrical wound electrode body 5 formed by using the welding method according to the present invention is inserted, and a non-aqueous electrolytic solution (not shown) is filled.

In this case, the negative electrode lead 6 as the negative electrode conductor of the spirally wound electrode body 5 is electrically and mechanically attached to the bottom of the negative electrode can 2 through the negative electrode current collector plate 7 and the negative electrode current collector lead 8 in this order. It is connected to the.

The positive electrode lead 9 as the positive electrode conductor of the spirally wound electrode body 5 is electrically and mechanically connected to the positive electrode lid 4 through the positive electrode current collector plate 10 and the positive electrode current collector lead 11 in this order. ing.

As a result, in the non-aqueous electrolyte secondary battery 1, the battery voltage generated by the discharge reaction in the internal spirally wound electrode body 5 (actually, the positive electrode active material for the positive electrode and the negative electrode active material for the negative electrode) is It can be output to the outside through the negative electrode can 2 and the positive electrode lid 4.

By the way, the spirally wound electrode body 5 used in the non-aqueous electrolyte secondary battery 1 can be formed in accordance with the following procedure shown in FIGS.

That is, as shown in FIG. 2, in the first step, one end in the width direction of the positive electrode current collector 12 is formed on both surfaces of the positive electrode current collector 12 made of a strip-shaped aluminum foil or the like. Part (hereinafter, referred to as side edge part), the positive electrode active material 13 is applied in a film form, and the positive electrode active material 13 of the positive electrode current collector 12 is not applied to the side edge part (hereinafter, referred to as “side edge part”). A positive electrode material 14 having a plurality of strip-shaped positive electrode leads 9 provided on its uncoated side edge portion is used.

Incidentally, the positive electrode lead 9 is the positive electrode current collector 1
2 is formed in a comb shape along the longitudinal direction.

Similarly to the positive electrode material 14 described above, the negative electrode active material 16 is formed on both sides of the negative electrode current collector 15 made of strip-shaped copper foil, avoiding the side edges of the negative electrode current collector 15. Is applied in the form of a film, and a plurality of strip-shaped negative electrode leads 6 are provided on the uncoated side edge of the negative electrode current collector 15, and the negative electrode leads 6 are comb-shaped along the longitudinal direction of the negative electrode current collector 15. The negative electrode material 18 formed into a shape is used.

Then, the positive electrode material 14 and the negative electrode material 18
Together with the first and second separators 19 and 20, the positive electrode material 14, the first separator 19, the negative electrode material 18 and the second
The separators 20 are stacked in this order, and the positive electrode material 14 is placed inside and wound around the winding core 21 to form a cylindrical winding body 22.

At this time, as shown in FIG. 3 (A), each positive electrode lead 9 projects from one end of the wound body 22, and the other of the wound body 22 not shown. Each negative electrode lead 6 projects from the end of the.

Next, as shown in FIG. 3 (B), in the second step, each positive electrode lead 9 at one end of the wound body 22 is inserted into the ring 23 as an aggregating member, After the positive electrode leads 9 are once aggregated in the ring 23 so that they do not disperse, the tip portions of the aggregated positive electrode leads 9 are radially spread to the outside of the ring 23 as shown in FIG. 3C.

Subsequently, as shown in FIG. 4 (A), the positive electrode current collector plate 10 made of aluminum in the form of a disk is used as a current collector member on the radially expanded positive electrode lead 9 to form a ring. Each positive electrode lead 9 is sandwiched between the upper surface 23A of FIG. 23 (FIG. 3B) and the lower surface of the positive electrode current collector plate 10.

Then, as shown in FIG. 4B, the outer peripheral edge of the upper surface 10A of the positive electrode current collector plate 10 (the edge portion between the upper surface 10A of the positive electrode current collector plate 10 and the side surface 10B) 10C.
By irradiating the laser beam L2 over one round, the positive electrode current collector plate 10, the positive electrode lead 9, and the ring 23 are heated and welded.

In practice, as shown in FIG. 5, in the positive electrode current collector plate 10, the outer peripheral edge 10C is the edge of the outer peripheral edge of the ring 23 (the upper surface 23A of the ring 23 and the side surface 23B of the ring 23 (FIG. 5)). Part) 23C, and a step portion having a small thickness is provided on the outer peripheral portion of the lower surface corresponding to the ring 23, so that each positive electrode lead is provided between the step portion and the ring 23. 9 is sandwiched.

Therefore, as shown in FIG. 6, when the thin outer peripheral edge 10C of the positive electrode current collector plate 10 is heated and melted by the irradiation of the laser beam L2, the melted portion gradually expands to form an inclined surface. To flow to each positive electrode lead 9 to heat and melt each positive electrode lead 9, and
The outer peripheral end 10C of the positive electrode current collector plate 10 and the melted portion of the positive electrode lead 9 reach the ring 23 and are heated and melted.
Predetermined portions of the positive electrode lead 9 and the ring 23 are integrated by heating them.

Here, the outer peripheral edge 10C of the positive electrode current collector plate 10
Then, the melted portion Y2 at a predetermined portion of the positive electrode lead 9 and the ring 23 is heated by the irradiation with the laser beam L2, so that the volume thereof is expanded.

The molten portion Y2 is the positive electrode current collector plate 1.
By forming a significantly wide slope (hereinafter referred to as the outside air contact slope) YG2 at the step between 0 and the ring 23, the area of the portion exposed to the outside air is significantly increased by the outside air contact slope YG2. There is.

As a result, the molten portion Y2 efficiently radiates heat from the outside air contact slope YG2, and as a result, the base portion of the positive electrode lead 9 sandwiched between the positive electrode current collector plate 10 and the ring 23 functions as a heat radiating plate. This can be prevented, and thus, the root portion of the positive electrode lead 9 can be solidified while being surely integrated.

Further, as shown in FIG. 7, in the melting portion Y2, heat is radiated from the outside air contact slope YG2 having a relatively large area, so that the outside air contact slope YG2 side is more rapidly than the root side of the positive electrode lead 9. It contracts, and as a result, the boundary between the outside air contact slope YG2 and the tip of the positive electrode lead 9 is stretched and cut.

Therefore, in this welding method, the elastic modulus of aluminum is compared during the natural cooling of the molten portion Y2 without using the ultrasonic cutter on the tip portion of the positive electrode lead 9 protruding outward from the positive electrode current collector plate 10. By using the extremely low property, the melted portion Y2 can be naturally cut by the contracting action.

As for the negative electrode lead 6 side (FIG. 1) of the wound body 22, the negative electrode current collector plate 7 (made of copper material) is formed in the same manner as the procedure for the positive electrode lead 9 side described above with reference to FIGS. The negative electrode current collector plate 7, the negative electrode lead 6 and the ring made of a copper material are integrally welded by irradiating the outer peripheral end of FIG. 1) with laser light over the entire circumference.

Thus, according to such a process, as shown in FIG.
As shown in (C), the spirally wound electrode body 5 used in the non-aqueous electrolyte secondary battery 1 can be formed.

In the above construction, in this welding method,
The positive electrode leads 9 protruding from one end of the wound body 22 are inserted into the ring 23, the positive electrode leads 9 are once collected by the ring 23, and then the collected positive electrode leads 9 are collected.
The positive electrode current collector plate 10 is mounted by radially spreading the tip end portion of the positive electrode current collector plate 10 on the outer side of the ring 23 so that each positive electrode lead 9 is placed between the upper surface 23A of the ring 23 and the lower surface of the positive electrode current collector plate 10. Make sure you sandwich it.

The outer peripheral edge 10C of the positive electrode current collector plate 10
The laser light L2 is radiated over the entire circumference, and the positive electrode current collector plate 10 is heated and melted integrally from the outer peripheral end 10C to the positive electrode lead 9 and the ring 23, and then naturally cooled, and the outer peripheral ends of the positive electrode current collector plates 10 are collected. 10C, positive electrode lead 9 and ring 23
To weld.

Therefore, in this welding method, the molten portion Y2
In the above, by forming a remarkably wide outside air contact slope YG2 from the positive electrode current collector plate 10 to the ring 23,
The melting portion Y is generated by the heat radiation from the outside air contact slope YG2
2 can be efficiently cooled, and as a result, the root portion of the positive electrode lead 9 does not function as a heat dissipation plate, and the molten portion Y2 and the root portion of the positive electrode lead 9 are solidified while being joined, The lead 9 and the positive electrode current collector plate 10 can be reliably joined electrically and mechanically.

Further, in this welding method, the area of the outside air contact slope YG2 of the melted portion Y2 is remarkably widened and the outside air contact slope YG2 side is rapidly contracted during cooling. Therefore, the tip portion of the positive electrode lead 9 can be naturally cut, and thus the work of cutting the positive electrode lead 9 by the ultrasonic cutter when forming the wound electrode body 5 can be omitted, and the welding process is simplified. be able to.

Further, in this welding method, the contraction effect at the time of cooling as described above causes the melted portion Y2 to pass through the positive electrode lead 9
Since the tip portion of is cut naturally, it is possible to substantially eliminate the generation of chips and burrs as compared with the case where the tip portion of the positive electrode lead 9 is cut with an ultrasonic cutter as in the conventional case.

Therefore, in the non-aqueous electrolyte secondary battery 1 using the spirally wound electrode body 5 formed by applying this welding method, it is possible to prevent the occurrence of internal short circuit due to cutting chips and burrs.

Further, in this welding method, the positive electrode leads 9 are inserted into the ring 23 and collected, and the collected positive electrode leads 9 are radially spread to the outside of the upper surface 23A of the ring 23 to collect the positive electrode current collector plate. After mounting 10 on the positive electrode current collector plate 10, the outer peripheral edge 10C of the positive electrode current collector plate 10 is welded, so that all the positive electrode leads 9 are securely attached to the upper surface 23A of the ring 23 and the lower surface of the positive electrode current collector plate 10. It is possible to sandwich all the positive electrode leads 9 to the positive electrode current collector plate 10 reliably and electrically and mechanically.

In addition, in this welding method, the outer peripheral edge 10C of the positive electrode current collector plate 10 is the outer peripheral edge 23C of the ring 23.
By selecting the inside, the step can be provided between the positive electrode current collector plate 10 and the ring 23.
By allowing the portion melted by the laser beam L2 to flow to the positive electrode lead 9 and the upper surface 23A of the ring 23, the remarkably wide outside air contact slope YG2 can be reliably formed.

In this welding method, even when an aluminum material having a relatively high linear expansion coefficient and a relatively low elastic coefficient is generally used for the positive electrode current collector plate 10, the positive electrode lead 9 and the ring 23. All the positive electrode leads 9 can be reliably welded to the positive electrode current collector plate 10.

According to the above configuration, the outer peripheral edge 10C of the positive electrode current collector plate 10 is irradiated with the laser beam L2 to be heated and melted, and the melted portion Y2 is transferred from the positive electrode current collector plate 24 to the upper surface 23A of the ring 23. The base portion of the positive electrode lead 9 functions as a heat dissipation plate by making the outside air contact slope YG2 remarkably wider by flowing and efficiently cooling and solidifying the entire melting portion Y2 by the heat dissipation of the outside air contact slope YG2. It is possible to prevent the positive electrode lead 9
The root portion of the positive electrode and the positive electrode current collector plate 10 can be welded in a state where they are securely electrically and mechanically joined, and thus, the yield at the time of welding can be improved.

In the above embodiment, the case where the cylindrical wound electrode body 5 is formed by using the welding method according to the present invention has been described, but the present invention is not limited to this. The welding method according to the present invention may be used to form wound electrode bodies having various other shapes such as a flattened electrode shape, an elliptical shape, and a diamond-shaped wound electrode body.

By the way, when forming a spirally wound electrode body having various shapes as described above, a ring and a positive electrode having various shapes such as a flat rectangular shape, an elliptical shape, and a rhombus shape are formed according to the shape. A current collector plate may be used.

In the above embodiment, the case where the positive electrode current collector plate 10 and the negative electrode current collector plate 7 are melted by using the welding method according to the present invention has been described, but the present invention is not limited to this. Alternatively, the positive electrode current collector plate 10 may be melted using the welding method according to the present invention, and the negative electrode current collector plate 7 may be melted using the conventional welding method.

Further, in the above-mentioned embodiment, the case where the strip-shaped positive electrode lead 9 and the negative electrode lead 6 are provided on the side edge portions of the positive electrode current collector 12 and the negative electrode current collector 15 has been described. The present invention is not limited to this, and the positive electrode lead and the negative electrode lead having various shapes such as a linear shape may be provided on the side edges of the positive electrode current collector 12 and the negative electrode current collector 15.

Further, in the above-mentioned embodiment, the case where the positive electrode lead 9 is welded to the positive electrode current collector plate 10 by using the ring 23 without being scattered is described, but the present invention is not limited to this. Instead of using the ring 23, the positive electrode leads 9 may be welded to the positive electrode current collector plate 10 without being scattered.

In this case, the work of inserting the positive electrode lead 9 and the negative electrode lead 6 at one end and the other end of the winding body 22 into the ring 23 can be omitted, and the welding process can be further simplified. can do.

Further, in the above embodiment, the positive electrode current collector plate 10, the positive electrode lead 9 and the ring 23 are made of an aluminum material which can be heated and melted by the laser beam L2, and the negative electrode current collector plate 7 and the negative electrode lead 6 are used. The case where the copper material that can be heated and melted by laser light is used for the ring and the ring has been described, but the present invention is not limited to this, and the positive electrode current collector, the positive electrode lead, the ring, and the like can be heated and melted by laser light Other various materials may be used.

Further, in the above embodiment, the outer peripheral end 10C of the positive electrode current collector plate 10 is replaced with the outer peripheral end 2 of the ring 23.
By selecting inside 3C, the positive electrode current collector plate 1
0 and the ring 23 are formed with a step, and the melted portion is flowed to the upper surface 23A of the ring 23 by the welding method according to the present invention to form the outside air contact slope YG2. The invention is not limited to this, and the outer peripheral end 10C of the positive electrode current collector plate 10 is connected to the outer peripheral end 2 of the ring 23.
By selecting outside 3C, the positive electrode current collector plate 1
It is also possible to form a step between the 0 and the ring 23, and use the welding method according to the present invention to allow the melted portion to flow along the longitudinal side surface of the winding body 22 to form the outside air contact slope. .

Furthermore, in the above-described embodiment, the case where the welding method according to the present invention is used when manufacturing the non-aqueous electrolyte secondary battery 1 has been described, but the present invention is not limited to this, and the nickel-hydrogen secondary battery is not limited thereto. The welding method according to the present invention may be used when manufacturing various other batteries such as various secondary batteries such as secondary batteries and various primary batteries such as lithium primary batteries.

Further, in the above-described embodiment, the case where the laser beam L2 is used as the heating and melting means has been described, but the present invention is not limited to this, and the positive electrode current collector plate 10 and the positive electrode lead 9 are used. If the ring 23 and the like can be heated and melted, various other heating and melting means such as ultrasonic welding may be used.

[0076]

As described above, according to the present invention, a positive electrode having a strip shape and a plurality of positive electrode conductors provided in one side edge portion in the width direction in a comb shape, and a positive electrode having a strip shape are formed. A plurality of negative electrode conductors are provided on one side edge portion in the width direction and the negative electrode provided in a comb shape with respect to the wound body formed by winding the other side in the width direction so as to overlap each other. In a welding method of welding a current collecting member to each positive electrode conductor at one end along the longitudinal direction of the wound body and / or each negative electrode conductor at the other end along the longitudinal direction of the wound body, the longitudinal direction of the wound body The positive electrode conductor or the negative electrode conductor at one end or the other end along the radial direction is bent and radially expanded, and the positive electrode conductor or the negative electrode conductor that is radially expanded is mounted with a current collecting member and heated. The outer peripheral edge of the current collecting member is heated by the melting means, and the current collecting member and each positive electrode conductor or each negative electrode conductor It was to be heated and melted together.

Therefore, in the present invention, by forming a wide slope in contact with the outside air in the melted portion, the melted portion is efficiently cooled through the slope, and as a result, the positive electrode conductor or the negative electrode conductor is radiated. Without functioning as a board,
The current collecting member and the positive electrode conductor or the negative electrode conductor can be solidified and reliably welded in a joined state, thus improving the yield during welding.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a non-aqueous electrolyte secondary battery according to the present invention.

FIG. 2 is a schematic perspective view showing a state in which a positive electrode material, a first separate material, a negative electrode material and a second separate material are stacked.

FIG. 3 is a schematic perspective view showing a winding electrode body forming step (1).

FIG. 4 is a schematic perspective view showing a winding electrode body forming step (2).

FIG. 5 is a schematic cross-sectional view showing a state in which a positive electrode current collector plate is stacked on a ring.

FIG. 6 is a schematic cross-sectional view for explaining a melting portion by laser light.

FIG. 7 is a schematic cross-sectional view showing a state of contraction due to solidification of a molten portion.

FIG. 8 is a schematic diagram showing configurations of a positive electrode material and a negative electrode material.

FIG. 9 is a schematic diagram showing a state of a positive electrode lead and a negative electrode lead of a wound body.

FIG. 10 is a schematic perspective view showing a configuration of a wound body provided in a high-power type non-aqueous electrolyte secondary battery.

FIG. 11 is a schematic perspective view showing a state of a step of forming a wound electrode body.

FIG. 12 is a schematic cross-sectional view showing a state in which a positive electrode current collector plate is stacked on a ring.

FIG. 13 is a schematic cross-sectional view showing a state of a melting portion by laser light.

FIG. 14 is a schematic cross-sectional view showing a state of expansion of a melted portion by laser light.

FIG. 15 is a schematic cross-sectional view showing a manner of cutting the positive electrode lead in a molten portion.

FIG. 16 is a schematic cross-sectional view showing a state of contraction due to solidification of a molten portion.

[Explanation of symbols]

1 ... Non-aqueous electrolyte secondary battery, 5 ... Winding electrode body, 6 ...
Negative electrode lead, 7 ... Negative electrode current collector plate, 9 ... Positive electrode lead,
10 ... Current collector for positive electrode, 14 ... Positive electrode material, 18 ... Negative electrode material, 19, 20 ... Separator, 22 ... Winding body, 23
…… Ring, L2 …… Laser light.

Continued front page    F-term (reference) 4E068 BH01 DA09 DA16                 5H022 AA09 AA18 BB02 BB03 BB17                       BB19 BB25 BB30 CC02 CC08                       CC20 CC30 EE04                 5H029 AJ14 BJ02 BJ14 CJ03 CJ04                       CJ05 CJ06 CJ07 DJ05 DJ07                       EJ01 HJ12                 5H050 AA19 BA15 DA08 DA20 FA05                       GA02 GA03 GA07

Claims (4)

[Claims] 1. A positive electrode, which is formed in a strip shape and has a plurality of positive electrode conductors provided in a comb tooth shape at one side edge portion in the width direction, and a plurality of strip electrodes, which are formed in a strip shape at one side edge portion in the width direction. The negative electrode conductor of the negative electrode and the negative electrode provided in the shape of a comb tooth are wound along the longitudinal direction of the wound body by winding the other side in the width direction of the wound body. In a welding method of welding a current collecting member to each of the positive electrode conductors at one end and / or each of the negative electrode conductors at the other end along the longitudinal direction of the wound body, the welding method is performed along the longitudinal direction of the wound body. A bending step of radially expanding each of the positive electrode conductors or the negative electrode conductors at one end or the other end, and a step of radially expanding the positive electrode conductors or the negative electrode conductors with the current collecting member. The current collecting member is mounted by the mounting step and the heating and melting means. Heating the outer peripheral edge,
A welding method comprising: a heating and melting step of integrally heating and melting the current collecting member and each of the positive electrode conductors or the negative electrode conductors. 2. An aggregate step of aggregating the positive electrode conductors or the negative electrode conductors at the one end or the other end along the longitudinal direction of the wound body with a predetermined aggregating member, the bending step comprising: The respective positive electrode conductors or the respective negative electrode conductors are radially spread by bending at the portion where they are aggregated by the aggregating member, and the above-mentioned step is the radially expanded positive electrode conductors or the respective negative electrode conductors described above. The welding according to claim 1, wherein the positive electrode conductor or the negative electrode conductor is sandwiched between the collecting member and the current collecting member by mounting the current collecting member. Method. 3. The welding method according to claim 2, wherein the outer peripheral end of the current collecting member is inside the outer peripheral end of the collecting member. 4. The welding method according to claim 3, wherein the positive electrode conductor, the negative electrode conductor, the current collecting member, and the collecting member are made of aluminum.