JP2007026945A - Battery and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a well-joined battery between a connection terminal and a lead while it is fixed in a case. <P>SOLUTION: The battery comprises an electrode body 12 provided with a core comprising a positive electrode and a negative electrode and one or a plurality of positive electrode leads 24 and negative electrode leads 20 protruding outside from it, a case 14 in which a housing 22 for housing the electrode body is formed, a positive electrode connection terminal 32 which is fixed to the case and is electrically jointed to the positive electrode lead, and a negative electrode connection terminal 16 which is fixed to the case and is electrically jointed to the lead of the negative electrode. A relay terminal 30 is provided which is jointed to both in such mode as relays between the lead and the connection terminal, in at least one polarity, positive electrode or negative electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery in which an electrode body is housed in a case and the electrode body is joined to a connection terminal extending inside and outside the case, and a manufacturing method thereof. In particular, the present invention relates to a battery in which a joint structure between a connection terminal fixed to a case and an electrode body is improved, and a manufacturing method thereof.

The battery includes an electrode body in which a metal foil to which a positive electrode active material layer is attached, a separator, a metal foil to which a negative electrode active material layer is attached, and a separator are laminated in multiple stages. A roll-shaped electrode body around which a long sheet is wound, a flat roll-shaped electrode body obtained by crushing it from both sides in the diameter direction, a hexahedral electrode body in which a plurality of short sheets are stacked, etc. It has been known.
Each type of electrode body includes a metal foil to which a positive electrode active material layer is attached, a separator, a metal foil to which a negative electrode active material layer is attached, and a core portion in which separators are laminated in multiple stages, and a contour of the core portion. The lead portion is extended from a part of “a metal foil having the same polarity is laminated in multiple stages”. If it is a roll or flat roll electrode body, the same polarity metal foil extends from the end face of the roll or flat roll. If it is a hexahedral electrode body, the same polarity metal foil extends from one side of the electrode body. Is extended.
The electrode body is accommodated in the case. In order to take out electric power from a case, the connection terminal extended over the inside and outside of a case is utilized. In the case, the lead portion “the metal foils having the same polarity are stacked in multiple stages” and the connection terminal are joined.
The present invention relates to a technique for joining a lead portion and a connection terminal in a case. The form of the electrode body is not limited.

  Various techniques for joining the lead portion and the connection terminal have been developed. For example, in Patent Document 1, a metal disk (corresponding to a connection terminal) and a metal flat plate ring are sandwiched between lead portions, and the surface of the metal disk is irradiated with a laser so that the metal disk, the lead portion, and the metal flat plate ring. Techniques for welding are described.

JP 2001-118561 A

A technique has been developed in which a connection terminal that extends over the inside and outside of a case that houses an electrode body is fixed to a wall that forms the case. By integrally molding the case and the connection terminal, the positional relationship between the case and the connection terminal can be accurately aligned with a predetermined one. Or the reliability at the time of maintaining between a case and a connection terminal in a liquid-tight state or maintaining an insulation state improves.
In this case, the lead portion and the connection terminal must be joined in the case. Since the case at this stage is not yet closed (the opening for inserting the electrode body is not closed), the lead portion and the connection terminal must be joined in the case using this opening.

Practical techniques for joining by processing from one side are limited to limited methods such as laser welding. In order to perform ultrasonic bonding, jigs must be set on both the front and back surfaces of the bonded portion. Although a method in which a pair of conductive chips are brought into contact with one side of the joint portion and a current is passed between the conductive chips may be adopted, conditions under which the method can be used are limited, and the method cannot be used in many cases.
When a metal foil forming a lead portion is superimposed on a connection terminal fixed to the case, and the overlapped metal foil is welded by laser irradiation, the metal foil is easily cut between the welded portion and the non-welded portion. When a metal plate is further stacked on the surface of the metal foil, and welding is performed by irradiating a laser with the metal foil interposed between the metal plate and the connection terminal, a blow hole is likely to be generated in the welded portion. In any case, it is difficult to satisfactorily weld the metal foil and the connection terminal with a laser welding technique that requires an operation from one side.

  An object of the present invention is to provide a method capable of reliably joining a connection terminal and a lead part when joining the connection terminal and the lead part fixed to the case in the case. Another object is to provide a battery structure suitable for the above.

The battery provided by the present invention includes an electrode body, a case housing the electrode body, and a connection terminal fixed to the case.
The electrode body includes a core portion in which a metal foil to which a positive electrode active material layer is attached and a metal foil to which a negative electrode active material layer is attached are laminated in multiple stages via a separator. The type of the electrode body is not limited. A lead portion extends from a part of the outline of the core portion. In the lead portion, metal foils having the same polarity are laminated in multiple stages. The connection terminal penetrates the wall forming the case and extends inside and outside the case, and is fixed to the wall forming the case.
The battery of the present invention includes a relay terminal joined to both the lead portion and the connection terminal.

  The relay terminal may exist between the positive electrode lead portion and the positive electrode connection terminal, may exist between the negative electrode lead portion and the negative electrode connection terminal, or may exist between both. If the lead portion and the connection terminal are used in a portion that is difficult to join in the case, the advantages of the present invention can be enjoyed.

In the battery of the present invention, at least one of the positive and negative electrodes is joined with a relay terminal interposed between the lead portion and the connection terminal. As described above, it is difficult to directly join the laminated metal foils to the connection terminals fixed to the case in the case.
In the battery of the present invention, the lead portion can be joined to the relay terminal before the electrode body is accommodated in the case, that is, outside the case. Since the joining work can be performed outside the case, necessary jigs can be arranged on both sides of the joining portion, and the laminated metal foil can be firmly joined to the relay terminal. High reliability can be secured at the joint.
In the battery of the present invention, it is not necessary to join the laminated metal foil to the connection terminal in the case, and the relay terminal may be joined to the connection terminal in the case. If it is metal plates, the joining method which requires the process from the single side | surface side, such as laser welding, can be utilized, and a connection terminal can be joined to a connection terminal firmly stably.

The present invention is particularly useful when a lead portion in which aluminum foil is laminated in multiple stages is joined to a connection terminal. In this case, it is preferable that a lead portion in which aluminum foil is laminated in multiple stages and a relay terminal formed of aluminum are solid-phase bonded.
The solid phase bonding here means that the surface is denatured and the foils are bonded to each other in a state where the solid state is maintained at the central portion in the thickness direction of the foil.
When the aluminum foil is melted, it is easy to cut between the non-melted portion and the welded portion. Also, blow holes are likely to occur when the aluminum foil melts and solidifies. Aluminum foil is difficult to weld. The aluminum foil is satisfactorily bonded by bonding the surfaces (solid phase bonding) while maintaining the solid phase at the central portion in the thickness direction. When a lead portion in which aluminum foil is laminated in multiple stages is solid-phase bonded to a relay terminal made of aluminum, cracks and breakage are unlikely to occur at the bonded portion, and current collection efficiency is high. A battery having excellent performance and high reliability can be obtained.

  In the battery of the present invention, it is preferable that the relay terminal and the connection terminal are joined at a position where the lead portion does not exist. Since there is no lead portion, the relay terminal and the connection terminal can be firmly and securely joined. The metal foil present in the lead portion is not damaged.

There is a battery in which aluminum foil is laminated in multiple stages at the positive electrode lead portion and copper foil is laminated in multiple stages at the negative electrode lead portion. In this case, it is preferable that the positive electrode lead portion is bonded to the positive electrode connection terminal via the relay terminal, and the negative electrode lead portion is directly bonded to the negative electrode connection terminal not via the relay terminal.
While it is difficult to join the aluminum foil to the connection terminal in the case, the copper foil can be joined to the connection terminal in the case relatively easily. The advantage of the present invention can be fully enjoyed only by using a structure in which only the positive electrode is joined to the connection terminal via the relay terminal. Of course, the present invention may be applied to the negative electrode or to both the positive electrode and the negative electrode.

  The present invention also provides a new method for manufacturing a battery. The battery manufacturing method of the present invention includes a core part in which a metal foil to which a positive electrode active material layer is attached and a metal foil to which a negative electrode active material layer is attached are laminated in multiple stages via a separator, and a core part A step of manufacturing an electrode body having a lead portion extending from a part of the contour of the metal foil having the same polarity and stacked in multiple stages, and a case for housing the electrode body, the connection terminal Extending through the wall forming the case and extending into and out of the case, and connecting the terminal to the wall, manufacturing the case, joining the relay terminal to the lead portion, relaying The step of joining the connection terminal to the terminal is provided.

In the manufacturing method described above, the lead portion in which the metal foil is laminated in multiple stages is joined to the relay terminal. The relay terminal is not fixed to the case, and the lead portion and the relay terminal can be joined outside the case. In order to join outside the case, a space for joining work can be secured, and a method in which metal foils laminated in multiple stages can be reliably joined to the relay terminal can be adopted. When joining the metal foil laminated | stacked in multiple steps to a relay terminal, the joining technique in which peeling, a crack, etc. do not arise in a junction part is employable.
The connection terminal fixed to the case may be joined with a relay terminal instead of a multi-layered metal foil. The connection terminal and the relay terminal can be reliably joined in the case.
According to this manufacturing method, a highly reliable battery can be efficiently manufactured.

In some batteries, a lead portion in which aluminum foil is laminated in multiple stages and a relay terminal formed of aluminum may be joined. In this case, it is preferable to solid-phase join the lead portion in which the aluminum foil is laminated in multiple stages and the relay terminal made of aluminum.
As described above, the aluminum foil is difficult to weld. The aluminum foil is well bonded by solid phase bonding. When a lead portion in which aluminum foil is laminated in multiple stages and a relay terminal made of aluminum are solid-phase bonded, good bonding can be achieved.

When joining a relay terminal and a connection terminal, it is preferable to irradiate the laser which advances to the connection terminal side from the relay terminal side to the single side | surface of a relay terminal, and to join.
In laser welding, the laser may be irradiated from one side. When the laser welding technique is employed, the relay terminal can be reliably joined to the connection terminal fixed to the case by operation in the case.

  It is preferable to join the relay terminal and the connection terminal at a position where there is no lead portion. When joining the relay terminal and the connection terminal, it is possible to prevent the lead portion where the metal foil is laminated from being adversely affected.

A positive electrode lead portion “aluminum foil is laminated in multiple stages” and a negative electrode lead portion “a copper foil is laminated in multiple stages” may extend from a part of the outline of the core portion.
In this case, in the method of the present invention, for the positive electrode lead portion, the positive electrode lead portion is bonded to the relay terminal, and the relay terminal is bonded to the connection terminal. On the other hand, with respect to the negative electrode lead portion, the negative electrode lead portion is directly joined to the negative electrode connection terminal without using a relay terminal.
The advantage of the present invention can be enjoyed only by adopting the method of the present invention to the positive electrode lead portion that is difficult to be joined to the connection terminal fixed to the case.

The “battery” in this specification refers to a battery that can extract electric energy, and is not limited to the principle of power storage. A secondary battery such as a lithium secondary battery or an electric double layer capacitor is also a typical example included in the battery referred to here. A module in which a plurality of these power storage elements are joined is also included in the “battery” referred to herein.
The “electrode body” in the present specification refers to a structure including at least one positive electrode and at least one negative electrode and constituting the main body of the battery.
The “connection terminal” in this specification refers to a conductor that is fixed to the case and extends inside and outside the case. In the connection terminal, there are an external bonding terminal for taking out electricity to the outside and an internal bonding terminal for bonding between the batteries.
The “case” in the present specification refers to a member that can physically accommodate the electrode body, and there is no limitation on its shape. Roughly, the shape of the frame, box, etc. is also the typical shape (outer shape) of the case here.

The main features of the embodiments described in detail below are listed first.
(Form 1) The battery is a lithium secondary battery.
(Form 2) The case is made of a thermoplastic resin (polypropylene).
(Form 3) The case has a flat box shape.
(Mode 4) The connection terminal is a flat plate, and is fixed to the case by insert molding when the resin case is injection molded.
(Mode 5) The connection terminal is a flat plate, one side is open, and the opposite side is blocked by a case. The connection terminal is fixed to the case so that it can be approached only from one side.
(Embodiment 6) The electrode body is a laminated electrode body in which a plurality of positive electrode plates and a plurality of negative electrode plates are laminated via separators, and a plurality of metal foils are laminated also on each polar lead portion. It is configured in the form.

  First, the rough form of the battery 10 according to the present embodiment will be described with reference to FIG. In the battery 10 of this embodiment, a flat box-shaped case 14 having an open upper surface accommodates a flat laminated electrode body 12, and the upper surface of the case 14 is sealed with a laminate film (not shown). Next battery. FIG. 1 shows the battery 10 before sealing with a laminate film (that is, in a state where the laminate film is removed). As shown in FIG. 1, the battery 10 according to the present embodiment mainly includes a case 14, an electrode body 12, a negative electrode connection terminal 16, a positive electrode connection terminal 32, and a relay terminal 30. The negative electrode connection terminal 16 and the positive electrode connection terminal 32 are fixed to the case 14 and extend over the inside and outside of the case 14. The electrode body 12 includes a core portion 19, a positive electrode lead portion 24 extending leftward from the core portion 19, and a negative electrode lead portion 20 extending rightward from the core portion 19. The negative electrode lead portion 20 is directly bonded to the negative electrode connection terminal 16. The positive electrode lead portion 24 is joined to the positive electrode connection terminal 32 via the relay terminal 30. That is, the positive electrode lead portion 24 is bonded to the relay terminal 30, and the relay terminal 30 is bonded to the positive electrode connection terminal 32.

In the electrode body 12 according to this example, an aluminum foil to which a positive electrode active material layer is attached, a separator, a copper foil to which a negative electrode active material layer is attached, and a separator are laminated in multiple stages.
The aluminum foil has a planar shape combining the core portion 19 and the positive electrode lead portion 24, and the positive electrode active material layer is applied to the core portion 19. The copper foil has a planar shape in which the core portion 19 and the negative electrode lead portion 20 are combined, and the negative electrode active material layer is applied to the core portion 19.
In the core portion 19, an aluminum foil coated with a positive electrode active material layer, a separator, a copper foil coated with a negative electrode active material layer, and a separator are laminated in multiple stages. As a result, only the aluminum foil extends on the left side of the core portion 19, and only the copper foil extends on the right side of the core portion 19. FIG. 2 shows a side view of the vicinity of the left side of the electrode body 12, and it is understood that only the aluminum foil is laminated in the positive electrode lead part 24 extending to the left side of the core part 19. .

The configuration itself of the electrode body 12 does not limit the present invention, and various materials conventionally used may be used. A positive electrode active material layer for a lithium secondary battery is used for the positive electrode. As the positive electrode active material, one or more kinds of conventionally used substances can be used without any particular limitation. Preferable examples include LiMn ₂ O ₄ , LiCoO ₂ , LiNiO _{2 and the} like. On the other hand, a negative electrode active material layer for a lithium secondary battery is used for the negative electrode. As the negative electrode active material, one or more kinds of conventionally used substances can be used without any particular limitation. Preferable examples include carbon-based materials such as graphite carbon and amorphous carbon, and lithium-containing transition metal oxides and transition metal nitrides.
A suitable separator used between the positive and negative electrodes is a sheet made of a porous olefin resin.

The case 14 is made of a polypropylene resin that is a thermoplastic resin. Polypropylene resin is preferably applied to this type of battery because it is excellent in adhesion to a laminate film used for sealing the battery and has rigidity. In addition, a polystyrene resin, a polyethylene resin, etc. can also be used.
The case 14 has a rectangular flat box structure and has an accommodating portion 22 inside. By housing the electrode body 12 in the housing portion 22 of the case 14, the electrode body 12 is physically protected, and deformation or breakage due to stress from the outside can be prevented. For this reason, a highly reliable lithium secondary battery is obtained.

  The positive electrode connection terminal 32 is a thin long plate member made of aluminum. The negative electrode connection terminal 16 is a thin long plate member made of copper. The positive electrode connection terminal 32 and the negative electrode connection terminal 16 are fixed to the case 14 by insert molding when the case 14 is injection molded. One end of each of the positive electrode connection terminal 32 and the negative electrode connection terminal 16 protrudes outward from the case 14, and the other end is exposed in the case 14. In the part where the positive electrode connection terminal 32 and the negative electrode connection terminal 16 are located in the case 14, as shown in FIG. 4, only one side is open, and the other side is blocked by the case 14. There is no space for inserting anything on the back surfaces of the positive electrode connection terminal 32 and the negative electrode connection terminal 16 fixed to the case 14 (see FIG. 4).

  Next, a method of joining the positive electrode lead portion 24 of the electrode body 12 to the positive electrode connection terminal 32 fixed to the case 14 will be described with reference to FIGS. FIG. 2 shows a state in which a plurality of aluminum foils extend from the core portion 19 of the electrode body 12 to form the positive electrode lead portion 24. FIG. 3 shows a state in which a plurality of aluminum foils forming the positive electrode lead portion 24 are converged and solid-phase bonded to the relay terminal 30. FIG. 4 shows a state where the electrode body 12 is accommodated in the case 14. FIG. 5 shows a state in which the relay terminal 30 to which the positive electrode lead portion 24 of the electrode body 12 accommodated in the case 14 is solid-phase bonded is bonded to the positive electrode connection terminal 32 fixed to the case 14. FIG. 5 shows how the relay terminal 30 is laser-welded to the positive electrode connection terminal 32 (broken line portion in FIG. 5).

As shown in FIG. 2, in the initial state of the electrode body 12, a plurality of aluminum foils extend to the positive electrode lead portion 24. The plurality of aluminum foils are laminated with a space therebetween. Therefore, these aluminum foils are bundled and superposed on the relay terminal 30.
Next, a plurality of the aluminum foils and the relay terminals 30 that have been superposed are placed on an anvil (base) 35 of an ultrasonic welder, and static pressure is applied in the stacking direction with a pencil-type welding pin 34 from above. Apply ultrasonic vibration. As a result, the plurality of aluminum foils and the interface between the aluminum foil and the relay terminal 30 are rubbed. The oxide film formed on the surface of the aluminum foil or the relay terminal 30 is scraped off by friction, and a rapid plastic flow is generated, and the interface is solid-phase bonded. Such solid-phase bonding is performed at five locations, and the relay terminal 30 and the positive electrode lead portion 24 are reliably bonded. The joint portion 26 is also shown in FIG.
The positive electrode lead portion 24 and the relay terminal 30 in this embodiment are made of aluminum. Solid state bonding by ultrasonic welding is excellent for bonding a plurality of metal layers having an oxide film on the surface, such as aluminum. The joint 26 is unlikely to be damaged such as cracking or peeling. In the joint portion 26 joined by solid phase joining, the aluminum foil maintains a laminated structure and is joined in a state peculiar to solid phase joining. In the solid phase bonded portion, breakage, cracks, and the like are unlikely to occur. Since ultrasonic welding itself does not characterize the present invention, detailed description thereof is omitted.

Next, as shown in FIG. 4, the electrode body 12 is housed in the electrode body housing portion 22 of the case 14. At this time, the relay terminal 30 joined to the positive electrode lead portion 24 is accommodated so as to be disposed on the upper side of the positive electrode connection terminal 32. The positive electrode connection terminal 32 is held in a state of being recessed into the case 14 as described above.
Next, as shown in FIG. 5, the relay terminal 30 is laser-welded to the positive electrode connection terminal 32 by irradiating the upper surface of the relay terminal 30 with a laser traveling from the relay terminal 30 side to the positive electrode connection terminal 32 side.
Since the positive electrode connection terminal 32 is recessed into the case 14, the back surface of the positive electrode connection terminal 32 cannot be approached. In laser welding, since the upper surface of the relay terminal 30 may be irradiated with laser, the relay terminal 30 can be welded to the positive electrode connection terminal 32 that cannot approach the back surface. In this embodiment, laser welding is performed at two locations, and joints 28 are formed at 10 locations. The joint portion 28 is also shown in FIG.

Laser welding, which can be performed with a one-sided approach, has strong welding energy. As described above, the member on the positive electrode side of the lithium secondary battery is made of aluminum, and a non-conductive oxide film is formed on the surface of the member. Since the oxide film of aluminum is strong, it is necessary to increase the welding energy of laser welding. When a plurality of aluminum foils are laser welded to the positive electrode connection terminal 32 without the relay terminal 30 interposed therebetween, breakage such as cracking or peeling is likely to occur at the joint. In the battery 10 of the present embodiment, the relay terminal 30 made of an aluminum plate is interposed. Specifically, as shown in FIG. 5, after joining the positive lead portion 24 and the relay terminal 30, the relay terminal 30 is placed on the positive connection terminal 32 and the laser 36 is irradiated to form the joint 28. Thus, the relay terminal 30 and the positive electrode connection terminal 32 are joined. Although the relay terminal 30 which is a plate material and the positive electrode connection terminal 32 which is a plate material are both aluminum, since welding is performed between single members, it is easy to control welding energy. Moreover, since each member has thickness, even if the laser 36 of strong energy is irradiated at the time of welding, it is hard to be damaged, and it can join reliably.
When the positive electrode lead portion 24 and the positive electrode connection terminal 32 are joined via the relay terminal 30, the power from the plurality of positive electrode sheets is reliably transmitted to the positive electrode connection terminal 32. The battery 10 of this example employing such a structure has good current collection efficiency.

On the other hand, on the negative electrode side, the negative electrode lead portion 20 is converged and then directly joined to the negative electrode connection terminal 16. The negative electrode lead portion 20 and the negative electrode connection terminal 16 are made of copper and can be resistance-welded. That is, a stack of copper foils constituting the negative electrode lead portion 20 and the copper negative electrode connection terminal 16 are overlapped, a pair of conductive chips are brought into contact with one surface thereof, and a current is passed between the pair of conductive chips. Then, the copper foils and the negative electrode connection terminal 16 made of copper foil copper are well welded. In FIG. 1, reference numeral 18 denotes a trace of current flowing between a pair of conductive chips. Note that the series type spot welding (a technique in which a current is passed between a pair of conductive tips) itself is a conventional technique and does not characterize the present invention.
In this embodiment, the negative electrode lead portion 20 is laminated on the negative electrode connection terminal 16, the pair of tungsten spot conductive chips are pressed against the joint portions 18, 18, and welding is performed by passing a welding current between the pair of conductive chips. did. The member on the negative electrode side made of copper can be satisfactorily bonded by such a method without damaging the member.

The electrode body is accommodated as described above, and after the lead portions of each polarity are joined to the connection terminals of each polarity, the upper surface of the opening is sealed with a laminate film. At this time, an appropriate electrolyte (for example, a non-aqueous electrolyte such as a mixed solvent of diethyl carbonate and ethylene carbonate containing a suitable amount of a lithium salt such as LiPF ₆ ) is injected and sealed, and the lithium of this embodiment is sealed. The assembly of the secondary battery 10 is completed. The film exterior and the electrolyte injection process may be the same as those used in the manufacture of conventional lithium secondary batteries, and do not characterize the present invention.

  The preferred embodiments of the present invention have been described in detail above, but these are only examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the above-described embodiments.

  For example, the electrode body provided in the battery is not particularly limited as long as it is a power storage element capable of storing and discharging predetermined power. There is no restriction | limiting in particular in the shape and size of an electrode body, It can comprise in a desired form and size. Typical power storage elements include various types of primary batteries (eg, lithium primary batteries, manganese batteries), secondary batteries (eg, lithium secondary batteries, nickel metal hydride batteries), or capacitors (eg, electric double layer capacitors). be able to.

  The size and shape of the battery case of the present invention or the electrode body housing portion can be appropriately changed depending on the type, size, shape, etc. of the electrode body to be housed. A case formed from a material that is an impact resistant material and is resistant to a reaction product caused by the use of the electrolyte and the electricity storage element constituting the electricity storage element to be accommodated (held) is preferable. Typically, it is preferable to select an insulating material. Synthetic resin materials have a relatively low manufacturing cost, are easily molded into a desired shape, and often satisfy the above-described conditions. For these reasons, the synthetic resin can be preferably used as a constituent material of the case. For example, polyolefin resins such as polyethylene and polypropylene, ethylene-propylene-diene copolymer (EPDM) and the like are preferably selected. Further, PPS (polyphenylene sulfide resin), polystyrene resin, polyimide resin, polyamideimide resin, fluorine resin, PEEK (polyether ether ketone resin), PES (polyether sulfone resin), or the like may be used. The case may be composed of a single resin material selected from these resins, or may be composed of a material in which two or more kinds of resins are mixed.

In addition, the connection terminals provided in the battery include at least a pair of external connection terminals (typically, a battery (specifically, a positive electrode and a negative electrode of an electrode body accommodated in the case) and an external electric circuit (electric device). Is a total positive electrode connection terminal and a total negative electrode connection terminal) of the whole battery. In addition, in the case of a battery module in which a plurality of electrode bodies are arranged and housed, in addition to the external connection terminals, there are connection terminals for electrically joining the electrode bodies housed in the case. It is only necessary that at least one of the connection terminals fixed to the case has a relay terminal, and the battery of the present invention is such that all of the connection terminals of the battery have relay terminals. Not limited. It may be provided only in any one of the connection terminals where the joint is formed at a position close to the case.
The positive electrode connecting terminal and the negative electrode connecting terminal for external bonding are not particularly limited in shape and composition as long as they can electrically bond the battery and an external electric circuit. Similarly, the connection terminal between batteries should just be what can electrically join between two electrode bodies, and there is no limitation in particular in the shape and composition. A shape that can be easily formed integrally with the case, for example, a substantially plate-like or substantially rod-like connection terminal is preferable. The material constituting the connection terminal is typically made of metal, and examples thereof include metal materials such as copper, aluminum, gold, silver, platinum, and nickel. For example, when the present invention is applied to a lithium secondary battery, copper is used as the external connection terminal on the negative electrode side, and aluminum is used as the external connection terminal on the positive electrode side. In the inter-battery connection terminal that joins the two electrode bodies in series, it is possible to use an electrode in which the positive electrode side bonding portion is made of aluminum and the negative electrode side bonding portion is made of copper.
The relay terminal is not particularly limited as long as it can electrically join the electrode body and the connection terminal. Any shape that can be easily joined to both the lead portion and the connection terminal is acceptable, and a plate-like shape is preferable. The material constituting the relay terminal is not particularly limited as long as it is made of metal that can be easily solid-phase bonded. Typically, a material similar to the material of the connection terminal to be joined is selected.

  As a means for forming the connection terminal integrally with the case, a general molding method selected according to the material may be applied, and a special process is not required for carrying out the present invention. For example, an insert processing method, a press-fit processing method, a caulking processing method, a thermocompression bonding (hot press) processing method, and the like can be given. When the case is made of synthetic resin and the connection terminal is made of metal, a so-called insert processing (insert molding) method in which a predetermined shape of the connection terminal is arranged in the mold to produce a resin molded body is particularly preferable.

  The technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

It is a side view which shows typically the structure of the battery of an Example. It is a schematic diagram which shows the lamination | stacking part and lead part of the electrode body of an Example. . It is a schematic diagram which shows the joining operation | work of the lead part and relay terminal which concern on an Example. It is a schematic diagram which shows a mode that the electrode body joined to the relay terminal is arrange | positioned to the case where the relay terminal which concerns on an Example was fixed. It is VV sectional drawing of the battery which concerns on an Example, and has shown the joining operation | work of an electrode body (relay terminal) and a connection terminal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Battery 12 Electrode body 14 Case 16 Negative electrode connection terminal 18 Joint part 20 of a negative electrode lead part and a negative electrode connection terminal Negative electrode lead part 22 Electrode body accommodating part 24 Positive electrode lead part 26 Junction part 28 of a relay terminal and positive electrode lead part Junction 30 of relay terminal Relay terminal 32 Positive electrode connection terminal

Claims (9)

The metal foil to which the positive electrode active material layer is attached and the metal foil to which the negative electrode active material layer is attached are stacked in multiple stages via a separator, and extends from a part of the outline of the core part. An electrode body having a lead portion, wherein the same polarity metal foil is laminated in multiple stages,
A case housing the electrode body;
A connection terminal that extends through the wall forming the case and extends inside and outside the case, and is fixed to the wall;
A relay terminal joined to both the lead portion and the connection terminal;
Equipped with a battery.   2. The battery according to claim 1, wherein a lead portion in which aluminum foil is laminated in multiple stages and a relay terminal made of aluminum are solid-phase bonded.   The battery according to claim 1 or 2, wherein the relay terminal and the connection terminal are joined at a position where the lead portion does not exist. The electrode body includes a positive electrode lead portion “multi-layered aluminum foil” and a negative electrode lead portion “multi-layered copper foil” extending from a part of the contour of the core portion. ,
The positive electrode lead portion is joined to the positive electrode connection terminal via the relay terminal,
The battery according to any one of claims 1 to 3, wherein the negative electrode lead portion is directly joined to the negative electrode connection terminal without using a relay terminal. The metal foil to which the positive electrode active material layer is attached and the metal foil to which the negative electrode active material layer is attached are stacked in multiple stages via a separator, and extends from a part of the outline of the core part. A step of manufacturing an electrode body having a lead portion, wherein metal foils of the same polarity are laminated in multiple stages;
A case for housing an electrode body, wherein the connection terminal extends through the inside and outside of the case through the wall forming the case, and the case where the connection terminal is fixed to the wall is manufactured,
Joining the relay terminal to the lead part;
Joining the connection terminal to the relay terminal;
A method for manufacturing a battery comprising:   6. The method according to claim 5, wherein a lead portion in which aluminum foil is laminated in multiple stages and a relay terminal formed of aluminum are solid-phase bonded.   The manufacturing method according to claim 5 or 6, wherein the relay terminal and the connection terminal are joined to one surface of the relay terminal by irradiating a laser that proceeds from the relay terminal side to the connection terminal side.   The manufacturing method according to claim 7, wherein the relay terminal and the connection terminal are joined at a position where the lead portion does not exist. The electrode body manufacturing stage includes a positive lead portion extending from a part of the outline of the core portion, “aluminum foil is laminated in multiple stages”, and a negative lead portion “a copper foil is laminated in multiple stages”. Manufacturing the electrode body
For the positive lead part, the step of joining the positive lead part to the relay terminal and the step of joining the relay terminal to the connection terminal are carried out,
The manufacturing method according to claim 5, wherein the step of directly joining the negative electrode lead portion to the negative electrode connection terminal without using a relay terminal is performed for the negative electrode lead portion.

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