JP2012064346A - Power storage device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably hold a collector of a power storage device.SOLUTION: In this manufacturing method, a power storage element which stores electric power with a positive electrode plate and a negative electrode plate is provided in a metal housing BC, and a metal collector 4 to electrically connect an electrode terminal 5 arranged outside the housing BC and each of the positive electrode plate and the negative electrode plate is provided. The collector 4 installs a power storage device, which is formed by a first posture part FP extending along a face where the electrode terminals 5 are arranged and a second posture part SP extended in a direction crossing with the first posture part FP being connected to the power storage element, to a position facing the first posture part FP of the collector 4 in an inner surface of the housing BC, also installs a connecting member 14, in which a resin layer 14a and a metal layer 14b are laminated, so that the resin layer 14a is positioned in an inner side of the housing BC, and finally installs the metal layer 14b of the connecting member 14 and the collector 4.

Description

  The present invention includes a positive electrode plate and a negative electrode plate, and a power storage element for storing electricity is provided in a metal housing, and an electrode terminal disposed on the outer side of the housing; the positive electrode plate and the negative electrode plate; A current collector that is electrically connected to each other, and the current collector extends along a surface on which the electrode terminals are disposed, and is fixed to the housing; The present invention relates to a power storage device that includes a second posture portion that extends in a direction intersecting with the first posture portion and is connected to the power storage element, and a method for manufacturing the power storage device.

  Such a power storage device is described in, for example, Patent Document 1 below as a wiring form for electrically connecting a power storage element that is a power supply source and an electrode terminal installed on the outer side of the device housing. A metal current collector is bent into, for example, an L shape, and one of the two intersecting portions (the first posture portion) is formed along the casing surface on which the electrode terminals are disposed. There is a case where the power storage element is connected to the other (the second posture portion) in an extended posture.

JP 2007-073317 A

However, in the above conventional configuration, since the load of the power storage element acts on the current collector, the load is supported at the location where the current collector is attached.
In such a power storage element support mode, when an external force such as vibration or impact acts on the power storage device, the force applied to the location where the current collector is attached becomes extremely large.
The current collector is attached to the wiring member that penetrates the housing of the power storage device because of the function of the current collector to electrically connect the power storage element and the electrode terminal on the outside of the housing. Alternatively, the current collector may be extended as it is and penetrate the housing.
Therefore, if a very large force is applied to the location where the current collector is attached, liquid leakage may occur or the current collector may be damaged if an extremely large force is applied. There is also a possibility.
The present invention has been made in view of such circumstances, and an object thereof is to enable a current collector to be stably supported.

  According to a first aspect of the present application, an electricity storage element that includes a positive electrode plate and a negative electrode plate for storing electricity is provided in a metal housing, and an electrode terminal disposed on an outer side of the housing; and the positive electrode plate And a current collector made of metal for electrically connecting the negative electrode plate and at least one of the current collectors extends along a surface on which the electrode terminal is disposed. A first posture portion fixed to the housing and a second posture portion that extends in a direction intersecting the first posture portion and is connected to the power storage element. A bonding member in which a resin layer and a metal layer are laminated at a position facing the first posture portion of the current collector on the inner surface of the housing, the resin layer is positioned on the inner surface side of the housing The metal layer and the current collector are fixed to each other.

In other words, the current collector is stably supported by fixing the current collector and the housing with the above-described joining member separately from the location where the current collector is originally fixed for electrical wiring with the electrode terminal. To do. In the case where the current collector and the electrode terminal are directly connected, even when an external force is applied to the electrode terminal in the rotational direction around its axis, the current collector is interlocked with the electrode terminal. Rotation is suppressed. This effect is noticeable when the electrode terminal has a connection mechanism by screw tightening as a connection mechanism with an external circuit. Specifically, when the electrode terminal is threaded and configured as a terminal bolt, when the nut is tightened to the electrode terminal, the current collector may rotate if excessive torque is applied. When the rotation of the power storage element, the position of the power storage element may change to contact other members such as a casing to cause a short circuit, or the power storage element may be twisted to reduce power storage performance / discharge performance. In addition, it is thought that the fall of electrical storage performance and discharge performance arises when the space | interval between electrodes changes.
As in the present invention, by fixing the current collector and the housing separately from the locations where the current collector and the housing are originally fixed, the positional deviation in the rotation direction can be effectively suppressed. Generation | occurrence | production of the internal short circuit which occurred when using an apparatus, and the fall of electrical storage performance and discharge performance can be suppressed.
However, since the current collector constitutes the energization path of the electrical wiring, it is necessary to ensure electrical insulation between the current collector and simply connecting the housing and the current collector to each other is not possible. Can not.
Therefore, the resin layer of the joining member is disposed between the current collector and the housing to ensure electrical insulation, and the metal layer and the current collector of the joining member are fixed to each other.
The joining member as described above has not only a function of fixing the inner surface of the housing and the current collector, but also a function of maintaining the distance between the inner surface of the housing and the current collector with high accuracy. This is because the dimension in the thickness direction of the joining member does not change before and after the attachment process. When the rivet is fixed instead of the joining member, the rivet may be plastically deformed. If the rivet is plastically deformed, it is difficult to control the distance between the inner surface of the housing and the current collector.
Furthermore, according to the present invention, when the current collector is fixed to the inner surface of the housing with the packing interposed therebetween, the dimension of the joining member in the thickness direction is made substantially the same as that of the packing, thereby increasing the height of the battery. It becomes possible to provide a joining member with the same size as before. A design in which the inner surface of the housing and the first posture portion of the current collector are arranged in parallel is also possible.

  The second invention of the present application includes a positive electrode plate and a negative electrode plate, and a power storage element for storing electricity is provided in a metal housing, and an electrode terminal disposed on the outer side of the housing; A metal current collector is provided to electrically connect the positive electrode plate and the negative electrode plate, respectively, and at least one of the current collectors is along a surface on which the electrode terminals are disposed. In the method of manufacturing the power storage device, the first posture portion extending in a direction and the second posture portion extending in a direction intersecting with the first posture portion and connected to the power storage element. A bonding member in which a resin layer and a metal layer are laminated is attached to a position on the inner surface facing the first posture portion of the current collector in a state where the resin layer is positioned on the inner surface side of the housing. A joining member attaching step, and the metal layer and the current collector in the joining member And a current collector attaching step of fixing the door to each other.

That is, in the bonding member mounting step, the bonding member in which the resin layer and the metal layer are laminated on the inner surface of the housing is mounted in a state where the resin layer is positioned on the inner surface side of the housing, and the current collector mounting step The metal layer of the joining member and the current collector are fixed to each other by welding or the like.
Thus, apart from the location where the current collector is originally fixed for electrical wiring with the electrode terminal, the current collector and the housing are fixed by the bonding member, so that the resin layer of the bonding member The current collector is stably supported while ensuring electrical insulation from the housing.

According to a third invention of the present application, in addition to the structure of the second invention, the current collector is arranged together with a wiring member arranged in a state of penetrating the casing for electrical connection with the electrode terminal. A wiring process for fixing a body to the housing is further included, and the current collector mounting process is performed after the wiring process.
That is, the wiring process for fixing the current collector together with the wiring member connected to the current collector to the housing of the power storage device is generally large for the current collector for fixing the current collector, for example, rivet fixing. A force may be applied and the current collector may be slightly deformed.
Therefore, if the wiring step is performed after the current collector mounting step, stress may act on the mounting portion between the metal layer of the joining member and the current collector, which may reduce the bonding strength due to welding or the like. is there.
Therefore, the bonding strength between the metal layer of the bonding member and the current collector can be maintained in a good state by performing the current collector mounting step after the wiring step. This effect is significant when attached by welding.

According to a fourth invention of the present application, in addition to the configuration of the second or third invention, the joining member attaching step attaches the joining member to the housing by using a metal-resin joining technique. Is done.
Adhesives caused by metal-resin bonding technology that caused problems when mounting with adhesives, that is, the dissolution of adhesive components into the electrolyte, oxidation resistance, and reduction resistance The risk of problems such as deterioration of the adhesive and aging of the adhesive can be avoided. In addition, the bonding strength can be increased. These actions are particularly useful in a secondary battery equipped with a nonaqueous electrolyte in the housing.

Further, in a fifth invention of the present application, in addition to the configuration of any one of the second to fourth inventions, the current collector attaching step includes the metal layer and the current collector in the joining member. This is done by fixing them together by welding.
By using welding, the work is as simple as the method of fixing using an adhesive, the material cost can be reduced to the same level, and the joint strength is greatly increased depending on the welding conditions. It becomes possible.

According to the first aspect of the invention, the joining member in a state where the resin layer and the metal layer are laminated is fixed to the inner surface of the housing, and the metal layer and the current collector of the joining member are fixed. The current collector can be stably supported while ensuring electrical insulation between the body and the current collector.
According to the second aspect of the invention, the joining member in a state where the resin layer and the metal layer are laminated is fixed to the inner surface of the housing, and the metal layer and the current collector of the joining member are fixed. The current collector can be stably supported while ensuring electrical insulation between the body and the current collector.
In addition, according to the third invention, by performing the current collector mounting step after the wiring step, the bonding strength between the metal layer of the bonding member and the current collector can be maintained in a good state. The reliability of the storage battery device can be further improved.
In addition, according to the fourth aspect of the invention, by attaching the joining member to the casing using metal-resin joining technology, the adverse effect on the electrolyte and the deterioration of the joining state are suppressed as compared with the case where an adhesive is used. can do.
According to the fifth aspect of the invention, the joining member and the current collector are fixed by welding, so that the workability is maintained at the same level as compared with the method of fixing using an adhesive. It is possible to significantly increase the bonding strength while keeping the material cost at the same low level.

1 is an external perspective view of a power storage device according to an embodiment of the present invention. The perspective view which shows the internal structure of the electrical storage apparatus concerning embodiment of this invention The principal part expanded sectional view of the electrical storage apparatus concerning embodiment of this invention The front view which shows the internal structure of the electrical storage apparatus concerning embodiment of this invention The perspective view of the component of the electrical storage apparatus concerning embodiment of this invention

Hereinafter, embodiments of a power storage device of the present invention will be described with reference to the drawings.
In the present embodiment, a nonaqueous electrolyte secondary battery (more specifically, a lithium ion battery) that is an example of a secondary battery will be described as an example of a power storage device.
[Configuration of Nonaqueous Electrolyte Secondary Battery RB]
As shown in the perspective views of FIGS. 1 and 2 and the front view of FIG. 4, the nonaqueous electrolyte secondary battery RB of the present embodiment has a bottomed cylindrical shape (more specifically, a bottomed rectangular cylindrical shape). The metal can body 1 is formed by covering the open surface of the metal can body 1 formed on the metal cover 2 with a metal lid portion 2 formed in a substantially flat plate shape and welding it. The lid portion 2 is formed in a strip-like rectangle, and the casing BC has a flat rectangular parallelepiped shape as a whole. FIG. 2 illustrates the internal configuration of the casing BC by removing the can body 1 from the completed secondary battery RB (shown in FIG. 1).

The storage element 3 and the metal current collectors 4 and 6 indicated by a two-dot chain line in FIGS. 2 and 4 are housed and disposed in the housing BC in a state of being immersed in the electrolytic solution. In the present embodiment, the case where the power storage device is configured as the secondary battery RB is illustrated, so that the power storage element 3 is provided on each of a pair of electrode plates including a foil-shaped positive electrode plate and a foil-shaped negative electrode plate. The active material is applied and wound around a separator.
The power storage element 3 has an uncoated portion 3a that is not coated with an active material on a foil-shaped positive electrode plate, is laterally extended and welded to the current collector 4, and an active material is coated on the foil-shaped negative electrode plate. An uncoated portion 3b that does not exist extends to the side opposite to the uncoated portion 3b and is welded to the current collector 6.

The lid 2 made of metal (specifically, made of aluminum) has a current collector 4 on the positive electrode side, a terminal bolt 5 which is a positive electrode terminal connected to the current collector 4, and a negative electrode side current collector 4. A current collector 6 and a terminal bolt 7 that is a negative electrode terminal connected to the current collector 6 are attached to the outer side of the housing BC. The current collectors 4 and 6 electrically connect the terminal bolts 5 and 7 to the positive electrode plate and the negative electrode plate of the electricity storage element 3, respectively.
The current collectors 4 and 6 are formed by bending a metal plate in a substantially L shape as a whole as shown in FIG. 4 and the current collector 4 on the positive electrode side, as shown in FIG. , A first posture portion FP extending along the plane of the lid 2 which is a surface on which the terminal bolts 5 and 7 are arranged, and a second posture portion SP extending in a direction intersecting with the first posture portion FP at 90 degrees. It is made up of.
The first posture portion FP is fixed to the lid portion 2 for electrical connection with the terminal bolts 5 and 7 at the end opposite to the side continuous with the second posture portion SP.
In the second posture portion SP, the connection portions 4a and 6a that are bent so as to protrude on the power storage element 3 side are welded to the uncoated portions 3a and 3b, respectively, as described above.
As shown in the sectional view of FIG. 3, the terminal bolt 5 is integrally formed so as to have a rivet portion 5 a on the head side thereof, and the rivet portion 5 a penetrates the electrode mounting hole 8 formed in the lid portion 2. It is arranged in the state to do.
The terminal bolt 5 sandwiches the lid 2 and the current collector 4 with a pair of packings 9 and 10 interposed therebetween, and is fixed by caulking the rivet portion 5a.
The attachment structure of the terminal bolt 7 on the negative electrode side is the same as that on the positive electrode side, and the lid 2 and the current collector 6 are sandwiched with the pair of packings 11 and 12 interposed therebetween, and the rivet portion 7a is caulked and fixed. Has been.
In the mounting structure of the terminal bolts 5 and 7, including the current collectors 4 and 6, only the material of the metal member is different between the positive electrode side and the negative electrode side. The metal member on the positive electrode side is made of aluminum, and the metal member on the negative electrode side is made of copper.
As shown in FIGS. 1 and 2, the lid 2 is further provided with a safety valve 13 at the center in the longitudinal direction, and current collectors 4, 6 on the surface that is the inner surface of the casing BC at both ends in the longitudinal direction. The joining members 14 and 15 for connecting and fixing the are attached. The attachment positions of the joining members 14 and 15 are set to positions facing the first posture portion FP of the current collectors 4 and 6, respectively. The joining members 14 and 15 will be described in detail in the manufacturing process of the secondary battery RB described below.
The safety valve 13 opens the valve body and releases the inside air when the internal pressure in the casing BC of the secondary battery RB becomes higher than a predetermined operating pressure.

[Manufacturing process of secondary battery RB]
Next, the manufacturing process of the secondary battery RB will be schematically described.
First, the casing BC of the secondary battery RB is assembled.
[Storage element assembly process]
In the state where the uncoated portions 3a and 3b are present at the end portions in the width direction as described above, the electricity storage element 3 is respectively provided with the positive electrode active material and the negative electrode active material on the long strip-like foil-like positive electrode plate and foil-like negative electrode plate. After applying and drying, the separator is sandwiched and wound, and pressed to form a flat shape.

[Joint member installation process]
Next, the assembly process of the lid part 2 will be described.
The lid 2 has an electrode mounting hole 8 for attaching the terminal bolts 5 and 7 and a safety valve mounting hole 16 for attaching the safety valve 13 to an aluminum plate formed in a strip shape, and then, as shown in FIG. , 15 are attached. As described above, the attachment positions of the joining members 14 and 15 are positions facing the first posture portion FP of the current collectors 4 and 6. The joining members 14 and 15 are preferably attached to both the positive electrode side and the negative electrode side, but may be attached to only one of them.
As shown in the cross-sectional view of FIG. 3, the bonding member 14 is formed by laminating a resin layer 14 a in contact with the surface of the lid 2 and a metal layer 14 b formed on the resin layer 14 a. Similarly, the bonding member 15 on the negative electrode side has a laminated structure of a resin layer 15a and a metal layer 15b.
However, the metal layer 14b of the bonding member 14 on the positive electrode side is made of aluminum, and the metal layer 15b of the bonding member 15 on the negative electrode side is made of copper.
The attachment positions of the joining members 14 and 15 are set to positions facing the upper end surfaces of the current collectors 4 and 6, respectively.
Attachment of the joining members 14 and 15 to the lid 2 is performed by a so-called metal-resin joining technique. In addition, as a mounting method, although the method of apply | coating an adhesive agent between the cover part 2 and the joining members 14 and 15 may be used, it is more preferable to use a metal-resin joining technique.
As this metal-resin bonding technique, for example, a metal surface is surface-treated to form a minute recess, the surface-treated metal is placed in a mold, and a resin is injection-molded. There is a technology to firmly bond, or a technology to apply a film to the metal surface by organic plating and then injection-mold a resin on the treated surface to firmly bond the metal and the resin. -Resin bonding technology can be used as appropriate.
Specifically, after the above-described surface treatment is performed on the metal plates 14b and 15b and the lid portion 2 of the joining members 14 and 15, the distance corresponding to the thickness of the resin layers 14a and 15a. Is placed in a mold having a predetermined shape, and a resin is injected into the space between the metal plate 14b and 15b and the lid 2 and molded.

[Wiring process]
Next, terminal bolts 5, 7 and the like are attached to the lid portion 2 to which the joining members 14, 15 are attached as described above, and electrical wiring is performed over the inside and outside of the housing BC.
The electrical wiring from the positive electrode plate and the negative electrode plate of the power storage element 3 to the terminal bolts 5 and 7 requires a wiring member that is attached in a state of penetrating the housing BC, and this wiring member is connected to the current collectors 4 and 6. To be installed.
In the present embodiment, the rivet portions 5a and 7a of the terminal bolts 5 and 7 are used as the wiring member.
Specifically, the packings 9, 10, 11, 12 are fitted on both sides of the electrode mounting hole 8 of the lid 2, and the rivets 5a, 7a of the terminal bolts 5, 7 are inserted. 6 is fitted into the rivet portions 5a and 7a, and the rivet portions 5a and 7a are caulked and fixed. The current collectors 4 and 6 are fixed so that the first posture portion FP is in a posture along the longitudinal direction of the lid portion 2.
Accordingly, the current collectors 4 and 6 together with the rivet portions 5a and 7a are mechanically fixed to the lid portion 2, and the rivet portions 5a and 7a are connected to the current collectors 4 and 6, Current collectors 4 and 6 and terminal bolts 5 and 7 are electrically connected via rivet portions 5a and 7a.
Furthermore, electrical insulation between the cover 2 and the wiring from the current collectors 4, 6 to the terminal bolts 5, 7 is ensured by the packings 9, 10, 11, 12.
[Current collector mounting process]
Next, the current collectors 4 and 6 and the joining members 14 and 15 are welded with the current collectors 4 and 6 assembled to the lid portion 2 as described above. In place of the attachment method by welding, a method of applying an adhesive between the current collectors 4 and 6 and the joining members 14 and 15 and fixing them together may be used. preferable.
For this welding, resistance welding, laser welding, or the like can be used. For example, when resistance welding is used, a current is applied between the metal layers 14 b and 15 b of the joining members 14 and 15 and the current collectors 4 and 6 in a state where the current collectors 4 and 6 are pressed to the lid 2 side. Flow to join the interfaces. As an actual resistance welding operation, welding can also be performed by a method in which a pair of electrodes of a resistance welding apparatus is brought into contact with the metal layer 14b and the current collector 4 to flow current, but both of the pair of electrodes are collected. Welding can also be performed by passing a current between the pair of electrodes while pressing the current collector 4 and pressurizing the current collector 4 toward the lid 2 side. The latter method is superior in workability compared to the former method.
Since this current collector mounting step is performed after the wiring step, the stress associated with the work of fixing the current collectors 4 and 6 in the wiring step is applied to the welded portions of the metal layers 14b and 15b and the current collectors 4 and 6. There is no effect.

[Case assembly process]
Next, after attaching the safety valve 13 and the like, the uncoated portions 3a and 3b of the electricity storage element 3 are welded to the current collectors 4 and 6, respectively, and the electricity storage element 3 is accommodated and disposed in the can 1 and the lid 2 And the can 1 are welded to complete the assembly of the casing BC.
[Initial charging process]
When the assembly of the casing BC is completed, an electrolyte is then injected into the casing BC from a liquid injection hole (not shown). When the injection of the electrolyte is completed, the initial charging of the secondary battery RB is performed under predetermined charging conditions. (Preliminary charging) is performed, and after the gas in the casing BC is discharged from the liquid injection hole, the liquid injection hole is sealed.
Thereafter, processing such as aging is appropriately performed to complete the secondary battery RB.

[Another embodiment]
Hereinafter, other embodiments of the present invention will be listed.
(1) In the above embodiment, the non-aqueous electrolyte secondary battery RB has been exemplified as the power storage device. However, other types of batteries such as alkaline storage batteries, and further power storage devices such as electric double layer capacitors The present invention can also be applied to.
(2) In the above embodiment, in order to electrically connect the terminal bolts 5 and 7 disposed on the outer side of the casing BC and the current collectors 4 and 6, the current collectors 4 and 6 are connected. The case where the rivets 5a and 7a of the terminal bolts 5 and 7 are used as the wiring members to be provided is illustrated, but the current collectors 4 and 6 are placed outside the casing BC in a state of passing through the lid 2. The extending portion of the current collectors 4 and 6 is used as the wiring member, for example, by sealing the passage position of the lid 2 in the current collectors 4 and 6 by metal-resin bonding. You may comprise.

3 Power storage element 4, 6 Current collector 5, 7 Electrode terminal 5a, 7a Wiring member 14, 15 Joining member 14a, 15a Resin layer 14b, 15b Metal layer BC Housing FP First posture portion SP Second posture portion

Claims (5)

A power storage element for storing electricity with a positive electrode plate and a negative electrode plate is provided in a metal housing,
A metal current collector for electrically connecting the electrode terminal disposed on the outer side of the housing, the positive electrode plate and the negative electrode plate, respectively;
At least one of the current collectors extends along a surface on which the electrode terminals are arranged, and crosses the first posture portion that is fixed to the housing and the first posture portion. A power storage device formed with a second posture portion extending in a direction and connected to the power storage element,
A bonding member in which a resin layer and a metal layer are laminated at a position facing the first posture portion of the current collector on the inner surface of the housing, the resin layer is positioned on the inner surface side of the housing A power storage device that is attached in a state where the metal layer and the current collector are fixed to each other. A power storage element for storing electricity with a positive electrode plate and a negative electrode plate is provided in a metal housing,
A metal current collector for electrically connecting the electrode terminal disposed on the outer side of the housing, the positive electrode plate and the negative electrode plate, respectively;
At least one of the current collectors includes a first posture portion extending along a surface on which the electrode terminals are disposed, and a power storage element extending in a direction intersecting the first posture portion. A method of manufacturing a power storage device formed with a second posture portion to be connected,
A bonding member in which a resin layer and a metal layer are laminated at a position facing the first posture portion of the current collector on the inner surface of the housing, and the resin layer is positioned on the inner surface side of the housing A joining member attaching step to attach in a state to do,
A method for manufacturing a power storage device, comprising: a current collector mounting step for fixing the metal layer and the current collector to each other in the joining member. A wiring step of fixing the current collector to the casing together with a wiring member disposed in a state of penetrating the casing for electrical connection with the electrode terminal;
The method for manufacturing a power storage device according to claim 2, wherein the current collector mounting step is performed after the wiring step.   The method for manufacturing a power storage device according to claim 2, wherein the joining member attaching step is performed by attaching the joining member to the housing using a metal-resin joining technique.   5. The method of manufacturing a power storage device according to claim 2, wherein the current collector mounting step is performed by fixing the metal layer and the current collector of the joining member to each other by welding.

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