WO2012090600A1

WO2012090600A1 - Rectangular secondary battery and method for manufacturing same

Info

Publication number: WO2012090600A1
Application number: PCT/JP2011/076037
Authority: WO
Inventors: 服部　高幸; 毅典木村; 山内　康弘; 能間　俊之
Original assignee: 三洋電機株式会社
Priority date: 2010-12-29
Filing date: 2011-11-11
Publication date: 2012-07-05
Also published as: JP2014053072A

Abstract

[Problem] To provide a rectangular secondary battery in which the amount of stress acting on a resistance-welded section is small, the stress being caused by an expansion/contraction of an electrode body during charging/discharging; the resistance of the welded section can be reduced; and the quality of resistance-welded portions is more stable. [Solution] This rectangular secondary battery has a configuration in which: a core-exposed section (14) of an electrode body (11) that has been layered or rolled to a flat shape is bisected; a plurality of groups of electroconductive first members (24B) and second members (24C) are linearly arranged therebetween and disposed so that one end surface of each of the first members (24B) and second members (24C) is positioned on an inner-surface side of the bisected core-exposed section (14), and the other end surfaces face each other at a distance from each other; and a pair of current-collecting members (16) are positioned so as to be in contact with, and resistance-welded to, both surfaces on the outermost side of the bisected core-exposed section (14).

Description

Rectangular secondary battery and manufacturing method thereof

The present invention relates to a prismatic secondary battery having a stacked or wound positive electrode core exposed portion and negative electrode core exposed portion and a method for manufacturing the same. Specifically, in the present invention, at least one side of the positive electrode core exposed portion and the negative electrode core exposed portion is divided into two, and a conductive member is disposed between the core exposed portion and the current collecting member, and the core exposed. There is little stress on the resistance weld due to the expansion and contraction of the electrode body due to charge and discharge, and the resistance of the weld is reduced, and the quality of the welded part is achieved. The present invention relates to a prismatic secondary battery in which is stabilized.

In recent years, environmental protection movements have increased, and emission regulations that cause global warming, such as carbon dioxide gas, have been strengthened. Therefore, in the automobile industry, electric vehicles (EV) and hybrid electric vehicles (HEV) are actively developed in place of vehicles using fossil fuels such as gasoline, diesel oil, and natural gas. As such EV and HEV batteries, nickel-hydrogen secondary batteries and lithium ion secondary batteries are used. However, in recent years, a lightweight and high capacity battery can be obtained. Non-aqueous electrolyte secondary batteries such as secondary batteries are increasingly used.

In EV and HEV applications, it is necessary not only to respond to the environment, but also to improve the basic performance as an automobile, that is, the driving performance such as acceleration performance and climbing performance. In order to satisfy such a demand, not only the battery capacity is increased but also a high output secondary battery is required. In general, as secondary batteries for EV and HEV, a rectangular secondary battery in which a power generation element is housed in a rectangular outer can is used in many cases. However, when a high output is discharged, a large current flows through the battery. It is necessary to reduce the internal resistance as much as possible. For this reason, various improvements have been made to reduce the internal resistance by preventing poor welding between the core exposed portion of the electrode plate and the current collecting member in the power generation element of the battery. There are mechanical caulking methods, welding methods, and the like as methods for collecting electrical power by electrically connecting the core exposed portion of the electrode plate of the battery power generation element and the current collecting member, but high output is required. As a battery current collecting method, a welding method is suitable because it is easy to realize low resistance and hardly changes with time.

However, an electrode body of a square secondary battery such as a lithium ion secondary battery for EV and HEV has a configuration in which a positive electrode plate and a negative electrode plate are stacked or wound via a separator. The core body exposed portions of the positive electrode plate and the negative electrode plate are arranged so as to be located on different sides, and the core body exposed portions of the positive electrode plate are laminated and welded to the positive electrode current collector member. The core exposed portion of the plate is also laminated and welded to the negative electrode current collector. The number of stacked positive electrode core exposed portions and negative electrode core exposed portions is very large when the capacity of a prismatic secondary battery such as a lithium ion secondary battery for EV and HEV is large. Therefore, in the electrode body of a prismatic secondary battery such as a lithium ion secondary battery for EV and HEV, further improvement is desired with respect to the exposed portion of the core body of the electrode electrode plate and the current collecting member.

On the other hand, in Patent Document 1 below, in the electrode body in which the positive electrode plate and the negative electrode plate are wound in a flat shape with a separator interposed therebetween, the lamination width of the core exposed portion of each electrode protruding from the separator is reduced. In order to do this, an invention of an electricity storage element in which the core exposed portion of each electrode is divided into two portions and welded to a current collecting member is disclosed. Here, a configuration of a power storage element disclosed in Patent Document 1 described below will be described with reference to FIGS. 12A is a cross-sectional view of an electric double layer capacitor as a power storage element disclosed in Patent Document 1 below, FIG. 12B is a cross-sectional view taken along line XIIB-XIIB in FIG. 12A, and FIG. FIG. 5 is a cross-sectional view taken along line XIIC-XIIC. 13 is a view showing a welding process between the electrode core exposed portion and the current collecting member in FIG.

As shown in FIGS. 12A to 12C, the storage element 50 includes a wound electrode body 51 in which a positive electrode plate and a negative electrode plate are laminated via a separator (both not shown) and wound in a flat shape. The wound electrode body 51 is disposed in a rectangular aluminum outer can 52. Further, each of the positive electrode current collecting member 53a and the negative electrode current collecting member 53b of the electric storage element 50 is formed with U-shaped wing parts 54a to 54b at one end, respectively, and the core of the positive electrode plate. The exposed portion 55a is connected to the core exposed portion 55b of the negative electrode plate, and the other end is connected to the positive terminal 56a or the negative terminal 56b. The core body exposed portion 55a of the positive electrode plate is bundled and divided into two parts, which are welded to two locations on the outer surface side of one U-shaped wing portion 54a, respectively. The part 55b is also divided into two parts and welded to two locations on the outer surface side of the other U-shaped wing part 54b.

For example, if the welding is on the positive electrode plate side, as shown in FIG. 13, one of the core exposed portions 55a of the positive electrode plate divided into two is arranged on the outer surface of the U-shaped wing portion 54a. Then, the horn 57 of an ultrasonic welding device (not shown) is brought into contact with the outer surface of the core exposed portion 55a, and the anvil 58 is disposed on the inner surface side of the U-shaped wing portion 54a, so that ultrasonic welding is performed. Has been done. In addition, ultrasonic welding is performed by the same method with respect to the other of the core exposed portions 55a of the two divided positive electrode plates, and the same applies to the negative electrode plate side.

JP 2003-249423 A Japanese Utility Model Publication No.58-113268 Japanese Unexamined Patent Publication No. 2000-40501

According to the invention disclosed in Patent Document 1, since the exposed widths of the positive electrode core exposed portion and the negative electrode core exposed portion can be reduced, the volume efficiency of the power storage device is improved. However, in this invention, in order to weld the positive electrode current collector or the negative electrode current collector to the positive electrode plate or the negative electrode plate, a plurality of weldings are required, respectively, and the center portion of the wound electrode body Requires an opening space for placing a U-shaped wing part of a positive electrode current collecting member or a negative electrode current collecting member for welding, and inside the U-shaped wing part during ultrasonic welding. There is a problem that manufacturing equipment becomes complicated, such as the need to arrange an anvil.

Moreover, although the said patent document 1 describes that it is especially preferable to use an ultrasonic welding process for the process of connecting an electrode electrode plate, the winding number in an Example is 16 times (it is 8 in one side divided into 2 parts). The lamination thickness is 320 μm. On the other hand, in a sealed battery having a large capacity such as a lithium ion secondary battery for EV and HEV, the number of stacked positive electrode core exposed portions and negative electrode core exposed portions is larger than that of the invention disclosed in Patent Document 1. And the stacking thickness is much thicker.

Therefore, in a prismatic secondary battery having a large capacity such as a lithium ion secondary battery for EV and HEV, ultrasonic waves are used as a welding method between the stacked positive electrode core exposed portion and the negative electrode core exposed portion and the current collecting member. In order to weld in a stable state using a welding method, a large pressure is applied to bring the stacked positive electrode core exposed portion and negative electrode core exposed portion into close contact with the current collecting member, and ultrasonic vibration is stacked. Large energy is required to reach the other end side of the exposed positive electrode core exposed portion and negative electrode core exposed portion. In the invention disclosed in the above-mentioned Patent Document 1, since it is necessary to receive pressure and ultrasonic energy with the anvil disposed inside the U-shaped current collecting member, the anvil needs to have appropriate rigidity, In addition, it is technically very difficult to find a more stable welding condition while receiving a large pressure with an anvil having a size that can be supplied to the inside of the U-shaped current collecting member.

Note that, in Patent Document 2, as shown in FIG. 14,

electrode core groups

64 a and 64 b in which the core body 64 of the electrode body 63 is divided into two parts and focused on both sides of the base portion 62 of the current collecting member 61. The electrode plate core assembly apparatus 60 is shown in which a series spot welding is performed together with a pair of

contact plates

65a and 65b disposed outside the

electrode core groups

64a and 64b. Further, in Patent Document 3, as shown in FIGS. 15A and 15B, the positive electrode plate and the negative electrode plate are respectively opposite to the positive electrode core exposed portion 71 and the negative electrode core exposed portion 72 through the separator. As shown in FIG. 2, the flat electrode member 73 is provided in a flat shape, and for example, the edge portion fitted in the wound central space 71a of the positive electrode core exposed portion 71 is curved. A terminal of the positive electrode terminal 74 is used by using a positive electrode terminal 74 including a rectangular connection portion 74a, a terminal portion 74b protruding in a flat shaft length direction orthogonal to the winding axis direction, and a short connection portion 74c for connecting the two. After fitting the portion 74b in the central space 71a wound around the positive electrode core exposed portion 71 (see FIG. 15A), electrical connection is made by series spot welding from both sides of the positive electrode core exposed portion 71. Flat wound electrode 70 is shown.

In the case of a prismatic secondary battery having a large capacity, such as a lithium ion secondary battery for EV and HEV, the number of stacked positive electrode core exposed portions and negative electrode core exposed portions is very large, and the positive electrode core and positive electrode Aluminum or an aluminum alloy is used as the current collecting member, and copper or a copper alloy is used as the negative electrode core and the negative electrode current collecting member. Since these aluminum, aluminum alloy, copper or copper alloy are materials having low electrical resistance and good thermal conductivity, the space between the positive electrode core exposed portion and the positive electrode terminal and the negative electrode core exposed portion and the negative electrode terminal A large amount of welding energy is required to reduce the internal resistance of the welded portion by reliably resistance welding to increase the welding strength.

In addition, in the case of a prismatic secondary battery having a large capacity, such as a lithium ion secondary battery for EV and HEV, a resistance is provided at a plurality of locations between the current collecting member and the core exposed portion in order to reduce the internal resistance. Welding is preferable, but when resistance welding is performed one by one, a current flows through the previously resistance-welded part and the reactive current increases, so a large amount of welding energy that accounts for the reactive current is expected. Is required. In order to suppress the reactive current at the time of resistance welding, it can be achieved by resistance welding at a plurality of locations at the same time. However, even in this case, a large amount of welding energy is required. Furthermore, when the resistance welding structure as described in FIGS. 14 and 15 is employed, the core-divided portion divided into two parts is resistance-welded to both surfaces of one plate-like current collecting member. In the rectangular secondary battery, the electrode body repeatedly expands and contracts due to charging and discharging, and therefore the core body exposed portion moves in synchronization therewith. When the core body exposed portion moves as described above, stress is applied to the resistance welded portion between the core exposed portion and the current collecting member, and the resistance welded portion may be peeled off.

The present invention has been made to solve the above-described problems of the prior art, and the core exposed portion on at least one side of the stacked or wound positive electrode core exposed portion and negative electrode core exposed portion is The conductive member is arranged in between and resistance welding is performed between the core exposed portion and the current collecting member and between the core exposed portion and the conductive member. It is an object of the present invention to provide a prismatic secondary battery that is difficult to be subjected to stress due to expansion and contraction of the electrode body, and that can realize low resistance and quality stabilization of a welded portion, and a method of manufacturing the same.

In order to achieve the above object, a prismatic secondary battery according to the present invention includes an electrode body having a positive electrode core exposed portion and a negative electrode core exposed portion that are stacked or wound, and an electrical connection to the positive electrode core exposed portion. The positive electrode core body of the electrode body in a rectangular secondary battery comprising: a positive electrode current collector member, a negative electrode current collector member electrically connected to the negative electrode core exposed portion, and a rectangular outer casing At least one of the exposed portion and the negative electrode core exposed portion is divided into two so that the conductive first member and the second member are arranged linearly in the stacking direction of the stacked core exposed portions. In addition, one of the end surfaces of the first member and the second member is located on the inner surface side of the two-divided core body exposed portion, and the other is arranged so as to face each other without being coupled, On the outermost both sides of the core exposed part on the side divided in two A pair of current collecting members are arranged, and between one of the pair of current collecting members, one of the two divided core exposed parts and the first member, and the other of the pair of current collecting members And the other of the two divided core body exposed portions and the second member are respectively resistance welded.

According to the prismatic secondary battery of the present invention, the first member and the second member are directly coupled to each other even if the core exposed portion divided into two parts moves due to the expansion / contraction of the electrode body associated with charge / discharge. Therefore, it moves in synchronization with the movement of the two-divided core body exposed portion, and stress is hardly applied to the resistance welded portion between the two-divided core body exposed portion and the first member and the second member. Therefore, according to the prismatic secondary battery of the present invention, each of the resistance welded portions between the current collector, the core exposed portion divided into two, the first member, and the second member even when charging and discharging are repeated. It becomes possible to manufacture a high-quality prismatic secondary battery with little deterioration in quality.

In addition, as the conductive first member and the second member, those having a shape that is difficult to deform such as a columnar shape, a prismatic shape, an elliptical columnar shape, and the like can be adopted. The same material as the positive electrode core or negative electrode core such as aluminum or aluminum alloy, or a material made of a high melting point metal such as tungsten or molybdenum that promotes heat generation can be used. In addition, the “current collecting member” in the present invention is not only directly connected to the electrode terminal, but also has a conductive member interposed between the electrode terminal and directly connected to the electrode terminal. It is used in the meaning including “current collecting receiving member”.

Moreover, in the prismatic secondary battery of the present invention, it is preferable that a plurality of sets of the conductive first member and the second member are provided.

When a plurality of sets of conductive first members and second members are provided, the core exposed portion on the side divided into two is resisted at a plurality of locations between the first member, the second member, and the current collecting member. It will be welded. Therefore, according to the prismatic secondary battery of the present invention, it is possible to obtain a prismatic secondary battery that not only has little deterioration in the quality of the resistance welded part but also has a small internal resistance and can be charged / discharged with a large current.

In the prismatic secondary battery of the present invention, it is preferable that the opposing surfaces of the conductive first member and the second member are separated from each other. In particular, when using a plurality of sets of the first member and the second member, it is preferable that the opposing surfaces of the first member and the second member in each set are separated from each other.

In the prismatic secondary battery of the present invention, the conductive first member and the second member may each have a groove formed on the outer periphery.

According to the prismatic secondary battery of the present invention, the core exposed portion which is divided into two in a stable state by using the holding member as the conductive first member and the second member when manufacturing the prismatic secondary battery of the present invention. Therefore, it is possible to obtain a rectangular secondary battery in which the quality of the resistance welded portion is stabilized. *

In the prismatic secondary battery of the present invention, the conductive first member and the second member are divided into two parts in a state in which the conductive first member and the second member are slidably disposed in holes formed in the insulating intermediate member. Further, the conductive first member and the second member may be disposed between the exposed portions of the core body, and the conductive first member and the second member are fixed to the cantilever formed on the insulating intermediate member. You may arrange | position between the divided | segmented core exposure parts.

In the prismatic secondary battery of the present invention, the first member and the second member become mutually insulating intermediate members even if the core exposed portion divided into two parts moves due to expansion / contraction of the electrode body accompanying charge / discharge. In the formed hole or by the cantilever beam formed on the insulating intermediate member, the core body is moved in synchronism with the movement of the core body exposed portion divided into two parts. Stress is hardly applied to the resistance weld between the member and the second member. In addition, the conductive first member and the second member can be disposed between the core exposed portions divided into two in a stable state by the insulating intermediate member when the prismatic secondary battery of the present invention is manufactured. Therefore, according to the prismatic secondary battery of the present invention, each of the resistance welded portions between the current collector, the core exposed portion divided into two, the first member, and the second member even when charging and discharging are repeated. It becomes possible to manufacture a high-quality prismatic secondary battery with little deterioration in quality.

As the insulating intermediate member of the present invention, for example, a resin material such as polypropylene, polyethylene, polyvinylidene chloride, polyacetal, polyamide, polycarbonate, polyphenylene sulfide or the like can be used. Further, the width of the insulating intermediate member may be such that the surface of the insulating intermediate member facing the core exposed portion is in contact with the core exposed portion after welding in the vicinity of the resistance welding portion. Preferably, in other portions, for example, a groove may be formed in the outer peripheral portion or a cavity may be formed inside in order to improve gas venting during resistance welding. *

Furthermore, in order to achieve the above object, the prismatic secondary battery of the present invention includes an electrode body having a positive electrode core body exposed portion and a negative electrode core body exposed portion that are stacked or wound, and the positive electrode core body exposed portion electrically A prismatic secondary battery comprising: a positive electrode current collecting member joined to a negative electrode current collecting member; a negative electrode current collecting member electrically joined to the negative electrode core exposed portion; and a square exterior body. At least one of the positive electrode core exposed portion and the negative electrode core exposed portion is divided into two parts, and the conductive first member and the second member are on one side of the respective surfaces of the first member and the second member. A plurality of protrusions are formed on the inner surface side of the two-divided core body exposed portions, and the first member and the second member are disposed apart from each other, The plurality of protrusions are arranged on the outermost side of the divided core exposed portion. The plurality of current collecting members are in contact with each other at positions corresponding to the plurality of current collecting members, the two-divided core body exposed portions, and the plurality of protrusions of the first member. Resistance welding is performed between each of the plurality of current collector members, and between the plurality of current collecting members, the two-divided core body exposed portions, and each of the plurality of protrusions of the second member.

According to the prismatic secondary battery of the present invention, the first member and the second member are separated from each other even if movement occurs in the core body exposed portion divided into two due to expansion / contraction of the electrode body accompanying charge / discharge. Therefore, it moves in synchronization with the movement of the core body exposed portion divided into two parts, and stress is hardly applied to the resistance welded portion between the core body exposed portion divided into two parts and the first member and the second member. A high-quality prismatic secondary battery with little deterioration in the quality of the resistance welded portion between the core exposed portion divided into the first member and the second member can be obtained even if the above is repeated.

In the prismatic secondary battery of the present invention, the conductive first member and the second member may be disposed in grooves formed in the insulating intermediate member so as to be slidable.

According to the prismatic secondary battery of the present invention, the conductive first member and the second member can be disposed between the core exposed portions divided into two in a stable state by the insulating intermediate member at the time of manufacture. Thus, a prismatic secondary battery with a stabilized quality of the resistance weld is obtained.

Furthermore, in order to achieve the above object, a method for manufacturing a prismatic secondary battery according to the present invention includes a stacked or wound electrode body having a positive electrode core exposed portion and a negative electrode core exposed portion, and the positive electrode core exposed portion. In a method for manufacturing a rectangular secondary battery, comprising: a positive electrode current collecting member electrically bonded to a negative electrode current collecting member; a negative electrode current collecting member electrically bonded to the negative electrode core exposed portion; A first conductive step between a first step of dividing at least one of the positive electrode core exposed portion and the negative electrode core exposed portion of the electrode body into two and a core exposed portion on the two divided sides; End surfaces of the first member and the second member are arranged such that the first member and the second member are linearly arranged in the stacking direction of the core exposed portions where the first member and the second member are stacked. Are positioned on the inner surface side of the core exposed portion divided into two parts. A second step in which the other is disposed so as to face each other, and the pair of current collecting members on the two divided sides are respectively brought into contact with both outermost surfaces of the two divided core body exposed portions; A pair of resistance welding electrodes are brought into contact with the surfaces of the pair of current collecting members, respectively, while applying a pressing force to the pair of resistance welding electrodes to short-circuit between the first member and the second member, Between one of the pair of current collecting members, one of the two divided core exposed portions and the first member, and the other of the pair of current collecting members and the other of the two divided core exposed portions And a second step in which the first member and the second member are not resistance welded, and a fourth step of removing the pair of resistance welding electrodes. And a process.

In the method for manufacturing a rectangular secondary battery according to the present invention, the first member and the second member at the place where the pair of resistance welding electrodes are in contact with each other apply a pressing force to the pair of resistance welding electrodes in the third step. When it is applied, it is short-circuited and resistance welding is performed. The resistance between the short-circuited conductive first member and the second member is small because the contact area between both is large, and since the heat capacity of the first member and the second member is large, the first member and the second member Is less likely to occur than the fusion between the two-divided core exposed portion and the first member and the fusion between the two-divided core exposed portion and the second member. . Accordingly, one of the pair of current collecting members, one of the two exposed core bodies and the first member, and the other of the pair of current collecting members and the other of the two core exposed sections and the first member. The two members can be welded, and the first member and the second member can be not welded.

In the prismatic secondary battery manufactured in this way, the first member and the second member are directly coupled to each other even if movement occurs in the core body exposed portion divided in two due to expansion / contraction of the electrode body due to charge / discharge. Therefore, it moves in synchronism with the movement of the two-divided core body exposed portion, and stress is hardly applied to the resistance welded portion between the two-divided core body exposed portion and the first member and the second member. Therefore, according to the manufacturing method of the square secondary battery of the present invention, each resistance between the current collector, the core exposed portion divided into two parts, the first member, and the second member even when charging and discharging are repeated. It becomes possible to manufacture a high-quality prismatic secondary battery with little deterioration in the quality of the welded portion.

In the second step, the conductive first member and the second member are disposed between the two core exposed portions and the outermost surfaces of the two split core exposed portions. It is arbitrary which of the step of contacting the pair of current collecting members is performed first.

In the method for manufacturing a rectangular secondary battery according to the present invention, a plurality of sets of the conductive first member and the second member are used, and the third step and the fourth step are performed as the conductive first member and the second member. It is preferable to repeat sequentially for each set of two members.

In addition, it is preferable that the opposing surfaces of the first member and the second member are separated from each other after removing the resistance welding electrode in the fourth step performed for each group.

In the method for manufacturing a rectangular secondary battery of the present invention, the first member and the second member that have been short-circuited are separated from each other after the pair of resistance welding electrodes are removed in the fourth step after the end of resistance welding. State. Therefore, even when resistance welding is sequentially performed for each group of the first member and the second member, no current flows through the other groups of the conductive first member and the second member. Only the current that flows around the core on the formed side becomes the reactive current. This reactive current is very small compared to the resistance welding current because the core is thin and has high resistance.

Therefore, according to the method for manufacturing a non-aqueous electrolyte secondary battery of the present invention, the current collector member and the core exposed portion divided into two parts are also provided between the plurality of sets of the conductive first member and the second member. Since good resistance welding is performed between one and the first member and between the second member and the other of the core exposed portion divided into two and the current collecting member, the resistance of the welded portion is reduced. Thus, it is possible to manufacture a prismatic secondary battery in which large current charge / discharge is possible and the quality of the welded portion is stabilized.

In the method for manufacturing a rectangular secondary battery of the present invention, in the second step, the conductive first member and the second member are respectively insulated between the core-exposed portions on the two divided sides. It is preferable that the insulating holding jig is disposed while being held by a holding jig and the insulating holding jig is removed in the fourth step.

According to the method for manufacturing a rectangular secondary battery of the present invention, since the arrangement state of the conductive first member and the second member is stabilized between the core exposed portions divided into two at the time of resistance welding, the book The effects of the invention can be achieved better. Since the insulating holding jig is removed in the fourth step, it does not get in the way when the rectangular secondary battery is manufactured.

In the method for manufacturing a rectangular secondary battery of the present invention, in the second step, the conductive first member and the second member are respectively insulated between the core-exposed portions on the two divided sides. And holding the conductive intermediate member between the conductive first member and the second member, and in the third step, for the pair of resistance welding Resistance welding is performed while applying a pressing force to the electrode to short-circuit the first member and the second member via the conductive intermediate member, and in the fourth step, the insulating holder and the conductive member Preferably, the intermediate member is removed.

If the conductive first member and the second member are each held by an insulating holding jig and a conductive intermediate member is interposed therebetween, the conductivity between the two exposed core parts The arrangement state of the first member and the second member is stabilized, and even when a pressing force is applied to the pair of resistance welding electrodes during resistance welding, the deformation of the core exposed portion divided into two parts is reduced. Therefore, according to the method for manufacturing a prismatic secondary battery of the present invention, better resistance welding is performed, and a prismatic secondary battery in which the quality of the welded portion is stabilized can be manufactured.

In the method for manufacturing a rectangular secondary battery of the present invention, in the second step, the conductive first member and the second member each having a groove formed on the outer periphery thereof are used. It is preferable to hold the first member and the second member on the insulating holding jig by fitting an insulating holding jig.

When the conductive first member and the second member are each formed with a groove on the outer periphery, and the insulating holding jig is fitted in the groove, the conductive first member and the second member are insulated. The holding state of the conductive first member and the second member is stabilized between the two exposed core parts. Therefore, according to the method for manufacturing a prismatic secondary battery of the present invention, good resistance welding is performed, and a prismatic secondary battery in which the quality of the welded portion is stabilized can be manufactured.

Further, in the method for manufacturing a rectangular secondary battery of the present invention, in the second step, the conductive first member and the second member are respectively disposed between the core body exposed portions on the two divided sides. The insulating intermediate member is slidable in a state in which the side facing the inner surface of the core exposed portion on the two divided sides is exposed, and the conductive first member and the second member are opposed to each other. It is preferable to use what is arranged in a state of being arranged in the formed hole.

The conductive first member and the second member are slidable in a state in which the side facing the inner surface of the core body exposed portion on the two divided sides is exposed, and the conductive first member and the second member If it arrange | positions in the hole formed in the insulating intermediate member so that it may mutually oppose, it will arrange | position between the core exposed part of the side divided into 2 in the state where the electroconductive 1st member and 2nd member were stabilized. be able to. In addition, since the conductive first member and the second member are slidably opposed to each other, when a pressing force is applied to the pair of resistance welding electrodes during resistance welding, the first member and the second member are short-circuited. Then, resistance welding is performed, but when the pair of resistance welding electrodes are removed after resistance welding, the first member and the second member are naturally separated by the elastic force of the two exposed core bodies. Therefore, according to the method for manufacturing a prismatic secondary battery of the present invention, each of the current collector, the core exposed portion divided into two parts, and the first member and the second member, even when charging and discharging are repeated, is performed. It becomes possible to manufacture a high-quality prismatic secondary battery with little deterioration in the quality of the resistance weld.

In the method for manufacturing a rectangular secondary battery according to the present invention, in the second step, the conductive first member and the second member are disposed between the core-exposed portions on the two divided sides. You may make it use what was arrange | positioned in the state fixed to the cantilever formed in the insulating intermediate member so that the electroconductive 1st member and 2nd member may mutually oppose.

The conductive first member and the second member are fixed to the cantilever beams formed on the insulating intermediate member between the two exposed portions of the core body. If it arrange | positions, the electroconductive 1st member and 2nd member can be arrange | positioned between the core exposed parts of the side divided into 2 in the stable state. In addition, when a pressing force is applied to the pair of resistance welding electrodes during resistance welding, the first member and the second member are short-circuited and resistance welding is performed. However, if the pair of resistance welding electrodes are removed after resistance welding, insulation is achieved. The first member and the second member are naturally separated from each other by the elastic force of the cantilever formed on the intermediate member. Therefore, according to the method for manufacturing a prismatic secondary battery of the present invention, each of the current collector, the core exposed portion divided into two parts, and the first member and the second member, even when charging and discharging are repeated, is performed. It becomes possible to manufacture a high-quality prismatic secondary battery with little deterioration in the quality of the resistance weld.

In the method for manufacturing a rectangular secondary battery according to the present invention, as the conductive first member and the second member, a protrusion is formed on the side facing the inner surface of the core-exposed portion on the two divided sides. It is preferable to use what is.

As the conductive first member and the second member, if a projection is formed on the side facing the inner surface of the core exposed portion on the divided side, the projection acts as a so-called projection. Good resistance welding is performed between the first member and the second member and the core exposed portion. Therefore, according to the method for manufacturing a prismatic secondary battery of the present invention, better resistance welding is performed, and a prismatic secondary battery in which the quality of the welded portion is stabilized can be manufactured.

As a material for forming the protrusions formed on the conductive first member and the second member, the same material as the positive electrode core or the negative electrode core, or a material made of a refractory metal that promotes heat generation, such as tungsten or molybdenum, is used. It can be used, and the protrusion is nickel-plated, and the protrusion and the vicinity of the protrusion are changed to a metal material that promotes heat generation such as tungsten or molybdenum, and the conductive first member and the second member What joined to the edge part of one side by brazing etc. can be used.

Furthermore, in order to achieve the above object, a method for manufacturing a prismatic secondary battery according to the present invention includes a stacked or wound electrode body having a positive electrode core exposed portion and a negative electrode core exposed portion, and the positive electrode core exposed portion. In a method for manufacturing a rectangular secondary battery, comprising: a positive electrode current collecting member electrically bonded to a negative electrode current collecting member; a negative electrode current collecting member electrically bonded to the negative electrode core exposed portion; A first conductive step between a first step of dividing at least one of the positive electrode core exposed portion and the negative electrode core exposed portion of the electrode body into two and a core exposed portion on the two divided sides. A plurality of protrusions are formed on one side of the surface of each of the first member and the second member, and the plurality of protrusions are respectively positioned on the inner surface side of the two-divided core body exposed portion. The first member and the second member are disposed apart from each other. And a second step of bringing the plurality of current collecting members into contact with each other at positions corresponding to the plurality of protrusions on the outermost side of the two-divided core body exposed portion; For each outermost surface side of the exposed core body, a pair of resistance welding electrodes are brought into contact with two surfaces of the plurality of current collecting members, and a pressing force is applied to the pair of resistance welding electrodes. A third step of resistance welding between the first member and the two-divided core body exposed portion and between the second member and the two-divided core body exposed portion; and the pair of resistors And a fourth step of removing the welding electrode.

In the method for manufacturing a prismatic secondary battery according to the present invention, in the second step, the conductive first member and the second member are connected between the core exposed portion on the divided side, and the first member and the second member. A plurality of protrusions are formed on one side of each of the surfaces, and the plurality of protrusions are positioned on the inner surface side of the core exposed portion divided into two, and the first member and the second member are arranged in a state of being separated from each other is doing. When such a method is adopted, the plurality of protrusions of the first member come into contact with one inner surface side of the core body exposed portion on the two divided sides, and the plurality of second members are similarly contacted with the other inner surface side. The first member and the second member are separated from each other. In the second step, the step of disposing the conductive first member and the second member between the core exposed portions on the two divided sides and the outermost surfaces of the two divided core exposed portions. Which one of the steps of contacting the current collecting member first is arbitrary.

Then, in the second step, a plurality of current collecting members are brought into contact with each other at positions corresponding to the plurality of protrusions of the first member on the outermost side of the core body exposed portion divided into two parts. The plurality of current collecting members are brought into contact with each other at positions corresponding to the plurality of protrusions of the member, and in the fourth step, for example, any two current collecting members on the side corresponding to the first member (hereinafter referred to as the first member) , Referred to as “first current collecting member” and “second current collecting member”), a pair of resistance welding electrodes are brought into contact with each other, and resistance welding is performed while applying a pressing force to these resistance welding electrodes. ing. When such a method is adopted, the resistance welding current is one of the resistance welding electrodes → the first current collecting member → the one of the two core exposed portions → the one protrusion of the first member → the first member → Another projection of the first member → one of the two exposed core bodies → second current collecting member → flows to the other of the pair of resistance welding electrodes.

In addition, since the first member and the second member are not in direct contact with each other, the welding current hardly flows through the second member, and the reactive current is only the current that flows around the core exposed portion. The reactive current value is small because the thickness of the electrode is thin and the internal resistance is large. Therefore, one of the first current collecting member and one of the two exposed core members and one protrusion of the first member, and one of the other protrusions of the first member and the two exposed core members. Good resistance welding is performed between the first current collecting member and the second current collecting member. Further, in resistance welding on the second member side, since the first member and the second member are not in direct contact with each other, good resistance welding can be performed as in the case of resistance welding on the first member side. .

In addition, the prismatic secondary battery manufactured by such a method for manufacturing a prismatic secondary battery also has a first effect even when the core exposed portion divided into two parts due to expansion / contraction of the electrode body due to charge / discharge causes movement. Since the member and the second member are separated from each other, the member moves in synchronization with the movement of the two-divided core body exposed portion, and resistance welding is performed between the two-divided core body exposed portion and the first and second members. It becomes difficult to apply stress to the club. Therefore, according to the method for manufacturing a rectangular secondary battery of the present invention, the quality of the resistance welded portion between the core exposed portion divided into two parts and the first member and the second member is deteriorated even if charging and discharging are repeated. A small number of high-quality prismatic secondary batteries can be manufactured.

In the method for manufacturing a rectangular secondary battery of the present invention, in the second step, the conductive first member and the second member are respectively insulated between the core-exposed portions on the two divided sides. The insulating holding jig may be removed while being held by a holding jig, and the insulating holding jig may be removed in the fourth step.

When the conductive first member and the second member are respectively held between the core body exposed portions divided into two while being held by an insulating holding jig, the first member between the core exposed portions on the two divided sides is arranged. The arrangement of the first member and the second member is stabilized.

In the method for manufacturing a prismatic secondary battery according to the present invention, in the second step, the conductive first member and the second member are insulative between the core-exposed portions on the two divided sides. You may make it arrange | position so that it may be slidably hold | maintained in the groove | channel formed in the intermediate member.

When the conductive first member and the second member are arranged in a state of being separated from each other in the groove formed in the insulating intermediate member, the conductive first member and the second member are divided into two in a stable state. It can arrange | position between the core exposure parts on the other side. In addition, in the manufactured prismatic secondary battery, the first member and the second member are insulative intermediate members even if movement occurs in the core exposed portion divided into two due to expansion / contraction of the electrode body accompanying charging / discharging. Since it is slidably held in the groove formed in the groove, it moves in synchronization with the movement of the two-divided core body exposed portion, so that the two-divided core body exposed portion and the first and second members are moved. It becomes difficult to apply stress to the resistance weld between the two. Therefore, according to the manufacturing method of the square secondary battery of the present invention, each resistance between the current collector, the core exposed portion divided into two parts, the first member, and the second member even when charging and discharging are repeated. It becomes possible to manufacture a high-quality prismatic secondary battery with little deterioration in the quality of the welded portion.

1A is a cross-sectional view of the prismatic nonaqueous electrolyte secondary battery of Embodiment 1, FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A, and FIG. 1C is taken along the IC-IC line in FIG. 1A. FIG. 2A is a plan view of the positive electrode intermediate member of Embodiment 1, FIG. 2B is a right side view of FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line IIC-IIC of FIG. 2B. FIG. 3 is a side sectional view showing a resistance welding state in the first embodiment. 6 is a side cross-sectional view showing an arrangement state of a positive electrode intermediate member portion after welding according to Embodiment 2. FIG. 5A is a plan view of the positive electrode intermediate member of Embodiment 3, FIG. 5B is a right side view of FIG. 5A, and FIG. 5C is a cross-sectional view taken along the line VC-VC of FIG. 5B. FIG. 6A to FIG. 6C are process diagrams for step-by-step description of the resistance welding method for the conductive first member and the second member according to the fourth embodiment. FIG. 7B is an enlarged plan view of the conductive first member and the second member used in Embodiment 4, FIG. 7B is also a right side view, and FIG. 7C is a cross-sectional view taken along the line VIIC-VIIC in FIG. 7B. . FIG. 8A to FIG. 8C are process diagrams for step-by-step explanation of the resistance welding method for the conductive first member and the second member of the fifth embodiment. FIG. 9 is an enlarged plan view of the conductive first member and the second member used in Embodiment 6, FIG. 9B is also a right side view, and FIG. 9C is a cross section taken along the line IXC-IXC in FIG. 9B. FIG. It is side part sectional drawing which shows the resistance welding state in Embodiment 7. 11A is an enlarged plan view of the conductive first member and the second member used in Embodiment 7, FIG. 11B is also a right side view, and FIG. 11C is a cross section taken along line XIC-XIC in FIG. 11B. FIG. 12A is a cross-sectional view of an electric double layer capacitor as a conventional power storage element, FIG. 12B is a cross-sectional view taken along line XIIB-XIIB in FIG. 12A, and FIG. 12C is a cross-sectional view taken along line XIIC-XIIC in FIG. FIG. It is a figure which shows the welding process between the core exposed part of an electrode in FIG. 12, and a current collection member. It is sectional drawing of the conventional electrode plate core assembly apparatus which carried out the series spot welding. FIG. 15A is an exploded perspective view showing a state before welding of another conventional positive electrode terminal and the positive electrode core exposed portion, and FIG. 15B is a perspective view after welding.

Hereinafter, an embodiment for carrying out the present invention will be illustrated and described in detail. However, each embodiment shown below is illustrated for understanding the technical idea of the present invention, and is not intended to specify the present invention to this embodiment. The present invention can be equally applied to various modifications without departing from the technical idea shown in the scope. In addition, in each drawing used for the description in this specification, in order to make each member a size that can be recognized on the drawing, the scale is appropriately changed for each member. It is not displayed in proportion to the actual dimensions. Moreover, the power generation element that can be used in the present invention is formed by laminating or winding the positive electrode plate and the negative electrode plate via a separator, so that a plurality of positive electrode core exposed portions are formed at one end, The present invention can be applied to a flat shape in which a plurality of negative electrode core exposed portions are formed at the other end portion, but the following description will be made on behalf of a flat wound electrode body.

[Embodiment 1]
First, a prismatic nonaqueous electrolyte secondary battery will be described with reference to FIGS. 1 to 3 as an example of the prismatic secondary battery of the first embodiment. 1A is a cross-sectional view of the prismatic nonaqueous electrolyte secondary battery according to Embodiment 1, FIG. 1B is a cross-sectional view taken along line IB-IB of FIG. 1A, and FIG. 1C is an IC-IC of FIG. 1A. It is sectional drawing along a line. 2A is a plan view of the positive electrode intermediate member of Embodiment 1, FIG. 2B is a right side view of FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line IIC-IIC of FIG. 2B. FIG. 3 is a side sectional view showing a resistance welding state in the first embodiment.

The rectangular nonaqueous electrolyte secondary battery 10 has a flat wound electrode body 11 in which a positive electrode plate and a negative electrode plate are wound via a separator (both not shown). The positive electrode plate is produced by applying a positive electrode active material mixture on both surfaces of a positive electrode core made of aluminum foil, drying and rolling, and then slitting the aluminum foil so as to be exposed in a strip shape. The negative electrode plate is produced by applying a negative electrode active material mixture on both surfaces of a negative electrode core made of copper foil, drying and rolling, and then slitting so that the copper foil is exposed in a strip shape.

Then, the positive electrode plate and the negative electrode plate obtained as described above are so arranged that the aluminum foil exposed portion of the positive electrode plate and the copper foil exposed portion of the negative electrode plate do not overlap with the facing active material layers. And is wound through a polyethylene microporous separator, so that one end in the winding axis direction is provided with a plurality of overlapping positive electrode core exposed portions 14, and the other end is overlapped with a plurality of sheets. Further, a flat wound electrode body 11 having the negative electrode core exposed portion 15 is produced.

The plurality of positive electrode core exposed portions 14 are laminated and connected to the positive electrode terminal 17 via the positive electrode current collecting member 16, and the plurality of negative electrode core exposed portions 15 are similarly laminated to form the negative electrode current collecting member 18. To the negative electrode terminal 19. Here, an example in which the positive electrode current collecting member 16 and the negative electrode core exposed portion 15 are directly connected to the positive electrode terminal 17 and the negative electrode terminal 19, respectively, is shown. The exposed portion 15 may be connected to the positive electrode terminal 17 and the negative electrode terminal 19 through a separate conductive member. The positive terminal 17 and the negative terminal 19 are fixed to the sealing plate 13 via insulating

members

20 and 21, respectively. In the rectangular nonaqueous electrolyte secondary battery 10 according to the first embodiment, an insulating resin sheet 23 is interposed around the flat wound electrode body 11 produced as described above except for the sealing plate 13 side. After being inserted into the rectangular battery outer can 12, the sealing plate 13 is laser welded to the opening of the battery outer can 12, and then a nonaqueous electrolytic solution is injected from the electrolytic solution injection hole 22. It is produced by sealing the liquid hole 22.

As shown in FIGS. 1B to 1C, the flat wound electrode body 11 includes a plurality of stacked positive electrode core exposed portions 14 divided into two on the positive electrode plate side, and a positive electrode intermediate member therebetween. 24A is arranged. As shown in FIGS. 2A to 2C, the positive electrode intermediate member 24A includes a plurality of first members 24B and second members 24C made of a conductive material in holes formed in an insulating intermediate member 24D made of a resin material. The sets, here two sets, are slidably arranged. The first member 24B and the second member 24C of each set are arranged in a straight line in the stacking direction of the stacked positive electrode core exposed portions 14, respectively, and a surface facing the positive electrode core exposed portion 14 of the first member 24B. The opposite surface and the surface opposite to the surface facing the positive electrode core exposed portion 14 of the second member 24C are spaced apart from each other in the hole formed in the insulating intermediate member 24D to form a gap 24E. Facing each other. In each drawing, the distance between the first member 24B and the second member 24C is depicted as being somewhat separated, but this is for convenience in order to facilitate understanding of the principle of the present invention. In actuality, the first member 24B and the second member 24C have a minute distance that does not electrically short-circuit each other.

Similarly, on the negative electrode plate side, a plurality of laminated negative electrode core exposed portions 15 are divided into two, and a plurality of sets of first and second members (both not shown) made of a conductive material are interposed between them. Similarly to the positive electrode side, the negative electrode intermediate member 25A is disposed so as to be slidable in the hole formed in the insulating intermediate member made of resin material in two pairs. Here, the first member and the second member are arranged in a straight line in the stacking direction of the stacked negative electrode core exposed portions 15, and are opposite to the surface of the first member facing the negative electrode core exposed portion 15. The surface on the side opposite to the surface facing the negative electrode core exposed portion 15 of the second member faces each other in a state of being separated by a minute distance so as not to be electrically short-circuited.

Further, positive current collecting members 16 are arranged on both outermost surfaces of the positive electrode core exposed portion 14 located on both sides of the positive electrode intermediate member 24A, and are located on both sides of the negative electrode intermediate member 25A. Negative electrode current collecting members 18 are respectively disposed on the outermost surfaces of the negative electrode core exposed portion 15. Specific configurations and operations of the positive electrode intermediate member 24A and the negative electrode intermediate member 25A will be described later.

The first member 24B and the second member 24C constituting the positive electrode intermediate member 24A are made of aluminum, which is the same material as the positive electrode core, and the first member and the second member constituting the negative electrode intermediate member 25A are the negative electrode. Although it is made of copper, which is the same material as the core body, each shape may be the same or different. In addition, examples of materials that can be used as the insulating intermediate member 24D made of the resin material constituting the positive electrode intermediate member 24A and the intermediate intermediate member 25A for the negative electrode include polypropylene (PP), polyethylene (PE), poly Examples thereof include vinylidene chloride (PVDC), polyacetal (POM), polyamide (PA), polycarbonate (PC), polyphenylene sulfide (PPS), and the like.

Further, in the rectangular nonaqueous electrolyte secondary battery 10 of Embodiment 1, as shown in FIGS. 1A, 1B, and 2, the positive electrode intermediate member 24A and the negative electrode intermediate member 25A are each made of an insulating material made of a resin material. An example in which two sets of conductive first member 24B and second member 24C are used as the intermediate member 24D is shown. However, the set of the first member 24B and the second member 24C is a required battery. Depending on the output, etc., one set may be used, or three or more sets may be used. If two or more sets are used, two or more sets of the conductive first member 24B and the second member 24C are slidably disposed in the hole formed in the insulating intermediate member 24D made of one resin material. Therefore, the conductive first member and the second member of each set can be positioned and arranged in a stable state between the core exposed portions on the divided side.

Between the positive electrode current collecting member 16 and the outermost surface of the positive electrode core exposed portion 14 divided into two, the first member 24B and the second member 24C constituting the positive electrode intermediate member 24A are divided into two positive electrode cores. Both the inner surface of the body exposed portion 14 are resistance welded, and similarly, a negative electrode intermediate member 25A is formed between the negative electrode current collecting member 18 and the outermost surface of the divided negative electrode core body exposed portion 15. The first member and the second member to be welded together and the inner surface of the negative electrode core body exposed portion 15 divided into two are also resistance welded.

Hereinafter, a specific manufacturing method of the flat wound electrode body 11, and the positive electrode intermediate member having the positive electrode core exposed portion 14, the positive electrode current collecting member 16, the conductive first member 24B and the second member 24C. FIG. 2 shows a resistance welding method using 24A and a resistance welding method using a negative electrode core exposed portion 15, a negative electrode current collecting member 18, a negative electrode intermediate member 25A having a conductive first member and a second member. And it demonstrates in detail using FIG. However, in the first embodiment, the shape of the positive electrode intermediate member 24A and the shape of the negative electrode intermediate member 25A can be substantially the same, and the respective resistance welding methods are also substantially the same. In the following, description will be made by representing the positive electrode plate side.

First, the positive electrode plate and the negative electrode plate are shifted so that the aluminum foil exposed portion of the positive electrode plate and the copper foil exposed portion of the negative electrode plate do not overlap with the opposing active material layers of the electrode, respectively, The positive electrode core exposed portion 14 of the flat wound electrode body 11 obtained by winding through a separator is divided into two on both sides from the winding center portion, and the positive electrode core is centered on 1/4 of the electrode body thickness. The body exposed part 14 was collected. Here, the thickness of the collected aluminum foil is about 660 μm on one side, and the total number of laminated layers is 88 (44 on one side). Further, the positive electrode current collecting member 16 was manufactured by punching an aluminum plate having a thickness of 0.8 mm and bending it. The positive electrode current collecting member 16 may be manufactured from an aluminum plate by casting or the like.

Then, the positive electrode current collector member 16 is disposed on both surfaces of the outermost peripheral side of the positive electrode core exposed portion 14, the positive electrode intermediate member 24A having the first member 24B and the second member 24C on the inner peripheral side, the first member 24B and the first member 24B. The

conical projections

24b and 24c on both sides of the two members 24C are inserted between the positive electrode core exposed portions 14 divided into two so that the positive electrode core exposed portions 14 abut each other.

Here, a specific configuration of the positive electrode intermediate member 24A used in the first embodiment will be described with reference to FIGS. 2A to 2C. The positive electrode intermediate member 24A includes a first member 24B and a second member 24C having the same shape. The first member 24B and the second member 24C are initially separated by a minute distance L and are slidably disposed in a hole formed in the insulating intermediate member 24D made of a resin material. When the pressing force is applied from both ends (the left and right ends in FIGS. 2A to 2C) of the first member 24B and the second member 24C, the minute distance L is in contact with the first member 24B and the second member 24C. When the pressing force is removed, it is selected within a range in which the contact with the first member 24B and the second member 24C is substantially released.

The first member 24B and the second member 24C have, for example, a columnar shape, and truncated cone-shaped

protrusions

24b and 24c are formed at both ends, respectively. An opening may be formed in each of the

frustoconical protrusions

24b and 24c. The height of the

frustoconical protrusions

24b and 24c may be approximately the same as that of the protrusion (projection) generally formed on the resistance welding member, that is, approximately several millimeters.

In addition, the diameter and length of the first member 24B and the second member 24C constituting the positive electrode intermediate member 24A vary depending on the flat wound electrode body 11 and the battery outer can 12 (see FIG. 1). It may be about 3 mm to several tens of mm. Here, the shape of the first member 24B and the second member 24C constituting the positive electrode intermediate member 24A has been described as a cylindrical shape. However, as long as it is a metal block shape such as a prismatic shape or an elliptical columnar shape. Arbitrary shapes can be used. *

In the positive electrode intermediate member 24A according to the first embodiment, two sets of the first member 24B and the second member 24C are integrally held in holes formed in the insulating intermediate member 24D made of a resin material. In this case, the first member 24B and the second member 24C of each set are held so as to be parallel to each other, and the stacking direction of the positive electrode core exposed portion 14 in which the first member 24B and the second member 24C are stacked. Positive electrode core exposure in which one of the end surfaces of the first member 24B and the second member 24C, that is, the side on which the

frustoconical protrusions

24b and 24c are formed is divided into two, respectively. The other end surface of the first member 24B and the second member 24C is disposed so as to face each other with a minute distance L therebetween. The shape of the insulating intermediate member 24D made of a resin material constituting the positive electrode intermediate member 24A can be any shape such as a prismatic shape or a cylindrical shape, but is stable between the two positive electrode core exposed portions 14. Here, in order to be positioned and fixed to, a horizontally long prismatic shape is used here. *

The length w of the positive electrode intermediate member 24A varies depending on the size of the prismatic nonaqueous electrolyte secondary battery, but can be 20 mm to several tens of mm. The width h of the positive electrode intermediate member 24A is equal to that of the positive electrode intermediate member 24A. In the vicinity, it is preferable to set so that the side surface of the insulating intermediate member 24D made of a resin material facing the positive electrode core exposed portion 14 is in contact with the positive electrode core exposed portion 14 after resistance welding. However, in other portions, for example, a groove may be formed in the outer peripheral portion or a cavity may be formed inside in order to improve gas venting during resistance welding.

Next, as shown in FIG. 3, the positive electrode current collector 16 between the pair of resistance welding

electrode rods

31 and 32 arranged above and below, and the positive electrode intermediate member between the two divided positive electrode core exposed portions 14 24A is disposed as a flat wound electrode body 11, and a pair of resistance welding

electrode rods

31 and 32 are disposed on both sides of the outermost peripheral side of the positive electrode core body exposed portion 14, respectively. 16 is contacted. The positive electrode current collecting member 16 is arranged on both surfaces of the outermost peripheral side of the positive electrode core exposed portion 14 before the positive electrode intermediate member 24A is arranged between the two divided positive electrode core exposed portions 14. Or later.

When an appropriate pressing force is applied between the pair of resistance welding

electrode rods

31 and 32, the first member 24B and the second member 24C come into contact with each other as shown by the arrow III portion on the left side of FIG. As a result, it is electrically short-circuited. When resistance welding is performed in this state under a predetermined condition, the resistance welding current is, for example, from the resistance welding electrode rod 31 to the lower positive electrode current collecting member 16 and the divided positive electrode core exposed portion 14. The first member 24B, the second member 24C, the divided core exposed portion 14, the upper positive electrode current collecting member 16, and the resistance welding electrode rod 32 flow. Thereby, between the lower-side positive electrode current collecting member 16 and the outermost surface side of the two-divided positive electrode core body exposed portion 14, the inner surface side of the bifurcated positive electrode core body exposed portion 14 and the first member 24B Between the second member 24C and the inner surface side of the positive electrode core exposed portion 14, a resistance welding portion is formed between the outermost surface side of the positive electrode core exposed portion 14 and the upper positive electrode current collecting member 16. The

At this time, the resistance between the short-circuited conductive first member 24B and the second member 24C is small because the contact area between both is large, and the heat capacity of the first member 24B and the second member 24C is large, The fusion between the first member 24B and the second member 24C is the fusion between the core body exposed portion 14 divided into two and the first member 24B, and the core exposed portion 14 divided into two and the second member 24B. It is less likely to occur than fusion with the member 24C. Therefore, when the pair of resistance welding

electrode rods

31 and 32 is removed after resistance welding, the pressed positive electrode core exposed portion 14 divided into two returns to a state close to the shape before resistance welding due to elasticity. Since the conductive first member 24B and the second member 24C are welded to the divided positive electrode core exposed portion 14, respectively, the first member 24B and the second member 24C move in opposite directions. Then leave. Therefore, after resistance welding, the first member 24B and the second member 24C of each set are not in direct contact.

That is, during resistance welding, current does not flow through the other conductive first member 24B and second member 24C, so that only the current that flows around the positive electrode core on the divided side is the reactive current. It becomes. This reactive current has a large resistance because the thickness of the positive electrode core is thin, and is very small compared to the resistance welding current. Therefore, also between each of the two sets of the conductive first member 24B and the second member 24C, the positive electrode divided into two parts between the positive electrode current collecting member 16 and one of the two divided positive electrode core exposed portions 14 Between one of the core body exposed portions 14 and the first member 24B, between the second member 24C and the other of the positive electrode core exposed portion 14 divided into two, and the other of the two divided core body exposed portions 14 and the positive electrode Good resistance welding is also performed between the current collecting member 16 and the current collecting member 16.

In addition, at the time of resistance welding, the positive electrode intermediate member 24A is arranged in a stably positioned state between the two divided positive electrode core exposed portions 14, so that resistance welding is performed accurately and stably. Therefore, it is possible to suppress a variation in welding strength, to realize a reduction in resistance of the welded portion, and to manufacture a rectangular secondary battery capable of charging and discharging a large current.

Moreover, in the obtained rectangular non-aqueous electrolyte secondary battery 10, even if movement occurs in the positive electrode core exposed portion 14 that is divided into two by expansion and contraction of the flat wound electrode body 11 that accompanies charging and discharging, Since the first member 24B and the second member 24C are separated from each other, the first member 24B and the second member 24C move in synchronization with the movement of the divided positive electrode core exposed portion 14. Therefore, in the prismatic nonaqueous electrolyte secondary battery 10 manufactured in the first embodiment, even if charging / discharging is repeated, the positive electrode core body exposed portion 14 divided between the first member 24B and the second member 24C is divided into two parts. It is difficult to apply stress to the resistance welded portion, and the quality of the resistance welded portion between the positive electrode core exposed portion 14 divided into two parts and the first member 24B and the second member 24C is less deteriorated. The water electrolyte secondary battery 10 can be obtained. Here, the positive electrode current collector 16 connected to both outermost peripheral sides of the positive electrode core exposed portion 14 is an integrated body obtained by bending a single aluminum plate material. Since the parts located on both outermost peripheral sides can bend, the first member 24B and the second member 24C are not prevented from moving individually.

In the first embodiment, the example in which the

projections

24b and 24c are formed as the conductive first member 24B and the second member 24C that form the positive electrode intermediate member 24A has been described. It is not always necessary to provide the

protrusions

24b and 24c, and the protrusions may not be formed. Further, in the case where the protrusions are provided, the example of using the truncated cone shape as the shape of the

protrusions

24b and 24c is shown. A thing with which opening (dent) is formed in the tip part of a projection can also be used. When the

projections

24b and 24c are not formed with openings, the operations of the

projections

24b and 24c are the same as those of the projection at the time of conventional resistance welding. Since current concentrates around the opening, the heat generation state becomes good, and resistance welding can be performed more satisfactorily.

[Embodiment 2]
In addition, in the said Embodiment 1, the example (refer FIG. 3) which made the positive electrode current collection member 16 contact | abut on both surfaces of the outermost peripheral side of the positive electrode core exposure part 14 divided into 2 was shown. However, in the present invention, it is not always necessary to bring the positive electrode current collector 16 connected to the positive electrode terminal 17 into contact with both surfaces of the outermost peripheral side of the positive electrode core exposed portion 14 divided into two, The positive electrode current collector member 16 may be brought into contact with the outermost one surface of the positive electrode core body exposed portion 14 divided into at least two portions and resistance-welded.

The positive electrode intermediate member after welding according to the second embodiment, in which the positive electrode current collecting member 16 connected to the positive electrode terminal 17 is brought into contact with the outermost surface of the positive electrode core body exposed portion 14 divided into at least two parts. The arrangement state of the member 24A portion will be described with reference to FIG. FIG. 4 is a side cross-sectional view showing an arrangement state of the positive electrode intermediate member portion after welding according to the second embodiment. In the second embodiment, the flat wound electrode body 11 and the positive electrode intermediate member 24A are the same as those used in the first embodiment, and the same as those in the first embodiment. The same reference numerals are given to the constituent parts, and detailed description thereof is omitted.

In the second embodiment, as shown in FIG. 4, the positive electrode current collecting member 16 connected to the positive electrode terminal 17 is placed in contact with the outermost one surface of the divided positive electrode core exposed portion 14. At the same time, the current collector receiving member 16a is disposed in contact with the other outermost surface of the two-divided positive electrode core exposed portion 14, and a pair is provided between the positive electrode current collecting member 16 and the current collecting receiving member 16a. Resistance welding was performed by contacting the electrode rod for resistance welding. In this case, in the second embodiment, the current collection receiving member 16a is not directly connected to the positive electrode terminal 17 and plays the role of receiving one side of the pair of resistance welding electrode rods during resistance welding.

The “current collecting member” in the present invention is used to include such a “current collecting member”. In addition, resistance welding can be performed in the state where the direction which arrange | positioned the current collection member on the outermost both surfaces of the core body exposure part divided into 2 is physically stable.

[Embodiment 3]
In the first embodiment, the conductive first member 24B and the second member 24C that form the positive electrode intermediate member 24A are provided in the holes formed in the insulating intermediate member 24D made of a resin material for each set. In the third embodiment, a cantilever is formed on the insulating intermediate member 24D made of a resin material, and the conductive first member 24B and the second member are formed on the cantilever. 24C was fixed. The positive electrode intermediate member 24A of Embodiment 3 will be described with reference to FIG.

In the insulating intermediate member 24D made of a resin material forming the positive electrode intermediate member 24A used in the third embodiment, two cantilevers 24f are formed at both ends in the length direction. In this cantilever beam 24f, the conductive first member 24B and the second member 24C forming the positive electrode intermediate member 24A are straight in the stacking direction of the stacked positive electrode core exposed portions 14 for each set. Positive electrode core exposed portion 14 in which one of the end surfaces of the first member 24B and the second member 24C, that is, the side on which the

frustoconical protrusions

24b and 24c are formed, is divided into two. The other end surfaces of the first member 24B and the second member 24C are fixed so as to face each other with a minute distance L therebetween.

When the positive electrode intermediate member 24A of the third embodiment is arranged between the two divided positive electrode core exposed portions 14 and resistance welding is performed in the same manner as in the first embodiment, it is fixed to the cantilever beam 24f during resistance welding. The conductive first member 24B and the second member 24C are short-circuited, but when the resistance welding electrode rod is removed, the conductive first member 24B and the second member 24C are separated from each other. Similar actions and effects can be achieved.

[Embodiment 4]
In the first to third embodiments, the conductive first member 24B and the second member 24C are shown as examples using the positive electrode intermediate member 24A held by the insulating intermediate member 24D made of a resin material. 4, the positive electrode core body exposed portion divided into two while holding the conductive first member 24 B and the second member 24 C by an insulating holding jig without using the insulating intermediate member 24 D made of a resin material. The insulating holding jig is removed after resistance welding. A resistance welding method for the conductive first member 24B and the second member 24C according to the fourth embodiment will be described with reference to FIGS. 6A to 6C are process diagrams for explaining the resistance welding method for the conductive first member 24B and the second member 24C of Embodiment 4 in order. 7A is an enlarged plan view of the conductive first member 24B and the second member 24C used in Embodiment 4, FIG. 7B is a right side view of the same, and FIG. 7C is a line VIIC-VIIC in FIG. 7B. FIG.

That is, in the fourth embodiment, as shown in FIG. 6A, each set of conductive first member 24B and second member 24C is attached to holding

jigs

27a and 27b formed of a pair of insulating materials. Use a removably fixed one. The pair of holding

jigs

27a and 27b may be held and operated, or may be separately attached to an automatically controlled device such as a robot arm. As shown in FIG. 6B, the pair of holding

jigs

27a and 27b holding the conductive first member 24B and the second member 24C in this way are arranged on the outermost side of the positive electrode core exposed portion 14 divided into two parts. After the positive electrode current collector member 16 is disposed on each of the two surfaces, the positive electrode current collector member 16 is inserted into the positive electrode core exposed portion 14 divided into two parts, and a pair of resistance welding

electrode rods

31 and 32 are brought into contact with the surface of the positive electrode current collector member 16. Resistance welding is performed while applying a pressing force between the pair of resistance welding

electrode rods

31 and 32.

Then, since the conductive first member 24B and the second member 24C are short-circuited, if resistance welding is performed in this state under a predetermined condition, the resistance welding current is reduced from, for example, the resistance welding electrode rod 31. Side positive electrode current collecting member 16, two divided positive electrode core exposed portions 14, first member 24B, second member 24C, two divided core body exposed portions 14, upper positive electrode current collecting member 16, resistance welding It flows to the electrode rod 32 for use. Thereby, between the lower-side positive electrode current collecting member 16 and the outermost surface side of the two-divided positive electrode core body exposed portion 14, the inner surface side of the bifurcated positive electrode core body exposed portion 14 and the first member 24B Between the second member 24C and the inner surface side of the positive electrode core exposed portion 14, a resistance welding portion is formed between the outermost surface side of the positive electrode core exposed portion 14 and the upper positive electrode current collecting member 16. The

electrode rods

31 and 32 is removed after resistance welding and the holding

jigs

27a and 27b are removed, the pressed positive electrode core body exposed portion 14 is elastically bonded to the resistance welding before the resistance welding. 6C, since the conductive first member 24B and the second member 24C are welded to the positive electrode core exposed portion 14 divided into two parts, respectively. As described above, the first member 24B and the second member 24C are separated from each other. Therefore, after resistance welding, the first member 24B and the second member 24C of each set are not in direct contact.

Thereafter, when resistance welding is performed in the same manner as described above using another pair of holding

jigs

27a and 27b with the conductive first member 24B and the second member 24C fixed, resistance welding is first performed. Since the first member 24B and the second member 24C are separated from each other at this point, no resistance welding current flows. Therefore, only the current that flows around the positive electrode core on the two divided sides is the reactive current. It becomes. This reactive current has a large resistance because the thickness of the positive electrode core is thin, and is very small compared to the resistance welding current. Therefore, also in the subsequent resistance welding, between the positive electrode current collecting member 16 and one of the two divided positive electrode core exposed portions 14, one of the two divided positive electrode core exposed portions 14 and the first member 24B. Between the second member 24C and the other half of the core exposed portion 14 divided into two, and between the other end of the core exposed portion 14 divided into two and the positive electrode current collecting member 16, good resistance welding is performed. Is called.

Further, in the fourth embodiment, after the resistance welding, the pair of holding

jigs

27a and 27b are removed, so that there is no obstacle in assembling the rectangular secondary battery. In addition, since the conductive first member 24B and the second member 24C are disposed in a stably positioned state between the positive electrode core exposed portions 14 divided into two by the holding

jigs

27a and 27b, Effects and effects similar to those of the first embodiment can be obtained.

As shown in FIGS. 7A to 7C, the conductive first member 24B and the second member 24C are formed with

grooves

24d and 24e on the outer periphery, and a pair of holding jigs in the

grooves

24d and 24e, respectively. It is preferable to fix by engaging the tip portions of 27a and 27b. When such a groove is formed, the conductive first member 24B and the second member 24C can be stably attached to the pair of holding

jigs

27a and 27b, so that the resistance can be more accurately and stably maintained. It becomes possible to weld, and it is suppressed that welding strength varies.

[Embodiment 5]
In the fifth embodiment, the conductive first member 24B and the second member 24C are held by the insulating holding

jigs

27a and 27b, respectively, and the conductive first member 24B and the second member 24C are electrically conductive. In the state where the intermediate member 27c is disposed, the intermediate member 27c is disposed between the positive electrode core exposed portions 14 divided into two parts, and the insulating holding jig is removed after resistance welding. A resistance welding method for the conductive first member 24B and the second member 24C of the fifth embodiment will be described with reference to FIG. 8A to 8C are process diagrams for explaining the resistance welding method for the conductive first member 24B and the second member 24C of Embodiment 5 in order. In the fifth embodiment, the flat wound electrode body 11 and the positive electrode intermediate member 24A are the same as those used in the first embodiment, and are the same as those in the first embodiment. The same reference numerals are given to the constituent parts, and detailed description thereof is omitted.

That is, in the fifth embodiment, as shown in FIG. 8A, each set of conductive first member 24B and second member 24C is attached to holding

jigs

27a and 27b formed of a pair of insulating materials. A member in which a conductive intermediate member 27c made of, for example, the same material as the first member 24B and the second member 24C is disposed between the first member 24B and the second member 24C is used. The pair of holding

jigs

27a and 27b and the conductive intermediate member 27c may be held and operated, or may be separately attached to an automatically controlled device such as a robot arm. In this way, the pair of holding

jigs

27a and 27b and the conductive intermediate member 27c holding the conductive first member 24B and the second member 24C are divided into two as shown in FIG. 8B. After being inserted into the portion 14, the positive electrode current collecting members 16 are disposed on both outermost surfaces of the two-divided positive electrode core exposed portion 14, and a pair of resistance welding electrodes are formed on the surfaces of these positive electrode current collecting members 16 The

rods

31 and 32 are brought into contact with each other, and resistance welding is performed while applying a pressing force between the pair of resistance welding

electrode rods

31 and 32.

Then, since the conductive first member 24B, the second member 24C, and the conductive intermediate member 27c are short-circuited, if resistance welding is performed in this state under a predetermined condition, the resistance welding current is, for example, resistance welding From the electrode bar 31, the lower-side positive electrode current collecting member 16, the divided positive electrode core exposed portion 14, the first member 24B, the conductive intermediate member 27c, the second member 24C, and the divided core exposed portion 14, flows to the upper positive electrode current collecting member 16 and the resistance welding electrode rod 32. Thereby, between the lower-side positive electrode current collecting member 16 and the outermost surface side of the two-divided positive electrode core body exposed portion 14, the inner surface side of the bifurcated positive electrode core body exposed portion 14 and the first member 24B Between the second member 24C and the inner surface side of the positive electrode core exposed portion 14, a resistance welding portion is formed between the outermost surface side of the positive electrode core exposed portion 14 and the upper positive electrode current collecting member 16. The

At this time, the resistance between each of the conductive first member 24B, the conductive intermediate member 27c, and the second member 24C short-circuited with each other is small because the contact area between them is large, and the first member 24B, Since the heat capacity of the conductive intermediate member 27c and the second member 24C is large, the fusion between the first member 24B, the conductive intermediate member 27c and the second member 24C is performed by dividing the core exposed portion 14 divided into the first member 24 and the first member 24C. It is less likely to occur than the fusion between the member 24B and the fusion between the divided core exposed portion 14 and the second member 24C. Therefore, when the pair of resistance welding

electrode rods

31 and 32 are removed after resistance welding, and the holding

jigs

27a and 27b and the conductive intermediate member 27c are removed, the positive electrode core exposed portion 14 divided into two parts is pressed. The shape returns to the state before resistance welding due to elasticity, but the conductive first member 24B and the second member 24C are welded to the positive electrode core exposed portion 14 divided into two parts, respectively. As shown in FIG. 8C, the first member 24B and the second member 24C are separated from each other. Therefore, after resistance welding, the first member 24B and the second member 24C of each set are not in direct contact.

Thereafter, the conductive first member 24B and the second member 24C are fixed to another pair of holding

jigs

27a and 27b, and the conductive intermediate member 27c is interposed between the conductive first member 24B and the second member 24C. When resistance welding is performed in the same manner as described above, the first member 24B and the second member 24C are in a state of being separated from each other at the location where resistance welding is first performed. Since no current flows, only the current that flows around the positive electrode core on the divided side becomes a reactive current. This reactive current has a large resistance because the thickness of the positive electrode core is thin, and is very small compared to the resistance welding current. Therefore, also in the subsequent resistance welding, between the positive electrode current collecting member 16 and one of the two divided positive electrode core exposed portions 14, one of the two divided positive electrode core exposed portions 14 and the first member 24B. Between the second member 24C and the other half of the core exposed portion 14 divided into two, and between the other end of the core exposed portion 14 divided into two and the positive electrode current collecting member 16, good resistance welding is performed. Is called.

Moreover, in the fifth embodiment, after the resistance welding, the pair of holding

jigs

27a and 27b and the conductive intermediate member 27c are removed, so that there is no hindrance when assembling the rectangular secondary battery. The conductive first member 24B and the second member 24C are arranged in a stably positioned state between the positive electrode core exposed portion 14 divided into two by the holding

jigs

27a and 27b and the conductive intermediate member 27c. Therefore, substantially the same operations and effects as in the case of the first embodiment can be achieved. Note that the conductive first member 24B and the second member 24C used in the fifth embodiment also have a groove formed on the outer periphery, similar to the fourth embodiment shown in FIGS. 7A to 7C. Can be used.

[Embodiment 6]
Next, a method for manufacturing the prismatic secondary battery according to the sixth embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is an enlarged plan view of the conductive first member and the second member used in the sixth embodiment. 9B is a right side view, and FIG. 9C is a cross-sectional view taken along the line IXC-IXC in FIG. 9B. FIG. 10 is a side sectional view showing a resistance welding state in the sixth embodiment.

In Embodiment 6 described above, in the groove formed in the portion facing the inner surface side of the divided positive electrode core body exposed portion 14 of the insulating intermediate member 24J made of a prismatic resin material as the positive electrode intermediate member 24G, A pair of conductive first member 24H and second member 24I, which are slidably arranged, was used. A pair of

frustoconical protrusions

24g and 24h are formed on the side of the first member 24H facing the inner surface of the positive electrode core exposed portion 14, and the positive electrode core exposed portion 14 of the second member 24I A pair of

frustoconical protrusions

24i and 24j are also formed on the side facing the inner surface. The conductive first member 24H and the second member 24I are electrically insulated by the insulating intermediate member 24J.

As shown in FIG. 10, the positive electrode intermediate member 24 G having such a shape is positioned on the inner surface side of the positive electrode core body exposed portion 14 in which the pair of

protrusions

24 g and 24 h of the first member 24 H are each divided into two. Further, the pair of

protrusions

24i and 24j of the second member 24I are disposed between the two divided positive electrode core exposed portions 14 so as to be located on the inner surface side of the divided positive electrode core exposed portion 14, respectively. Then, the positive electrode current collecting member 16 electrically connected to the positive electrode terminal 17 is divided into one of the first members 24H (left side in FIG. 10) on both outermost surfaces of the positive electrode core exposed portion 14 divided into two. The frustoconical protrusion 24g and one of the second members 24I are disposed at positions facing the frustoconical protrusion 24i.

Further, on the outermost both surfaces of the positive electrode core exposed portion 14 obtained by dividing the pair of positive electrode current collector receiving members 16a into two, the other (right side in FIG. 10) frustoconical protrusions 24h and the second ones of the first member 24H. The member 24I is disposed at a position facing the other frustoconical protrusion 24j. At this time, the positive electrode current collecting member 16 and the positive electrode current collecting member 16a are not directly connected but are electrically connected to each other via the positive electrode core exposed portion 14 divided into two parts. To.

In this state, as shown in FIG. 10, for example, the pair of resistance welding

electrode rods

31 and 32 are brought into contact with each other between the positive electrode current collecting member 16 and the positive electrode current collecting member 16a on the second member 24I side. Resistance welding is performed while applying a pressing force to the resistance

welding electrode rods

31 and 32 toward the second member 24I side. Then, the resistance welding current is, for example, the resistance welding electrode rod 31 → the positive electrode current collecting member 16 → the divided positive electrode core exposed portion 14 → the truncated cone-shaped protrusion 24i → the second member 24I → the truncated cone shape. It flows through the projection 24j → the positive electrode core exposed portion 14 divided into two → the current collecting member 16a for positive electrode → the electrode rod 32 for resistance welding.

During this resistance welding, the first member 24H and the second member 24I are not directly electrically connected. Therefore, no welding current flows through the second member 24I, and the reactive current bypasses the positive electrode core exposed portion 14. Although the current flows only, the reactive current value is small because the positive electrode core is thin and the internal resistance is large. Thereby, between the positive electrode current collector 16 and the positive electrode core exposed portion 14 divided in two, between the positive electrode core exposed portion 14 divided in two and the truncated cone-shaped protrusion 24i, a truncated cone-shaped protrusion Resistance welding portions are formed between the positive electrode core exposed portion 14 divided into 24j and the positive electrode core exposed portion 14 divided into two and the positive current collecting member 16a.

Further, in resistance welding on the first member 24H side, since the first member 24H and the second member 24I are not directly electrically connected, the resistance welding is good as in the case of resistance welding on the second member 24I side. Resistance welding can be performed. Moreover, in the prismatic secondary battery produced in the sixth embodiment, even if movement occurs in the positive electrode core exposed portion 14 divided into two by expansion and contraction of the flat wound electrode body 11 due to charge and discharge, Since the first member 24H and the second member 24I are slidably arranged in the groove formed in the insulating intermediate member 24J, the first member 24H and the second member 24I move in synchronization with the movement of the divided positive electrode core exposed portion 14. Therefore, substantially the same operation and effect as in the case of the first embodiment can be achieved.

[Embodiment 7]
In the sixth embodiment, the conductive first member 24H and the second member 24I are shown as examples using the positive electrode intermediate member 24G held by the insulating intermediate member 24J made of a resin material. Without using the insulating intermediate member 24J made of a resin material, the conductive first member 24H and the second member 24I are each made of an insulating holding jig as in the case of the fourth embodiment shown in FIG. It is arranged between the positive electrode core exposed portions 14 divided into two while being held by (not shown), and the insulating holding jig is removed after resistance welding. A specific configuration of the conductive first member 24H and the second member 24J of the seventh embodiment will be described with reference to FIG.

11A is an enlarged plan view of the conductive first member and the second member used in Embodiment 7, FIG. 11B is a right side view, and FIG. 11C is along the XIC-XIC line in FIG. 11B. FIG.

That is, in the seventh embodiment, as shown in FIG. 11A, the insulating intermediate member 24J made of a resin material is removed from the positive electrode intermediate member 24G of the sixth embodiment as the conductive first member 24H and the second member 24I. Furthermore, a groove 24k is provided between the

frustoconical protrusions

24g and 24h on both sides of the first member 24H, and a groove 24m is provided between the

frustoconical protrusions

24i and 24j on both sides of the second member 24I. Are respectively formed. As in the case of the fourth embodiment, the

grooves

24k and 24m are positions to be held by an insulating holding jig.

In resistance welding, the first member 24H and the second member 24I are detachably held by a pair of holding jigs and placed between the positive electrode core exposed portions 14 divided into two, and the embodiment shown in FIG. In the same manner as in the sixth embodiment, for example, resistance welding on the second member side is performed. Accordingly, as in the case of the sixth embodiment, the positive electrode current collector member 16 and the positive electrode core body exposed portion 14 divided in half are divided into two divided positive electrode core body exposed portions 14 and truncated cone-shaped protrusions 24i. Resistance welding between the frustoconical protrusion 24j and the divided positive electrode core exposed portion 14 and between the divided positive electrode core exposed portion 14 and the positive electrode current collector receiving member 16a. Part is formed.

Then, when resistance welding on the first member side is performed in the same manner, the positive electrode core divided in two is also provided on the first member side between the positive electrode current collecting member 16 and the divided positive electrode core exposed portion 14. Between the body exposed portion 14 and the truncated cone-shaped protrusion 24g, between the truncated cone-shaped projection 24h and the divided positive electrode core exposed portion 14, and divided into two divided positive electrode core exposed portions 14 and a positive electrode collection. Resistance welding portions are formed between the power receiving member 16a and each. Thereafter, by removing the pair of holding jigs, the resistance welding process of the seventh embodiment is completed.

In this embodiment 7, after resistance welding, since the removed pair of holding jigs, without hinder when assembling the prismatic secondary battery, The first electrically conductive member 24H and the second member 24I is arranged closer in a state of being stably positioned between the two segments of the positive electrode substrate exposed portion 14 by the holding jig, because apart from each other in the case of substantially embodiment 1 The same operation and effect can be achieved.

Having described the embodiments of the present invention, in the present invention, the production of the prismatic secondary battery, as the first and second members and the first and second members for the negative electrode for the positive electrode, the shape of each protrusion Different ones can also be used.

In the above embodiments and drawings, for the sake of brevity, in Embodiments 1, 2, 4 and 5, an example using two sets of the first member and the second member is shown. Depending on the size, required output, etc., one set or three or more sets can be used. In the third embodiment, an example in which one positive electrode intermediate member having two sets of the first member and the second member is used is shown. In the sixth and seventh embodiments, a pair of the first member and the second member is used. In this case, a plurality of sets of positive electrode intermediate members can be used according to the size of the battery, the required output, and the like. In the above embodiments, although the case of the positive electrode substrate exposed portion has been described as a substrate exposed portion of the two divided side can be similarly applied to the case of the negative electrode substrate exposed portion, further Can be applied simultaneously to both the positive electrode core exposed portion side and the negative electrode core exposed portion.

DESCRIPTION OF SYMBOLS 10 ... Square nonaqueous electrolyte secondary battery 11 ... Flat wound electrode body 12 ... Battery outer can 13 ... Sealing plate 14 ... Positive electrode core exposed part 15 ... Negative electrode core exposed part 16 ... Current collecting member 16a for positive electrodes Current collecting member for positive electrode 17 ... Positive electrode terminal 18 ... Current collecting member for negative electrode 19 ...

Negative electrode terminal

20, 21 ... Insulating member 22 ... Electrolyte injection hole 23 ...

Resin sheet

24A, 24G ... Intermediate member for

positive electrode

24B, 24H ... First member 24C, 24I ...

Second member

24D, 24J ... Insulating intermediate member 24E ...

Gap

24b, 24c, 24g to 24j ... Frustum-shaped

projections

24d, 24e, 24k, 24m ... Groove 24f ... Cantilever 25A ... Intermediate member for

negative electrode

27a, 27b ... Holding jig 27c ... Conductive

intermediate member

31, 32 ... Electrode rod for resistance welding

Claims

A laminated or wound electrode body having a positive electrode core exposed portion and a negative electrode core exposed portion, a positive electrode current collecting member electrically joined to the positive electrode core exposed portion, and a negative electrode core exposed portion In a square secondary battery comprising a negative electrode current collector member that is electrically joined, and a square exterior body,
At least one of the positive electrode core exposed portion and the negative electrode core exposed portion of the electrode body is divided into two, and a conductive first member and a second member are stacked between the stacked core exposed portions. One end surface of each of the first member and the second member is positioned on the inner surface side of the two-divided core body exposed portion, and the other is not coupled to each other so as to be linearly arranged in the direction. Arranged to face each other,
A pair of current collecting members are disposed on both outermost surfaces of the two-sided core body exposed portion, and one of the pair of current collecting members and one of the two-divided core body exposed portion, Resistance welding is performed between the first member and between the other of the pair of current collecting members and the other of the two divided core exposed portions and the second member. Square secondary battery.
2. The prismatic secondary battery according to claim 1, wherein a plurality of sets of the conductive first member and the second member are provided.
3. The prismatic secondary battery according to claim 1, wherein opposing surfaces of the conductive first member and the second member are separated from each other.
3. The prismatic secondary battery according to claim 1, wherein the conductive first member and the second member each have a groove formed on an outer periphery thereof. 4.
Said conductive first member and a second member, being disposed between the two divided core exposed portion in a state in which the hole formed in the insulating intermediate member is slidably disposed, respectively The prismatic secondary battery according to claim 1 or 2.
Said conductive first member and a second member, and characterized in that it is arranged between the two divided core exposed portion in a state of being fixed in a cantilever formed on the respective insulating intermediate member The prismatic secondary battery according to claim 1 or 2.
An electrode body having a positive electrode substrate exposed portion wound laminated to the winding and the negative electrode substrate exposed portions, the positive electrode substrate exposed positive electrode current collector is electrically joined to the section member, the negative electrode substrate exposed portion a negative electrode current collector member is electrically connected, in the prismatic secondary battery and a prismatic outer member, at least one of the positive electrode substrate exposed portion and the negative electrode substrate exposed portion of the electrode body, 2 The conductive first member and the second member are divided into a plurality of protrusions on one side of the surface of each of the first member and the second member, and the plurality of protrusions are divided into the two parts. located on the inner surface side of the substrate exposed portion, wherein the first member and the second member are disposed mutually separated state, the outermost of the two divided substrate exposed portion, corresponding to the plurality of projections A plurality of the current collecting members are applied in an independent state at each position to be operated. And between the plurality of current collecting members, the two-divided core exposed portion and the plurality of protrusions of the first member, and between the plurality of current collecting members and the two-divided core. A prismatic secondary battery, wherein the body exposed portion and each of the plurality of protrusions of the second member are resistance-welded.
The prismatic secondary battery according to claim 7, wherein the conductive first member and the second member are respectively disposed in grooves formed in the insulating intermediate member so as to be slidable.
A laminated or wound electrode body having a positive electrode core exposed portion and a negative electrode core exposed portion, a positive electrode current collecting member electrically joined to the positive electrode core exposed portion, and a negative electrode core exposed portion In a method for manufacturing a rectangular secondary battery comprising a negative electrode current collecting member that is electrically joined, and a rectangular exterior body,
A first conductive member between a first step of dividing at least one of the positive electrode core exposed portion and the negative electrode core exposed portion of the electrode body into two and a core exposed portion on the two divided sides And the second member so that the first member and the second member are linearly arranged in the stacking direction of the stacked core exposed portions, and the end surfaces of the first member and the second member One is located on the inner surface side of the two-divided core body exposed portion, and the other is arranged so as to face each other, and the pair of current collecting members on the two-divided side is divided into the two-divided core bodies A second step of contacting each of the outermost surfaces of the exposed portion, and a pair of resistance welding electrodes abutting on the surfaces of the pair of current collecting members, respectively, and applying a pressing force to the pair of resistance welding electrodes While short-circuiting between the first member and the second member, Between one of the pair of current collecting members, one of the two divided core exposed portions and the first member, and the other of the pair of current collecting members and the other of the two divided core exposed portions And a second step in which the first member and the second member are not resistance welded, and a fourth step of removing the pair of resistance welding electrodes. A process for producing a rectangular secondary battery.
A plurality of sets of the conductive first member and the second member are used, and the third step and the fourth step are sequentially repeated for each set of the conductive first member and the second member. method for manufacturing a prismatic secondary battery according to claim 9, opposing surfaces of the fourth in the step and the first member after removal of the resistance welding electrode a second member, characterized in that a separated state to perform the .
In the second step, the conductive first member and the second member are respectively disposed between the two divided core exposed portions while being held by an insulating holding jig, and the fourth step The method of manufacturing a prismatic secondary battery according to claim 9 or 10, wherein the insulating holding jig is removed in the step.
In the second step, the conductive first member and the second member are respectively held by an insulating holding jig between the core body exposed parts on the two divided sides, and the conductive In the third step, a pressing force is applied to the pair of resistance welding electrodes, and the conductive intermediate member is interposed between the first member and the second member. Then, resistance welding is performed while the first member and the second member are short-circuited, and the insulating holder and the conductive intermediate member are removed in the fourth step. The manufacturing method of the square secondary battery of Claim 9 or 10.
In the second step, the conductive first member and the second member are each formed with a groove formed on the outer periphery, and the insulating holding jig is fitted into the groove to thereby provide the insulating property. The method for manufacturing a prismatic secondary battery according to claim 11, wherein the first member and the second member are held by a holding jig.
Facing in the second step, the between the substrate exposed portion of the two divided side, the first and second members of said electrically conductive, the inner surface of the substrate exposed portion of each of the two divided side slidably in a state of side is exposed, and so that the first and second members of said conductive face each other, in a state arranged in a bore formed in the insulating intermediate member, that it has arranged The method for producing a prismatic secondary battery according to claim 9 or 10, characterized in that
In the second step, the conductive first member and the second member are opposed to each other, and the conductive first member and the second member are opposed to each other between the core body exposed portions on the two divided sides. The method of manufacturing a prismatic secondary battery according to claim 9 or 10, wherein the prismatic battery is arranged in a state of being fixed to a cantilever formed on an insulating intermediate member.
10. The conductive first member and the second member, each having a protrusion formed on the side facing the inner surface of the core exposed portion on the two divided sides, respectively. A method for producing the prismatic secondary battery according to 10.
An electrode body having a positive electrode substrate exposed portion wound laminated to the winding and the negative electrode substrate exposed portions, the positive electrode substrate exposed positive electrode current collector is electrically joined to the section member, the negative electrode substrate exposed portion a negative electrode current collector member is electrically connected, in the manufacturing method of the prismatic secondary battery and a prismatic outer member, at least one of the positive electrode substrate exposed portion and the negative electrode substrate exposed portion of the electrode body The conductive first member and the second member are arranged on one side of the surface of each of the first member and the second member between the first step of dividing the core into two parts and the core body exposed portion on the two divided sides. together with the plurality of projections with a plurality of projections are formed is positioned on the inner surface of each of the two divided substrate exposed portion is placed in a state where the first member and the second member is spaced apart from each other, the On the outermost side of the core exposed portion divided into two, the plurality of protrusions are paired. 2 of the plurality of current collecting members for each of the second step of contacting the plurality of current collecting members in an independent state for each position and the outermost surface side of the two-divided core body exposed portion. A pair of resistance welding electrodes are brought into contact with one surface, and a pressing force is applied to the pair of resistance welding electrodes, while the second member is divided between the first member and the core exposed portion divided into two and the second A square secondary battery comprising: a third step of resistance welding between a member and the two-divided core exposed portion; and a fourth step of removing the pair of resistance welding electrodes. Manufacturing method.
In the second step, the conductive first member and the second member are respectively disposed between the two divided core exposed portions while being held by an insulating holding jig, and the fourth step The method of manufacturing a prismatic secondary battery according to claim 17, wherein the insulating holding jig is removed in the step.
In the second step, the conductive first member and the second member are slidably held in a groove formed in the insulating intermediate member between the core exposed portions on the two divided sides. The method of manufacturing a prismatic secondary battery according to claim 17, wherein the prismatic battery is disposed in a closed state.