JP5183251B2

JP5183251B2 - Assembled battery

Info

Publication number: JP5183251B2
Application number: JP2008049392A
Authority: JP
Inventors: 喜紀横山; 和洋北岡; 順康石丸; 裕政杉井
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2008-02-29
Filing date: 2008-02-29
Publication date: 2013-04-17
Anticipated expiration: 2028-02-29
Also published as: JP2009206024A

Description

本発明は、一方の単電池の負極外部端子となる外装缶の底面と、当該単電池に相隣接する他方の単電池の正極外部端子となる正極キャップを備えた封口体とが金属製接続部材に溶接されて複数の単電池間が直列接続された組電池に関する。 In the present invention, the bottom surface of the outer can serving as the negative electrode external terminal of one unit cell and the sealing body including the positive electrode cap serving as the positive electrode external terminal of the other unit cell adjacent to the unit cell are metal connection members The present invention relates to an assembled battery in which a plurality of single cells are connected in series.

一般に、ニッケル−水素蓄電池、ニッケル−カドミウム蓄電池などのアルカリ蓄電池あるいはリチウム二次電池は、正極および負極の間にセパレータを介在させ、これらを渦巻状に巻回した後、正極および負極の端部に集電体を接続して電極体を形成し、この電極体を金属製外装缶に収納して正極集電体から延伸するリード部を封口体に溶接した後、封口体を外装缶の開口部に絶縁ガスケットを介在させて装着することにより密閉して構成されている。このようなアルカリ蓄電池がＨＥＶ（ＨｙｂｒｉｄＥｌｅｃｔｒｉｃＶｅｈｉｃｌｅｓ）やＰＥＶ（ＰｕｒｅＥｌｅｃｔｒｉｃＶｅｈｉｃｌｅｓ）などの電気自動車の用途に用いられる場合、高出力が要求されるため、複数の単電池を直列に接続して組電池にして使用されるのが一般的である。 In general, alkaline storage batteries such as nickel-hydrogen storage batteries and nickel-cadmium storage batteries or lithium secondary batteries have a separator interposed between a positive electrode and a negative electrode, and after winding them in a spiral shape, A current collector is connected to form an electrode body, the electrode body is accommodated in a metal outer can, and a lead portion extending from the positive electrode current collector is welded to the sealing body, and then the sealing body is opened to the outer can It is configured to be hermetically sealed by mounting with an insulating gasket interposed therebetween. When such an alkaline storage battery is used for an electric vehicle such as HEV (Hybrid Electric Vehicles) or PEV (Pure Electric Vehicles), a high output is required. Therefore, a plurality of unit cells are connected in series to form an assembled battery. Generally, it is used.

このような組電池においては、複数の単電池を直列に接続する必要があり、例えば、特許文献１（特開２００１−２６６８４３号公報）などで種々の接続法が提案されている。この場合、特許文献１にて提案された組電池３０においては、図７および図８に示すように、一方の単電池３０ａと、この単電池３０ａに相隣接する他方の単電池３０ｂが金属製接続部材４０によって直列接続されている。ここで、金属製接続部材４０は平面部（フランジ部）４１と、この平面部（フランジ部）４１より膨出した膨出部４２とを備え、平面部（フランジ部）４１に形成された４か所のプロジェクション突起４１ａが金属製外装缶３１の底面に溶接され、膨出部４２に形成された４か所のプロジェクション突起４２ｃが封口体３２に溶接されている。 In such an assembled battery, it is necessary to connect a plurality of single cells in series. For example, various connection methods have been proposed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-266843). In this case, in the assembled battery 30 proposed in Patent Document 1, as shown in FIGS. 7 and 8, one unit cell 30a and the other unit cell 30b adjacent to the unit cell 30a are made of metal. The connection members 40 are connected in series. Here, the metal connecting member 40 includes a flat surface portion (flange portion) 41 and a bulging portion 42 bulged from the flat surface portion (flange portion) 41, and is formed on the flat surface portion (flange portion) 41. The projection projections 41 a at the locations are welded to the bottom surface of the metal outer can 31, and the four projection projections 42 c formed at the bulging portion 42 are welded to the sealing body 32.

この場合、金属製接続部材４０と各単電池３０ａ，３０ｂ・・・との接続においては、複数の単電池３０ａ，３０ｂ・・・間に金属製接続部材４０を配置した後、これらの両端部間を加圧しながら、一方の溶接電極（図示せず）を先頭に配置された単電池の外装缶３１に押し当て、他方の溶接電極（図示せず）を最後尾に配置された単電池の外装缶３１に押し当てる。この後、これらの一対の溶接電極間に溶接電流を流すことにより、平面部（フランジ部）４１に形成された４か所のプロジェクション突起４１ａが一方の単電池３０ａの金属製外装缶３１の底面に溶接され、膨出部４２に形成された４か所のプロジェクション突起４２ｃが他方の単電池３０ｂの封口体３２に溶接されこととなる。 In this case, in the connection between the metal connection member 40 and each of the single cells 30a, 30b,..., After the metal connection member 40 is disposed between the plurality of single cells 30a, 30b,. While pressurizing the gap, one welding electrode (not shown) is pressed against the outer can 31 of the single cell arranged at the top, and the other welding electrode (not shown) is arranged at the rear of the single cell. Press against the outer can 31. Thereafter, by passing a welding current between the pair of welding electrodes, the four projection protrusions 41a formed on the flat surface portion (flange portion) 41 become the bottom surface of the metal outer can 31 of one unit cell 30a. The four projection projections 42c formed on the bulging portion 42 are welded to the sealing body 32 of the other unit cell 30b.

このような金属製接続部材４０を用いた単電池間接続を、所望の出力電圧が得られる数だけの単電池３０ａ，３０ｂ・・・を連結することにより、所望の出力電圧となる組電池３０を構成することができる。この場合、単電池３０ａ，３０ｂ間の接続は電流経路が最短となる金属製接続部材４０により接続されることとなるので、出力低下（抵抗増加）を抑制した組電池３０が得られるようになる。
特開２００１−２６６８４３号公報 A battery pack 30 having a desired output voltage is obtained by connecting the unit cells 30a, 30b,. Can be configured. In this case, since the connection between the single cells 30a and 30b is connected by the metal connecting member 40 having the shortest current path, the assembled battery 30 in which the output decrease (resistance increase) is suppressed can be obtained. .
JP 2001-266843 A

ところが、この種の組電池３０に用いられる単電池３０ａ，３０ｂ・・・においては、電極群３３の一方の端部に正極集電体３４が溶接され、他方の端部に負極集電体３５が溶接されている。この場合、これらの集電体３４，３５においては、通常、図９（なお、図９においては負極集電体３５を示しているが、円板部の形状は正極集電体３４においてもほぼ同様である）に示すように、電極板との電気的接続を行うための多数のバーリング孔３５ａと、溶接時の無効電流を低減させるためのスリット３５ｂとが形成されている。また、バーリング孔３５ａの周囲とスリット３５ｂの周囲の少なくとも一方には突起部が形成されていて、電極群３３の端部に突出した電極板との接触を良好にして集電効率が向上するようになされている。 However, in the unit cells 30a, 30b,... Used for this type of assembled battery 30, the positive electrode current collector 34 is welded to one end of the electrode group 33, and the negative electrode current collector 35 is connected to the other end. Are welded. In this case, these current collectors 34 and 35 are usually shown in FIG. 9 (note that the negative electrode current collector 35 is shown in FIG. 9, but the shape of the disk portion is almost the same in the positive electrode current collector 34 as well. As shown in FIG. 2, a number of burring holes 35a for electrical connection with the electrode plate and slits 35b for reducing reactive current during welding are formed. Further, a protrusion is formed on at least one of the periphery of the burring hole 35a and the periphery of the slit 35b, so that the contact with the electrode plate protruding at the end of the electrode group 33 is improved and the current collection efficiency is improved. Has been made.

ここで、この種の単電池３０ａ，３０ｂ・・・においては、負極集電体３５と外装缶３１の底面とがスポット溶接されて、負極集電体３５と外装缶３１とが電気的に接続されることとなる。ところが、負極集電体３５と外装缶３１とのスポット溶接による溶接箇所は限られている（通常は、負極集電体３５の中心部のみが溶接箇所３５ｄとなる）ため、負極集電体３５と外装缶３１の底面とは完全には接触しておらず、隙間が存在することとなる。なお、負極集電体３５には、このようなスポット溶接時の加圧力による負極集電体３５の変形を防止するために、負極集電体３５の中心部（後に溶接箇所３５ｄとなる部位）の周囲にはＵ字状のスリット３５ｃが形成されている。 Here, in this type of single battery 30a, 30b,..., The negative electrode current collector 35 and the bottom surface of the outer can 31 are spot-welded, and the negative electrode current collector 35 and the outer can 31 are electrically connected. Will be. However, since the welding location by spot welding between the negative electrode current collector 35 and the outer can 31 is limited (usually, only the central portion of the negative electrode current collector 35 becomes the welding location 35d), the negative electrode current collector 35 And the bottom surface of the outer can 31 are not completely in contact with each other, and a gap exists. In addition, in order to prevent the negative electrode current collector 35 from being deformed by the applied pressure at the time of spot welding, the negative electrode current collector 35 has a central portion (a portion to be a welding location 35d later). Is formed with a U-shaped slit 35c.

そして、上述のように複数の単電池３０ａ，３０ｂ・・・間に金属製接続部材４０を配置した後、これらの両端部間を加圧しながら、一対の溶接電極（図示せず）を外装缶３１に押し当て、これらの一対の溶接電極間に溶接電流を流した場合、各単電池３０ａ，３０ｂ・・・内に溶接電流が流れることとなる。この場合、溶接時の押圧力により、金属製接続部材４０の各プロジェクション突起４１ａと接触した外装缶３１の底面が内側に変形して、負極集電体３５と接触する事態が生じることとなる。ここで、図９に示す領域Ｚは複数のプロジェクション突起４１ａで形成される同心円の領域に対応する部位であることを示しており、この領域Ｚにおいて外装缶３１の底面と負極集電体３５とが接触することとなる。 And after arrange | positioning the metal connection member 40 between several cell 30a, 30b ... as mentioned above, a pair of welding electrodes (not shown) are attached to an exterior can, pressurizing between these both ends. When the welding current is passed between the pair of welding electrodes, the welding current flows in each of the single cells 30a, 30b. In this case, due to the pressing force during welding, the bottom surface of the outer can 31 in contact with each projection projection 41a of the metal connection member 40 is deformed inward, and a situation of contacting with the negative electrode current collector 35 occurs. Here, the region Z shown in FIG. 9 indicates that the region corresponds to the concentric region formed by the plurality of projection protrusions 41a. In this region Z, the bottom surface of the outer can 31 and the negative electrode current collector 35 Will come into contact.

このような事態が生じると、外装缶３１の底面と負極集電体３５との接触部に溶接電流が流れ、電池内部にスパッタが発生することがある。ここで、図８に示す点線のＣ−ＣおよびＤ−Ｄのように、溶接位置が負極集電体３５に形成された開口３５ａあるいはスリット３５ｂと重なった場合、発生したスパッタが電極群の内部に飛散して、内部ショートが発生するという問題が生じた。
そこで、本発明は上記問題点に鑑みてなされたものであって、金属製接続部材と各単電池との溶接時に電池内部にスパッタが発生しても、発生したスパッタが電極群の内部に飛散しないようにして、内部ショートが発生しない組電池を提供できるようにすることを目的とする。 When such a situation occurs, a welding current may flow through the contact portion between the bottom surface of the outer can 31 and the negative electrode current collector 35, and spatter may occur inside the battery. Here, when the welding position overlaps the opening 35a or the slit 35b formed in the negative electrode current collector 35 as indicated by dotted lines CC and DD shown in FIG. 8, the generated spatter is generated inside the electrode group. The problem of internal short-circuiting occurred.
Therefore, the present invention has been made in view of the above problems, and even if spatter is generated inside the battery during welding of the metal connecting member and each unit cell, the generated spatter is scattered inside the electrode group. An object of the present invention is to provide an assembled battery that does not cause an internal short circuit.

本発明の組電池は、一方の単電池の負極外部端子となる外装缶の底面と、当該単電池に相隣接する他方の単電池の正極外部端子となる正極キャップを備えた封口体とが金属製接続部材に溶接されて複数の単電池間が直列接続されている。そして、上記目的を達成するため、金属製接続部材は一方の単電池の外装缶の底面に向けて突出する複数の第１突起部が同心円状に形成されているとともに、他方の単電池の封口体に向けて突出する複数の第２突起部が同心円状に形成されており、外装缶内に収納された正極板と負極板とセパレータとからなる電極群の一方の端部には負極集電体が溶接されているとともに、当該負極集電体は外装缶の底面に電気的に接続されており、負極集電体には金属製接続部材の第１突起部で形成された同心円に対向する部位を除いて多数のバーリング孔およびスリットが形成されている。 In the assembled battery of the present invention, the bottom surface of the outer can serving as the negative electrode external terminal of one unit cell and the sealing body including the positive electrode cap serving as the positive electrode external terminal of the other unit cell adjacent to the unit cell are metal. A plurality of single cells are connected in series by being welded to the connecting member. In order to achieve the above object, the metal connecting member has a plurality of first protrusions projecting toward the bottom surface of the outer can of one unit cell and is concentrically formed, and the sealing of the other unit cell A plurality of second protrusions projecting toward the body are formed concentrically, and a negative electrode current collector is provided at one end of an electrode group comprising a positive electrode plate, a negative electrode plate, and a separator housed in an outer can. The negative electrode current collector is electrically connected to the bottom surface of the outer can, and the negative electrode current collector faces the concentric circle formed by the first protrusion of the metal connection member. Except for the portion, a large number of burring holes and slits are formed.

上述した金属製接続部材を用いて、一方の単電池の外装缶の底面と他方の単電池の封口体とを溶接する場合、負極集電体は外装缶内部に収納されているため、金属製接続部材の位置決めが困難となる。そこで、負極集電体に、金属製接続部材の第１突起部で形成された同心円に対向する部位を除いて多数のバーリング孔およびスリットを形成するようにすると、溶接時の加圧により外装缶内部でスパッタが発生しても、バーリング孔やスリットが溶接部位の近辺に存在しないため、電極群の内部へのスパッタの飛散が防止できるようになる。これにより、本発明の課題となる内部ショートが発生しない組電池を提供することが可能となる。 When the bottom surface of the outer can of one unit cell and the sealing body of the other unit cell are welded using the metal connecting member described above, the negative electrode current collector is housed inside the outer can. Positioning of the connecting member becomes difficult. Therefore, if a large number of burring holes and slits are formed on the negative electrode current collector excluding a portion facing the concentric circle formed by the first protrusion of the metal connection member, the outer can can be formed by pressurization during welding. Even if spatter is generated inside, burring holes and slits do not exist in the vicinity of the welded portion, so that it is possible to prevent the spatter from scattering into the electrode group. As a result, it is possible to provide an assembled battery in which an internal short circuit that is a subject of the present invention does not occur.

この場合、金属製接続部材は一方の単電池の外装缶の底面に向けて突出する複数の第２突起部が同心円状に形成されているとともに、他方の単電池の封口体に向けて突出する複数の第１突起部が同心円状に形成されており、外装缶内に収納された正極板と負極板とセパレータとからなる電極群の一方の端部には負極集電体が溶接されているとともに、当該負極集電体は外装缶の底面に電気的に接続されており、負極集電体には金属製接続部材の第２突起部で形成された同心円に対向する部位を除いて多数のバーリング孔およびスリットが形成されているようにしても、上述と同様な効果を奏することが可能となる。なお、第１突起部で形成された同心円の径は外装缶の底面の径よりは小さく、かつ第２突起部で形成された同心円の径よりは大きく形成されていればよい。 In this case, the metal connecting member has a plurality of second protrusions projecting toward the bottom surface of the outer can of one unit cell and is concentrically formed, and projects toward the sealing body of the other unit cell. A plurality of first protrusions are formed concentrically, and a negative electrode current collector is welded to one end of an electrode group consisting of a positive electrode plate, a negative electrode plate, and a separator housed in an outer can. In addition, the negative electrode current collector is electrically connected to the bottom surface of the outer can, and the negative electrode current collector has a large number of parts except for a portion facing the concentric circle formed by the second protrusion of the metal connection member. Even if the burring hole and the slit are formed, the same effect as described above can be obtained. In addition, the diameter of the concentric circle formed by the 1st projection part should just be formed smaller than the diameter of the bottom face of an exterior can, and larger than the diameter of the concentric circle formed by the 2nd projection part.

本発明においては、金属製接続部材と各単電池との溶接時に電池内部にスパッタが発生しても、発生したスパッタが電極群の内部に飛散しないようになされているので、本発明の課題となる内部ショートが発生しない組電池を提供できるようになる。 In the present invention, even if spatter is generated inside the battery during welding of the metal connecting member and each unit cell, the generated spatter is prevented from scattering inside the electrode group. It becomes possible to provide an assembled battery in which no internal short circuit occurs.

以下に、本発明の組電池の一実施の形態を図１〜図６に基づいて説明する。この場合、組電池に用いられる単電池としてニッケル−水素蓄電池を用いた場合について説明するが、本発明はこれに限定されるものでなく、その要旨を変更しない範囲で適宜変更して実施することができる。 Below, one Embodiment of the assembled battery of this invention is described based on FIGS. In this case, a case where a nickel-hydrogen storage battery is used as a unit cell used in the assembled battery will be described. However, the present invention is not limited to this, and may be appropriately changed and implemented without changing the gist thereof. Can do.

なお、図１は本発明の金属製接続部材を模式的に示す図であり、図１（ａ）はその上面図であり、図１（ｂ）はその側面図である。図２は単電池に用いられる第１実施例の負極集電体を模式的に示す上面図である。図３は、図１と同様な金属製接続部材を模式的に示す図であり、図３（ａ）はその下面図であり、図３（ｂ）はその側面図である。図４は単電池に用いられる第２実施例の負極集電体を模式的に示す上面図である。図５は、一方の単電池に相隣接する他方の単電池が金属製接続部材によって直列接続される状態を模式的に示す一部破断の側面図である。図６は、一方の単電池に相隣接する他方の単電池が金属製接続部材によって直列接続された状態を模式的に示す断面図である。 FIG. 1 is a view schematically showing a metal connecting member of the present invention, FIG. 1 (a) is a top view thereof, and FIG. 1 (b) is a side view thereof. FIG. 2 is a top view schematically showing the negative electrode current collector of the first embodiment used for a unit cell. FIG. 3 is a view schematically showing a metal connecting member similar to FIG. 1, FIG. 3 (a) is a bottom view thereof, and FIG. 3 (b) is a side view thereof. FIG. 4 is a top view schematically showing a negative electrode current collector of a second embodiment used for a unit cell. FIG. 5 is a partially broken side view schematically showing a state in which the other unit cell adjacent to the one unit cell is connected in series by a metal connecting member. FIG. 6 is a cross-sectional view schematically showing a state in which the other unit cell adjacent to one unit cell is connected in series by a metal connecting member.

１．金属製接続部材
単電池間を接続する金属製接続部材１０は、鉄、銅、ニッケルやそれらの合金などの導電性が良好な金属板のプレス成形により形成されており、図１（図３も同様である）に示すように、外径が後述する金属製外装缶２１の底面の外径よりも小径に形成された環状の平面部（フランジ部）１１と、この環状の平面部（フランジ部）１１より膨出する膨出部１２とを備えている。ここで、平面部（フランジ部）１１には、膨出部１２の反対側に突出するように４か所のプロジェクション突起（第１突起部）１１ａが中心より同心円状（図１（ａ）に領域ｘで示す）に等間隔に形成されている。 1. Metal connection member The metal connection member 10 for connecting the cells is formed by press-molding a metal plate having good conductivity such as iron, copper, nickel, or an alloy thereof. The same), an annular flat surface portion (flange portion) 11 having an outer diameter smaller than the outer diameter of the bottom surface of the metal outer can 21 described later, and the annular flat surface portion (flange portion). ) And a bulging portion 12 bulging from 11. Here, on the flat surface portion (flange portion) 11, four projection projections (first projection portions) 11a are concentrically formed from the center so as to project to the opposite side of the bulging portion 12 (in FIG. 1A). (Shown by region x) at equal intervals.

また、膨出部１２には、その中心部に後述する正極キャップ２２ａの外径よりも大径で円形の中心開口１２ａが形成されているとともに、この中心開口１２ａより放射状に延出する４つのスリット部１２ｂが等間隔に形成されている。そして、これらの４つのスリット部１２ｂ間の中央部には、膨出部１２からさらに突出するように４か所のプロジェクション突起（第２突起部）１２ｃが中心より同心円状（図３（ａ）に領域ｙで示す）に等間隔に形成されている。なお、膨出部１２の高さは正極キャップ２２ａの高さよりも若干高くなるように形成されている。 The bulging portion 12 is formed with a circular central opening 12a having a diameter larger than the outer diameter of a positive electrode cap 22a, which will be described later, at the center thereof, and four radially extending from the central opening 12a. Slit portions 12b are formed at equal intervals. At the center between these four slit portions 12b, four projection projections (second projections) 12c are concentric from the center so as to further protrude from the bulging portion 12 (FIG. 3A). In the region y). The height of the bulging portion 12 is formed to be slightly higher than the height of the positive electrode cap 22a.

この場合、相隣接する２つの単電池間と金属製接続部材１０との接続状態には、第１のの接続状態と、第２の接続状態との２つの接続状態がある。ここで、第１の接続状態においては、平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａが外装缶２１の底面に溶接され、膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃが封口体２２に溶接されることとなる。一方、第２の接続状態においては、平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａが封口体２２に溶接され、膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃが外装缶２１の底面に溶接されることとなる。 In this case, there are two connection states, a first connection state and a second connection state, between the two adjacent single cells and the metal connection member 10. Here, in the first connection state, four projection projections (first projection portions) 11 a formed on the flat surface portion (flange portion) 11 are welded to the bottom surface of the outer can 21, and The four projection protrusions (second protrusions) 12 c formed are welded to the sealing body 22. On the other hand, in the second connection state, the four projection projections (first projection portions) 11 a formed on the flat surface portion (flange portion) 11 are welded to the sealing body 22 and formed on the bulging portion 12. The four projection protrusions (second protrusions) 12 c are welded to the bottom surface of the outer can 21.

２．負極集電体
そして、これらの２つの接続状態が採用されることにより、これらの接続状態に対応するために２種類の負極集電体２５あるいは負極集電体２６を使い分ける必要がある。ここで、第１の接続状態とするために用いられるものを実施例１の負極集電体２５とし、第２の接続状態とするために用いられるものを実施例２の負極集電体２６とし、それらの詳細な説明を以下に述べることとする。 2. Negative electrode current collector Then, by adopting these two connection states, it is necessary to use two types of negative electrode current collectors 25 or negative electrode current collectors 26 in order to cope with these connection states. Here, the negative electrode current collector 25 of Example 1 is used for the first connection state, and the negative electrode current collector 26 of Example 2 is used for the second connection state. Detailed description thereof will be described below.

（１）実施例１
実施例１の負極集電体２５は、図２に示すように、略円形（最大で直径が３０ｍｍ）に形成されていて、中心部（後に溶接点２５ｄとなる部位）の周囲から端部に向けて多数のバーリング孔（例えば、直径が２ｍｍで、バーリング高さが０．４ｍｍで、バーリング厚みが０．１ｍｍのもの）２５ａが形成されている。また、負極集電体２５の外周部には、無効な溶接電流を減少させ、有効な溶接電流を増大させるために、端縁に向けて開口する一対のスリット２５ｂが形成されている。さらに、中心部（後に溶接点２５ｄとなる部位）の周囲には、略Ｕ字状バーリング孔２５ｃが形成されていて、中心部２５ｄが外装缶２１の底面に溶接された際に、負極集電体２５が変形されるのを防止するようにしている。 (1) Example 1
As shown in FIG. 2, the negative electrode current collector 25 of Example 1 is formed in a substantially circular shape (the maximum diameter is 30 mm), and extends from the periphery of the central portion (the portion that later becomes the welding point 25 d) to the end portion. A large number of burring holes 25a (for example, having a diameter of 2 mm, a burring height of 0.4 mm, and a burring thickness of 0.1 mm) are formed. In addition, a pair of slits 25b that open toward the edge are formed on the outer peripheral portion of the negative electrode current collector 25 in order to reduce the invalid welding current and increase the effective welding current. Furthermore, a substantially U-shaped burring hole 25c is formed around the central portion (the portion that will later become the welding point 25d), and when the central portion 25d is welded to the bottom surface of the outer can 21, the negative electrode current collector is collected. The body 25 is prevented from being deformed.

ここで、本実施例１の負極集電体２５においては、図１に示す金属製接続部材１０の平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａで形成される同心円の領域ｘに対応する領域Ｘには、バーリング孔２５ａやスリット２５ｂが形成されていないことに特徴を有する。これにより、後の溶接工程において、外装缶２１の底面と負極集電体２５との間にスパッタが発生したとしても、発生したスパッタがバーリング孔２５ａやスリット２５ｂを介して電極群の内部に飛散することが防止できるようになる。 Here, in the negative electrode current collector 25 of Example 1, four projection projections (first projection portions) 11a formed on the flat portion (flange portion) 11 of the metal connecting member 10 shown in FIG. The region X corresponding to the region x of the concentric circle formed in (5) is characterized in that no burring hole 25a or slit 25b is formed. Thereby, even if spatter is generated between the bottom surface of the outer can 21 and the negative electrode current collector 25 in the subsequent welding process, the generated spatter is scattered inside the electrode group through the burring holes 25a and the slits 25b. Can be prevented.

（２）実施例２
実施例２の負極集電体２６は、図４に示すように、略円形（最大で直径が３０ｍｍ）に形成されていて、中心部（後に溶接点２６ｄとなる部位）の周囲から端部に向けて多数のバーリング孔（例えば、直径が２ｍｍで、バーリング高さが０．４ｍｍで、バーリング厚みが０．１ｍｍのもの）２６ａが形成されている。また、負極集電体２６の外周部には、無効な溶接電流を減少させ、有効な溶接電流を増大させるために、端縁に向けて開口する一対のスリット２６ｂが形成されている。この場合は、中心部（後に溶接点２６ｄとなる部位）の周囲には、略Ｕ字状バーリング孔が形成されていないので、実施例１の負極集電体２５よりも、一対のスリット２６ｂの長さを長くすることが可能となるとともに、バーリング孔２６ａの数も多くすることが可能となる。 (2) Example 2
As shown in FIG. 4, the negative electrode current collector 26 of Example 2 is formed in a substantially circular shape (maximum diameter is 30 mm), and extends from the periphery of the central portion (the portion that later becomes the welding point 26 d) to the end portion. A large number of burring holes 26a (for example, those having a diameter of 2 mm, a burring height of 0.4 mm, and a burring thickness of 0.1 mm) are formed. In addition, a pair of slits 26b that open toward the edge are formed on the outer peripheral portion of the negative electrode current collector 26 in order to reduce the invalid welding current and increase the effective welding current. In this case, since a substantially U-shaped burring hole is not formed around the central portion (the portion that will later become the welding point 26d), the pair of slits 26b is more than the negative electrode current collector 25 of Example 1. The length can be increased and the number of burring holes 26a can be increased.

ここで、本実施例２の負極集電体２６においては、図３に示す金属製接続部材１０の膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃで形成される同心円の領域ｙに対応する領域Ｙには、バーリング孔２６ａやスリット２６ｂが形成されていないことに特徴を有する。これにより、後の溶接工程において、外装缶２１の底面と負極集電体２６との間にスパッタが発生したとしても、発生したスパッタがバーリング孔２６ａやスリット２６ｂを介して電極群の内部に飛散することが防止できるようになる。 Here, the negative electrode current collector 26 of Example 2 is formed of four projection protrusions (second protrusions) 12c formed on the bulging portion 12 of the metal connecting member 10 shown in FIG. The region Y corresponding to the concentric region y is characterized in that no burring hole 26a or slit 26b is formed. Thereby, even if spatter is generated between the bottom surface of the outer can 21 and the negative electrode current collector 26 in the subsequent welding process, the generated spatter is scattered inside the electrode group through the burring hole 26a and the slit 26b. Can be prevented.

２．ニッケル−水素蓄電池（単電池）
ついで、上述のような構成となる負極集電体２５および負極集電体２６を用いて、単電池となるニッケル−水素蓄電池を作製する例について以下に説明するが、その作製法は負極集電体２５を用いても、あるいは負極集電体２６を用いてもほぼ同様であるので、この場合は、負極集電体２５を用いた場合のニッケル−水素蓄電池の作製例について説明することとする。 2. Nickel-hydrogen storage battery (single cell)
Next, an example of producing a nickel-hydrogen storage battery to be a unit cell using the negative electrode current collector 25 and the negative electrode current collector 26 having the above-described configuration will be described below. Even if the body 25 or the negative electrode current collector 26 is used, it is almost the same. In this case, an example of producing a nickel-hydrogen storage battery using the negative electrode current collector 25 will be described. .

まず、パンチングメタルからなる極板芯体の表面にニッケル焼結多孔体を形成した後、化学含浸法により水酸化ニッケルを主体とする活物質を同ニッケル焼結多孔体内に充填する。ついで、これを乾燥させた後、所定の厚みになるまで圧延し、所定の寸法になるように切断してニッケル正極板を作製する。また、パンチングメタルからなる極板芯体の表面に水素吸蔵合金からなるペースト状負極活物質を塗布し、乾燥させた後、所定の厚みになるまで圧延し、所定の寸法になるように切断して水素吸蔵合金負極板を作製する。 First, a nickel sintered porous body is formed on the surface of an electrode plate core made of punching metal, and then the nickel sintered porous body is filled with an active material mainly composed of nickel hydroxide by a chemical impregnation method. Subsequently, after drying this, it rolls until it becomes a predetermined thickness, and cut | disconnects so that it may become a predetermined dimension, and produces a nickel positive electrode plate. In addition, a paste-like negative electrode active material made of a hydrogen storage alloy is applied to the surface of an electrode plate core made of punching metal, dried, rolled to a predetermined thickness, and cut to a predetermined size. Thus, a hydrogen storage alloy negative electrode plate is produced.

これらのニッケル正極板と水素吸蔵合金負極板との間にセパレータを介在させて渦巻状に巻回して渦巻状電極群２３を作製する。この後、図５，６に示すように、この渦巻状電極群２３の下端面に露出するニッケル正極板の極板芯体に正極集電体２４を溶接する。また、渦巻状電極群２３の上端面に露出する水素吸蔵合金負極板の極板芯体に負極集電体２５を溶接して電極体とする。この後、鉄にニッケルメッキを施した有底筒状の外装缶（底面の外面は負極外部端子となる）２１内に収納し、水素吸蔵合金負極板に溶接された負極集電体２５を外装缶２１の内底面に溶接する。 A spiral electrode group 23 is manufactured by winding a separator between the nickel positive electrode plate and the hydrogen storage alloy negative electrode plate. Thereafter, as shown in FIGS. 5 and 6, the positive electrode current collector 24 is welded to the electrode plate core body of the nickel positive electrode plate exposed at the lower end surface of the spiral electrode group 23. Further, the negative electrode current collector 25 is welded to the electrode plate core body of the hydrogen storage alloy negative electrode plate exposed at the upper end surface of the spiral electrode group 23 to form an electrode body. Thereafter, the negative electrode current collector 25 which is housed in a bottomed cylindrical outer can made of nickel-plated iron (the outer surface of the bottom surface becomes a negative electrode external terminal) 21 and welded to the hydrogen storage alloy negative electrode plate is packaged. Weld to the inner bottom surface of the can 21.

これにより、図２に示すように、負極集電体２５の中心部に溶接点２５ｄが形成される（負極集電体２６を用いた場合は、図４に示すような溶接点２６ｄとなる）こととなる。ついで、封口体２２の底面に正極集電体２４から延出した正極用リード２４ａを溶接する。なお、封口体２２の下部には正極キャップ（正極外部端子）２２ａが設けられており、この正極キャップ２２ａ内には弁板２２ｂとスプリング２２ｃからなる弁体を備えている。また、封口体２２の中央にはガス抜き孔が形成されている。そして、封口体２２の周縁には、予め絶縁ガスケット２７が嵌着されている。 As a result, as shown in FIG. 2, a welding point 25d is formed at the center of the negative electrode current collector 25 (when the negative electrode current collector 26 is used, the welding point 26d is as shown in FIG. 4). It will be. Next, the positive electrode lead 24 a extending from the positive electrode current collector 24 is welded to the bottom surface of the sealing body 22. A positive electrode cap (positive electrode external terminal) 22a is provided below the sealing body 22, and a valve element including a valve plate 22b and a spring 22c is provided in the positive electrode cap 22a. A gas vent is formed in the center of the sealing body 22. An insulating gasket 27 is fitted on the periphery of the sealing body 22 in advance.

ついで、外装缶２１の上部内周側に防振リング（図示せず）を挿入し、外装缶２１の上部外周側に溝入れ加工を施して防振リングの上端部に環状凹部２１ａを形成する。この後、外装缶２１内に３０質量％の水酸化カリウム（ＫＯＨ）水溶液からなるアルカリ電解液を注入する。この後、外装缶２１の開口端縁を内方にかしめて電池を封口することにより単電池２０ａ，２０ｂ・・・となるニッケル−水素蓄電池が得られる。 Next, an anti-vibration ring (not shown) is inserted into the upper inner peripheral side of the outer can 21, and a groove is formed on the upper outer peripheral side of the outer can 21 to form an annular recess 21 a at the upper end of the anti-vibration ring. . Thereafter, an alkaline electrolyte made of a 30% by mass potassium hydroxide (KOH) aqueous solution is injected into the outer can 21. Then, the nickel-hydrogen storage battery used as unit cell 20a, 20b ... is obtained by crimping the opening edge of the armored can 21 inward and sealing a battery.

３．組電池
ついで、上述のように作製されたニッケル−水素蓄電池（単電池）の複数個を用いて、これらの各単電池２０ａ，２０ｂ・・・の間に金属製接続部材１０を介在させて、各単電池２０ａ，２０ｂ・・・を直列に接続して組電池とする例について、以下に説明する。なお、ここでは、単電池として、負極集電体２５を用いて作製したニッケル−水素蓄電池を用いているので、上述した第１の接続状態となるような配置構造が採用される。即ち、平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａが外装缶２１の底面に溶接され、膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃが封口体２２に溶接されるような配置構造となる。 3. Next, using a plurality of nickel-hydrogen storage batteries (unit cells) produced as described above, a metal connecting member 10 is interposed between these unit cells 20a, 20b,. An example in which the unit cells 20a, 20b,... Are connected in series to form a battery pack will be described below. Here, since the nickel-hydrogen storage battery manufactured using the negative electrode current collector 25 is used as the unit cell, the arrangement structure that achieves the first connection state described above is employed. That is, four projection projections (first projection portions) 11 a formed on the flat surface portion (flange portion) 11 are welded to the bottom surface of the outer can 21, and four projection projections formed on the bulging portion 12. The arrangement structure is such that the (second protrusion) 12 c is welded to the sealing body 22.

まず、図示しない絶縁性を有する載置台の上に複数個（例えば、４〜６個で、この場合は５個とする）の各単電池２０ａ，２０ｂ・・・を一列に整列配置するとともに、各単電池２０ａ，２０ｂ・・・の間に金属製接続部材１０を配置する。このとき、接続部材１０が金属製外装缶２１の開口端縁のかしめ部に接触すると短絡が生じるため、このかしめ部と接続部材１０との間に円筒状絶縁体（図示せず）を配設するのが好ましい。そして、図５および図６に示すように、平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａが外装缶２１の底面に当接し、膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃが封口体２２に当接するように配置する。 First, a plurality of (for example, 4-6, 5 in this case) unit cells 20a, 20b,... Are arranged in a row on an insulating mount (not shown). The metal connection member 10 is disposed between the unit cells 20a, 20b,. At this time, when the connecting member 10 comes into contact with the caulking portion of the opening edge of the metal outer can 21, a short circuit occurs. Therefore, a cylindrical insulator (not shown) is disposed between the caulking portion and the connecting member 10. It is preferable to do this. As shown in FIGS. 5 and 6, the four projection projections (first projection portions) 11 a formed on the flat surface portion (flange portion) 11 abut against the bottom surface of the outer can 21, and the bulging portion 12. The four projection projections (second projections) 12 c formed in the above are arranged so as to contact the sealing body 22.

ついで、図示しない一方の加圧部材を先頭の単電池の封口体２２に押し当てるとともに、他方の加圧部材を最末尾の単電池の外装缶２１の底面に押し当てる。なお、これらの加圧部材の少なくとも一方には、コイルスプリングやエアシリンダなどの加圧手段が設けられており、この加圧手段により、これらの各単電池２０ａ，２０ｂ・・・間は所定の圧力（例えば、３００Ｎ／ｍ²の圧力）で押圧されるようになされている。 Next, one pressure member (not shown) is pressed against the sealing body 22 of the first unit cell, and the other pressure member is pressed against the bottom surface of the outer can 21 of the last unit cell. Note that at least one of these pressurizing members is provided with pressurizing means such as a coil spring or an air cylinder, and by this pressurizing means, there is a predetermined space between each of the unit cells 20a, 20b. The pressure is applied (for example, a pressure of 300 N / m ² ).

ついで、一対の溶接電極（図示せず）を用意した後、先頭の単電池の外装缶２１に一方の溶接電極を押し当て、最末尾の単電池の外装缶２１に他方の溶接電極を押し当てる。ついで、溶接用電源を駆動させて、一対の溶接電極間に所定の電圧値の直流電圧を印加（この場合は、５．０ｋＡのパルス電流が５０ｍｓ間流れるように印加）する。これにより、例えば、単電池２０ａと２０ｂとの間においては、単電池２０ａの外装缶２１→単電池２０ａの外装缶２１の底面と接続部材１０の平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａ→接続部材１０の膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃ→単電池２０ｂの封口体２２→単電池２０ｂ内の順に、溶接電流（例えば、５．０ｋＡの直流パルス電流）が所定の時間（例えば、５０ｍｓ）だけ流れるようになる。 Then, after preparing a pair of welding electrodes (not shown), one welding electrode is pressed against the outer can 21 of the first unit cell, and the other welding electrode is pressed against the outer can 21 of the last unit cell. . Next, the welding power source is driven to apply a DC voltage having a predetermined voltage value between the pair of welding electrodes (in this case, a 5.0 kA pulse current is applied for 50 ms). Thereby, for example, between the unit cells 20a and 20b, 4 formed on the outer can 21 of the unit cell 20a → the bottom surface of the outer can 21 of the unit cell 20a and the flat portion (flange portion) 11 of the connecting member 10. Projection projections (first projections) 11a → 4 projection projections (second projections) 12c formed on the bulging part 12 of the connection member 10 → sealing body 22 of the unit cell 20b → unit cell 20b In this order, a welding current (for example, a direct current pulse current of 5.0 kA) flows for a predetermined time (for example, 50 ms).

上述のように、各単電池２０ａ，２０ｂ・・・間に所定の圧力（例えば、３００Ｎ／ｍ²の圧力）を付与して押圧し、かつ一対の溶接電極間に所定の電圧値の直流電圧を印加すると、例えば、単電池２０ａの外装缶２１の底面と接続部材１０との接触部（４か所のプロジェクション突起１１ａが形成された部位）、および単電池２０ｂの封口体２２と接続部材１０との接触部（４か所のプロジェクション突起１２ｃが形成された部位）にジュール熱が発生して溶融するため、各接触部が溶接されるようになる。これにより、接続部材１０を介して単電池２０ａ，２０ｂ・・・の間が直列に接続して溶接された組電池２０が作製されることとなる。 As described above, a predetermined pressure (for example, a pressure of 300 N / m ² ) is applied between each unit cell 20a, 20b... And pressed, and a DC voltage having a predetermined voltage value is set between the pair of welding electrodes. Is applied, for example, the contact portion between the bottom surface of the outer can 21 of the unit cell 20a and the connection member 10 (the portion where the four projection protrusions 11a are formed), and the sealing body 22 and the connection member 10 of the unit cell 20b. Joule heat is generated and melted at the contact portions (portions where the four projection projections 12c are formed), so that each contact portion is welded. Thereby, the assembled battery 20 in which the cells 20a, 20b,... Are connected in series via the connecting member 10 and welded is produced.

この場合、各単電池２０ａ，２０ｂ・・・に配設された負極集電体２５は、図１，２，５，６に示すように、金属製接続部材１０の平面部（フランジ部）１１に形成された４か所のプロジェクション突起１１ａで形成される同心円の領域ｘに対応する領域Ｘには、図６の点線のＡ−Ａ線やＢ−Ｂ線で示すように、バーリング孔２５ａやスリット２５ｂが形成されていない。このため、上述した溶接において、外装缶２１の底面と負極集電体２５との間にスパッタが発生したとしても、発生したスパッタがバーリング孔２５ａやスリット２５ｂを介して電極群の内部に飛散することが防止できるようになる。 In this case, the negative electrode current collector 25 disposed in each of the unit cells 20a, 20b,... Is a flat portion (flange portion) 11 of the metal connecting member 10, as shown in FIGS. In the region X corresponding to the concentric region x formed by the four projection protrusions 11a formed in the burring holes 25a and BB as shown by dotted lines AA and BB in FIG. The slit 25b is not formed. For this reason, in the above-described welding, even if spatter is generated between the bottom surface of the outer can 21 and the negative electrode current collector 25, the generated spatter is scattered inside the electrode group through the burring hole 25a and the slit 25b. Can be prevented.

また、負極集電体２６を用いて単電池２０ａ，２０ｂ・・・となるニッケル−水素蓄電池を作製した場合においては、上述した第２の接続状態となるような配置構造が採用される。即ち、膨出部１２に形成された４か所のプロジェクション突起（第２突起部）１２ｃが外装缶２１の底面に溶接され、平面部（フランジ部）１１に形成された４か所のプロジェクション突起（第１突起部）１１ａが封口体２２に溶接されるような配置構造となされる。このため、負極集電体２６を用いた場合であっても、金属製接続部材１０の膨出部１２に形成された４か所のプロジェクション突起１２ｃで形成される同心円の領域ｙに対応する領域Ｙには、バーリング孔２６ａやスリット２６ｂが形成されていない。このため、上述した溶接において、外装缶２１の底面と負極集電体２６との間にスパッタが発生したとしても、発生したスパッタがバーリング孔２６ａやスリット２６ｂを介して電極群の内部に飛散することが防止できるようになる。 Moreover, when the nickel-hydrogen storage battery used as the cell 20a, 20b ... is produced using the negative electrode collector 26, the arrangement structure which will be in the 2nd connection state mentioned above is employ | adopted. That is, four projection protrusions (second protrusions) 12 c formed on the bulging portion 12 are welded to the bottom surface of the outer can 21, and four projection protrusions formed on the flat surface portion (flange portion) 11. The arrangement structure is such that the (first protrusion) 11 a is welded to the sealing body 22. For this reason, even when the negative electrode current collector 26 is used, a region corresponding to the concentric region y formed by the four projection protrusions 12 c formed on the bulging portion 12 of the metal connection member 10. In Y, the burring hole 26a and the slit 26b are not formed. For this reason, in the above-described welding, even if spatter is generated between the bottom surface of the outer can 21 and the negative electrode current collector 26, the generated spatter is scattered inside the electrode group through the burring hole 26a and the slit 26b. Can be prevented.

なお、上述した実施の形態においては、金属製接続部材１０を介して複数個の単電池２０ａ，２０ｂ・・・を一列に整列配置した後、先頭の単電池の外装缶に一方の溶接電極を押し当て、最末尾の単電池の外装缶に他方の溶接電極を押し当てて、複数個の単電池間を同時に溶接する例について説明したが、本発明の組電池においてはこのような溶接法に限られることはない。例えば、各単電池２０ａ，２０ｂ・・・の封口体あるいは外装缶の底面の一方に金属製接続部材１０を溶接した後、これらを一列に整列配置した後、先頭の単電池の外装缶に一方の溶接電極を押し当て、最末尾の単電池の外装缶に他方の溶接電極を押し当てて、未溶接部を溶接するようにしてもよい。
また、上述した実施の形態においては、４か所のプロジェクション突起（第１突起部）１１ａ、および４か所のプロジェクション突起（第２突起部）１２ｃを設ける例について説明したが、各プロジェクション突起の数はこれに限られることなく、適宜、増減できるのは勿論である。 In the above-described embodiment, a plurality of unit cells 20a, 20b,... Are arranged in a line through the metal connection member 10, and then one welding electrode is attached to the outer can of the first unit cell. Although the example in which the other welding electrode is pressed against the outer can of the single cell at the end and the plurality of single cells are welded at the same time has been described, in the assembled battery of the present invention, such a welding method is used. There is no limit. For example, after welding the metal connection member 10 to one of the sealing body of each unit cell 20a, 20b ... or the bottom surface of the outer can, these are aligned and arranged in a line, and then one side is placed on the outer can of the first unit cell. The other welding electrode may be pressed against the outer can of the last cell, and the unwelded portion may be welded.
In the above-described embodiment, the example in which the four projection projections (first projection portions) 11a and the four projection projections (second projection portions) 12c are provided has been described. Of course, the number is not limited to this and can be increased or decreased as appropriate.

本発明の金属製接続部材を模式的に示す図であり、図１（ａ）はその上面図であり、図１（ｂ）はその側面図である。It is a figure which shows typically the metal connection member of this invention, Fig.1 (a) is the top view, FIG.1 (b) is the side view. 単電池に用いられる第１実施例の負極集電体を模式的に示す上面図である。It is a top view which shows typically the negative electrode electrical power collector of 1st Example used for a cell. 図１と同様な金属製接続部材を模式的に示す図であり、図３（ａ）はその下面図であり、図３（ｂ）はその側面図である。It is a figure which shows typically the metal connection members similar to FIG. 1, FIG. 3 (a) is the bottom view, FIG.3 (b) is the side view. 単電池に用いられる第２実施例の負極集電体を模式的に示す上面図である。It is a top view which shows typically the negative electrode electrical power collector of 2nd Example used for a cell. 一方の単電池に相隣接する他方の単電池が金属製接続部材によって直列接続される状態を模式的に示す一部破断の側面図である。It is a partially broken side view which shows typically the state by which the other unit cell adjacent to one unit cell is connected in series by the metal connection member. 一方の単電池に相隣接する他方の単電池が金属製接続部材によって直列接続された状態を模式的に示す断面図である。It is sectional drawing which shows typically the state by which the other unit cell adjacent to one unit cell was connected in series by the metal connection member. 従来例の一方の単電池に相隣接する他方の単電池が金属製接続部材によって直列接続される状態を模式的に示す一部破断の側面図である。It is a partially broken side view which shows typically the state by which the other unit cell adjacent to one unit cell of a prior art example is connected in series by the metal connection member. 従来例の一方の単電池に相隣接する他方の単電池が金属製接続部材によって直列接続された状態を模式的に示す断面図である。It is sectional drawing which shows typically the state by which the other unit cell adjacent to one unit cell of a prior art example was connected in series by the metal connection member. 単電池に用いられる従来例の負極集電体を模式的に示す上面図である。It is a top view which shows typically the negative electrode collector of the prior art example used for a cell.

Explanation of symbols

１０…金属製接続部材、１１…平面部（フランジ部）、１１ａ…プロジェクション突起（第１突起部）、１２…膨出部、１２ａ…中心開口、１２ｂ…スリット部、１２ｃ…プロジェクション突起（第２突起部）、ｘ…プロジェクション突起（第１突起部）の形成領域、ｙ…プロジェクション突起（第２突起部）の形成領域、２０…組電池、２０ａ…単電池，２０ｂ…単電池、２１…金属製外装缶、２１ａ…環状凹部、２２…封口体、２２ａ…正極キャップ、２３…電極群、２４…正極集電体、２５…負極集電体、２５ａ…バーリング孔、２５ｂ…スリット、２５ｃ…略Ｕ字状スリット、２５ｄ…溶接点、Ｘ…無孔の領域、２６…負極集電体、２６ａ…バーリング孔、２６ｂ…スリット、２６ｄ…溶接点、Ｙ…無孔の領域、２７…絶縁ガスケット DESCRIPTION OF SYMBOLS 10 ... Metal connection member, 11 ... Planar part (flange part), 11a ... Projection protrusion (1st protrusion part), 12 ... Projection part, 12a ... Center opening, 12b ... Slit part, 12c ... Projection protrusion (2nd Projection projection), x ... Projection projection (first projection) formation region, y ... Projection projection (second projection) formation region, 20 ... Battery, 20a ... Single cell, 20b ... Single cell, 21 ... Metal Canned outer case, 21a ... annular recess, 22 ... sealing body, 22a ... positive electrode cap, 23 ... electrode group, 24 ... positive electrode current collector, 25 ... negative electrode current collector, 25a ... burring hole, 25b ... slit, 25c ... abbreviated U-shaped slit, 25d ... welding point, X ... non-porous region, 26 ... negative current collector, 26a ... burring hole, 26b ... slit, 26d ... welding point, Y ... non-porous region, 27 ... insulating gasket

Claims

The bottom surface of the outer can serving as the negative electrode external terminal of one unit cell and the sealing body including the positive electrode cap serving as the positive electrode external terminal of the other unit cell adjacent to the unit cell are welded to the metal connecting member. An assembled battery in which a plurality of single cells are connected in series,
The metal connecting member has a plurality of first protrusions projecting toward the bottom surface of the outer can of the one unit cell and is concentrically formed, and projects toward the sealing body of the other unit cell. A plurality of second protrusions are formed concentrically,
A negative electrode current collector is welded to one end of an electrode group consisting of a positive electrode plate, a negative electrode plate, and a separator housed in the outer can, and the negative electrode current collector is attached to the bottom surface of the outer can. Electrically connected,
The assembled battery, wherein the negative electrode current collector is formed with a number of burring holes and slits excluding a portion facing the concentric circle formed by the first protrusion of the metal connecting member.

The bottom surface of the outer can serving as the negative electrode external terminal of one unit cell and the sealing body including the positive electrode cap serving as the positive electrode external terminal of the other unit cell adjacent to the unit cell are welded to the metal connecting member. An assembled battery in which a plurality of single cells are connected in series,
The metal connecting member has a plurality of second protrusions projecting toward the bottom surface of the outer can of the one unit cell and is concentrically formed, and projects toward the sealing body of the other unit cell. A plurality of first protrusions are formed concentrically,
A negative electrode current collector is welded to one end of an electrode group consisting of a positive electrode plate, a negative electrode plate, and a separator housed in the outer can, and the negative electrode current collector is attached to the bottom surface of the outer can. Electrically connected,
The assembled battery, wherein a plurality of burring holes and slits are formed in the negative electrode current collector except for a portion facing a concentric circle formed by the second protrusion of the metal connecting member.

The diameter of the concentric circle formed by the first protrusion is smaller than the diameter of the bottom surface of the outer can and larger than the diameter of the concentric circle formed by the second protrusion. The assembled battery according to claim 1 or 2.