JP5383154B2

JP5383154B2 - Cylindrical secondary battery

Info

Publication number: JP5383154B2
Application number: JP2008281545A
Authority: JP
Inventors: 竜山下; 篤俊赤穗; 誠越智; 裕政杉井; 祐二篠原; 和洋北岡
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2008-10-31
Filing date: 2008-10-31
Publication date: 2014-01-08
Anticipated expiration: 2028-10-31
Also published as: JP2010108847A

Description

本発明は、ニッケル−水素蓄電池、ニッケル−カドミウム蓄電池などの二次電池に係り、特に、セパレータを間にして正極板と負極板とが渦巻状に巻回された渦巻状電極群の上部より延出する一方極の芯体に一方極の集電体が溶接されているとともに、当該集電体が円筒状の金属製外装缶の開口部を封止する封口体に内部空間が形成された集電リードを介して溶接された円筒型二次電池に関する。 The present invention relates to a secondary battery such as a nickel-hydrogen storage battery or a nickel-cadmium storage battery, and in particular, extends from an upper part of a spiral electrode group in which a positive electrode plate and a negative electrode plate are wound spirally with a separator interposed therebetween. A collector in which a current collector of one electrode is welded to a core body of the one electrode to be taken out and an inner space is formed in a sealing body that seals an opening of a cylindrical metal outer can. The present invention relates to a cylindrical secondary battery welded via an electric lead.

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円筒型二次電池は、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。このような円筒型二次電池が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、電池内部の抵抗を低減する必要がある。 In general, a cylindrical secondary battery such as a nickel-hydrogen storage battery or a nickel-cadmium storage battery interposes a separator between a positive electrode and a negative electrode, winds them in a spiral shape, and then collects current at the ends of the positive electrode and the negative electrode. After forming the electrode body by connecting the bodies, housing the electrode body in a metal outer can and welding the lead portion extending from the positive electrode current collector to the sealing body, the sealing body is insulated from the opening of the outer can It is hermetically sealed by mounting with a gasket interposed. When such a cylindrical secondary battery is used for an electric vehicle such as HEV (Hybrid Electric Vehicles) or PEV (Pure Electric Vehicles), high output is required, and thus it is necessary to reduce the resistance inside the battery. is there.

そこで、例えば、特許文献１（特開２００４−２３５０３６号公報）にて、電池内部の抵抗を低減するための手法が提案されるようになった。この特許文献１で提案された内部抵抗低減化の手法においては、正極集電体と封口体との間を筒状の集電リードで溶接して接続するようになされている。このような筒状の集電リードを用いることにより、正極集電体と封口体との間の集電経路が短くなるため、内部抵抗を低減させることが可能となる。 Therefore, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-235036) has proposed a method for reducing the resistance inside the battery. In the method of reducing internal resistance proposed in Patent Document 1, a positive electrode current collector and a sealing body are welded and connected with a cylindrical current collector lead. By using such a cylindrical current collecting lead, the current collecting path between the positive electrode current collector and the sealing body is shortened, so that the internal resistance can be reduced.

ところで、上述した特許文献１にて提案された筒状の集電リード３０においては、図６に示されるように、正極集電体４５と溶接される底部３２と、封口体４８（図１０参照）と溶接される頂部３１とが形成されている。そして、頂部３１で連続し、底部３２の中央部で突き合わされ、かつ底部３２は頂部３１よりも突出するように予め所定形状に形成された金属板を折り曲げ成型することにより形成されている。ここで、底部３２の中央部に対して対称の位置に正極集電体４５との溶接点となる突起部（プロジェクション突起）３２ｂが形成されていて、正極集電体４５に集電リード３０が溶接されることとなる。 Incidentally, in the cylindrical current collecting lead 30 proposed in Patent Document 1 described above, as shown in FIG. 6, a bottom portion 32 welded to the positive electrode current collector 45 and a sealing body 48 (see FIG. 10). ) And the top 31 to be welded. And it continues by the top part 31, is faced | matched by the center part of the bottom part 32, and the bottom part 32 is formed by bending and forming the metal plate previously formed in the predetermined shape so that it may protrude rather than the top part 31. Here, protrusions (projection protrusions) 32b that are welding points with the positive electrode current collector 45 are formed at positions symmetrical to the center of the bottom 32, and the current collector lead 30 is provided on the positive electrode current collector 45. It will be welded.

この場合、溶接点となる各突起部（プロジェクション突起）３２ｂは底部３２の中央部の中間点を中心とする同心円上に位置するように形成されることとなる。なお、頂部３１の中心部には中心開口３１ａが形成されているとともに、この中心開口３１ａの周囲に中心開口３１ａの中心部を中心とする同心円上に位置するように封口体（図示せず）との溶接点となる突起部（プロジェクション突起）３１ｂが形成されていて、封口体４８（図１０参照）に集電リード３０が溶接されることとなる。
特開２００４−２３５０３６号公報 In this case, each projection (projection projection) 32b serving as a welding point is formed so as to be located on a concentric circle centering on an intermediate point of the center of the bottom 32. A central opening 31a is formed in the central portion of the top portion 31 and a sealing body (not shown) is disposed around the central opening 31a so as to be located on a concentric circle centering on the central portion of the central opening 31a. The projection part (projection protrusion) 31b used as the welding point is formed, and the current collecting lead 30 is welded to the sealing body 48 (see FIG. 10).
Japanese Patent Laid-Open No. 2004-235036

ところが、正極集電体４５との溶接点となる各突起部（プロジェクション突起）３２ｂが底部３２の限られた平面上に形成されているため、突起部（プロジェクション突起）３２ｂの配置個数には限界があった。このため、渦巻状電極群の複数箇所から均等に集電できないこととなり、集電性に不均一性が生じるという問題を生じた。そして、この集電性の不均一性に起因して、内部抵抗が増大し、結果的に抵抗発熱が増大して出力ロスが発生するという問題を生じた。 However, since each protrusion (projection protrusion) 32b that becomes a welding point with the positive electrode current collector 45 is formed on a limited plane of the bottom 32, the number of protrusions (projection protrusions) 32b is limited. was there. For this reason, current collection cannot be performed uniformly from a plurality of locations of the spiral electrode group, resulting in a problem of non-uniformity in current collection. Further, due to the non-uniformity of the current collecting property, the internal resistance increases, resulting in a problem that resistance heat generation increases and output loss occurs.

この場合、集電リードのサイズを大きくすることで、電極群の複数箇所からの集電が可能となる。ところが、集電リードのサイズを大きくすると、集電リードの強度が大きくなりすぎることとなる。このため、封口体の集電リードとの溶接時および封口時に集電リードが潰れ難くなるという問題が生じるようになり、電池全高のバラツキが発生するようになって、本来の集電リードの機能が維持できなくなってしまうという新たな問題を生じるようになった。 In this case, it is possible to collect current from a plurality of locations in the electrode group by increasing the size of the current collecting lead. However, when the size of the current collecting lead is increased, the strength of the current collecting lead becomes too large. For this reason, the problem that the current collecting lead becomes difficult to be crushed during welding and sealing with the current collecting lead of the sealing body, and the variation of the total battery height occurs, and the function of the original current collecting lead is generated. Has become a new problem that can no longer be maintained.

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、筒状（内部空間が形成されたもの）の集電リードを用いても電極群の内外周部から均等に集電できるようにして内部抵抗が低減した円筒型二次電池を提供できるようにすることを目的とするものである。 Therefore, the present invention has been made in view of the above problems, and even when a cylindrical (with an internal space) current collecting lead is used, current can be collected evenly from the inner and outer peripheral portions of the electrode group. Thus, an object of the present invention is to provide a cylindrical secondary battery with reduced internal resistance.

本発明の円筒型二次電池は、セパレータを間にして正極板と負極板とが渦巻状に巻回された渦巻状電極群の上部より延出する一方極の芯体に一方極の集電体が溶接されているとともに、当該集電体が円筒状の金属製外装缶の開口部を封止する封口体に内部空間が形成された集電リードを介して溶接されている。そして、上記目的を達成するため、内部空間が形成された集電リードは１枚の金属板の折曲加工により形成されていて、集電体に溶接された底部と封口体に溶接された頂部とを備えており、底部は頂部を間にして互いに相対向するように位置した２つの同一形状の半円形状部からなるとともに当該２つの半円形状部により形成される外形形状は集電体の外形形状と略同一になるようになされており、頂部は底部より連続して立設するとともに内部空間が形成されるように折曲して形成されている。さらに、底部の２つの半円形状部にはそれぞれ当該底部より前記集電体に向けて突出する複数のプロジェクション突起が形成されていて当該複数のプロジェクション突起が集電体との溶接点となされているとともに、頂部の中心部には中心開口が形成されていて当該中心開口の周囲に当該頂部より封口体に向けて突出する複数のプロジェクション突起が形成されて当該複数のプロジェクション突起が封口体との溶接点となされていることを特徴とする。
The cylindrical secondary battery of the present invention has a current collector of one electrode on a core of one electrode extending from the upper part of a spiral electrode group in which a positive electrode plate and a negative electrode plate are wound in a spiral shape with a separator in between. While the body is welded, the current collector is welded via a current collecting lead in which an internal space is formed in a sealing body that seals an opening of a cylindrical metal outer can. And in order to achieve the said objective, the current collection lead in which the interior space was formed is formed by the bending process of one metal plate, and the top part welded to the sealing part and the bottom part welded to the current collector And the bottom part is composed of two semicircular parts of the same shape positioned so as to face each other with the top part in between, and the outer shape formed by the two semicircular parts is a current collector The top part is formed so as to be continuously provided from the bottom part and bent so that an internal space is formed . Further, a plurality of projection protrusions projecting from the bottom portion toward the current collector are formed on the two semicircular portions at the bottom, respectively, and the plurality of projection protrusions serve as welding points with the current collector. In addition, a central opening is formed in the center of the top, and a plurality of projection protrusions projecting from the top toward the sealing body are formed around the central opening, and the plurality of projection protrusions are connected to the sealing body. It is characterized by being a welding point .

ここで、底部は２つの同一形状の半円形状部からなり、これらの２つの半円形状部により形成される外形形状が集電体の外形形状と略同一になるようになされていると、極板の各部から均等に集電することが可能となり、電極群の内外周から効率良く集電リードに電流が流れるようになる。また、頂部は底部より連続して立設するとともに内部空間が形成されるように折曲して形成されていると、集電リードから封口体に効率良く電流が流れるようになる。この結果、電池の内部抵抗が低減できるようになって、高出力な円筒型二次電池を提供することが可能となる。
そして、底部の２つの半円形状部にはそれぞれ当該底部より集電体に向けて突出する複数のプロジェクション突起が形成されていて当該複数のプロジェクション突起が集電体との溶接点となされているとともに、頂部の中心部には中心開口が形成されていて当該中心開口の周囲に当該頂部より封口体に向けて突出する複数のプロジェクション突起が形成されて当該複数のプロジェクション突起が封口体との溶接点となされていると、極板の各部から抵抗損失を伴うことなく、均等に集電することが可能となる。これにより、電極群の内外周から抵抗損失を伴うことなく、効率良く集電リードに電流が流れるようになる。
Here, the bottom portion is composed of two semicircular portions having the same shape, and the outer shape formed by these two semicircular portions is substantially the same as the outer shape of the current collector. It becomes possible to collect current evenly from each part of the electrode plate, and current flows efficiently from the inner and outer circumferences of the electrode group to the current collecting lead. In addition, when the top portion is continuously formed from the bottom portion and is bent so as to form an internal space, a current efficiently flows from the current collecting lead to the sealing body. As a result, the internal resistance of the battery can be reduced, and a high-power cylindrical secondary battery can be provided.
The two semicircular portions at the bottom are each formed with a plurality of projection protrusions protruding from the bottom toward the current collector, and the plurality of projection protrusions serve as welding points with the current collector. In addition, a central opening is formed at the center of the top, and a plurality of projection protrusions projecting from the top toward the sealing body are formed around the central opening, and the plurality of projection protrusions are welded to the sealing body. If it is set as a point, it will become possible to collect current equally from each part of an electrode plate, without being accompanied by resistance loss. As a result, current flows efficiently from the inner and outer peripheries of the electrode group to the current collecting lead without causing a resistance loss.

この場合、底部は中央部と略半円形状の第１半円形状部と略半円形状の第２半円形状部とからなるとともに、これらの第１半円形状部と第２半円形状部とが中央部を間にして互いに相対向して位置していて、これらの第１半円形状部と第２半円形状部とにより形成さ
れた外形形状は集電体の外形形状と略同一になるようになされており、頂部は略長方形状の第１長方形状部と略長方形状の第２長方形状部とからなるとともに、これらの第１長方形状部と第２長方形状部は底部の中央部より連続して立設するとともに内部空間が形成されるように折曲されて互いに相対向するように形成されているようにすればよい。
さらに、集電リードと集電体とを強固に溶接するためには、複数のプロジェクション突起は集電体に形成された開口に一致しない位置に形成する必要がある。なお、第１半円形状部および第２半円形状部の少なくとも一方には集電体に形成された開口に一致する位置決め用の開口が形成されていると、この集電リードを集電体に配置する際の位置決めが容易になって好ましい。
In this case, the bottom portion is composed of a central portion, a substantially semicircular first semicircular shape portion and a substantially semicircular second semicircular shape portion, and these first semicircular shape portion and second semicircular shape. The outer shape formed by the first semicircular portion and the second semicircular portion is substantially the same as the outer shape of the current collector. The top part is composed of a substantially rectangular first rectangular part and a substantially rectangular second rectangular part, and the first rectangular part and the second rectangular part are bottom parts. It is sufficient to be formed so as to be opposed to each other by being bent continuously so as to form an internal space while being continuously provided from the central portion.
Furthermore, in order to firmly weld the current collector lead and the current collector, the plurality of projection protrusions need to be formed at positions that do not coincide with the openings formed in the current collector. When at least one of the first semicircular part and the second semicircular part has a positioning opening that matches the opening formed in the current collector, the current collector lead is connected to the current collector. Positioning at the time of disposing is easy and preferable.

または、底部は頂部を間にして互いに相対向するように配置された略半円形状の第１半円形状部と略半円形状の第２半円形状部とからなるとともに、これらの第１半円形状部と第２半円形状部とにより形成された外形形状は集電体の外形形状と略同一になるようになされており、頂部は第１半円形状部との境界部および第２半円形状部との境界部を折曲加工ならび押圧加工することにより形成されていて、これらの第１半円形状部および第２半円形状部に連続して立設するとともに内部空間が形成されるように折曲されて形成されているようにしてもよい。 Alternatively, the bottom portion includes a substantially semicircular first semicircular portion and a substantially semicircular second semicircular portion disposed so as to face each other with the top portion therebetween, and the first The outer shape formed by the semicircular shape portion and the second semicircular shape portion is substantially the same as the outer shape of the current collector, and the top portion is the boundary between the first semicircular shape portion and the first shape. It is formed by bending and pressing the boundary portion with the two semicircular portions, and the internal space is erected continuously with the first semicircular portion and the second semicircular portion. You may make it be formed so that it may be formed.

本発明においては、電極群の内外周から効率良く集電リードに電流が流れるようになるため、電池の内部抵抗を低減することが可能となって、高出力な円筒型二次電池を提供することが可能となる。 In the present invention, since the current flows efficiently from the inner and outer circumferences of the electrode group to the current collecting lead, the internal resistance of the battery can be reduced, and a high-power cylindrical secondary battery is provided. It becomes possible.

以下に、本発明の円筒型二次電池の一実施の形態を図１〜図１０に基づいて説明する。この場合、円筒型二次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。なお、図１は実施例１の正極集電リードを示す図であり、図１（ａ）は折り曲げ成型により形成された正極集電リードを模式的に示す正面図であり、図１（ｂ）は、図１（ａ）のＡ矢視の側面図である。 Below, one Embodiment of the cylindrical secondary battery of this invention is described based on FIGS. In this case, the case where a nickel-hydrogen storage battery is used as the cylindrical secondary battery will be described. However, the present invention is not limited to this, and can be implemented with appropriate modifications within a range not changing the gist thereof. . 1 is a view showing a positive electrode current collecting lead of Example 1, FIG. 1 (a) is a front view schematically showing a positive electrode current collecting lead formed by bending, and FIG. 1 (b). These are side views of the arrow A in FIG.

図２は実施例１の正極集電リードを示す図であり、図２（ａ）は、図１に示す実施例１の正極集電リードの折り曲げ成型される前の状態を模式的に示す正面図であり、図２（ｂ）は、実施例１の正極集電リードを渦巻状電極群の正極板の端部に溶接された正極集電体に溶接された状態を模式的に示す正面図である。図３は実施例２の正極集電リードを示す図であり、図３（ａ）は折り曲げ成型により形成された正極集電リードを模式的に示す正面図であり、図３（ｂ）は、図３（ａ）のＡ矢視の側面図である。 2 is a view showing the positive electrode current collecting lead of Example 1, and FIG. 2A is a front view schematically showing a state before the positive electrode current collecting lead of Example 1 shown in FIG. 1 is bent. FIG. 2B is a front view schematically showing a state in which the positive electrode current collector lead of Example 1 is welded to the positive electrode current collector welded to the end of the positive electrode plate of the spiral electrode group. It is. FIG. 3 is a view showing a positive electrode current collecting lead of Example 2, FIG. 3 (a) is a front view schematically showing a positive electrode current collecting lead formed by bending, and FIG. It is a side view of the A arrow view of Fig.3 (a).

図４は実施例２の正極集電リードを示す図であり、図４（ａ）は、図３に示す実施例２の正極集電リードの折り曲げ成型される前の状態を模式的に示す正面図であり、図３（ｂ）は、実施例２の正極集電リードを渦巻状電極群の正極板の端部に溶接された正極集電体に溶接された状態を模式的に示す正面図である。図５は変形例の正極集電リードを模式的に示す正面図である。図６は比較例（従来例）の正極集電リードを示す図であり、図６（ａ）は折り曲げ成型により形成された正極集電リードを模式的に示す斜視図であり、図６（ｂ）は比較例（従来例）の正極集電リードを渦巻状電極群の正極板の端部に溶接された正極集電体に溶接された状態を模式的に示す図である。 4 is a diagram showing a positive electrode current collecting lead of Example 2, and FIG. 4A is a front view schematically showing a state before the positive electrode current collecting lead of Example 2 shown in FIG. 3 is bent. FIG. 3B is a front view schematically showing a state in which the positive electrode current collector lead of Example 2 is welded to the positive electrode current collector welded to the end of the positive electrode plate of the spiral electrode group. It is. FIG. 5 is a front view schematically showing a modified positive electrode current collecting lead. 6 is a view showing a positive electrode current collecting lead of a comparative example (conventional example), and FIG. 6 (a) is a perspective view schematically showing a positive electrode current collecting lead formed by bending, and FIG. ) Is a diagram schematically showing a state in which the positive electrode current collector lead of the comparative example (conventional example) is welded to the positive electrode current collector welded to the end of the positive electrode plate of the spiral electrode group.

図７は渦巻状電極群を模式的に示す斜視図である。図８は、図７に示す渦巻状電極群の両端部に溶接される集電体を示す図であり、図８（ａ）は負極集電体を模式的に示す正面図であり、図８（ｂ）は正極集電体を模式的に示す正面図である。図９は外装缶内に収納された渦巻状電極群の一方の端部に接続された正極集電体の上に、本発明の正極集電リードと、封口体を配置した後、これらを溶接する状態を模式的に示す断面図である。図１０は本発明のニッケル−水素蓄電池を模式的に示す断面図である。 FIG. 7 is a perspective view schematically showing a spiral electrode group. 8 is a view showing a current collector welded to both ends of the spiral electrode group shown in FIG. 7, and FIG. 8 (a) is a front view schematically showing the negative electrode current collector. (B) is a front view schematically showing a positive electrode current collector. FIG. 9 shows a case where the positive electrode current collector lead of the present invention and a sealing body are arranged on the positive electrode current collector connected to one end of the spiral electrode group housed in the outer can, and these are welded. It is sectional drawing which shows the state to do typically. FIG. 10 is a cross-sectional view schematically showing a nickel-hydrogen storage battery of the present invention.

１．正極集電リード
（１）実施例１
本実施例１の正極集電リード１０はニッケルめっきが施された鋼板（この場合は、厚さが０．４ｍｍのものとした）が所定の筒状形状になるように、打ち抜き加工および折曲加工することにより形成されたものである。そして、図１（ａ）に示すように、中心開口１２ａを備えて後述する正極集電体４５に溶接された底部１１と、中心開口１８を備えて後述する封口体４８（図１０参照のこと）の底面に溶接される頂部１５とを備えている。 1. Positive electrode current collector lead (1) Example 1
The positive electrode current collector lead 10 of Example 1 is punched and bent so that a nickel-plated steel plate (in this case, a thickness of 0.4 mm) has a predetermined cylindrical shape. It is formed by processing. As shown in FIG. 1 (a), a bottom 11 provided with a central opening 12a and welded to a positive electrode current collector 45 described later, and a sealing body 48 provided with a central opening 18 (see FIG. 10). ) And a top portion 15 welded to the bottom surface.

ここで、底部１１は中心部に中心開口１２ａを有する中央部（図２（ａ）参照）１２を間にして互いに相対向するように配置された略半円形状の第１半円形状部１３と第２半円形状部１４からなるものである。そして、これらの２つの第１半円形状部１３と第２半円形状部１４とにより形成される外形形状は正極集電体４５の外形形状と略同一になる（図２（ｂ）参照）ようになされている。この場合、これらの２つの第１半円形状部１３および第２半円形状部１４の複数箇所（この場合は、それぞれ６箇所とした）には、正極集電体４５の上面に溶接された際の溶接点となるために正極集電体４５に向けて（図１（ａ）、図２（ａ）においては紙面の表面から裏面に向けて）突出するプロジェクション突起１３ａ，１４ａがそれぞれ形成されている。これにより、正極集電体４５から正極集電リード１０に均等に集電されるようになる。 Here, the bottom portion 11 has a substantially semicircular first semicircular portion 13 disposed so as to face each other with a central portion (see FIG. 2A) 12 having a central opening 12a at the center. And the second semicircular portion 14. And the external shape formed by these two 1st semicircle-shaped parts 13 and the 2nd semicircle-shaped part 14 becomes substantially the same as the external shape of the positive electrode collector 45 (refer FIG.2 (b)). It is made like that. In this case, the two first semicircular portion 13 and the second semicircular portion 14 were welded to the upper surface of the positive electrode current collector 45 at a plurality of locations (in this case, 6 locations). Projection projections 13a and 14a projecting toward the positive electrode current collector 45 (in FIG. 1 (a) and FIG. 2 (a) from the front surface to the back surface in FIG. 2) are formed. ing. As a result, current is evenly collected from the positive electrode current collector 45 to the positive electrode current collector lead 10.

一方、頂部１５は略長方形状の第１長方形状部１６と第２長方形状１７とから構成されるとともに、これらの第１長方形状部１６と第２長方形状１７とが底部１１の中央部１２より連続して立設され（切り起こされ）、互いに相対向するように折曲加工されて形成されている。この場合、第１長方形状部１６と第２長方形状１７との先端部には半円形状に湾曲した湾曲部１６ａ，１７ａがそれぞれ形成されていて、これらの湾曲部１６ａ，１７ａが互いに相対向するように突き合わされることにより、溶接電極挿入用の円形状の中心開口１８が形成されている。 On the other hand, the top portion 15 is composed of a substantially rectangular first rectangular portion 16 and a second rectangular shape 17, and the first rectangular portion 16 and the second rectangular shape 17 are the central portion 12 of the bottom portion 11. It is formed by being continuously erected (cut and raised) and bent so as to face each other. In this case, curved portions 16a and 17a that are curved in a semicircular shape are formed at the distal ends of the first rectangular portion 16 and the second rectangular shape 17, respectively, and these curved portions 16a and 17a are opposed to each other. Thus, a circular center opening 18 for inserting the welding electrode is formed.

この場合、この中心開口１８の周囲の複数箇所（この場合は、４箇所とした）には封口体４８の底面に溶接された際の溶接点となるために封口体４８に向けて（図１（ａ）においては紙面の裏面から表面に向けて、図２（ａ）においては紙面の表面から裏面に向けて）突出するプロジェクション突起１６ｂ，１７ｂがそれぞれ形成されている。これにより、正極集電リード１０から封口体４８に均等に集電されるようになる。 In this case, a plurality of locations (in this case, four locations) around the central opening 18 are welded points when being welded to the bottom surface of the sealing body 48 and are directed toward the sealing body 48 (FIG. 1). Projection projections 16b and 17b are formed so as to protrude from the back surface to the front surface in FIG. 2A and from the front surface to the back surface in FIG. As a result, current is evenly collected from the positive electrode current collecting lead 10 to the sealing body 48.

上述の構成となる正極集電リード１０は以下のようにして作製される。まず、ニッケルめっきが施された鋼板（この場合は、厚さが０．４ｍｍのものとした）１０Ａを用意し、これを図２（ａ）に示すような形状になるように切断（打ち抜き成型）する。
即ち、中心部の中心開口１２ａと、中央部（後に折り曲げ成型されて底部の中央部となる）１２と、中央部１２の上側に延出する略半円形状の第１半円形状部（後に折り曲げ成型されて底部の一部となる）１３と、中央部１２の下側に延出する略半円形状の第２半円形状部（後に折り曲げ成型されて底部の一部となる）１４と、中央部１２の左側に延出する略長方形状の第１長方形状部１６と、中央部１２の右側に延出する略長方形状の第２長方形状部１７と、第１長方形状部１６の端部の湾曲部１６ａと、第２長方形状部１７の端部の湾曲部１７ａとが形成されるように平板状の鋼板１０Ａを打ち抜き成型する。 The positive electrode current collecting lead 10 having the above-described configuration is manufactured as follows. First, a nickel-plated steel plate (in this case, a thickness of 0.4 mm) 10A is prepared and cut (punched) into a shape as shown in FIG. 2 (a). )
That is, the central opening 12a in the central portion, the central portion (which is later bent and molded to become the central portion of the bottom portion) 12, and the substantially semicircular first semicircular portion extending to the upper side of the central portion 12 (later And a second semicircular part of a substantially semicircular shape extending below the central part 12 (which is later folded and becomes a part of the bottom part) 14. The first rectangular portion 16 having a substantially rectangular shape extending to the left side of the central portion 12, the second rectangular portion 17 having a substantially rectangular shape extending to the right side of the central portion 12, and the first rectangular portion 16 The flat steel plate 10A is stamped and formed so that the curved portion 16a at the end and the curved portion 17a at the end of the second rectangular portion 17 are formed.

これにより、平板状の鋼板１０Ａが略円形状で中央部が帯状に突出した外形形状で、その中心部に中心開口１２ａが形成されるとともに、第１半円形状部１３と第１長方形状部１６および第２長方形状部１７との間および第２半円形状部１４と第１長方形状部１６および第２長方形状部１７との間にそれぞれ切欠部ａ，ｂ，ｃ，ｄが形成されることとなる。また、第１長方形状部１６の端部に半円形状に湾曲する湾曲部１６ａが形成され、第２長方形状部１７の端部に半円形状に湾曲する湾曲部１７ａが形成されることとなる。 As a result, the flat steel plate 10A has a substantially circular shape and an outer shape in which the central portion protrudes in a band shape, and a central opening 12a is formed at the central portion, and the first semicircular portion 13 and the first rectangular portion Notches a, b, c, and d are formed between the first rectangular portion 16 and the second rectangular portion 17 and between the second semicircular portion 14 and the first rectangular portion 16 and the second rectangular portion 17, respectively. The Rukoto. Further, a curved portion 16a that is curved in a semicircular shape is formed at the end of the first rectangular portion 16, and a curved portion 17a that is curved in a semicircular shape is formed at the end of the second rectangular portion 17. Become.

ここで、中央部１２と第１半円形状部１３と第２半円形状部１４とで、後に折り曲げ成型された際に正極集電リード１０の底部１１が形成され、第１長方形状部１６と第２長方形状部１７とで、後に折り曲げ成型された際に正極集電リード１０の頂部１５が形成されることとなる。この場合は、第１長方形状部１６および第２長方形状部１７は、第１半円形状部１３および第２半円形状部１４よりも若干突出するように形成しているが、これらの第１長方形状部１６および第２長方形状部１７の長さを適宜調整することにより、正極集電リード１０の高さを調整することが可能となる。 Here, the bottom portion 11 of the positive electrode current collector lead 10 is formed when the center portion 12, the first semicircular shape portion 13, and the second semicircular shape portion 14 are bent and formed later, and the first rectangular shape portion 16 is formed. And the second rectangular portion 17, the top portion 15 of the positive electrode current collecting lead 10 is formed when it is bent and formed later. In this case, the first rectangular portion 16 and the second rectangular portion 17 are formed so as to protrude slightly from the first semicircular portion 13 and the second semicircular portion 14, but these first By appropriately adjusting the lengths of the first rectangular portion 16 and the second rectangular portion 17, the height of the positive electrode current collecting lead 10 can be adjusted.

なお、この打ち抜き成型と同時、あるいは打ち抜き成型後に、第１半円形状部１３および第２半円形状部１４のそれぞれ所定の６箇所に、図２（ａ）の表面から裏面に向けて突出するようにプロジェクション突起１３ａ，１４ａをそれぞれ形成する。また、これと同時に、半円形の切欠部１６ａ，１７ａの周囲のそれぞれ２箇所に、図２（ａ）の表面から裏面に向けて突出するようにプロジェクション突起１６ｂ，１７ｂを形成する。なお、これらの各プロジェクション突起１３ａ，１４ａは正極集電体４５と溶接された際の溶接点となるものであり、各プロジェクション突起１６ｂ，１７ｂは封口体と溶接された際の溶接点となるものである。 At the same time as the punching molding or after the punching molding, the first semicircular portion 13 and the second semicircular portion 14 project from the front surface to the back surface in FIG. Thus, the projection protrusions 13a and 14a are respectively formed. At the same time, projection protrusions 16b and 17b are formed at two locations around the semicircular cutouts 16a and 17a so as to protrude from the front surface to the back surface in FIG. Each of the projection protrusions 13a and 14a serves as a welding point when welded to the positive electrode current collector 45, and each of the projection protrusions 16b and 17b serves as a welding point when welded to the sealing body. It is.

ついで、上述のように打ち抜き成型された鋼板１０Ａを、第１長方形状部１６と中央部１２との境界および中央部１２と第２長方形状部１７との境界から立設（切り起こし）させるとともに、互いに相対向するように折曲加工を行う。これにより、第１長方形状部１６と第２長方形状部１７とが略突き合わされて、第１長方形状部１６の端部に形成された半円形状の湾曲部１６ａと、第２長方形状部１７の端部に形成された半円形状の湾曲部１７ａとにより円形状の開口１８が形成されることとなる。これにより、図１（ａ）（ｂ）に示すように、中心開口１２ａを備えた中央部１２と第１半円形状部１３と第２半円形状部１４とからなる底部１１と、底部１１の中央部１２から連続して立設するように折曲された第１長方形状部１６と第２長方形状部１７とからなり、中心開口１８を備え、内部空間を有する実施例１の集電リード１０が作製されることとなる。 Next, the steel plate 10A punched and molded as described above is erected (cut up) from the boundary between the first rectangular portion 16 and the central portion 12 and the boundary between the central portion 12 and the second rectangular portion 17. The bending process is performed so as to face each other. Thereby, the first rectangular portion 16 and the second rectangular portion 17 are substantially abutted to each other, and the semicircular curved portion 16a formed at the end of the first rectangular portion 16 and the second rectangular portion The circular opening 18 is formed by the semicircular curved portion 17 a formed at the end of 17. Thereby, as shown in FIGS. 1A and 1B, the bottom portion 11 including the central portion 12 having the central opening 12 a, the first semicircular shape portion 13, and the second semicircular shape portion 14, and the bottom portion 11. The current collector of the first embodiment is composed of a first rectangular portion 16 and a second rectangular portion 17 bent so as to be continuously provided upright from the central portion 12, and has a central opening 18 and has an internal space. The lead 10 is manufactured.

（３）実施例２
本実施例２の正極集電リード２０はニッケルめっきが施された鋼板（この場合は、厚さが０．４ｍｍのものとした）が所定の筒状形状になるように、打ち抜き加工および折曲加工することにより形成されたものである。そして、図３（ａ）に示すように、後述する正極集電体４５に溶接された底部２１と、中心開口２４ａを備えて後述する封口体４８（図１０参照のこと）の底面に溶接される頂部２４とを備えている。 (3) Example 2
The positive electrode current collecting lead 20 of Example 2 is punched and bent so that a nickel-plated steel plate (in this case, a thickness of 0.4 mm) has a predetermined cylindrical shape. It is formed by processing. Then, as shown in FIG. 3A, a bottom portion 21 welded to a positive electrode current collector 45 described later and a bottom surface of a sealing body 48 (see FIG. 10) described later having a central opening 24a are welded. The top 24 is provided.

ここで、底部２１は頂部２４を間にして互いに相対向するように配置された略半円形状の第１半円形状部２２と第２半円形状部２３からなるものである。そして、これらの２つの第１半円形状部２２と第２半円形状部２３とにより形成される外形形状は正極集電体４５の外形形状と略同一になる（図４（ｂ）参照）ようになされている。この場合、これらの２つの第１半円形状部２２および第２半円形状部２３の複数箇所（この場合は、それぞれ６箇所とした）には、正極集電体４５の上面に溶接された際の溶接点となるために正極集電体４５に向けて（図３（ａ）においては紙面の表面から裏面に向けて）突出するプロジェクション突起２２ａ，２３ａがそれぞれ形成されている。これにより、正極集電体４５から正極集電リード２０に均等に集電されるようになる。 Here, the bottom portion 21 is composed of a substantially semicircular first semicircular portion 22 and a second semicircular portion 23 which are arranged so as to face each other with the top portion 24 therebetween. The outer shape formed by the two first semicircular portions 22 and the second semicircular portions 23 is substantially the same as the outer shape of the positive electrode current collector 45 (see FIG. 4B). It is made like that. In this case, these two first semicircular portions 22 and second semicircular portions 23 are welded to the upper surface of the positive electrode current collector 45 at a plurality of locations (in this case, 6 locations). Projection projections 22a and 23a projecting toward the positive electrode current collector 45 (in FIG. 3A, from the front surface to the back surface in FIG. 3) are formed. As a result, current is evenly collected from the positive electrode current collector 45 to the positive electrode current collector lead 20.

一方、頂部２４は第１半円形状部２２との境界部（図４（ａ）のＸ−Ｘ線参照）および第２半円形状部２３との境界部（図４（ａ）のＹ−Ｙ線参照）を押し込むように折曲加工し、さらに押し込まれた部分を押圧加工することにより形成されていて、これらの第１半円形状部２２および第２半円形状部２３に連続して形成されている。そして、頂部２４の中心部には円形状の中心開口２４ａが形成されている。この場合、この中心開口２４ａの周囲の複数箇所（この場合は、４箇所とした）には封口体４８の底面に溶接された際の溶接点となるために封口体４８に向けて（図３（ａ）においては紙面の裏面から表面に向けて）突出するプロジェクション突起２４ｂが形成されている。これにより、正極集電リード２０から封口体４８に均等に集電されるようになる。 On the other hand, the top portion 24 has a boundary with the first semicircular portion 22 (see line XX in FIG. 4A) and a boundary with the second semicircular portion 23 (Y- in FIG. 4A). (See the Y line) is formed by bending so as to push in, and pressing is further performed on the pushed-in portion, and the first semicircular portion 22 and the second semicircular portion 23 are continuously formed. Is formed. A circular center opening 24 a is formed at the center of the top 24. In this case, a plurality of locations (in this case, four locations) around the center opening 24a are welded points when welded to the bottom surface of the sealing body 48 and are directed toward the sealing body 48 (FIG. 3). In (a), a projection projection 24b is formed that protrudes from the back surface to the front surface of the paper. As a result, current is evenly collected from the positive electrode current collecting lead 20 to the sealing body 48.

上述の構成となる正極集電リード２０は以下のようにして作製される。まず、ニッケルめっきが施された鋼板（この場合は、厚さが０．４ｍｍのものとした）２０Ａを用意し、これを図４（ａ）に示すような形状になるように切断（打ち抜き成型）する。
即ち、中心部の中心開口２４ａと、中央部（後に折り曲げ成型されて頂部の中央部となる）２４と、中央部２４の左側に延出する略半円形状の第１半円形状部（後に折り曲げ成型されて底部の一部となる）２２と、中央部２４の右側に延出する略半円形状の第２半円形状部（後に折り曲げ成型されて底部の一部となる）２３とが形成されるように平板状の鋼板１０Ａを打ち抜き成型する。 The positive electrode current collecting lead 20 having the above-described configuration is manufactured as follows. First, a nickel-plated steel plate (in this case having a thickness of 0.4 mm) 20A is prepared and cut (punched) into a shape as shown in FIG. 4 (a). )
That is, the central opening 24a in the central portion, the central portion (which is later bent and molded to become the central portion of the top portion) 24, and the substantially semicircular first semicircular portion extending to the left side of the central portion 24 (later And a second semicircular portion (substantially bent to become a part of the bottom) 23 that extends to the right side of the central portion 24. A flat steel plate 10A is punched and formed so as to be formed.

これにより、平板状の鋼板２０Ａが両端部が略扇形形状で、この略扇形形状から中心に向けて狭まるように傾斜した外形形状で、その中心部に中心開口２４ａが形成されることとなる。ここで、第１半円形状部２２と第２半円形状部とで、後に折り曲げ成型された際に正極集電リード１０の底部２１が形成され、中央部２４が後に折り曲げ成型された際に正極集電リード１０の頂部２４が形成されることとなる。 Accordingly, the flat steel plate 20A has a substantially sector shape at both ends, and has an outer shape inclined so as to narrow toward the center from the substantially sector shape, and the center opening 24a is formed at the center portion. Here, when the first semicircular portion 22 and the second semicircular portion are bent and formed later, the bottom 21 of the positive electrode current collector lead 10 is formed, and when the central portion 24 is bent and formed later. The top 24 of the positive electrode current collector lead 10 is formed.

なお、この打ち抜き成型と同時、あるいは打ち抜き成型後に、第１半円形状部２２および第２半円形状部２３のそれぞれ所定の６箇所に、図４（ａ）の表面から裏面に向けて突出するようにプロジェクション突起２２ａ，２３ａをそれぞれ形成する。また、これと同時に、中心開口２４ａの周囲の４箇所に、図４（ａ）の裏面から表面に向けて突出するようにプロジェクション突起２４ｂを形成する。なお、これらの各プロジェクション突起２２ａ，２３ａは正極集電体４５と溶接された際の溶接点となるものであり、各プロジェクション突起２４ａは封口体と溶接された際の溶接点となるものである。 At the same time as this punching molding or after punching molding, the first semicircular portion 22 and the second semicircular portion 23 protrude from the front surface to the back surface in FIG. Thus, the projection protrusions 22a and 23a are respectively formed. At the same time, projection protrusions 24b are formed at four locations around the center opening 24a so as to protrude from the back surface of FIG. 4A toward the front surface. Each of the projection protrusions 22a and 23a serves as a welding point when welded to the positive electrode current collector 45, and each projection protrusion 24a serves as a welding point when welded to the sealing body. .

ついで、上述のように打ち抜き成型された鋼板２０Ａを、第１半円形状部２２との境界部（図４（ａ）のＸ−Ｘ線参照）および第２半円形状部２３との境界部（図４（ａ）のＹ−Ｙ線参照）を押し込むように折曲加工した後、この押し込まれた部分に押圧加工を施すことにより、第１半円形状部２２および第２半円形状部２３からなる底部２１に連続する頂部２４が形成されることとなる。これにより、図３（ａ）（ｂ）に示すように、第１半円形状部２２および第２半円形状部２３からなる底部２１と、これらの底部２１に連続する中心開口２４ａを備えた頂部２４とからなり、内部空間を有する実施例２の集電リード２０が作製されることとなる。この場合、第１半円形状部２２との境界部（図４（ａ）のＸ−Ｘ線参照）および第２半円形状部２３との境界部（図４（ａ）のＹ−Ｙ線参照）の押し込み長さを適宜調整することにより、正極集電リード２０の高さを調整することが可能となる。 Subsequently, the steel plate 20A punched and formed as described above is subjected to a boundary portion with the first semicircular shape portion 22 (see line XX in FIG. 4A) and a boundary portion with the second semicircular shape portion 23. (Refer to the YY line in FIG. 4 (a)) After being bent so as to push in, the first semicircular portion 22 and the second semicircular portion are pressed by pressing the pushed portion. The top 24 that is continuous with the bottom 21 made of 23 is formed. As a result, as shown in FIGS. 3A and 3B, a bottom portion 21 composed of a first semicircular portion 22 and a second semicircular portion 23 and a central opening 24a continuous to the bottom portion 21 are provided. The current collection lead 20 of Example 2 which consists of the top part 24 and has internal space will be produced. In this case, the boundary with the first semicircular portion 22 (see the line XX in FIG. 4A) and the boundary with the second semicircular portion 23 (the YY line in FIG. 4A). It is possible to adjust the height of the positive electrode current collecting lead 20 by appropriately adjusting the pushing length of the reference).

なお、図５に示す変形例の集電リード１０ａのように、第１半円形状部１３の中央部の端部および第２半円形状部１４の中央部の端部において、正極集電体４５に形成された１つのバーリング孔４５ｂに一致する位置にそれぞれ位置決め用の開口１９，１９を設けるようにすると、この集電リード１０ａを正極集電体４５に溶接する際の位置決めが容易になるので好ましい。 In addition, like the current collector lead 10a of the modified example shown in FIG. 5, the positive electrode current collector at the end of the center of the first semicircular portion 13 and the end of the center of the second semicircular portion 14 If the positioning openings 19 and 19 are respectively provided at positions corresponding to one burring hole 45b formed in 45, positioning when welding the current collecting lead 10a to the positive electrode current collector 45 is facilitated. Therefore, it is preferable.

（４）比較例（従来例）
一方、比較例（従来例）の正極集電リード３０はニッケルめっきが施された鋼板（この場合は、厚さが０．４ｍｍのものとした）が筒状となるように折り曲げ成型することにより形成されたものであり、図６（ａ）に示すように、後述する封口体４８（図１０参照のこと）の底面に溶接される頂部３１と、正極集電体４５に溶接される底部３２とを備えている。そして、頂部３１で連続し、底部３２の中央部で互いに突き合わされているとともに、底部３２の一対の側部は頂部３１よりも突出するよう形成されている。 (4) Comparative example (conventional example)
On the other hand, the positive electrode current collecting lead 30 of the comparative example (conventional example) is formed by bending and forming a nickel-plated steel plate (in this case, having a thickness of 0.4 mm) into a cylindrical shape. As shown in FIG. 6A, a top portion 31 welded to the bottom surface of a sealing body 48 (see FIG. 10) described later and a bottom portion 32 welded to the positive electrode current collector 45 are formed. And. And it is continuous with the top part 31, and is mutually faced | matched by the center part of the bottom part 32, and a pair of side part of the bottom part 32 is formed so that it may protrude rather than the top part 31.

ここで、頂部３１の中心部には中心開口３１ａが設けられているとともに、この中心開口３１ａの周囲には封口体の底面に溶接された際の溶接点となるために封口体に向けて（図６（ａ）においては紙面の裏面から表面に向けて）突出するプロジェクション突起３１ｂが４箇所に形成されている。
一方、底部３２の中心部には互いに突き合わされることにより円形状に形成された溶接電極挿入用の中心開口（図示していないが、この中心開口は頂部３１に形成された中心開口３１ａと一致する位置に形成されることとなる）が設けられているとともに、互いに突き合わされた各端部側に正極集電体の上面に溶接された際の溶接点となるために正極集電体４５に向けて（図６（ａ）においては紙面の表面から裏面に向けて）突出するプロジェクション突起３２ｂが４箇所に形成されている。 Here, a central opening 31a is provided in the central portion of the top portion 31, and around the central opening 31a is a welding point when being welded to the bottom surface of the sealing body, and is directed toward the sealing body ( In FIG. 6A, projection projections 31b projecting from the back surface to the front surface are formed at four locations.
On the other hand, a central opening for inserting a welding electrode formed into a circular shape by abutting each other at the center of the bottom 32 (not shown, but this central opening coincides with the central opening 31a formed at the top 31). The positive electrode current collector 45 to be a welding point when welded to the upper surface of the positive electrode current collector at each end side abutted against each other. Projection projections 32b projecting toward (from the front surface to the back surface in FIG. 6A) are formed at four locations.

２．円筒型二次電池
（１）渦巻状電極群
まず、パンチングメタルからなる極板芯体４１ａの表面にニッケル焼結多孔体４１ｂ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４１ｂの多孔内に含浸する。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４１を作製する。ここで、ニッケル正極板４１の幅方向の一方の端部（図７において上部）には極板芯体４１ａが露出した芯体露出部４１ｃが形成されている。 2. Cylindrical secondary battery (1) Spiral electrode group First, a sintered nickel porous body 41b is formed on the surface of an electrode plate core body 41a made of punching metal, and then an active material mainly composed of nickel hydroxide by a chemical impregnation method. Is impregnated into the pores of the nickel sintered porous body 41b. Subsequently, after drying this, it rolls until it becomes predetermined thickness, and it cut | disconnects so that it may become a predetermined dimension, and the nickel positive electrode plate 41 is produced. Here, a core body exposed portion 41c where the electrode plate core body 41a is exposed is formed at one end (upper portion in FIG. 7) in the width direction of the nickel positive electrode plate 41.

また、パンチングメタルからなる極板芯体４２ａの表面に水素吸蔵合金を主体とするペースト状負極活物質４２ｂ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４２を作製する。ここで、水素吸蔵合金負極板４２の幅方向の一方の端部（図７において下部）には極板芯体４２ａが露出した芯体露出部４２ｃが形成されている。ついで、図７に示すように、これらのニッケル正極板４１と水素吸蔵合金負極板４２との間にセパレータ４３を介在させて渦巻状に巻回して渦巻状電極群４０ａを作製する。なお、この渦巻状電極群４０ａの高さ方向の一方の端部（図７において上部）には芯体露出部４１ｃが突出しているとともに、他方の端部（図７において下部）には芯体露出部４２ｃが突出している。 Further, a paste-like negative electrode active material 42b mainly composed of a hydrogen storage alloy is applied to the surface of the electrode plate core 42a made of punching metal, dried, and then rolled to a predetermined thickness to obtain a predetermined dimension. Thus, the hydrogen storage alloy negative electrode plate 42 is produced. Here, a core exposed portion 42c where the electrode plate core 42a is exposed is formed at one end in the width direction of the hydrogen storage alloy negative electrode plate 42 (lower portion in FIG. 7). Then, as shown in FIG. 7, a spiral electrode group 40a is produced by winding the separator 43 between the nickel positive electrode plate 41 and the hydrogen storage alloy negative electrode plate 42 in a spiral shape. A core body exposed portion 41c protrudes from one end (upper part in FIG. 7) in the height direction of the spiral electrode group 40a, and a core body from the other end (lower part in FIG. 7). The exposed part 42c protrudes.

（２）負極集電体
本実施例の負極集電体４４は、図８（ａ）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）４４ａが形成されている。また、負極集電体４４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４４ｂが形成されている。 (2) Negative electrode current collector As shown in FIG. 8A, the negative electrode current collector 44 of the present example is formed in a substantially circular shape (maximum diameter is 30 mm), and extends from the periphery of the central portion to the end portion. A large number of burring holes 44a (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 44b that open toward the edge are formed on the outer peripheral portion of the negative electrode current collector 44 in order to reduce the invalid welding current and increase the effective welding current.

（３）正極集電体
正極集電体４５は、図８（ｂ）に示すように、略円形（最大で直径が３０ｍｍ）に形成されていて、中心部に溶接電極挿入用の中心開口４５ａが形成されているとともに、この中心開口４５ａ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）４５ｂが形成されている。また、正極集電体４５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４５ｃが形成されている。 (3) Positive Electrode Current Collector As shown in FIG. 8B, the positive electrode current collector 45 is formed in a substantially circular shape (maximum diameter is 30 mm) and has a central opening 45a for inserting a welding electrode in the center. And a large number of burring holes (for example, those having a diameter of 2 mm, a burring height of 0.4 mm, and a burring thickness of 0.1 mm) 45b from the periphery of the central opening 45a to the end thereof 45b Is formed. In addition, a pair of slits 45c that open toward the edge are formed on the outer peripheral portion of the positive electrode current collector 45 in order to reduce an invalid welding current and increase an effective welding current.

（４）ニッケル−水素蓄電池
ついで、上述のような構成となる渦巻状電極群４０ａと、負極集電体４４と、正極集電体４５と、上述した正極集電リード１０（２０，３０）とを用いて、円筒型二次電池となるニッケル−水素蓄電池を作製する例について、図９および図１０に基づいて以下に説明する。
まず、渦巻状電極群４０ａの下端面に露出する水素吸蔵合金負極板４２の芯体露出部４２ｃに負極集電体４４を溶接する。また、渦巻状電極群４０ａの上端面に露出するニッケル正極板４１の芯体露出部４１ｃに正極集電体４５を溶接して電極体とする。 (4) Nickel-hydrogen storage battery Next, the spiral electrode group 40a configured as described above, the negative electrode current collector 44, the positive electrode current collector 45, and the positive electrode current collector lead 10 (20, 30) described above. An example of producing a nickel-hydrogen storage battery that will be a cylindrical secondary battery will be described below with reference to FIGS.
First, the negative electrode current collector 44 is welded to the core exposed portion 42c of the hydrogen storage alloy negative electrode plate 42 exposed at the lower end surface of the spiral electrode group 40a. Further, the positive electrode current collector 45 is welded to the core exposed portion 41c of the nickel positive electrode plate 41 exposed at the upper end surface of the spiral electrode group 40a to form an electrode body.

この後、渦巻状電極群４０ａの上端部に溶接された正極集電体４５の上に正極集電リード１０（２０，３０）を配置した後、プロジェクション突起１６ｂ，１７ｂ（２４ｂ，３１ｂ）の上面部に溶接電極を押し当てて、正極集電体４５に正極集電リード１０（２０，３０）をスポット溶接する。これにより、正極集電リード１０（２０，３０）の底部１１（２１，３２）に形成されたプロジェクション突起１３ａ，１４ａ（２２ａ，２３ａ，３２ｂ）が溶接点となって、正極集電リード１０（２０，３０）が正極集電体４５に溶接されることとなる。 Thereafter, the positive electrode current collector lead 10 (20, 30) is disposed on the positive electrode current collector 45 welded to the upper end of the spiral electrode group 40a, and then the upper surfaces of the projection protrusions 16b, 17b (24b, 31b). A welding electrode is pressed against the portion, and the positive electrode current collector lead 10 (20, 30) is spot-welded to the positive electrode current collector 45. Thereby, the projection protrusions 13a and 14a (22a, 23a and 32b) formed on the bottom 11 (21 and 32) of the positive electrode current collecting lead 10 (20 and 30) become welding points, and the positive electrode current collecting lead 10 ( 20, 30) are welded to the positive electrode current collector 45.

この場合、実施例１の正極集電リード１０を用いると、図２（ｂ）に示すように正極集電リード１０が正極集電体４５に溶接されることとなる。また、実施例２の正極集電リード２０を用いると、図４（ｂ）に示すように正極集電リード２０が正極集電体４５に溶接されることとなる。一方、比較例（従来例）の正極集電リード３０を用いると、図６（ｂ）に示すように正極集電リード３０が正極集電体４５に溶接されることとなる。 In this case, when the positive electrode current collector lead 10 of Example 1 is used, the positive electrode current collector lead 10 is welded to the positive electrode current collector 45 as shown in FIG. Further, when the positive electrode current collector lead 20 of Example 2 is used, the positive electrode current collector lead 20 is welded to the positive electrode current collector 45 as shown in FIG. On the other hand, when the positive electrode current collector lead 30 of the comparative example (conventional example) is used, the positive electrode current collector lead 30 is welded to the positive electrode current collector 45 as shown in FIG.

この後、正極集電体４５に正極集電リード１０（２０，３０）が溶接された渦巻状電極群４０ａを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）４７内に収納する。そして、渦巻状電極群４０ａの中心部に形成された空間部に溶接電極を挿入し、水素吸蔵合金負極板４２に溶接された負極集電体４４を外装缶４７の内底面にスポット溶接する。これにより、負極集電体４４が外装缶４７の内底面に溶接されることとなる。 Thereafter, a spiral-shaped electrode group 40a in which the positive electrode current collector lead 10 (20, 30) is welded to the positive electrode current collector 45, and a bottomed cylindrical outer can in which nickel is plated on iron (the outer surface of the bottom surface is outside the negative electrode) (To be a terminal) 47. And a welding electrode is inserted in the space part formed in the center part of the spiral electrode group 40a, and the negative electrode collector 44 welded to the hydrogen storage alloy negative electrode plate 42 is spot-welded to the inner bottom surface of the outer can 47. As a result, the negative electrode current collector 44 is welded to the inner bottom surface of the outer can 47.

ついで、外装缶４７の上部内周側に防振リング４９ｂを挿入し、外装缶４７の上部外周側に溝入れ加工を施して防振リング４９ｂの上端部に環状凹部４７ａを形成する。この後、外装缶４７内に７Ｎ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、この正極集電リード１０（２０，３０）の上に封口体４８を配置する。ここで、封口体４８は、図１０に示すように、封口板４８ａと正極キャップ（正極外部端子）４８ｂとからなり、この正極キャップ４８ｂ内には弁板４８ｃとスプリング４８ｄからなる弁体を備えているので、封口板４８ａの中心部は下方に突出して形成されている。また、封口体４８の中央にはガス抜き孔が形成されているとともに、その周縁には、予め絶縁ガスケット４９ａが嵌着されている。 Next, an anti-vibration ring 49b is inserted into the upper inner peripheral side of the outer can 47, and grooving is performed on the upper outer peripheral side of the outer can 47 to form an annular recess 47a at the upper end of the anti-vibration ring 49b. Thereafter, an alkaline electrolyte composed of a 7N potassium hydroxide (KOH) aqueous solution is injected into the outer can 47. Thereafter, the sealing body 48 is disposed on the positive electrode current collecting lead 10 (20, 30). Here, as shown in FIG. 10, the sealing body 48 includes a sealing plate 48a and a positive electrode cap (positive electrode external terminal) 48b. The positive electrode cap 48b includes a valve body including a valve plate 48c and a spring 48d. Therefore, the central portion of the sealing plate 48a is formed to protrude downward. In addition, a gas vent hole is formed in the center of the sealing body 48, and an insulating gasket 49a is fitted in advance on the periphery thereof.

ついで、図９に示すように、封口体４８の上部と外装缶４７の下部に一対の溶接電極Ｗ１，Ｗ２を配置した後、これらの一対の溶接電極Ｗ１，Ｗ２間に２×１０⁶Ｎ／ｍ²の圧力を負荷しながら２４Ｖの電圧を印加し、３ｋＡの溶接電流を１５ｍｓｅｃの時間だけ流す通電処理を施した。これにより、正極集電リード１０（２０，３０）の頂部１５（２４，３１）に形成された４箇所のプロジェクション突起１６ｂ，１７ｂ（２４ｂ，３１ｂ）が溶接点となって、封口体４８が正極集電リード１０（２０，３０）に溶接されることとなる。この後、外装缶４７の開口端縁４７ｂを内方にかしめて封口することにより、図１０に示すような６．０Ａｈのニッケル−水素蓄電池Ａ，Ｂ，Ｃが得られる。この場合、正極集電リード１０を用いたものを電池Ａとし、正極集電リード２０を用いたものを電池Ｂとし、正極集電リード３０を用いたものを電池Ｃとした。 Next, as shown in FIG. 9, after arranging a pair of welding electrodes W1, W2 on the upper part of the sealing body 48 and the lower part of the outer can 47, 2 × 10 ⁶ N / b between these pair of welding electrodes W1, W2. While applying a pressure of m ² , a voltage of 24 V was applied, and an energization process was performed in which a 3 kA welding current was applied for a time of 15 msec. As a result, the four projection protrusions 16b and 17b (24b and 31b) formed on the top 15 (24 and 31) of the positive electrode current collecting lead 10 (20 and 30) serve as welding points, and the sealing body 48 becomes the positive electrode. It will be welded to the current collecting lead 10 (20, 30). Thereafter, the open end edge 47b of the outer can 47 is caulked inward to seal it, thereby obtaining 6.0 Ah nickel-hydrogen storage batteries A, B, and C as shown in FIG. In this case, the battery using the positive electrode current collector lead 10 was designated as battery A, the battery using the positive electrode current collector lead 20 was designated as battery B, and the battery using the positive electrode current collector lead 30 was designated as battery C.

（５）評価試験
上述のように作製した各電池Ａ，Ｂ，Ｃについて、２５℃の温度雰囲で、１Ｉｔの充電電流でＳＯＣの１２０％まで充電し、１時間休止後に２５℃の温度雰囲で、１Ｉｔの放電電流で電池電圧が０．９Ｖになるまで放電させる充放電サイクルを１０回繰り返して、電池の活性化を行なった。この後、各電池Ａ，Ｂ，Ｃを２０セルづつ使用し、２５℃の温度雰囲気で、１Ｉｔの充電々流で電池容量に対して５０％まで充電を行った後、開路状態で１時間放置した後、最大２００Ａまで、各ステップ間に３０分の休止を入れながら１０秒間の充放電を繰り返し、各１０秒放電時電圧と各放電電流値から最小二乗法により求まる直線が０．９Ｖに達する時の電流値（放電出力）を求める放電性評価試験を、各電池Ａ，Ｂ，Ｃに行った。得られた１０秒目の放電出力において、電池Ｃの１０秒目の放電出力を１００とし、電池Ａ，Ｂの１０秒目の放電出力をそれとの比率（１０秒目放電出力比）として求めると、下記の表１に示すような結果が得られた。

(5) Evaluation test About each battery A, B, C produced as mentioned above, it is charged to 120% of SOC with a charging current of 1 It in a temperature atmosphere of 25 ° C., and after 25 hours at a temperature atmosphere of 25 ° C. The battery was activated by repeating a charge / discharge cycle in which the battery was discharged at a discharge current of 1 It until the battery voltage became 0.9 V 10 times. After that, each battery A, B, C was used 20 cells at a time and charged to 50% of the battery capacity with a charging current of 1 It in a temperature atmosphere of 25 ° C., and then left for 1 hour in an open circuit state. After that, up to 200 A, charging and discharging for 10 seconds is repeated with a pause of 30 minutes between each step, and a straight line obtained by the least square method reaches 0.9 V from each 10-second discharge voltage and each discharge current value. The batteries A, B, and C were subjected to a discharge evaluation test for determining the current value (discharge output) at the time. In the obtained discharge output at 10 seconds, the discharge output at 10 seconds of battery C is taken as 100, and the discharge output at 10 seconds of batteries A and B is determined as the ratio (10th discharge output ratio). The results shown in Table 1 below were obtained.

上記表１の結果から明らかなように、電池Ｃの１０秒目放電出力比は１００であるのに対して、電池Ａの１０秒目放電出力比は１０６で、電池Ｂの１０秒目放電出力は１０７で、いずれの電池Ａ，Ｂも電池Ｃよりも１０秒目放電出力比が向上していることが分かる。
これは、従来例（比較例）の電池Ｃにおいては、底部３２に形成された各プロジェクション突起３２ｂは同一の同心円上に位置するように形成された正極集電リード３０を用いているため、外周側からの集電効率が低下して電池電圧低下を抑制できなかったためと考えられる。 As is clear from the results in Table 1 above, the 10th second discharge output ratio of the battery C is 100, whereas the 10th second discharge output ratio of the battery A is 106, and the 10th second discharge output of the battery B. 107, it can be seen that both batteries A and B have a 10-second discharge output ratio improvement over battery C.
This is because the battery C of the conventional example (comparative example) uses the positive electrode current collecting lead 30 formed so that each projection protrusion 32b formed on the bottom 32 is positioned on the same concentric circle. This is considered to be because the current collection efficiency from the side declines and the battery voltage drop cannot be suppressed.

これに対して、電池Ａにおいては、図２（ｂ）に示されるように、２つの第１半円形状部１３と第２半円形状部１４とにより形成される外形形状は正極集電体４５の外形形状と略同一になるようになされている。そして、これらの第１半円形状部１３と第２半円形状部１４には、それぞれ６箇所のプロジェクション突起１３ａ，１４ａが形成された底部１１を備えた正極集電リード１０を用いている。このため、渦巻状電極群４０ａのあらゆる位置に正極集電体４５からの集電点が均等に分布することとなって、渦巻状電極群５０ａの内外周から効率良く集電リード１０に電流が流れ、電池電圧の低下を抑制することが可能になったと考えられる。 On the other hand, in the battery A, as shown in FIG. 2B, the outer shape formed by the two first semicircular portions 13 and the second semicircular portion 14 is the positive electrode current collector. It is made to be substantially the same as the outer shape of 45. In each of the first semicircular portion 13 and the second semicircular portion 14, the positive electrode current collecting lead 10 having the bottom portion 11 on which six projection projections 13 a and 14 a are formed is used. For this reason, current collection points from the positive electrode current collector 45 are evenly distributed at every position of the spiral electrode group 40a, and current is efficiently supplied to the current collector lead 10 from the inner and outer circumferences of the spiral electrode group 50a. It is thought that it was possible to suppress the flow and battery voltage drop.

また、電池Ｂにおいては、図５（ｂ）に示されるように、２つの第１半円形状部２２と第２半円形状部２３とにより形成される外形形状は正極集電体４５の外形形状と略同一になるようになされている。そして、これらの第１半円形状部２２と第２半円形状部２３には、それぞれ６箇所のプロジェクション突起２２ａ，２３ａが形成された底部２１を備えた正極集電リード２０を用いている。このため、渦巻状電極群５０ａのあらゆる位置に正極集電体４５からの集電点が均等に分布することとなって、渦巻状電極群４０ａの内外周から効率良く集電リード２０に電流が流れ、電池電圧の低下を抑制することが可能になったと考えられる。 In the battery B, as shown in FIG. 5B, the outer shape formed by the two first semicircular portions 22 and the second semicircular portion 23 is the outer shape of the positive electrode current collector 45. The shape is substantially the same. In each of the first semicircular portion 22 and the second semicircular portion 23, a positive electrode current collecting lead 20 having a bottom portion 21 on which six projection projections 22a and 23a are formed is used. For this reason, current collection points from the positive electrode current collector 45 are evenly distributed at every position of the spiral electrode group 50a, and current is efficiently supplied to the current collector lead 20 from the inner and outer circumferences of the spiral electrode group 40a. It is thought that it was possible to suppress the flow and battery voltage drop.

なお、上述した実施の形態においては、本発明をニッケル−水素蓄電池に適用する例について説明したが、本発明はニッケル−水素蓄電池に限られることなく、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イオン電池などにも適用できるのは勿論である。 In the above-described embodiment, an example in which the present invention is applied to a nickel-hydrogen storage battery has been described. However, the present invention is not limited to a nickel-hydrogen storage battery, but an alkaline storage battery such as a nickel-cadmium storage battery or a lithium ion battery. Of course, it can also be applied to batteries.

実施例１の正極集電リードを示す図であり、図１（ａ）は折り曲げ成型により形成された正極集電リードを模式的に示す正面図であり、図１（ｂ）は、図１（ａ）のＡ矢視の側面図である。It is a figure which shows the positive electrode current collection lead of Example 1, Fig.1 (a) is a front view which shows typically the positive electrode current collection lead formed by bending molding, FIG.1 (b) is FIG. It is a side view of A arrow view of a). 実施例１の正極集電リードを示す図であり、図２（ａ）は、図１に示す実施例１の正極集電リードの折り曲げ成型される前の状態を模式的に示す正面図であり、図２（ｂ）は、実施例１の正極集電リードを渦巻状電極群の正極板の端部に溶接された正極集電体に溶接された状態を模式的に示す正面図である。FIG. 2 is a diagram showing a positive electrode current collecting lead of Example 1, and FIG. 2A is a front view schematically showing a state before the positive electrode current collecting lead of Example 1 shown in FIG. 1 is bent. FIG. 2B is a front view schematically showing a state in which the positive electrode current collector lead of Example 1 is welded to the positive electrode current collector welded to the end portion of the positive electrode plate of the spiral electrode group. 実施例２の正極集電リードを示す図であり、図３（ａ）は折り曲げ成型により形成された正極集電リードを模式的に示す正面図であり、図３（ｂ）は、図３（ａ）のＡ矢視の側面図である。It is a figure which shows the positive electrode current collection lead of Example 2, Fig.3 (a) is a front view which shows typically the positive electrode current collection lead formed by bending molding, FIG.3 (b) is FIG. It is a side view of A arrow view of a). 実施例２の正極集電リードを示す図であり、図４（ａ）は、図３に示す実施例２の正極集電リードの折り曲げ成型される前の状態を模式的に示す正面図であり、図４（ｂ）は、実施例２の正極集電リードを渦巻状電極群の正極板の端部に溶接された正極集電体に溶接された状態を模式的に示す正面図である。FIG. 4A is a front view schematically showing a state before the positive electrode current collector lead of Example 2 shown in FIG. 3 is bent and molded. FIG. 4B is a front view schematically showing a state in which the positive electrode current collector lead of Example 2 is welded to the positive electrode current collector welded to the end portion of the positive electrode plate of the spiral electrode group. 変形例の正極集電リードの模式的に示す正面図である。It is a front view showing typically the positive electrode current collection lead of a modification. 比較例（従来例）の正極集電リードを示す図であり、図６（ａ）は折り曲げ成型により形成された正極集電リードを模式的に示す斜視図であり、図６（ｂ）は比較例（従来例）の正極集電リードを渦巻状電極群の正極板の端部に溶接された正極集電体に溶接された状態を模式的に示す図である。It is a figure which shows the positive electrode current collection lead of a comparative example (conventional example), Fig.6 (a) is a perspective view which shows typically the positive electrode current collection lead formed by bending molding, FIG.6 (b) is a comparison. It is a figure which shows typically the state by which the positive electrode current collection lead of the example (conventional example) was welded to the positive electrode current collector welded to the edge part of the positive electrode plate of a spiral electrode group. 渦巻状電極群を模式的に示す斜視図である。It is a perspective view which shows a spiral electrode group typically. 図７に示す渦巻状電極群の両端部に溶接される集電体を示す図であり、図８（ａ）は負極集電体を模式的に示す正面図であり、図８（ｂ）は正極集電体を模式的に示す正面図である。FIG. 8 is a view showing a current collector welded to both ends of the spiral electrode group shown in FIG. 7, FIG. 8A is a front view schematically showing the negative electrode current collector, and FIG. It is a front view which shows a positive electrode electrical power collector typically. 外装缶内に収納された渦巻状電極群の一方の端部に接続された正極集電体の上に、本発明の正極集電リードと、封口体を配置した後、これらを溶接する状態を模式的に示す断面図である。After the positive electrode current collector lead of the present invention and the sealing body are arranged on the positive electrode current collector connected to one end of the spiral electrode group housed in the outer can, the state in which these are welded It is sectional drawing shown typically. 本発明のニッケル−水素蓄電池を模式的に示す断面図である。It is sectional drawing which shows typically the nickel-hydrogen storage battery of this invention.

Explanation of symbols

１０Ａ…ニッケルメッキ鋼板、１０…実施例１の正極集電リード、１０ａ…変形例の集電リード、１１…底部、１２…中央部、１２ａ…中心開口、１３…第１半円形状部、１３ａ…プロジェクション突起、１４…第２半円形状部、１５…頂部、１６…第１長方形状部、１６ａ…湾曲部、１６ｂ…プロジェクション突起、１７…第２長方形状部、１７ａ…湾曲部、１８…中心開口、２０Ａ…ニッケルメッキ鋼板、２０…実施例２の正極集電リード、２１…底部、２２…第１半円形状部、２２ａ…プロジェクション突起、２３…第２半円形状部、２４…中央部、２４…頂部、２４ａ…中心開口、２４ｂ…プロジェクション突起、４０ａ…渦巻状電極群、４１…ニッケル正極板、４１ａ…極板芯体、４１ｂ…ニッケル焼結多孔体、４１ｃ…芯体露出部、４２…水素吸蔵合金負極板、４２ａ…極板芯体、４２ｂ…ペースト状負極活物質、４２ｃ…芯体露出部、４３…セパレータ、４４…負極集電体、４４ｂ…スリット、４５…正極集電体、４５ａ…中心開口、４５ｂ…バーリング孔、４５ｃ…スリット、４７…外装缶、４７ａ…環状凹部、４７ｂ…開口端縁、４８…封口体、４８ａ…封口板、４８ｂ…正極キャップ、４８ｃ…弁板、４８ｄ…スプリング、４９ａ…絶縁ガスケット、４９ｂ…防振リング DESCRIPTION OF SYMBOLS 10A ... Nickel plating steel plate, 10 ... Positive electrode current collection lead of Example 1, 10a ... Current collection lead of modification, 11 ... Bottom part, 12 ... Center part, 12a ... Center opening, 13 ... 1st semicircle shaped part, 13a Projection projection, 14 ... Second semicircular portion, 15 ... Top, 16 ... First rectangular portion, 16a ... Curved portion, 16b ... Projection projection, 17 ... Second rectangular portion, 17a ... Curved portion, 18 ... Center opening, 20A ... nickel-plated steel plate, 20 ... positive electrode current collecting lead of Example 2, 21 ... bottom, 22 ... first semicircular portion, 22a ... projection protrusion, 23 ... second semicircular portion, 24 ... center 24, top part, 24 a, central opening, 24 b, projection protrusion, 40 a, spiral electrode group, 41, nickel positive electrode plate, 41 a, electrode plate core body, 41 b, nickel sintered porous body, 41 c, core body exposure , 42 ... Hydrogen storage alloy negative electrode plate, 42a ... Electrode plate core, 42b ... Paste negative electrode active material, 42c ... Core body exposed part, 43 ... Separator, 44 ... Negative electrode current collector, 44b ... Slit, 45 ... Positive electrode collection Electrical body, 45a ... center opening, 45b ... burring hole, 45c ... slit, 47 ... exterior can, 47a ... annular recess, 47b ... opening edge, 48 ... sealing body, 48a ... sealing plate, 48b ... positive electrode cap, 48c ... Valve plate, 48d ... Spring, 49a ... Insulating gasket, 49b ... Vibration-proof ring

Claims

A current collector of one electrode is welded to a core of one electrode extending from an upper part of a spiral electrode group in which a positive electrode plate and a negative electrode plate are wound in a spiral shape with a separator interposed therebetween. A cylindrical secondary battery welded via a current collecting lead in which an internal space is formed in a sealing body that seals an opening of a cylindrical metal outer can,
The current collecting lead in which the internal space is formed is formed by bending a single metal plate, and includes a bottom part welded to the current collector and a top part welded to the sealing body,
The bottom is composed of two semicircular portions of the same shape positioned so as to face each other with the top interposed therebetween, and the outer shape formed by the two semicircular portions is the outer shape of the current collector It is made to be almost the same as
The top portion is formed continuously from the bottom portion and is bent so that an internal space is formed ,
A plurality of projection protrusions are formed on the two semicircular portions of the bottom portion so as to protrude from the bottom portion toward the current collector, and the plurality of projection protrusions serve as welding points with the current collector. And
A central opening is formed at the center of the top, and a plurality of projection protrusions projecting from the top toward the sealing body are formed around the central opening, and the plurality of projection protrusions are connected to the sealing body. A cylindrical secondary battery, characterized by being a welding point .

The cylindrical secondary battery according to claim 1 , wherein the plurality of projection protrusions are formed at positions that do not coincide with an opening formed in the current collector.

The bottom portion includes a central portion, a substantially semicircular first semicircular shape portion and a substantially semicircular second semicircular shape portion, and the first semicircular shape portion and the second semicircular shape portion. cylindrical secondary battery according to claim 1 or claim 2, characterized in that the opening for positioning that matches the opening formed in the current collector is formed on at least one.