JP2012185912A

JP2012185912A - Cylindrical secondary cell

Info

Publication number: JP2012185912A
Application number: JP2011046170A
Authority: JP
Inventors: Eiichi Isono; 栄一磯野; Uichi Ehata; 右一江幡
Original assignee: Hitachi Vehicle Energy Ltd
Current assignee: Vehicle Energy Japan Inc
Priority date: 2011-03-03
Filing date: 2011-03-03
Publication date: 2012-09-27

Abstract

PROBLEM TO BE SOLVED: To reduce cost by reducing the thickness of a connection member interposed between both members in a structure of welding a battery can and a collector member.SOLUTION: A negative electrode collector component 50 has a negative electrode collector member 20 having a bottom 23 arranged in parallel with the bottom 2c of a battery can 2, and a connection member 31 in the inner peripheral cylindrical portion 21 into which a shaft core 15 is inserted. The negative electrode collector member 20 is formed of copper, for example, and the connection member 31 is formed of nickel, for example. The connection member 31 is stacked on the bottom 23 of the negative electrode collector member 20 and bonded thereto by resistance-welding. With such a structure, resistance at the joint of the negative electrode collector component and the battery can 2 is decreased and thereby the thickness of the connection member 31 can be reduced.

Description

この発明は、円筒形二次電池に関し、より詳細には、正・負極電極の一方に接続された集電部材と電池缶とが溶接等により接合された円筒形二次電池に関する。 The present invention relates to a cylindrical secondary battery, and more particularly to a cylindrical secondary battery in which a current collecting member connected to one of positive and negative electrodes and a battery can are joined by welding or the like.

リチウム二次電池等に代表される円筒形二次電池は、円筒形の電池缶内に、正極電極と負極電極とがセパレータを介して軸芯の周囲に捲回された電極群が収容され、電解液が注入されて構成される。正・負極の電極は、それぞれ、正・負極の金属箔の両面に塗工された、正・負極の活物質を有する。正・負極の金属箔は、それぞれ、長手方向の片側縁に沿って所定のピッチで配列された多数の導電リードを有する。 A cylindrical secondary battery typified by a lithium secondary battery or the like contains an electrode group in which a positive electrode and a negative electrode are wound around a shaft core via a separator in a cylindrical battery can, An electrolyte is injected and configured. The positive and negative electrodes have positive and negative active materials coated on both sides of the positive and negative metal foils, respectively. Each of the positive and negative metal foils has a large number of conductive leads arranged at a predetermined pitch along one side edge in the longitudinal direction.

正・負極の金属箔の導電リードは、それぞれ、円筒形の正・負極の集電部材の外周に捲回され、導電リード同士が多数枚、重ね合わされた状態で集電部材に超音波溶接等により接合される。
正・負極の集電部材の一方は、電池缶の上部に配置された電池蓋に接合され、他方は電池缶の缶底に、例えば、抵抗溶接により接合される。
電池缶が鉄により形成され、集電部材が銅により形成されている場合、溶接による接合力が不足するため、通常、電池缶と集電部材との間にニッケルにより形成された接続部材を介在させることにより、十分な接合力が得られるようにしている。 The conductive leads of the positive and negative metal foils are wound around the outer circumference of the cylindrical positive and negative current collecting members, respectively, and ultrasonic welding is performed on the current collecting members in a state where a large number of conductive leads are overlapped with each other. Are joined together.
One of the positive and negative current collecting members is joined to a battery lid disposed on the top of the battery can, and the other is joined to the bottom of the battery can by, for example, resistance welding.
When the battery can is made of iron and the current collecting member is made of copper, the joining force by welding is insufficient, so a connecting member made of nickel is usually interposed between the battery can and the current collecting member. By doing so, a sufficient bonding force is obtained.

このような構造として、集電部材の中央に、軸芯が挿通される開口部を設け、集電部材の底面側に、この開口部を塞いで、この開口部の両側において外周側に延出される接続部材を接合する円筒形二次電池が知られている。この場合、接続部材における軸芯の開口部に対応する部分を、溶接用の電極棒により電池缶の缶底に圧接して溶接する（例えば、特許文献１参照）。 As such a structure, an opening through which the shaft core is inserted is provided at the center of the current collecting member, the opening is closed on the bottom surface side of the current collecting member, and extends to the outer peripheral side on both sides of the opening. 2. Description of the Related Art Cylindrical secondary batteries that join connecting members are known. In this case, a portion of the connecting member corresponding to the opening of the shaft core is welded by being pressed against the bottom of the battery can with a welding electrode rod (see, for example, Patent Document 1).

特開２００９−２８９７１４号公報JP 2009-289714 A

特許文献１に記載された円筒形二次電池では、電池缶の缶底に接合される接合領域の部材は接続部材のみであり、この部分における集電部材は開口部とされている。
接続部材は、集電部材よりも抵抗値が大きい材料により形成されているため、接合領域の抵抗値を小さくするためには、接続部材の厚さを厚くする必要がある。しかし、ニッケル等で構成される接続部材は、銅等により構成される集電部材よりも高価である。したがって、接続部材の厚さが厚い分だけコスト高となっていた。 In the cylindrical secondary battery described in Patent Document 1, the member of the joining region joined to the bottom of the battery can is only the connecting member, and the current collecting member in this portion is an opening.
Since the connection member is formed of a material having a larger resistance value than that of the current collecting member, it is necessary to increase the thickness of the connection member in order to reduce the resistance value of the joining region. However, the connecting member made of nickel or the like is more expensive than the current collecting member made of copper or the like. Therefore, the cost is increased by the thickness of the connecting member.

本発明の円筒形二次電池は、円筒状の軸芯の周囲に、正極電極と負極電極とをセパレータを介して捲回した電極群と、上部側に開口部を有し、電極群が収容され、電解液が注入された電池缶と、電池缶の上部側に配置された電池蓋と、電池缶の缶底と軸芯の下端部との間に配置され、正極電極および負極電極の一方が接続された集電部材と、集電部材に接合されるとともに、電池缶の缶底に接合された接続部材とを備え、集電部材は、軸芯に対応する中央領域に接合部を有し、接続部材は、電池缶に対して集電部材よりも大きな接合力で接合される材料により形成され、集電部材の接合部に接合されていることを特徴とする。 The cylindrical secondary battery of the present invention has an electrode group in which a positive electrode and a negative electrode are wound through a separator around a cylindrical shaft core, and an opening on the upper side. The battery can into which the electrolyte solution has been injected, the battery lid disposed on the upper side of the battery can, the can bottom of the battery can and the lower end of the shaft, and one of the positive electrode and the negative electrode Is connected to the current collecting member, and is connected to the bottom of the battery can. The current collecting member has a joint in the central region corresponding to the shaft core. The connecting member is formed of a material that is joined to the battery can with a larger joining force than the current collecting member, and is joined to the joining portion of the current collecting member.

この発明の円筒形二次電池によれば、集電部材の筒部の底部と接続部材が重ねられて電池缶の缶底に接合される。このため、高価な接続部材の厚さを薄くすることができ、コストを低減することができる。 According to the cylindrical secondary battery of the present invention, the bottom part of the cylindrical part of the current collecting member and the connecting member are overlapped and joined to the can bottom of the battery can. For this reason, the thickness of an expensive connection member can be made thin and cost can be reduced.

本発明に係る円筒形二次電池の一実施形態の断面図。Sectional drawing of one Embodiment of the cylindrical secondary battery which concerns on this invention. 図１に示された円筒形二次電池における電極群の詳細を示し、一部を切断した状態の斜視図。The perspective view of the state which showed the detail of the electrode group in the cylindrical secondary battery shown by FIG. 1, and cut | disconnected a part. 図１に図示された負極集電構成体の拡大断面図。The expanded sectional view of the negative electrode current collection structure illustrated in FIG. 図３に図示された負極集電構成体の分解断面図。FIG. 4 is an exploded cross-sectional view of the negative electrode current collector structure illustrated in FIG. 3. 図１に図示された円筒形二次電池の製造方法を説明するための図であり、発電ユニットの断面図。It is a figure for demonstrating the manufacturing method of the cylindrical secondary battery illustrated by FIG. 1, and sectional drawing of an electric power generation unit. 図５に続く工程を説明するための断面図。Sectional drawing for demonstrating the process following FIG. 図１に図示された電池蓋ユニットの断面図。FIG. 2 is a cross-sectional view of the battery lid unit illustrated in FIG. 1. 本発明の実施形態２を示す極集電構成体の断面図。Sectional drawing of the pole current collection structure which shows Embodiment 2 of this invention. 図８に図示された負極集電構成体の分解断面図。FIG. 9 is an exploded cross-sectional view of the negative electrode current collector structure illustrated in FIG. 8. 本発明の実施形態３を示す負極集電構成体の断面図。Sectional drawing of the negative electrode current collection structure which shows Embodiment 3 of this invention. 図１０に図示された負極集電構成体の製造方法を説明するための図であり、材料であるクラッド材の斜視図。It is a figure for demonstrating the manufacturing method of the negative electrode current collection structure shown in FIG. 10, and is a perspective view of the clad material which is a material. 図１０に図示された負極集電構成体の外観斜視図。FIG. 11 is an external perspective view of the negative electrode current collecting structure illustrated in FIG. 10.

（実施形態１）
--円筒形二次電池の構造--
以下、この発明の円筒形二次電池の一実施の形態を図面と共に説明する。
図１は、この発明の円筒形二次電池の一実施の形態を示す拡大断面図である。
円筒形二次電池１は、例えば、リチウムイオン二次電池であり、外形４０ｍｍφ、高さ１００ｍｍの寸法を有する。この円筒形二次電池１は、底部を有し、上部が開口された有底無頭の円筒形の電池缶２および電池缶２の上部を封口するハット型の電池蓋３で構成される電池容器４の内部に、以下に説明する発電用の各構成部材が収容され、非水電解液５が注入されて構成されている。 (Embodiment 1)
--Structure of cylindrical secondary battery--
Hereinafter, an embodiment of a cylindrical secondary battery of the present invention will be described with reference to the drawings.
FIG. 1 is an enlarged cross-sectional view showing an embodiment of a cylindrical secondary battery of the present invention.
The cylindrical secondary battery 1 is, for example, a lithium ion secondary battery, and has dimensions of an outer diameter of 40 mmφ and a height of 100 mm. The cylindrical secondary battery 1 includes a bottom, a headless cylindrical battery can 2 having an open top, and a hat-type battery lid 3 that seals the top of the battery can 2. Each component for power generation described below is housed inside the container 4 and is configured by injecting a non-aqueous electrolyte 5.

円筒形の電池缶２は、例えば、鉄（ＳＰＣＣ）製であり、内外両面にはニッケルめっきが施されている。電池缶２には、上端側に設けられた開口部２ｂ側に電池缶２の内側に突き出した溝２ａが形成されている。
電池缶２の中央部には、電極群１０が配置されている。電極群１０は、軸方向に沿う中空部を有する細長い円筒形の軸芯１５と、軸芯１５の周囲にセパレータを介して捲回された正極電極および負極電極とを備える。 The cylindrical battery can 2 is made of, for example, iron (SPCC), and nickel plating is applied to both the inner and outer surfaces. In the battery can 2, a groove 2 a protruding to the inside of the battery can 2 is formed on the opening 2 b provided on the upper end side.
An electrode group 10 is disposed at the center of the battery can 2. The electrode group 10 includes an elongated cylindrical shaft core 15 having a hollow portion along the axial direction, and a positive electrode and a negative electrode wound around the shaft core 15 via a separator.

軸芯１５は、軸に沿って形成された中空部を有する中空円筒状を有する。軸芯１５の軸方向（図面の上下方向）の上端部の内面には中空部よりも径大の溝１５ａが形成されている。また、軸芯１５の下端部には、軸方向に直交する方向に導出された複数の貫通孔１５ｂが形成されている。貫通孔１５ｂは、軸芯１５の上部側の中空部から注入される非水電解液５を軸芯１５の外部に流出させるためのものである。 The shaft core 15 has a hollow cylindrical shape having a hollow portion formed along the axis. A groove 15a having a diameter larger than that of the hollow portion is formed on the inner surface of the upper end portion of the shaft core 15 in the axial direction (vertical direction in the drawing). In addition, a plurality of through holes 15 b led out in a direction orthogonal to the axial direction are formed at the lower end portion of the shaft core 15. The through hole 15 b is for allowing the non-aqueous electrolyte 5 injected from the hollow portion on the upper side of the shaft core 15 to flow out of the shaft core 15.

図２は、電極群１０の構造の詳細を示し、一部を切断した状態の斜視図である。
図２に図示されるように、電極群１０は、軸芯１５の周囲に、正極電極１１、負極電極１２、および第１、第２のセパレータ１３、１４が捲回された構造を有する。 FIG. 2 is a perspective view showing the details of the structure of the electrode group 10, with a part thereof cut.
As shown in FIG. 2, the electrode group 10 has a structure in which a positive electrode 11, a negative electrode 12, and first and second separators 13 and 14 are wound around an axis 15.

軸芯１５には、第１のセパレータ１３、正極電極１１、第２のセパレータ１４および負極電極１２が捲回されている。第１のセパレータ１３および第２のセパレータ１４は、絶縁性の多孔質体で形成されている。なお、図示はしないが、軸芯１５の周面には第１、第２のセパレータ１３、１４が数周捲回される。また、最外周側は負極電極１２およびその外周に捲回された第２のセパレータ１４となっている。最外周の第２のセパレータ１４がポリプロピレン（ＰＰ）からなる接着テープ１９で止められる（図２参照）。 A first separator 13, a positive electrode 11, a second separator 14, and a negative electrode 12 are wound around the shaft core 15. The first separator 13 and the second separator 14 are formed of an insulating porous body. Although not shown, the first and second separators 13 and 14 are wound around the peripheral surface of the shaft core 15 several times. The outermost peripheral side is the negative electrode 12 and the second separator 14 wound around the outer periphery. The second separator 14 at the outermost periphery is fixed with an adhesive tape 19 made of polypropylene (PP) (see FIG. 2).

正極電極１１は、アルミニウム箔により形成され長尺な形状を有し、正極金属箔１１ａと、この正極金属箔１１ａの両面に正極合剤が塗布された正極合剤処理部１１ｂを有する。正極金属箔１１ａの長手方向に延在する上方側の側縁は、正極合剤が塗布されずアルミニウム箔が露出した正極合剤未処理部１１ｃとなっている。この正極合剤未処理部１１ｃには、軸芯１５の軸に沿って上方に突き出す多数の正極リード１６が等間隔に一体的に形成されている。正極リード１６は、正極合剤未処理部１１ｃの上部を、例えば、ロールカッタにより切断されて形成される。 The positive electrode 11 is formed of an aluminum foil and has a long shape. The positive electrode 11 includes a positive electrode metal foil 11a and a positive electrode mixture treatment portion 11b in which a positive electrode mixture is applied to both surfaces of the positive electrode metal foil 11a. The upper side edge extending in the longitudinal direction of the positive electrode metal foil 11a is a positive electrode mixture untreated portion 11c in which the positive electrode mixture is not applied and the aluminum foil is exposed. In the positive electrode mixture untreated portion 11c, a large number of positive electrode leads 16 protruding upward along the axis of the shaft core 15 are integrally formed at equal intervals. The positive electrode lead 16 is formed by cutting the upper portion of the positive electrode mixture untreated portion 11c with, for example, a roll cutter.

正極合剤は正極活物質と、正極導電材と、正極バインダとからなる。正極活物質はリチウム酸化物が好ましい。例として、コバルト酸リチウム、マンガン酸リチウム、ニッケル酸リチウム、リチウム複合酸化物（コバルト、ニッケル、マンガンから選ばれる２種類以上を含むリチウム酸化物）等が挙げられる。正極導電材は、正極合剤中におけるリチウムの吸蔵放出反応で生じた電子の正極電極への伝達を補助できるものであれば制限は無い。しかし中でも上述の材料である、コバルト酸リチウムとマンガン酸リチウムとニッケル酸リチウムとからなるリチウム複合酸化物を使用することにより良好な特性が得られる。 The positive electrode mixture includes a positive electrode active material, a positive electrode conductive material, and a positive electrode binder. The positive electrode active material is preferably lithium oxide. Examples include lithium cobaltate, lithium manganate, lithium nickelate, lithium composite oxide (lithium oxide containing two or more selected from cobalt, nickel, and manganese). The positive electrode conductive material is not limited as long as it can assist transmission of electrons generated by the occlusion / release reaction of lithium in the positive electrode mixture to the positive electrode. However, good characteristics can be obtained by using a lithium composite oxide composed of lithium cobaltate, lithium manganate, and lithium nickelate, which is the above-mentioned material.

正極バインダは、正極活物質と正極導電材を結着させ、また正極合剤と正極集電体を結着させることが可能であり、非水電解液５との接触により、大幅に劣化しなければ特に制限はない。正極バインダの例としてポリフッ化ビニリデン（ＰＶＤＦ）やフッ素ゴムなどが挙げられる。正極合剤よる正極合剤処理部１１ｂの形成方法は、正極電極上に正極合剤が形成される方法であれば制限はない。正極合剤による正極合剤処理部１１ｂの形成方法の例として、正極合剤の構成物質の分散溶液を正極金属箔１１ａ上に塗布する方法が挙げられる。このような方法で製造することにより特性の優れた正極合剤が得られる。 The positive electrode binder can bind the positive electrode active material and the positive electrode conductive material, and can bind the positive electrode mixture and the positive electrode current collector, and must be significantly deteriorated by contact with the non-aqueous electrolyte 5. There are no particular restrictions. Examples of the positive electrode binder include polyvinylidene fluoride (PVDF) and fluororubber. The formation method of the positive electrode mixture treatment part 11b by the positive electrode mixture is not limited as long as the positive electrode mixture is formed on the positive electrode. As an example of a method of forming the positive electrode mixture processing portion 11b by the positive electrode mixture, a method of applying a dispersion solution of constituent materials of the positive electrode mixture onto the positive electrode metal foil 11a can be mentioned. By producing by such a method, a positive electrode mixture having excellent characteristics can be obtained.

正極合剤を正極金属箔１１ａに塗布する方法の例として、ロール塗工法、スリットダイ塗工法、等が挙げられる。正極合剤に分散溶液の溶媒例として、Ｎ−メチルピロリドン（ＮＭＰ）や水等を添加し、混練したスラリを、厚さ２０μｍのアルミニウム箔の両面に均一に塗布し、乾燥させた後、プレスし、裁断する。正極合剤の塗布厚さの一例としては片側約４０μｍである。正極金属箔１１ａを裁断する際、正極リード１６を一体的に形成する。 Examples of the method for applying the positive electrode mixture to the positive electrode metal foil 11a include a roll coating method and a slit die coating method. As an example of a solvent for the dispersion solution in the positive electrode mixture, N-methylpyrrolidone (NMP) or water is added, and the kneaded slurry is uniformly applied to both sides of an aluminum foil having a thickness of 20 μm, dried, and then pressed. And cut. An example of the coating thickness of the positive electrode mixture is about 40 μm on one side. When cutting the positive electrode metal foil 11a, the positive electrode lead 16 is integrally formed.

負極電極１２は、銅箔により形成され長尺な形状を有し、負極金属箔１２ａと、この負極金属箔１２ａの両面に負極合剤が塗布された負極合剤処理部１２ｂを有する。負極金属箔１２ａの長手方向に延在する下方側の側縁は、負極合剤が塗布されず銅箔が露出した負極合剤未処理部１２ｃとなっている。この負極合剤未処理部１２ｃには、軸芯１５の軸に沿って正極リード１６とは反対方向に延出された、多数の負極リード１７が等間隔に一体的に形成されている。負極リード１７は、負極合剤未処理部１２ｃの上部を、例えば、ロールカッタにより切断されて形成される。 The negative electrode 12 is formed of a copper foil and has a long shape. The negative electrode 12 includes a negative electrode metal foil 12a and a negative electrode mixture treatment portion 12b in which a negative electrode mixture is applied to both surfaces of the negative electrode metal foil 12a. The lower side edge extending in the longitudinal direction of the negative electrode metal foil 12a is a negative electrode mixture untreated portion 12c where the negative electrode mixture is not applied and the copper foil is exposed. In the negative electrode mixture untreated portion 12c, a large number of negative electrode leads 17 extending in the direction opposite to the positive electrode lead 16 along the axis of the shaft core 15 are integrally formed at equal intervals. The negative electrode lead 17 is formed by cutting the upper portion of the negative electrode mixture untreated portion 12c with, for example, a roll cutter.

負極合剤は、負極活物質と、負極バインダと、増粘剤とからなる。負極合剤は、アセチレンブラックなどの負極導電材を有しても良い。負極活物質としては、黒鉛炭素を用いること、特に人造黒鉛を使用することが好ましい。黒鉛炭素を用いることにより、大容量が要求されるプラグインハイブリッド自動車や電気自動車向けのリチウムイオン二次電池が作製できる。負極合剤による負極合剤処理部１２ｂの形成方法は、負極金属箔１２ａ上に負極合剤が形成される方法であれば制限はない。しかしその中でも次に記載する方法により優れた特性の負極合剤が得られる。負極合剤を負極金属箔１２ａに塗布する方法の例として、負極合剤の構成物質の分散溶液を負極金属箔１２ａ上に塗布する方法が挙げられる。塗布方法の例として、ロール塗工法、スリットダイ塗工法等が挙げられる。 The negative electrode mixture includes a negative electrode active material, a negative electrode binder, and a thickener. The negative electrode mixture may have a negative electrode conductive material such as acetylene black. As the negative electrode active material, it is preferable to use graphitic carbon, particularly artificial graphite. By using graphite carbon, a lithium ion secondary battery for a plug-in hybrid vehicle or an electric vehicle requiring a large capacity can be manufactured. The formation method of the negative electrode mixture treatment part 12b by the negative electrode mixture is not limited as long as the negative electrode mixture is formed on the negative electrode metal foil 12a. However, among them, a negative electrode mixture having excellent characteristics can be obtained by the method described below. As an example of a method of applying the negative electrode mixture to the negative electrode metal foil 12a, a method of applying a dispersion solution of a constituent material of the negative electrode mixture onto the negative electrode metal foil 12a can be mentioned. Examples of the coating method include a roll coating method and a slit die coating method.

負極合剤を負極金属箔１２ａに塗布する方法の例として、負極合剤に分散溶媒としてＮ−メチル−２−ピロリドンや水を添加し、混練したスラリを、厚さ１０μｍの圧延銅箔の両面に均一に塗布し、乾燥させた後、プレスし、裁断する。負極合剤の塗布厚さの一例としては片側約４０μｍである。 As an example of a method for applying the negative electrode mixture to the negative electrode metal foil 12a, N-methyl-2-pyrrolidone or water as a dispersion solvent is added to the negative electrode mixture and the kneaded slurry is mixed on both sides of a rolled copper foil having a thickness of 10 μm. After uniformly applying to the substrate, drying, pressing and cutting. An example of the coating thickness of the negative electrode mixture is about 40 μm on one side.

第１のセパレータ１３および第２のセパレータ１４の幅をＷ_S、負極金属箔１２ａに形成される負極合剤処理部１２ｂの幅をＷ_C、正極金属箔１１ａに形成される正極合剤処理部１１１ｂの幅をＷ_Aとした場合、Ｗ_S＞Ｗ_C＞Ｗ_Aの関係式を満足するように形成される。
すなわち、正極合剤処理部１１ｂの幅Ｗ_Aよりも、常に、負極合剤処理部１２ｂの幅Ｗ_Cが大きい。これは、リチウムイオン二次電池の場合、正極活物質であるリチウムがイオン化してセパレータを浸透するが、負極側に負極活物質が形成されておらず負極金属箔１２ａが表出していると負極金属箔１２ａにリチウムが析出し、内部短絡を発生する原因となるからである。
同様な理由により、軸芯１５に捲回された状態では、負極電極１２の負極合剤処理部１２ｂは、軸芯１５への巻始め側の先端部は正極電極１１の正極合剤処理部１１ｂよりも、巻始め側に位置する。また、負極電極１２の負極合剤処理部１２ｂは、軸芯１５への巻終り側の終端部は正極電極１１の正極合剤処理部１１ｂよりも、巻終り側に位置する。 The width of the first separator 13 and the second separator 14 is W _S , the width of the negative electrode mixture treatment part 12b formed on the negative electrode metal foil 12a is W _C , and the positive electrode mixture treatment part formed on the positive electrode metal foil 11a When the width of 111b is W _A , it is formed so as to satisfy the relational expression W _S > W _C > W _A.
That is, the width W _C of the negative electrode mixture treatment unit 12b is always larger than the width W _A of the positive electrode mixture treatment unit 11b. This is because in the case of a lithium ion secondary battery, lithium as the positive electrode active material is ionized and penetrates the separator, but the negative electrode active material is not formed on the negative electrode side and the negative electrode metal foil 12a is exposed. This is because lithium is deposited on the metal foil 12a and causes an internal short circuit.
For the same reason, when wound around the shaft core 15, the negative electrode mixture treatment portion 12 b of the negative electrode 12 has a tip portion on the winding start side of the shaft core 15 at the positive electrode mixture treatment portion 11 b of the positive electrode 11. Rather than the winding start side. In addition, the negative electrode mixture treatment portion 12 b of the negative electrode 12 is positioned closer to the end of winding than the positive electrode mixture treatment portion 11 b of the positive electrode 11 at the end portion on the winding end side to the shaft core 15.

第１のセパレータ１３および第２のセパレータ１４は、それぞれ、例えば、厚さ４０μｍのポリプロピレン（ＰＰ）とポリエチレン（ＰＥ）の複合材料からなる多孔膜で形成されている。
図１において、中空な円筒形状の軸芯１５は軸方向（図面の上下方向）の上端部の内面に中空部よりも径大の溝１５ａが形成され、この溝１５ａに大略薄い円筒状の正極集電部材２７が圧入されている。正極集電部材２７は、例えば、アルミニウムにより形成され、円盤状の基部２７ａ、この基部２７ａの内周部において軸芯１５側に向かって突出し、軸芯１５の内面に圧入される下部筒部２７ｂ、および外周縁において電池蓋３側に突き出す上部筒部２７ｃを有する。正極集電部材２７の基部２７ａには、図示はしないが、電池内部で発生するガスを放出するための開口部が形成されている。 Each of the first separator 13 and the second separator 14 is formed of, for example, a porous film made of a composite material of polypropylene (PP) and polyethylene (PE) having a thickness of 40 μm.
In FIG. 1, a hollow cylindrical shaft core 15 is formed with a groove 15a having a diameter larger than that of the hollow portion on the inner surface of the upper end portion in the axial direction (vertical direction in the drawing). A current collecting member 27 is press-fitted. The positive electrode current collecting member 27 is made of, for example, aluminum, and has a disk-shaped base portion 27a, a lower cylindrical portion 27b that protrudes toward the shaft core 15 at the inner peripheral portion of the base portion 27a and is press-fitted into the inner surface of the shaft core 15. And an upper cylindrical portion 27c protruding toward the battery lid 3 at the outer peripheral edge. Although not shown, an opening for discharging gas generated inside the battery is formed in the base 27a of the positive electrode current collecting member 27.

正極金属箔１１ａの正極リード１６は、すべて、正極集電部材２７の上部筒部２７ｃに超音波溶接により接合される。正極リード１６は、正極集電部材２７の上部筒部２７ｃ上に重なり合って接合される。各正極リード１６は大変薄いため、１つでは大電流を取りだすことができない。このため、軸芯１５への巻き始めから巻き終わりまでの全長に亘り、多数の正極リード１６が所定間隔に形成されている。 All of the positive leads 16 of the positive metal foil 11a are joined to the upper cylindrical portion 27c of the positive current collecting member 27 by ultrasonic welding. The positive electrode lead 16 is overlapped and joined to the upper cylindrical portion 27 c of the positive electrode current collecting member 27. Since each positive electrode lead 16 is very thin, a large current cannot be taken out by one. Therefore, a large number of positive leads 16 are formed at predetermined intervals over the entire length from the start to the end of winding around the shaft core 15.

軸芯１５の下端部には、負極集電部材２０が圧入されて取り付けられている。負極集電部材２０は、例えば、銅により形成され、内周筒部２１と外周筒部２２とを有するほぼ円盤形状を有する。
負極集電部材２０の外周筒部２２の外周面には、負極金属箔１２ａの負極リード１７が溶接されている。負極金属箔１２ａの負極リード１７は、すべて、負極集電部材２０の外周筒部２２に超音波溶接等により溶接される。各負極リード１７は大変薄いため、大電流を取りだすために、軸芯１５への巻き始めから巻き終わりまで全長にわたり、所定間隔で多数形成されている。 A negative electrode current collecting member 20 is press-fitted and attached to the lower end portion of the shaft core 15. The negative electrode current collecting member 20 is made of, for example, copper and has a substantially disc shape having an inner peripheral cylindrical portion 21 and an outer peripheral cylindrical portion 22.
The negative electrode lead 17 of the negative electrode metal foil 12 a is welded to the outer peripheral surface of the outer peripheral cylindrical portion 22 of the negative electrode current collecting member 20. All of the negative electrode leads 17 of the negative electrode metal foil 12a are welded to the outer peripheral cylindrical portion 22 of the negative electrode current collecting member 20 by ultrasonic welding or the like. Since each negative electrode lead 17 is very thin, a large number of negative leads 17 are formed at predetermined intervals over the entire length from the start of winding to the shaft core 15 to take out a large current.

負極集電部材２０の内周筒部２１は底部（接合部）２３を有し、内周筒部２１の内側には、軸芯１５が下端面を底部２３に当接して圧入されている。内周筒部２１には、軸芯１５に形成された貫通孔１５ｂの位置に対応して貫通孔２４が形成されている。 The inner peripheral cylinder part 21 of the negative electrode current collecting member 20 has a bottom part (joint part) 23, and the shaft core 15 is press-fitted inside the inner peripheral cylinder part 21 with the lower end surface being in contact with the bottom part 23. A through hole 24 is formed in the inner peripheral cylinder portion 21 corresponding to the position of the through hole 15 b formed in the shaft core 15.

負極集電部材２０の内周筒部２１の底部２３には、ニッケルからなる接続部材３１が接合されている。
接続部材３１は、電池缶２の缶底２ｃに超音波溶接により接合されている。負極集電部材２０と接続部材３１は負極集電構成体５０として一体化された構造を有するものであるが、その詳細は後述する。 A connecting member 31 made of nickel is joined to the bottom 23 of the inner peripheral cylindrical portion 21 of the negative electrode current collecting member 20.
The connection member 31 is joined to the can bottom 2c of the battery can 2 by ultrasonic welding. The negative electrode current collecting member 20 and the connecting member 31 have a structure integrated as a negative electrode current collecting structure 50, and details thereof will be described later.

正極集電部材２７には、接続部材３１を電池缶２に溶接するための電極棒を挿通するための開口部２７ｄが形成されている。電極棒を正極集電部材２７に形成された開口部２７ｄから軸芯１５の中空部に差し込み、その先端部で接続部材３１を電池缶２の缶底２ｃの内面に押し付けて抵抗溶接を行う。負極集電部材２０に接続されている電池缶２の缶底２ｃは一方の出力端子として用いられる。 The positive electrode current collecting member 27 is formed with an opening 27 d for inserting an electrode rod for welding the connecting member 31 to the battery can 2. The electrode rod is inserted into the hollow portion of the shaft core 15 from the opening portion 27d formed in the positive electrode current collecting member 27, and the connecting member 31 is pressed against the inner surface of the can bottom 2c of the battery can 2 at the tip portion to perform resistance welding. The can bottom 2c of the battery can 2 connected to the negative electrode current collecting member 20 is used as one output terminal.

正極集電部材２７の基部２７ａの上面には、複数のアルミニウム箔が積層されて構成されたフレキシブルな接続リード４１が、その一端部を溶接されて接合されている。接続リード４１は、複数枚のアルミニウム箔を積層して一体化することにより、大電流を流すことが可能とされ、且つ、フレキシブル性を付与されている。つまり、大電流を流すには接続リード４１の厚さを大きくする必要があるが、１枚の金属板で形成すると剛性が大きくなり、フレキシブル性が損なわれる。そこで、板厚の小さな多数のアルミニウム箔を積層してフレキシブル性を持たせている。接続部材３３の厚さは、例えば、０．５ｍｍ程度であり、厚さ０．１ｍｍのアルミニウム箔を５枚積層して形成される。 On the upper surface of the base portion 27a of the positive electrode current collecting member 27, a flexible connection lead 41 constituted by laminating a plurality of aluminum foils is joined by welding one end thereof. The connection lead 41 can flow a large current by laminating and integrating a plurality of aluminum foils, and is provided with flexibility. That is, in order to flow a large current, it is necessary to increase the thickness of the connection lead 41. However, if the connection lead 41 is formed of a single metal plate, the rigidity increases and the flexibility is impaired. Therefore, a large number of aluminum foils having a small thickness are laminated to give flexibility. The connecting member 33 has a thickness of, for example, about 0.5 mm, and is formed by stacking five aluminum foils having a thickness of 0.1 mm.

正極集電部材２７の上部筒部２７ｃ上には、電池蓋ユニット４０が配置されている。電池蓋ユニット４０は、リング形状をした絶縁板４２、絶縁板４２に設けられた開口部に嵌入された接続板４３、接続板４３に溶接されたダイアフラム４４およびダイアフラム４４に、かしめにより固定された電池蓋３により構成される。 A battery lid unit 40 is disposed on the upper cylindrical portion 27 c of the positive electrode current collecting member 27. The battery lid unit 40 is fixed by caulking to a ring-shaped insulating plate 42, a connection plate 43 fitted into an opening provided in the insulating plate 42, a diaphragm 44 welded to the connection plate 43, and the diaphragm 44. The battery cover 3 is used.

図７は、電池蓋ユニット４０の拡大断面図である。
絶縁板４２は、円形の開口部を有するＰＰ等の絶縁性樹脂材料からなるリング形状を有し、正極集電部材２７の上部筒部２７ｃ上に載置されている。
絶縁板４２は、下方に延出され開口部側に突出する係止部４２ａを有している。絶縁板４２の開口部内には、係止部４２ａにより係合されて接続板４３が嵌合されている。接続板４３の下面には、接続リード４１の他端部が溶接されて接合されている。この場合、接続リード４１は他端部側において湾曲状に折り返されて、正極集電部材２７に溶接された面と同じ面が接続板４３に溶接されている。 FIG. 7 is an enlarged cross-sectional view of the battery lid unit 40.
The insulating plate 42 has a ring shape made of an insulating resin material such as PP having a circular opening, and is placed on the upper cylindrical portion 27 c of the positive electrode current collecting member 27.
The insulating plate 42 has a locking portion 42a that extends downward and protrudes toward the opening. The connection plate 43 is fitted into the opening of the insulating plate 42 by the engaging portion 42a. The other end of the connection lead 41 is welded and joined to the lower surface of the connection plate 43. In this case, the connection lead 41 is bent back at the other end, and the same surface as the surface welded to the positive electrode current collector 27 is welded to the connection plate 43.

接続板４３は、アルミニウム合金で形成され、中央部を除くほぼ全体が均一でかつ、中央側が厚いほぼ円盤形状を有している。接続板４３の厚さは、例えば、１ｍｍ程度である。
接続板４３の中央部は、ダイアフラム４４の中央部の底面に抵抗溶接または摩擦攪拌接合により接合されている。ダイアフラム４４はアルミニウム合金で形成され、図示はしないが、ダイアフラム４４の中心部を中心とする円形の切込みを有する。切込みはプレスにより上面側をＶ字形状に押し潰して、残部を薄肉にしたものである。ダイアフラム４４は、電池の安全性確保のために設けられており、電池の内圧が上昇すると、上方に反り、切込みにおいて開裂し、内部のガスを放出する機能を有する。 The connection plate 43 is made of an aluminum alloy and has a substantially disk shape that is substantially uniform except for the central portion and is thick on the central side. The thickness of the connection plate 43 is, for example, about 1 mm.
The central portion of the connection plate 43 is joined to the bottom surface of the central portion of the diaphragm 44 by resistance welding or friction stir welding. The diaphragm 44 is made of an aluminum alloy and has a circular cut centered on the center of the diaphragm 44, although not shown. The incision is made by crushing the upper surface side into a V shape by pressing and thinning the remainder. The diaphragm 44 is provided for ensuring the safety of the battery. When the internal pressure of the battery increases, the diaphragm 44 has a function of warping upward, cleaving at a notch, and releasing internal gas.

ダイアフラム４４は周縁部において電池蓋３の周縁部３ａを固定している。ダイアフラム４４の周壁４４ａは、当初、垂直に起立して形成されている。ダイアフラム４４の周壁４４ａ内に電池蓋３を収容し、かしめ加工により、周壁４４ａを電池蓋３の周縁部３ａの上面側に屈曲して固定する。 The diaphragm 44 fixes the peripheral portion 3a of the battery lid 3 at the peripheral portion. The peripheral wall 44a of the diaphragm 44 is initially formed to stand vertically. The battery lid 3 is accommodated in the peripheral wall 44a of the diaphragm 44, and the peripheral wall 44a is bent and fixed to the upper surface side of the peripheral edge portion 3a of the battery lid 3 by caulking.

電池蓋３は、鉄（ＳＰＣＣ）により形成されており、内外両面にてニッケルめっきが施されている。電池蓋３は、ダイアフラム４４に接触する円盤状の周縁部３ａと、この周縁部３ａから上方に突出す筒部３ｂを有するハット型を有する。 The battery lid 3 is made of iron (SPCC), and is nickel-plated on both the inside and outside. The battery lid 3 has a hat shape having a disc-shaped peripheral edge portion 3a that contacts the diaphragm 44 and a cylindrical portion 3b that protrudes upward from the peripheral edge portion 3a.

図１を参照して、ダイアフラム４４の周壁４４ａを覆ってガスケット４５が設けられている。ガスケット４５は、例えば、ペルフルオロアルコキシフッ素樹脂（ＰＦＡ）等により形成されている。
ガスケット４５の周壁４５ａは、当初、ほぼ垂直に起立して形成されている。
ガスケット４５の開口部内に電池蓋ユニット４０を収容し、プレス等により、電池缶２と共にガスケット４５の周壁４５ａを屈曲して、電池蓋３がかしめられたダイアフラム４４の周壁４４ａを軸方向に圧接してかしめ加工を行う。これにより、電池蓋３、ダイアフラム４４、絶縁板４２および接続板４３が一体に形成された電池蓋ユニット４０がガスケット４５を介して電池缶２に固定される。 Referring to FIG. 1, a gasket 45 is provided so as to cover the peripheral wall 44 a of the diaphragm 44. The gasket 45 is made of, for example, perfluoroalkoxy fluororesin (PFA).
The peripheral wall 45a of the gasket 45 is initially formed to stand substantially vertically.
The battery lid unit 40 is accommodated in the opening of the gasket 45, the peripheral wall 45a of the gasket 45 is bent together with the battery can 2 by pressing or the like, and the peripheral wall 44a of the diaphragm 44 on which the battery lid 3 is crimped is pressed in the axial direction. Perform caulking. Thereby, the battery lid unit 40 in which the battery lid 3, the diaphragm 44, the insulating plate 42 and the connection plate 43 are integrally formed is fixed to the battery can 2 via the gasket 45.

電池缶２の内部には、非水電解液５が所定量注入されている。非水電解液５の一例としては、リチウム塩がカーボネート系溶媒に溶解した溶液を用いることが好ましい。リチウム塩の例として、フッ化リン酸リチウム（ＬｉＰＦ_６）、フッ化ホウ酸リチウム（ＬｉＢＦ_６）、等が挙げられる。また、カーボネート系溶媒の例として、エチレンカーボネート（ＥＣ）、ジメチルカーボネート（ＤＭＣ）、プロピレンカーボネート（ＰＣ）、メチルエチルカーボネート（ＭＥＣ）、或いは上記溶媒の１種類以上から選ばれる溶媒を混合したものが挙げられる。 A predetermined amount of non-aqueous electrolyte 5 is injected into the battery can 2. As an example of the nonaqueous electrolytic solution 5, it is preferable to use a solution in which a lithium salt is dissolved in a carbonate solvent. Examples of the lithium salt include lithium fluorophosphate (LiPF ₆ ), lithium fluoroborate (LiBF ₆ ), and the like. Examples of carbonate solvents include ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), methyl ethyl carbonate (MEC), or a mixture of solvents selected from one or more of the above solvents. Can be mentioned.

ここで、負極集電部材２０と電池缶２との溶接について説明する。
図３は、負極集電部材２０と接続部材３１が接合された負極集電構成体５０の断面図であり、図４は、負極集電部材２０と接続部材３１とを接合する前の断面図である。
負極集電部材２０は、上述した如く、全体が銅により形成され、内周筒部２１と外周筒部２２とを有するほぼ円盤形状を有する。内周筒部２１と外周筒部２２とは、円環状の基部２０ａにより一体的に構成されている。内周筒部２１の下端面２１ａは外周筒部２２の下端面２１ａより、下方に位置している。 Here, the welding of the negative electrode current collecting member 20 and the battery can 2 will be described.
3 is a cross-sectional view of the negative electrode current collector structure 50 in which the negative electrode current collector member 20 and the connection member 31 are joined. FIG. 4 is a cross-sectional view before joining the negative electrode current collector member 20 and the connection member 31 together. It is.
As described above, the negative electrode current collecting member 20 is formed of copper as a whole and has a substantially disc shape having an inner peripheral cylindrical portion 21 and an outer peripheral cylindrical portion 22. The inner peripheral cylinder part 21 and the outer peripheral cylinder part 22 are integrally configured by an annular base 20a. The lower end surface 21 a of the inner peripheral cylinder portion 21 is located below the lower end surface 21 a of the outer peripheral cylinder portion 22.

内周筒部２１の上部側は開口され、上下方向における中間部には、上述した如く、非水電解液５を電池缶２側に流出するための貫通孔２４が形成されている。また、内周筒部２１の下部側には、軸芯１５の軸方向と直交する面、換言すれば、電池缶２の缶底２ｃと平行な面を有する底部２３が形成されている。底部２３は、内周筒部２１の下端面２１ａより内側に位置して形成されており、底部２３と内周筒部２１の下端面２１ａとの間には空隙部２９が設けられている。
底部２３は、基部２０ａ、内周筒部２１、外周筒部２２より厚さが薄いほぼ円盤型の板状部位であり、空隙部２９側に突き出すドーム形状の複数の突出部２３ａが形成されている。 The upper side of the inner peripheral cylinder part 21 is opened, and the through hole 24 for allowing the nonaqueous electrolyte 5 to flow out to the battery can 2 side is formed in the intermediate part in the vertical direction as described above. A bottom 23 having a surface orthogonal to the axial direction of the shaft core 15, in other words, a surface parallel to the can bottom 2 c of the battery can 2, is formed on the lower side of the inner peripheral cylinder portion 21. The bottom portion 23 is formed on the inner side of the lower end surface 21 a of the inner peripheral cylindrical portion 21, and a gap portion 29 is provided between the bottom portion 23 and the lower end surface 21 a of the inner peripheral cylindrical portion 21.
The bottom portion 23 is a substantially disk-shaped plate-like portion having a thickness smaller than that of the base portion 20a, the inner peripheral cylindrical portion 21, and the outer peripheral cylindrical portion 22, and is formed with a plurality of dome-shaped protruding portions 23a protruding toward the gap portion 29 side. Yes.

接続部材３１は、上述した如く、ニッケルにより形成されている。接続部材３１は、内周筒部２１の空隙部２９とほぼ同一の形状を有するほぼ円盤型の板状部材である。
接続部材３１は、底部２３の突出部２３ａを嵌入する複数の凹部３１ａを有し、また、中央部に肉厚部３１ｂを有する。肉厚部３１ｂの厚さは、空隙部２９の深さよりも僅かに大きい。 As described above, the connection member 31 is made of nickel. The connection member 31 is a substantially disk-shaped plate-like member having substantially the same shape as the gap portion 29 of the inner peripheral cylinder portion 21.
The connection member 31 has a plurality of concave portions 31a into which the protruding portions 23a of the bottom portion 23 are inserted, and has a thick portion 31b at the center. The thickness of the thick part 31 b is slightly larger than the depth of the gap part 29.

接続部材３１を、負極集電部材２０の空隙部２９に収容し、接続部材３１の凹部３１ａを底部２３の突出部２３ａに嵌合すると、接続部材３１と負極集電部材２０との位置決めがなされる。
この状態では、図３に図示される如く、接続部材３１の肉厚部３１ｂの下面は、負極集電部材２０の内周筒部２１の下端面２１ａから外部に突き出す。
接続部材３１の肉厚部３１ｂの下面を図示しない溶接治具により支持し、負極集電部材２０の底部２３の上面に図示しない溶接用の電極棒を押し付けて、抵抗溶接等により接合する。
これにより、負極集電部材２０と接続部材３１が接合された負極集電構成体５０が形成される。 When the connecting member 31 is accommodated in the gap portion 29 of the negative electrode current collecting member 20 and the concave portion 31a of the connecting member 31 is fitted into the protruding portion 23a of the bottom portion 23, the connecting member 31 and the negative electrode current collecting member 20 are positioned. The
In this state, as shown in FIG. 3, the lower surface of the thick portion 31 b of the connecting member 31 protrudes from the lower end surface 21 a of the inner peripheral cylindrical portion 21 of the negative electrode current collecting member 20 to the outside.
The lower surface of the thick portion 31b of the connection member 31 is supported by a welding jig (not shown), and an electrode rod for welding (not shown) is pressed against the upper surface of the bottom 23 of the negative electrode current collector member 20 to be joined by resistance welding or the like.
Thereby, the negative electrode current collecting structure 50 in which the negative electrode current collecting member 20 and the connecting member 31 are joined is formed.

負極集電構成体５０は、電池缶２の缶底２ｃに抵抗溶接により接合される。
ニッケルにより形成された接続部材３１は、銅よりも抵抗値が大きい。しかし、負極集電部材２０の底部２３は電池缶２の缶底２ｃと平行な面を有し、接続部材３１は、負極集電部材２０の底部２３に重ねて接合されている。つまり、電池缶２の缶底２ｃに接合された負極集電構成体５０の接合部は、接合部全面に亘り、接続部材３１と負極集電部材２０の底部２３の厚さの合計の厚さを有する。
このため、負極集電部材に底部が形成されていない従来の構造に対し、抵抗値が小さくなる。したがって、ニッケル等の高価な材料により作製する接続部材３１の厚さを小さくして、コストの低減を図ることが可能となる。
次に、図１に図示された円筒形二次電池１の製造方法の一実施の形態を説明する。 The negative electrode current collecting structure 50 is joined to the can bottom 2c of the battery can 2 by resistance welding.
The connection member 31 formed of nickel has a resistance value larger than that of copper. However, the bottom 23 of the negative electrode current collector 20 has a surface parallel to the can bottom 2 c of the battery can 2, and the connecting member 31 is overlapped and joined to the bottom 23 of the negative electrode current collector 20. That is, the joint portion of the negative electrode current collector structure 50 joined to the can bottom 2c of the battery can 2 covers the entire joint portion, and is the total thickness of the connection member 31 and the bottom portion 23 of the negative electrode current collector member 20. Have
For this reason, a resistance value becomes small with respect to the conventional structure where the bottom part is not formed in the negative electrode current collection member. Therefore, it is possible to reduce the thickness by reducing the thickness of the connecting member 31 made of an expensive material such as nickel.
Next, an embodiment of a method for manufacturing the cylindrical secondary battery 1 shown in FIG. 1 will be described.

--円筒形二次電池の製造方法--
〔電極群作製〕
先ず、電極群１０を作製する。
正極金属箔１１ａの両面に、正極合剤処理部１１ｂおよび正極合剤未処理部１１ｃが形成され、また、多数の正極リード１６が正極金属箔１１ａに一体に形成された正極電極１１を作製する。また、負極金属箔１２ａの両面に負極合剤処理部１２ｂおよび負極合剤未処理部１２ｃが形成され、多数の負極リード１７が負極金属箔１２ａに一体に形成された負極電極１２を作製する。 --Method of manufacturing cylindrical secondary battery--
[Production of electrode group]
First, the electrode group 10 is produced.
The positive electrode mixture 11 is formed on both surfaces of the positive electrode metal foil 11a. The positive electrode mixture treatment portion 11b and the positive electrode mixture untreated portion 11c are formed, and a large number of positive electrode leads 16 are integrally formed on the positive electrode metal foil 11a. . Moreover, the negative electrode mixture treatment part 12b and the negative electrode mixture untreated part 12c are formed on both surfaces of the negative electrode metal foil 12a, and the negative electrode 12 in which a number of negative electrode leads 17 are integrally formed on the negative electrode metal foil 12a is produced.

そして、軸芯１５に、第１のセパレータ１３、正極電極１１、第２のセパレータ１４および負極電極１２を捲回して電極群１０を作製する。この場合、第１のセパレータ１３および第２のセパレータ１４は最も内側の側縁部を軸芯１５に溶接しておくと、捲回時に加える荷重に抗して捲回することが容易となる。電極群１０の最外周の第２のセパレータ１４を接着テープ１９により接着する。 Then, the first separator 13, the positive electrode 11, the second separator 14, and the negative electrode 12 are wound around the shaft core 15 to produce the electrode group 10. In this case, if the innermost side edge of the first separator 13 and the second separator 14 is welded to the shaft core 15, it is easy to wind against the load applied during winding. The second separator 14 at the outermost periphery of the electrode group 10 is bonded with an adhesive tape 19.

［負極集電構成体作製］
次に、負極集電構成体５０を作製する。
上述した如く、接続部材３１を、負極集電部材２０の空隙部２９に収容し、接続部材３１の凹部３１ａを底部２３の突出部２３ａに嵌合して、接続部材３１と負極集電部材２０とを位置決めする（図３、図４参照）。
この状態で、接続部材３１の肉厚部３１ｂの下面は、負極集電部材２０の内周筒部２１の下端面２１ａから外部に突き出す。接続部材３１の肉厚部３１ｂの下面と負極集電部材２０の底部２３の上面とを、図示しない溶接用治具を押し当て抵抗溶接等により両部材を接合する。
これにより、負極集電部材２０と接続部材３１が接合された負極集電構成体５０が形成される。 [Production of negative electrode current collector structure]
Next, the negative electrode current collector structure 50 is produced.
As described above, the connection member 31 is accommodated in the gap portion 29 of the negative electrode current collector member 20, and the concave portion 31 a of the connection member 31 is fitted to the protruding portion 23 a of the bottom portion 23, so that the connection member 31 and the negative electrode current collector member 20 are fitted. Are positioned (see FIGS. 3 and 4).
In this state, the lower surface of the thick portion 31 b of the connection member 31 protrudes to the outside from the lower end surface 21 a of the inner peripheral cylindrical portion 21 of the negative electrode current collecting member 20. The lower surface of the thick portion 31b of the connecting member 31 and the upper surface of the bottom portion 23 of the negative electrode current collecting member 20 are pressed against a welding jig (not shown) to join both members by resistance welding or the like.
Thereby, the negative electrode current collecting structure 50 in which the negative electrode current collecting member 20 and the connecting member 31 are joined is formed.

〔発電ユニット作製〕
次に、作製された電極群１０を用いて発電ユニット３０を作製する。
図５は、発電ユニット３０の断面図である。
電極群１０の軸芯１５の下部に負極集電構成体５０の負極集電部材２０を嵌合する。この場合、軸芯１５の下端面を負極集電部材２０の底部２３の上面に当接することにより、負極集電部材２０の上下方向の位置が定まる。
次に、負極集電部材２０の外周筒部２２の外周面に、負極リード１７をほぼ均等に配分して密着し、超音波溶接等により、負極集電部材２０に負極リード１７を溶接する。 [Production of power generation unit]
Next, the power generation unit 30 is produced using the produced electrode group 10.
FIG. 5 is a cross-sectional view of the power generation unit 30.
The negative electrode current collecting member 20 of the negative electrode current collecting structure 50 is fitted to the lower part of the shaft core 15 of the electrode group 10. In this case, by bringing the lower end surface of the shaft core 15 into contact with the upper surface of the bottom 23 of the negative electrode current collector member 20, the vertical position of the negative electrode current collector member 20 is determined.
Next, the negative electrode lead 17 is almost uniformly distributed and adhered to the outer peripheral surface of the outer peripheral cylindrical portion 22 of the negative electrode current collecting member 20, and the negative electrode lead 17 is welded to the negative electrode current collecting member 20 by ultrasonic welding or the like.

次に、軸芯１５の正極集電部材２７の下部筒部２７ｂを軸芯１５の上端側に設けられた溝１５ａに嵌合する。そして、正極電極１１の正極リード１６を正極集電部材２７の上部筒部２７ｃの外面に密着させ、超音波溶接等により、正極集電部材２７の上部筒部２７ｃに正極リード１６を溶接する。そして、接続リード４１の一端を正極集電部材２７の基部２７ａの上面側に超音波溶接等により接合する。但し、この段階では、接続リード４１は、非水電解液５の注入の障害とならないように、負極集電部材２０の開口部２７ｄに対応する位置から外しておく。このようにして、発電ユニット３０が構成される。 Next, the lower cylindrical portion 27 b of the positive electrode current collecting member 27 of the shaft core 15 is fitted into a groove 15 a provided on the upper end side of the shaft core 15. Then, the positive lead 16 of the positive electrode 11 is brought into close contact with the outer surface of the upper cylindrical portion 27c of the positive current collecting member 27, and the positive lead 16 is welded to the upper cylindrical portion 27c of the positive current collecting member 27 by ultrasonic welding or the like. Then, one end of the connection lead 41 is joined to the upper surface side of the base portion 27a of the positive electrode current collecting member 27 by ultrasonic welding or the like. However, at this stage, the connection lead 41 is removed from the position corresponding to the opening 27d of the negative electrode current collecting member 20 so as not to obstruct the injection of the non-aqueous electrolyte 5. In this way, the power generation unit 30 is configured.

〔電池缶への収容〕
次に、発電ユニット３０を電池缶２に収容する。
図６は、発電ユニット３０を電池缶に２に収容した状態の断面図である。
発電ユニット３０を収容可能なサイズを有する金属製の電池缶２に、上述の工程を経て作製された発電ユニット３０を収容する。 [Containment in battery can]
Next, the power generation unit 30 is accommodated in the battery can 2.
FIG. 6 is a cross-sectional view of a state where the power generation unit 30 is housed in the battery can 2.
The power generation unit 30 produced through the above-described steps is accommodated in a metal battery can 2 having a size that can accommodate the power generation unit 30.

〔負極溶接〕
次に、発電ユニット３０の負極側を電池缶２に溶接する。
電池缶２内に発電ユニット３０を収容し、負極集電構成体５０を電池缶２の缶底２ｃの内面に抵抗溶接等により溶接する。
電池缶２に収容された負極集電構成体５０の接続部材３１に対応する電池缶２の缶底２ｃを溶接用治具９１により支持する。軸芯１５の上部側から、溶接用の電極棒９２を挿入し、電極棒９２の下端面を負極集電部材２０の底部２３に押し付け、負極集電構成体５０を電池缶２の缶底２ｃに抵抗溶接等により接合する。抵抗溶接により、接続部材３１の肉厚部３１ｂは溶融し、平坦となる。 [Negative electrode welding]
Next, the negative electrode side of the power generation unit 30 is welded to the battery can 2.
The power generation unit 30 is accommodated in the battery can 2, and the negative electrode current collector structure 50 is welded to the inner surface of the can bottom 2 c of the battery can 2 by resistance welding or the like.
The can bottom 2c of the battery can 2 corresponding to the connecting member 31 of the negative electrode current collecting structure 50 housed in the battery can 2 is supported by a welding jig 91. The electrode rod 92 for welding is inserted from the upper side of the shaft core 15, the lower end surface of the electrode rod 92 is pressed against the bottom 23 of the negative electrode current collecting member 20, and the negative electrode current collecting structure 50 is connected to the can bottom 2 c of the battery can 2. Are joined by resistance welding or the like. By the resistance welding, the thick part 31b of the connection member 31 is melted and flattened.

上述した如く、ニッケルにより形成された接続部材３１は、銅により形成された負極集電部材２０の板状部位の底部２３に重ねられて接合され、その状態で、電池缶２の缶底２ｃに接合される。このため、電池缶２の缶底２ｃに接合された負極集電構成体５０の接合部は、接合部全面に亘り、接続部材３１と負極集電部材２０の底部２３の厚さの合計の厚さを有し、抵抗値が小さいものとなる。 As described above, the connecting member 31 formed of nickel is overlapped and joined to the bottom 23 of the plate-like portion of the negative electrode current collector 20 formed of copper, and in this state, the connecting member 31 is connected to the can bottom 2c of the battery can 2. Be joined. For this reason, the junction part of the negative electrode current collection structural body 50 joined to the can bottom 2c of the battery can 2 is the total thickness of the thickness of the connection member 31 and the bottom part 23 of the negative electrode current collection member 20 over the entire joint part. Therefore, the resistance value is small.

次に、電池缶２の上端部側の一部を絞り加工して内方に突出し、外面にほぼＵ字状の溝２ａを形成する。
この工程において形成する溝２ａは、後述する如く、最終的な形状またはサイズではなく、仮の形状またはサイズのものである。 Next, a part on the upper end side of the battery can 2 is drawn and protrudes inward to form a substantially U-shaped groove 2a on the outer surface.
The groove 2a formed in this step has a temporary shape or size, not a final shape or size, as will be described later.

〔電解液注入〕
次に、電池缶２の内部に、非水電解液５を所定量注入する。
非水電解液５の一例としては、前述した如く、リチウム塩がカーボネート系溶媒に溶解した溶液を用いることが好ましい。リチウム塩の例として、フッ化リン酸リチウム（ＬｉＰＦ_６）、フッ化ホウ酸リチウム（ＬｉＢＦ_６）、等が挙げられる。また、カーボネート系溶媒の例として、エチレンカーボネート（ＥＣ）、ジメチルカーボネート（ＤＭＣ）、プロピレンカーボネート（ＰＣ）、メチルエチルカーボネート（ＭＥＣ）、或いは上記溶媒の１種類以上から選ばれる溶媒を混合したもの、が挙げられる。
非水電解液５は、軸芯１５の中空部の上部から注入される。軸芯１５の中空部の上部から注入された非水電解液５は、上述したように、軸芯１５の中空部を上部側から下部側に向けてに流動し、軸芯１５の貫通孔１５ｂおよび負極集電部材２０の貫通孔２４から電池缶２の缶底２ｃ側に流出し、電池缶２内に貯留される。電池缶２内への非水電解液５の注入が完了したら、接続リード４１を図６に点線で示すように、正極集電部材２７の開口部２７ｄに対応する位置に配置しておく。 [Injection of electrolyte]
Next, a predetermined amount of the non-aqueous electrolyte 5 is injected into the battery can 2.
As an example of the nonaqueous electrolytic solution 5, as described above, a solution in which a lithium salt is dissolved in a carbonate solvent is preferably used. Examples of the lithium salt include lithium fluorophosphate (LiPF ₆ ), lithium fluoroborate (LiBF ₆ ), and the like. Examples of carbonate solvents include ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), methyl ethyl carbonate (MEC), or a mixture of solvents selected from one or more of the above solvents, Is mentioned.
The non-aqueous electrolyte 5 is injected from the upper part of the hollow portion of the shaft core 15. As described above, the non-aqueous electrolyte 5 injected from the upper part of the hollow part of the shaft core 15 flows from the upper part toward the lower part of the shaft core 15, and the through hole 15 b of the shaft core 15. And it flows out from the through-hole 24 of the negative electrode current collection member 20 to the can bottom 2 c side of the battery can 2 and is stored in the battery can 2. When the injection of the non-aqueous electrolyte 5 into the battery can 2 is completed, the connection lead 41 is disposed at a position corresponding to the opening 27d of the positive electrode current collecting member 27 as shown by a dotted line in FIG.

〔蓋ユニット作製〕
一方、上記工程とは別に、電池蓋ユニット４０を作製しておく。
電池蓋ユニット４０は、上述した如く、絶縁板４２、接続板４３、ダイアフラム４４および電池蓋３により構成されている。
電池蓋ユニット４０の作製方法は、上述した通りである。 [Cover unit production]
On the other hand, a battery lid unit 40 is prepared separately from the above steps.
As described above, the battery lid unit 40 includes the insulating plate 42, the connection plate 43, the diaphragm 44, and the battery lid 3.
The method for producing the battery lid unit 40 is as described above.

〔正極溶接〕
電池缶２の溝２ａの上にガスケット４５を収容する。この状態におけるガスケット４５は、図６に図示するように、リング状の基部に対して周壁４５ａは垂直に形成されている。この形状で、ガスケット４５は、電池缶２の溝２ａ上部の内側に留まっている。このガスケット４５の上方に電池蓋ユニット４０を配置する。
電池蓋ユニット４０を傾斜させ、一端が正極集電部材２７の基部２７ａに溶接された接続リード４１の他端が視認できるようにする。そして、接続リード４１の他端部を接続板４３の下面に接触させ、この状態で、接続リード４１の他端部にレーザを照射して、接続リード４１の他端部を正極集電部材２７にレーザ溶接する。この溶接は、接続リード４１の他端部における接続板４３との接合面が、正極集電部材２７に溶接された接続リード４１の一端部の接合面と同じ面になるようにして行う。 [Positive electrode welding]
A gasket 45 is accommodated on the groove 2 a of the battery can 2. In the gasket 45 in this state, as shown in FIG. 6, the peripheral wall 45a is formed perpendicular to the ring-shaped base. With this shape, the gasket 45 remains inside the upper portion of the groove 2 a of the battery can 2. A battery lid unit 40 is disposed above the gasket 45.
The battery lid unit 40 is tilted so that the other end of the connection lead 41 whose one end is welded to the base portion 27a of the positive electrode current collecting member 27 is visible. Then, the other end of the connection lead 41 is brought into contact with the lower surface of the connection plate 43. In this state, the other end of the connection lead 41 is irradiated with a laser, and the other end of the connection lead 41 is connected to the positive current collecting member 27. Laser welded. This welding is performed so that the joint surface with the connection plate 43 at the other end of the connection lead 41 is the same as the joint surface of one end of the connection lead 41 welded to the positive electrode current collector 27.

〔封口〕
接続リード４１を正極集電部材２７に溶接した後は、電池蓋ユニット４０の下面側を水平にして、ダイアフラム４４の全周縁部をガスケット４５の基部上面に接面させる。 [Sealing]
After the connection lead 41 is welded to the positive electrode current collecting member 27, the lower surface side of the battery lid unit 40 is leveled and the entire peripheral edge portion of the diaphragm 44 is brought into contact with the upper surface of the base portion of the gasket 45.

この状態で、電池缶２の溝２ａと上端面の間の部分をプレスにより圧縮する、いわゆる、かしめ加工により、ガスケット４５と共にダイアフラム４４を電池缶２に固定する。
これにより、ダイアフラム４４、電池蓋３、接続板４３および絶縁板４２が一体化された電池蓋ユニット４０が、ガスケット４５を介して電池缶２に固定され、また、正極集電部材２７と電池蓋３が接続リード４１、接続板４３およびダイアフラム４４を介して導電接続され、図１に図示された円筒形二次電池１が作製される。 In this state, the diaphragm 44 together with the gasket 45 is fixed to the battery can 2 by a so-called caulking process in which a portion between the groove 2a and the upper end surface of the battery can 2 is compressed by pressing.
Thereby, the battery lid unit 40 in which the diaphragm 44, the battery lid 3, the connection plate 43, and the insulating plate 42 are integrated is fixed to the battery can 2 via the gasket 45, and the positive electrode current collecting member 27 and the battery lid are fixed. 3 is conductively connected through a connection lead 41, a connection plate 43 and a diaphragm 44, and the cylindrical secondary battery 1 shown in FIG. 1 is manufactured.

上記実施形態１においては、ニッケルにより形成された接続部材３１は、銅により形成された負極集電部材２０の板状部位の底部２３に重ねられ、負極集電構成体５０として構成されている。そして、この状態で、電池缶２の缶底２ｃに接合されている。
このため、負極集電部材に底部が形成されていない従来の構造に対し、抵抗値が小さくなる。これに伴い、接続部材３１の厚さを小さくして、コストの低減を図ることが可能となる。 In the first embodiment, the connection member 31 formed of nickel is superimposed on the bottom 23 of the plate-like portion of the negative electrode current collector member 20 formed of copper, and is configured as the negative electrode current collector structure 50. In this state, the battery can 2 is joined to the can bottom 2c.
For this reason, a resistance value becomes small with respect to the conventional structure where the bottom part is not formed in the negative electrode current collection member. Accordingly, the thickness of the connection member 31 can be reduced to reduce the cost.

また、負極集電部材２０の底部２３の面積は、軸芯１５の中空部の直径とほぼ同じ面積であり、接続部材３１は、負極集電部材２０の底部２３の面積とほぼ同じ面積でよい。この構造は、接続部材が、軸芯１５の中空部の面積とほぼ同じ面積の開口部を塞いで、負極集電部材２０の周縁部に接合される従来の構造に比し、接続部材の面積を小さくすることができる。したがって、面積が小さくなる分、接続部材３１のコストの低減を図ることが可能である。 Further, the area of the bottom 23 of the negative electrode current collector 20 is substantially the same as the diameter of the hollow part of the shaft core 15, and the connection member 31 may be substantially the same as the area of the bottom 23 of the negative electrode current collector 20. . This structure has an area of the connecting member as compared with the conventional structure in which the connecting member closes the opening of the hollow portion of the shaft core 15 and is joined to the peripheral portion of the negative electrode current collecting member 20. Can be reduced. Therefore, it is possible to reduce the cost of the connecting member 31 as the area is reduced.

（実施形態２）
図８は、本発明の実施形態２を示す負極集電構成体の断面図であり、図９は、接合する前の負極集電部材と接続部材の断面図である。
図８および図９を参照して、実施形態１との相違点を中心に負極集電構成体５０Ａの構成を説明することとし、実施形態１と同一の部材には、同一の符号を付して、適宜、説明を省略する。
負極集電部材２０Ａには、内周筒部２１の開口を塞ぐ底部２６の下面が、内周筒部２１の下端面と同一面に形成されており、空隙部２９ａは、底部２６の上面側に形成された凹部により形成されている。 (Embodiment 2)
FIG. 8 is a cross-sectional view of a negative electrode current collector structure showing Embodiment 2 of the present invention, and FIG. 9 is a cross-sectional view of a negative electrode current collector member and a connecting member before joining.
With reference to FIG. 8 and FIG. 9, the configuration of the negative electrode current collector structure 50 </ b> A will be described centering on differences from the first embodiment, and the same members as those in the first embodiment are denoted by the same reference numerals. Therefore, the description is omitted as appropriate.
In the negative electrode current collecting member 20 </ b> A, the bottom surface of the bottom portion 26 that closes the opening of the inner peripheral cylindrical portion 21 is formed on the same plane as the lower end surface of the inner peripheral cylindrical portion 21, and the gap portion 29 a is formed on the upper surface side of the bottom portion 26. It is formed by the recessed part formed in this.

空隙部２９ａが底部２６の上面側に形成されているため、複数のドーム状の突出部２６ａは、底部２６の上面側に形成されている。また、底部２６の中央には、開口部２６ｂが形成されている。 Since the gap portion 29 a is formed on the upper surface side of the bottom portion 26, the plurality of dome-shaped protrusions 26 a are formed on the upper surface side of the bottom portion 26. An opening 26 b is formed at the center of the bottom portion 26.

接続部材３２は、空隙部２９ａに対応する形状を有している。接続部材３２の下面には、負極集電部材２０Ａの底部２６に形成された突出部２６ａを嵌合する凹部３２ａが形成されている。
また、接続部材３１の中央には、負極集電部材２０Ａの底部２６に形成された開口部２６ｂに嵌入される肉厚部３２ｂが形成されている。肉厚部３２ｂの下面は、球面の一部の形状とされており、かつ、肉厚部３２ｂの中心が、最大厚さとなっている。肉厚部３２ｂの最大厚さは、負極集電部材２０Ａの底部２６の厚さより大きく形成されている。 The connecting member 32 has a shape corresponding to the gap portion 29a. On the lower surface of the connection member 32, a recess 32a is formed to fit the protrusion 26a formed on the bottom 26 of the negative electrode current collector 20A.
In addition, a thick portion 32b is formed in the center of the connection member 31 and is fitted into an opening 26b formed in the bottom portion 26 of the negative electrode current collecting member 20A. The lower surface of the thick portion 32b is a part of a spherical surface, and the center of the thick portion 32b is the maximum thickness. The maximum thickness of the thick part 32b is formed larger than the thickness of the bottom part 26 of the negative electrode current collector 20A.

負極集電部材２０Ａは、銅により、接続部材３２は、ニッケルにより形成されている。
接続部材３２の肉厚部３２ｂを、負極集電部材２０Ａの底部２６の開口部２６ｂに嵌入し、接続部材３２を負極集電部材２０Ａの空隙部２９ａに収容する。このとき、接続部材３２の凹部３２ａを底部２６の突出部２６ａに嵌合すると、接続部材３２と負極集電部材２０Ａとの位置決めがなされる。
この状態では、接続部材３２の肉厚部３２ｂの最大厚さ部である中央部の下面は、負極集電部材２０の底部２６の下から外部に突き出す。
接続部材３２の肉厚部３２ｂの下面を溶接治具（図示せず）により支持し、負極集電部材２０Ａの底部２３の上面に溶接用の電極棒（図しせず）を押し付けて、抵抗溶接等により接続部材３２を負極集電部材２０Ａに接合する。
これにより、負極集電部材２０Ａと接続部材３２が接合された負極集電構成体５０Ａが形成される。 The negative electrode current collecting member 20A is made of copper, and the connecting member 32 is made of nickel.
The thick part 32b of the connecting member 32 is fitted into the opening 26b of the bottom part 26 of the negative electrode current collecting member 20A, and the connecting member 32 is accommodated in the gap part 29a of the negative electrode current collecting member 20A. At this time, when the concave portion 32a of the connecting member 32 is fitted into the protruding portion 26a of the bottom portion 26, the connecting member 32 and the negative electrode current collecting member 20A are positioned.
In this state, the lower surface of the central portion, which is the maximum thickness portion of the thick portion 32 b of the connection member 32, protrudes from the bottom 26 of the negative electrode current collector member 20 to the outside.
The lower surface of the thick portion 32b of the connecting member 32 is supported by a welding jig (not shown), and a welding electrode rod (not shown) is pressed against the upper surface of the bottom 23 of the negative electrode current collecting member 20A. The connecting member 32 is joined to the negative electrode current collecting member 20A by welding or the like.
Thereby, the negative electrode current collecting member 50A in which the negative electrode current collecting member 20A and the connecting member 32 are joined is formed.

実施形態２においても、負極集電構成体５０Ａは、電池缶２の缶底２ｃに抵抗溶接により接合される。
ニッケルにより形成された接続部材３２は、銅により形成された負極集電部材２０Ａの板状部位の底部２６に重ねられて接合され、その状態で、電池缶２の缶底２ｃに接合される。したがって、電池缶２の缶底２ｃに接合された負極集電構成体５０の接合部の抵抗値が小さくなり、接続部材３２の厚さを薄くすることができる。
また、接続部材３２の面積も小さくすることができる。
よって、実施形態２においても、実施形態１と同様な効果を奏する。 Also in the second embodiment, the negative electrode current collecting structure 50A is joined to the can bottom 2c of the battery can 2 by resistance welding.
The connecting member 32 made of nickel is overlapped and joined to the bottom portion 26 of the plate-like portion of the negative electrode current collecting member 20A made of copper, and in this state, joined to the can bottom 2c of the battery can 2. Therefore, the resistance value of the joint portion of the negative electrode current collector structure 50 joined to the can bottom 2c of the battery can 2 is reduced, and the thickness of the connection member 32 can be reduced.
Moreover, the area of the connection member 32 can also be reduced.
Therefore, the second embodiment also has the same effect as the first embodiment.

（実施形態３）
図１０は、本発明の実施形態３を示す負極集電構成体５０Ｂの断面図である。
負極集電構成体５０Ｂが、図３に図示された実施形態１の負極集電構成体５０に対して最も相違する点は、負極集電部材２０Ｂと接続部材３３とが金属拡散接合によりに接合されている点である。
図１１は、図１０に図示された負極集電構成体５０Ｂを作製するためのクラッド材を示す断面図であり、図１２は、図１１に図示された負極集電構成体５０Ｂの外観斜視図である。但し、図１１および図１２は、図面を明確にするため、図１０に図示された負極集電構成体５０Ｂを下面側からみた図となっている。 (Embodiment 3)
FIG. 10 is a cross-sectional view of a negative electrode current collector structure 50B showing Embodiment 3 of the present invention.
The negative electrode current collecting structure 50B is most different from the negative electrode current collecting structure 50 of the first embodiment shown in FIG. 3 in that the negative electrode current collecting member 20B and the connecting member 33 are joined by metal diffusion bonding. It is a point that has been.
11 is a cross-sectional view illustrating a clad material for producing the negative electrode current collector structure 50B illustrated in FIG. 10, and FIG. 12 is an external perspective view of the negative electrode current collector structure 50B illustrated in FIG. It is. However, FIGS. 11 and 12 are views of the negative electrode current collecting structure 50B shown in FIG. 10 as viewed from the lower surface side for the sake of clarity.

負極集電構成体５０Ｂは、図１１に図示されるようなクラッド材により作製される。
クラッド材を作製するには、先ず、銅板２０Ｂ’に細長い溝３５を形成し、この溝３５に、ニッケル板３３’を嵌合する。ニッケル板３３’の厚さおよび幅は、銅板２０Ｂ’の溝３５の深さおよび幅よりも僅かに小さい寸法とされる。
そして、熱間圧延により、銅板２０Ｂ’とニッケル板３３’が接触している境界領域を金属拡散結合させる。 The negative electrode current collector 50B is made of a clad material as shown in FIG.
In order to produce a clad material, first, an elongated groove 35 is formed in the copper plate 20B ′, and a nickel plate 33 ′ is fitted into the groove 35. The thickness and width of the nickel plate 33 ′ are slightly smaller than the depth and width of the groove 35 of the copper plate 20 B ′.
Then, the boundary region where the copper plate 20B ′ and the nickel plate 33 ′ are in contact is subjected to metal diffusion bonding by hot rolling.

このようなクラッド材を、プレス加工して、図１２に図示されるような負極集電構成体５０Ｂを形成する。
負極集電構成体５０Ｂの接続部材３３は、負極集電部材２０Ｂの中央部を通り、両側の外周筒部２２の外周側面に露出するストライプ形状に形成されている。負極集電構成体５０Ｂは中心部に位置決め用の突出部３３ａを有している。この突出部３３ａは、図１０を参照して説明すると、負極集電部材２０Ｂの底部２３の上面側からプレス加工により形成される。 Such a clad material is pressed to form a negative electrode current collecting structure 50B as shown in FIG.
The connection member 33 of the negative electrode current collector structure 50B is formed in a stripe shape that passes through the central portion of the negative electrode current collector member 20B and is exposed on the outer peripheral side surfaces of the outer peripheral cylindrical portions 22 on both sides. The negative electrode current collector 50B has a positioning projection 33a at the center. If it demonstrates with reference to FIG. 10, this protrusion part 33a will be formed by press work from the upper surface side of the bottom part 23 of the negative electrode current collection member 20B.

接続部材３３は、負極集電部材２０Ｂの両側の外周筒部２２の外周面まで直線的に延出された長いものとなる。しかし、接続部材３３は、負極集電部材２０Ｂに金属拡散結合されているため、抵抗値が小さくなる。このため、接続部材３３の幅を、負極集電部材２０Ｂの底部２３の直径よりも小さくすることができる。
実施形態３として示す負極集電構成体５０Ｂにおいても、実施形態１と同様な効果を奏する。 The connecting member 33 is a long member extending linearly to the outer peripheral surface of the outer peripheral cylindrical portion 22 on both sides of the negative electrode current collecting member 20B. However, since the connecting member 33 is metal diffusion-bonded to the negative electrode current collecting member 20B, the resistance value becomes small. For this reason, the width | variety of the connection member 33 can be made smaller than the diameter of the bottom part 23 of the negative electrode current collection member 20B.
The negative electrode current collector structure 50B shown as the third embodiment also has the same effect as the first embodiment.

なお、上記実施形態３では、接続部材３３を、負極集電部材２０Ｂの中央部を通り、両側の外周筒部２２の外周側面に露出するストライプ形状を有する構造として説明した。しかし、接続部材３３を軸芯１５の中空部に対応する中央部のみに設ける構造としてもよい。 In the third embodiment, the connection member 33 has been described as a structure having a stripe shape that passes through the central portion of the negative electrode current collecting member 20B and is exposed on the outer peripheral side surfaces of the outer peripheral cylindrical portions 22 on both sides. However, the connection member 33 may be provided only in the central portion corresponding to the hollow portion of the shaft core 15.

逆に、実施形態１および２において、接続部材３１または３２を、負極集電部材２０、２０Ａの中央部を通り、両側の外周筒部２２まで延出されるストライプ形状を有する構造としてもよい。 On the contrary, in Embodiments 1 and 2, the connection member 31 or 32 may have a stripe shape that extends through the central portion of the negative electrode current collectors 20 and 20A to the outer peripheral cylindrical portions 22 on both sides.

上記実施形態においては、電池缶２の缶底２ｃに電極群１０の負極電極１２が接続される円筒形二次電池として説明した。しかし、本発明は、電池缶２の缶底２ｃに電極群１０の正極電極１１が接続される円筒形二次電池に対しても適用することができる。 In the said embodiment, it demonstrated as a cylindrical secondary battery by which the negative electrode 12 of the electrode group 10 is connected to the can bottom 2c of the battery can 2. FIG. However, the present invention can also be applied to a cylindrical secondary battery in which the positive electrode 11 of the electrode group 10 is connected to the can bottom 2 c of the battery can 2.

上記実施形態では、リチウムイオン円筒形二次電池の場合で説明した。しかし、本発明は、ニッケル水素電池またはニッケル・カドミウム電池、鉛蓄電池のように水溶性電解液を用いる円筒形二次電池にも適用が可能である。 In the said embodiment, the case of the lithium ion cylindrical secondary battery was demonstrated. However, the present invention can also be applied to a cylindrical secondary battery using a water-soluble electrolyte such as a nickel metal hydride battery, a nickel cadmium battery, or a lead storage battery.

上記実施形態では、電極群１０を、正極電極１１と負極電極１２との間に、第１、第２のセパレータ１３、１４を介在させた構造とした。しかし、セパレータを軸芯部で折り返し、１枚のセパレータにより正極・負極の電極１１、１２を分離する構造としてもよい。
その他、本発明の円筒形二次電池は、発明の趣旨の範囲内において、種々、変形して適用することが可能であり、要は、円筒状の軸芯の周囲に、正極電極と負極電極とをセパレータを介して捲回した電極群と、上部側に開口部を有し、電極群が収容され、電解液が注入された電池缶と、電池缶の上部側に配置された電池蓋と、電池缶の缶底と軸芯の下端部との間に配置され、正極電極および負極電極の一方が接続された集電部材と、集電部材に接合されるとともに、電池缶の缶底に接合された接続部材とを備え、集電部材は、軸芯に対応する中央領域に接合部を有し、接続部材は、電池缶に対して集電部材よりも大きな接合力で接合される材料により形成され、集電部材の接合部に接合されているものであればよい。 In the above embodiment, the electrode group 10 has a structure in which the first and second separators 13 and 14 are interposed between the positive electrode 11 and the negative electrode 12. However, the separator may be folded at the shaft core portion to separate the positive and negative electrodes 11 and 12 by a single separator.
In addition, the cylindrical secondary battery of the present invention can be variously modified and applied within the scope of the invention. In short, the positive electrode and the negative electrode are provided around the cylindrical shaft core. An electrode group wound through a separator, a battery can in which an electrode group is accommodated and an electrolyte is injected, and a battery lid disposed on the upper side of the battery can; The battery can is disposed between the bottom of the battery can and the lower end of the shaft core, and is connected to the current collector and the current collector connected to one of the positive electrode and the negative electrode. A material that is joined to the battery can with a greater joining force than the current collecting member. What is necessary is just to be joined to the junction part of a current collection member.

１円筒形二次電池
２電池缶
３電池蓋
４電池容器
５非水電解液
１０電極群
１１正極電極
１２負極電極
２０、２０Ａ、２０Ｂ負極集電部材
２１内周筒部
２２外周筒部
２３、２６底部（接合部）
２７正極集電部材
３０発電ユニット
３１、３２、３３接続部材
４０電池蓋ユニット
５０、５０Ａ、５０Ｂ負極集電構成体
DESCRIPTION OF SYMBOLS 1 Cylindrical secondary battery 2 Battery can 3 Battery cover 4 Battery container 5 Non-aqueous electrolyte 10 Electrode group 11 Positive electrode 12 Negative electrode 20, 20A, 20B Negative electrode current collection member 21 Inner peripheral cylinder part 22 Outer cylinder part 23, 26 Bottom (joint)
27 Positive electrode current collecting member 30 Power generation unit 31, 32, 33 Connection member 40 Battery lid unit 50, 50A, 50B Negative electrode current collecting structure

Claims

A battery can in which an electrode group in which a positive electrode and a negative electrode are wound through a separator and an opening on the upper side around the cylindrical shaft core, the electrode group is accommodated, and an electrolyte is injected When,
A battery lid disposed on the upper side of the battery can;
A current collecting member disposed between a bottom of the battery can and a lower end of the shaft core, to which one of the positive electrode and the negative electrode is connected;
A bonding member bonded to the current collecting member and bonded to the bottom of the battery can,
The current collecting member has a joint in a central region corresponding to the shaft core,
The connecting member is formed of a material that is bonded to the battery can with a larger bonding force than the current collecting member, and is joined to a joining portion of the current collecting member. battery.

2. The cylindrical secondary battery according to claim 1, wherein the current collecting member is made of copper, the battery can is made of iron, and the connecting member is connected by nickel. Next battery.

The cylindrical secondary battery according to claim 1 or 2, wherein the joint portion of the current collecting member and the connection member are joined by resistance welding.

The cylindrical secondary battery according to any one of claims 1 to 3, wherein the joint portion of the current collecting member and the connection member are joined by metal diffusion bonding. .

5. The cylindrical secondary battery according to claim 4, wherein a width of the connection member is smaller than a diameter of a joint portion of the current collecting member.

6. The cylindrical secondary battery according to claim 5, wherein the current collecting member has an outer cylinder part on an outer periphery of the cylinder part, and the connection member passes through a central part of the cylinder part of the current collector member. A cylindrical secondary battery having a stripe shape exposed on the outer peripheral side surfaces on both sides of the central portion.