WO2012063381A1

WO2012063381A1 - Battery module and method for welding battery module

Info

Publication number: WO2012063381A1
Application number: PCT/JP2011/003353
Authority: WO
Inventors: 英俊宇津呂; 西川　幸男; 知実田中; 俊樹糸井
Original assignee: パナソニック株式会社
Priority date: 2010-11-08
Filing date: 2011-06-14
Publication date: 2012-05-18
Also published as: KR101525331B1; JP5528571B2; CN102906902A; JPWO2012063381A1; CN102906902B; KR20130041232A

Abstract

Provided is a battery module comprising multiple cylindrical batteries, wherein electrodes of the individual cylindrical batteries are electrically connected, and wherein a connection plate (23) is placed at a position that is an end part of the cylindrical battery on a side on which a protruded part (11) of a positive electrode is arranged, and that is positioned between shoulder parts (21a) of a battery case (8) of the cylindrical battery. The connection plate (23) is closely adhered to the shoulder part (21a) that has a curvature, and the closely adhered part between the connection plate (23) and the shoulder part (21a) is connected through a negative electrode welding part (24). The shape of the negative electrode welding part is preferably a line that intersects the closely adhered part between the connection plate (23) and the shoulder part (21a).

Description

電池モジュールと電池モジュール溶接方法Battery module and battery module welding method

　本発明は、複数の電池を組み合わせて形成された電池モジュールに関するものである。 The present invention relates to a battery module formed by combining a plurality of batteries.

　近年、化石燃料の使用量の低減や、ＣＯ_２の排出量を削減するために、自動車などのモータ駆動用の電源として、電池モジュールの需要が高まっている。この電池モジュールは、所望の電圧や容量を得るために、電池を複数個搭載して構成されている。 In recent years, in order to reduce the amount of fossil fuel used and the amount of CO ₂ emission, the demand for battery modules is increasing as a power source for driving motors of automobiles and the like. This battery module is configured by mounting a plurality of batteries in order to obtain a desired voltage and capacity.

　ここで用いられる電池としては、省資源や省エネルギーの観点から、繰り返し使用できるニッケル水素、ニッケルカドミウムやリチウムイオンなどの２次電池が挙げられるが、中でも、リチウムイオン２次電池は、軽量でありながら、起電力が高く、高エネルギー密度であるため、電池モジュール用の電池として期待が大きくなっている。 Examples of the battery used here include secondary batteries such as nickel hydride, nickel cadmium, and lithium ion that can be used repeatedly from the viewpoint of resource saving and energy saving. Among them, the lithium ion secondary battery is lightweight. Since the electromotive force is high and the energy density is high, expectations are high as batteries for battery modules.

　筒型のリチウムイオン２次電池は、例えば、図１０に示すように、アルミニウム製の正極リード１を備えた正極２と、銅製の負極リード３を備え前記正極２と対向する負極４とを有する。 For example, as shown in FIG. 10, the cylindrical lithium ion secondary battery includes a positive electrode 2 having a positive electrode lead 1 made of aluminum, and a negative electrode 4 having a negative electrode lead 3 made of copper and facing the positive electrode 2. .

　そして、正極２と負極４を、セパレータ５を介して捲回した電極群６を、その上下に絶縁板７ａ，７ｂを装着して電池ケース８に挿入し、正極リード１の他方の端部を封口板１０に、負極リード３の他方の電池ケース８の底部に溶接する。 Then, the electrode group 6 in which the positive electrode 2 and the negative electrode 4 are wound through the separator 5 is inserted into the battery case 8 with the

insulating plates

7a and 7b attached to the upper and lower sides thereof, and the other end of the positive electrode lead 1 is attached. The sealing plate 10 is welded to the bottom of the other battery case 8 of the negative electrode lead 3.

　さらに、リチウムイオンを電解する非水電解質を電池ケース８内に注入し、電池ケース８の開放端部を、ガスケット９を介して封口板１０等とともにかしめた構成を有している。１１は正極キャップである。 Furthermore, a non-aqueous electrolyte that electrolyzes lithium ions is injected into the battery case 8, and the open end of the battery case 8 is caulked together with the sealing plate 10 and the like via the gasket 9. 11 is a positive electrode cap.

　この筒型のリチウムイオン２次電池を複数連結して構成された電池モジュール１２は、図１１～図１３に示すように構成されている。 The battery module 12 configured by connecting a plurality of cylindrical lithium ion secondary batteries is configured as shown in FIGS.

　電池モジュール１２は図１１に示したように、例えばポリカーボネート樹脂などの絶縁性樹脂材よりなる筐体１３および蓋体１４を有し、その内部に配線基板１５と複数の筒電池１６を収納して構成されている。配線基板１５は図１２の（ａ）（ｂ）（ｃ）に示すように、例えばガラス－エポキシ基板からなり各筒電池１６の正極と接続する接続端子１７と、各筒電池１６の負極と接続する接続板１８とを備え、隣接する接続端子１７と接続板１８とを接続する電源配線（パワーライン　図示せず）から構成されている。 As shown in FIG. 11, the battery module 12 has a casing 13 and a lid 14 made of an insulating resin material such as polycarbonate resin, and houses a wiring board 15 and a plurality of cylindrical batteries 16 therein. It is configured. As shown in FIGS. 12A, 12B, and 12C, the wiring board 15 is made of, for example, a glass-epoxy substrate, and is connected to the connection terminal 17 connected to the positive electrode of each cylindrical battery 16, and to the negative electrode of each cylindrical battery 16. The power supply wiring (power line not shown) which connects the adjacent connection terminal 17 and the connection board 18 is provided.

　なお、接続端子１７や接続板１８は、例えばニッケル板やリード線などで構成され、銅箔などで形成された前記電源配線と接続されている。 The connection terminal 17 and the connection plate 18 are made of, for example, a nickel plate or a lead wire, and are connected to the power supply wiring formed of copper foil or the like.

　そして、図１３に示すように、配線基板１５と電池ケース８の間には絶縁体１９が介装されている。筒電池１６の正極キャップ１１は、配線基板１５の接続端子１７と正極溶接部２０において接続されている。各筒電池１６，１６，・・・の負極２１は、負極溶接部２２において接続板１８と接続されている。 As shown in FIG. 13, an insulator 19 is interposed between the wiring board 15 and the battery case 8. The positive electrode cap 11 of the cylindrical battery 16 is connected to the connection terminal 17 of the wiring substrate 15 at the positive electrode welding portion 20. The negative electrode 21 of each

cylindrical battery

16, 16,... Is connected to the connection plate 18 at the negative electrode welded portion 22.

特開２０１０－１４０６９５号公報JP 2010-140695 A

　しかしながら、特許文献１に開示されるような電池モジュールでは、筒電池の底部で負極溶接を行うために接続板１８が必要となり、材料費が高くなるとともに、体積および重量が増加するという問題がある。 However, in the battery module as disclosed in Patent Document 1, the connection plate 18 is necessary to perform negative electrode welding at the bottom of the cylindrical battery, which increases the material cost and increases the volume and weight. .

　また、電池の昇温や冷却を行う際に、接続板１８が存在することがその効率を低下させるという問題がある。 Further, when the battery is heated or cooled, the presence of the connection plate 18 has a problem that the efficiency is lowered.

　本発明は、低コストで小型軽量な電池モジュール、また、電池の昇温や冷却を効率良く行える電池モジュールを実現することを目的とする。 An object of the present invention is to realize a low-cost, small and lightweight battery module and a battery module that can efficiently raise and cool the battery.

　本発明の電池モジュールは、複数の筒電池の電極を電気的に接続した電池モジュールであって、正極の突起部を配置した側の前記筒電池の端部で、前記筒電池の電池ケースの曲率を有した肩部と、接続板とを、負極溶接部にて接続したことを特徴とする。 The battery module of the present invention is a battery module in which the electrodes of a plurality of tubular batteries are electrically connected, and the curvature of the battery case of the tubular battery at the end of the tubular battery on the side where the positive electrode protrusion is disposed. The shoulder part having the above and the connecting plate are connected by a negative electrode welded part.

　また、本発明の電池モジュール溶接方法は、電池ケースのかしめて封口され曲率を有した肩部を同一方向にして配置した複数の筒電池の前記肩部に接続板を載せ、前記接続板の前記電池ケースの肩部との密着部とは反対側の面からレーザ光線を照射して、前記レーザ光線が前記密着部の予想位置と接するまたは横切ると思われる直前から直後にわたるタイミングに、前記接続板と前記電池ケースが電気接続された負極溶接部を形成することを特徴とする。 In the battery module welding method of the present invention, a battery plate is crimped and a shoulder plate having a curvature is placed in the same direction, a connection plate is placed on the shoulder portion of the plurality of cylindrical batteries, and the battery of the connection plate A laser beam is irradiated from the surface opposite to the contact portion with the shoulder portion of the case, and the connection plate and the timing between immediately before and immediately after the laser beam is supposed to touch or cross the expected position of the contact portion The battery case is formed with a negative electrode welded portion electrically connected thereto.

　この構成によれば、筒電池の肩部で負極を接続板と溶接するので、筒電池の底部に負極接続板を設ける必要がない。また、筒電池の長さにばらつきがあってもその影響を受けることなく接続できる。電池モジュールの昇温や冷却が必要な使用形態において、筒電池の端部の全体を温度調節された中間材料などに接触させて効率よく熱交換することができるため、昇温や冷却の効率を改善できる。 According to this configuration, since the negative electrode is welded to the connection plate at the shoulder of the cylindrical battery, it is not necessary to provide the negative electrode connection plate at the bottom of the cylindrical battery. Further, even if there is a variation in the length of the cylindrical battery, it can be connected without being affected by it. In usage forms that require temperature rise and cooling of the battery module, the entire end of the tubular battery can be brought into contact with the temperature-adjusted intermediate material, etc., so that heat can be exchanged efficiently. Can improve.

　また、接続板と電池ケースとの密着部の予想位置と接するまたは横切ると思われる直前から直後にわたるタイミングにレーザ溶接して線状のレーザ走査を行うことにより、溶接時の筒電池とレーザ軌跡の位置合わせが不要になり、短時間で溶接が可能である。特に、複数の筒電池の配列方向に沿って走査してレーザ光線を照射して負極溶接部を形成しているので、一つの筒電池の接続板への溶接を完了してから次の筒電池の接続板への溶接を実施する場合に比べて、一つの筒電池への単位時間当たりに与える熱の影響が少なく、接続板の歪みも少ない。 In addition, by performing linear laser scanning by laser welding at the timing immediately before and immediately after the expected position of the contact portion between the connection plate and the battery case, it is considered to contact or cross, Positioning is not required and welding can be performed in a short time. In particular, since the negative electrode welded portion is formed by scanning along the arrangement direction of a plurality of cylindrical batteries and irradiating a laser beam, the next cylindrical battery is completed after welding to the connection plate of one cylindrical battery is completed. Compared to the case of welding to the connecting plate, there is less influence of heat per unit time on one cylindrical battery, and there is less distortion of the connecting plate.

本発明に係る実施の形態１において溶接された筒電池の正極および負極の溶接部分を示す横断面図1 is a cross-sectional view showing welded portions of a positive electrode and a negative electrode of a tubular battery welded in Embodiment 1 according to the present invention. 本発明に係る実施の形態１における筒電池の溶接接合部の横断面図Cross-sectional view of a welded joint of a cylindrical battery according to the first embodiment of the present invention 本発明に係る実施の形態１において筒電池を溶接するレーザ軌跡を示す平面図The top view which shows the laser locus which welds a cylindrical battery in Embodiment 1 which concerns on this invention 本発明に係る実施の形態１において溶接された電池モジュールを示す斜視図The perspective view which shows the battery module welded in Embodiment 1 which concerns on this invention. 筒電池とレーザ軌跡の新たな課題を説明する平面図Plan view explaining new issues of cylindrical battery and laser trajectory 本発明に係る実施の形態２において筒電池を溶接するレーザ軌跡を示す平面図The top view which shows the laser locus which welds a cylindrical battery in Embodiment 2 which concerns on this invention 本発明に係る実施の形態３において筒電池を井桁状に溶接するレーザ軌跡を示す平面図The top view which shows the laser locus which welds a cylindrical battery in the shape of a cross in Embodiment 3 which concerns on this invention 本発明に係る実施の形態３において筒電池を井桁状に２重溶接するレーザ軌跡を示す平面図The top view which shows the laser locus which double-welds a cylindrical battery in the cross-beam shape in Embodiment 3 which concerns on this invention. 本発明に係る実施の形態５において行われるファイバレーザと半導体レーザを重ね合わせたハイブリッドレーザを用いた溶接を示す構成図The block diagram which shows the welding using the hybrid laser which piled up the fiber laser and semiconductor laser performed in Embodiment 5 which concerns on this invention 一般的な筒電池の断面図Sectional view of a typical cylindrical battery 特許文献１において開示されている電池モジュールの分解斜視図Exploded perspective view of battery module disclosed in Patent Document 1 （ａ）特許文献１の配線基板とその周辺の斜視図、（ｂ）図１２（ａ）のＡ－Ａ線断面図、（ｃ）図１２（ａ）の平面図(A) Perspective view of the wiring board of Patent Document 1 and its periphery, (b) AA line sectional view of FIG. 12 (a), (c) Plan view of FIG. 特許文献１において開示されている電池モジュールの筒電池の正極および負極の溶接部分を示す断面図Sectional drawing which shows the welding part of the positive electrode of a cylindrical battery of a battery module currently disclosed in patent document 1, and a negative electrode 本発明に係る実施の形態４において行われるキーホール溶接の拡大説明図Expansion explanatory drawing of keyhole welding performed in Embodiment 4 according to the present invention

　以下、本発明の電池モジュールと電池モジュール溶接方法を、図１～図９と図１４に基づいて説明する。 Hereinafter, the battery module and the battery module welding method of the present invention will be described with reference to FIGS. 1 to 9 and FIG.

　　（実施の形態１）
　図１～図４は、本発明の実施の形態１を示す。 (Embodiment 1)
1 to 4 show Embodiment 1 of the present invention.

　図１は実施の形態１の電池モジュール１２を示し、複数の筒電池１６，１６，・・・の負極２１の間を接続板２３で電気接続して構成されている。２４は負極２１と接続板２３との負極溶接部で、レーザ溶接されている。正極の突起部としての正極キャップ１１は配線基板１５の接続端子１７と正極溶接部２０で電気接続されている。配線基板１５と接続板２３の間には絶縁体１９が介装されている。 FIG. 1 shows the battery module 12 according to the first embodiment, which is configured by electrically connecting the negative electrodes 21 of a plurality of

cylindrical batteries

16, 16,. Reference numeral 24 denotes a negative electrode welding portion between the negative electrode 21 and the connection plate 23, which is laser-welded. The positive electrode cap 11 as the positive electrode protrusion is electrically connected to the connection terminal 17 of the wiring board 15 by the positive electrode welded part 20. An insulator 19 is interposed between the wiring board 15 and the connection plate 23.

　なお、各筒電池１６，１６，・・・の基本的な構造は図１０に示したものと同じであって、同じものには同一の符号を付けて説明するが、筒電池の間を電気接続する構造が図１１～図１３とは異なる。 The basic structure of each

cylindrical battery

16, 16,... Is the same as that shown in FIG. The connecting structure is different from that shown in FIGS.

　筒電池１６，１６，・・・は、正極２と負極４をセパレータ５を介して捲回した電極群６を、その上下に絶縁板７ａ，７ｂを装着して電池ケース８に挿入し、正極リード１の他方の端部を封口板１０に、負極リード３の他方の電池ケース８の底部に溶接する。 In the

cylindrical batteries

16, 16,..., The electrode group 6 in which the positive electrode 2 and the negative electrode 4 are wound through the separator 5 is inserted into the battery case 8 with the

insulating plates

7a and 7b mounted on the upper and lower sides thereof. The other end of the lead 1 is welded to the sealing plate 10 and the bottom of the other battery case 8 of the negative electrode lead 3.

　さらに、リチウムイオンを電解する非水電解質を電池ケース８内に注入し、電池ケース５の開放端部を、ガスケット９を介して封口板１０等とともにかしめて封口されている。 Furthermore, a non-aqueous electrolyte that electrolyzes lithium ions is injected into the battery case 8, and the open end of the battery case 5 is sealed with a sealing plate 10 or the like via a gasket 9.

電池ケース８の開放端部をかしめて封口した後に、次のようにして負極２１と接続板２３を接続する。 After the open end of the battery case 8 is crimped and sealed, the negative electrode 21 and the connection plate 23 are connected as follows.

　電池ケース８の開放端部をかしめて封口した筒電池１６は、図２に示すように電池ケース８の負極２１の肩部２１ａは表面に曲率を有するため、平板状の接続板２３を上に載置した場合に、接続板２３と電池ケース８の肩部との当接個所は図３に二点鎖線で示す円周状の密着部２５になる。接続板２３の前記電池ケース８との当接面とは反対側の面に、各筒電池１６ごとに密着部２５を倣うように走査を行ってレーザ光線２６を円周状に照射して、接続板２３と電池ケース８の当接部を順次溶接して負極溶接部２４を形成し、図４に示すように、複数の筒電池１６，１６，・・・の負極が接続板２３に溶接された状態に組み立てられる。 As shown in FIG. 2, the cylindrical battery 16 sealed by caulking the open end of the battery case 8 has a curved surface on the shoulder 21 a of the negative electrode 21 of the battery case 8. When placed, the contact portion between the connection plate 23 and the shoulder portion of the battery case 8 becomes a circumferential contact portion 25 indicated by a two-dot chain line in FIG. The surface opposite to the contact surface of the connection plate 23 with the battery case 8 is scanned so as to follow the contact portion 25 for each tubular battery 16 to irradiate the laser beam 26 circumferentially, The contact portions of the connection plate 23 and the battery case 8 are sequentially welded to form the negative electrode welded portion 24, and the negative electrodes of the plurality of

cylindrical batteries

16, 16,... Are welded to the connection plate 23 as shown in FIG. Assembled into a finished state.

　さらに図１に示すように、正極溶接部２０において正極キャップ１１と接続端子１７が接合されるが、接続板２３と配線基板１５は絶縁体１９によって絶縁されており、接続端子１７と配線基板１５は、はんだ等によって接続されている。 Further, as shown in FIG. 1, the positive electrode cap 11 and the connection terminal 17 are joined at the positive electrode weld 20, but the connection plate 23 and the wiring board 15 are insulated by the insulator 19, and the connection terminal 17 and the wiring board 15 are connected. Are connected by solder or the like.

　この構成によると、筒電池の底部で負極溶接を行っていた接続板が不要となり、従来に比べて材料費の低廉化、ならびに体積および重量を低減できる。また、隣接する筒電池１６の負極２１の接続は、各筒電池１６の正極キャップ１１の周囲に位置している負極２１の肩部２１ａの間を、隣接する筒電池１６の正極キャップ１１に対応して孔４８が形成されていて正極キャップ１１と接触しない接続板２３を介して、筒電池１６の正極キャップ１１の側だけで接続しているため、筒電池１６の長さにばらつきがあってもその影響を受けることなく接続できる。また、筒電池１６の正極キャップ１１の側とは反対側の端部４９には接続板などを設けなくても済むため、電池モジュールの昇温や冷却が必要な使用形態において、筒電池１６の端部４９の全体を温度調節された液体または衝撃吸収作用と温度伝達機能を併せ持ったゲルなどの中間材料などに接触させて効率よく熱交換することができるため、昇温や冷却の効率を改善できる。 This configuration eliminates the need for a connecting plate that has been subjected to negative electrode welding at the bottom of the cylindrical battery, thus reducing material costs and reducing the volume and weight compared to the prior art. Further, the connection of the negative electrode 21 of the adjacent battery cell 16 corresponds to the positive electrode cap 11 of the adjacent battery cell 16 between the shoulder portions 21a of the negative electrode 21 positioned around the positive electrode cap 11 of each battery cell 16. Since the holes 48 are formed and the connection is made only on the side of the positive electrode cap 11 of the cylindrical battery 16 via the connection plate 23 that does not come into contact with the positive electrode cap 11, the length of the cylindrical battery 16 varies. Can be connected without being affected. In addition, since it is not necessary to provide a connection plate or the like at the end 49 of the cylindrical battery 16 opposite to the positive electrode cap 11 side, the battery module 16 can be used in a usage mode in which the battery module needs to be heated or cooled. Since the entire end 49 can be brought into contact with temperature-adjusted liquid or an intermediate material such as a gel that has both a shock absorbing function and a temperature transfer function, the heat can be efficiently exchanged, improving the heating and cooling efficiency. it can.

　　（実施の形態２）
　筒電池の肩部の負極は、図２にも示したように表面に曲率を有するため、筒電池の外形形状精度が低い場合には、図５に示す密着部２５と筒電池１６自体との間に偏芯が生じ、接続板２３との密着部２５が楕円形になったりする。さらに筒電池１６自体を回転させてレーザ照射する場合には、筒電池１６自体が回転することにより密着部２５の軌跡が変化するため、レーザ軌跡を密着部２５に位置合わせすることが困難となる。その結果、このような円周状の溶接の場合には、密着部２５とレーザ軌跡２７の間にズレが生じることとなり、電池ケース８の肩かしめ部分とその上に乗せられた接続板２３との間に隙間が生じるため、接合面積が小さくなるとともに溶接強度が低下し、さらには隙間が大きい場合には接合されないという不具合が生じる。 (Embodiment 2)
Since the negative electrode of the shoulder portion of the cylindrical battery has a curvature on the surface as shown in FIG. 2, when the accuracy of the outer shape of the cylindrical battery is low, the contact portion 25 shown in FIG. Eccentricity occurs between them, and the contact portion 25 with the connection plate 23 becomes elliptical. Further, when the cylindrical battery 16 itself is rotated and laser irradiation is performed, the trajectory of the contact portion 25 is changed by the rotation of the cylindrical battery 16 itself, so that it is difficult to align the laser trajectory with the contact portion 25. . As a result, in the case of such a circumferential welding, a deviation occurs between the contact portion 25 and the laser locus 27, and the shoulder caulked portion of the battery case 8 and the connection plate 23 placed thereon are arranged. Since a gap is generated between the two, a welding area is reduced and a welding strength is reduced. Further, when the gap is large, there is a problem that the bonding is not performed.

　またこの微妙な位置ズレによって、溶接強度偏りや溶接強度バラツキが発生し、また円周状にレーザを走査するため溶接歪みが発生する可能性がある。さらに、２個以上の電池を溶接する際に、１個ずつ時系列に溶接する必要があるため、溶接に時間がかかるという問題もある。 Also, this slight misalignment may cause uneven welding strength and variations in welding strength, and may cause welding distortion due to scanning the laser in a circumferential shape. Furthermore, when two or more batteries are welded, it is necessary to weld them one by one in time series.

　この実施の形態２はレーザ光線２６の走査を、実施の形態１のそれとは変更することによって、溶接時の電池モジュールとレーザ軌跡の位置合わせが不要にできる。 In the second embodiment, the scanning of the laser beam 26 is changed from that in the first embodiment, thereby making it unnecessary to align the battery module and the laser locus during welding.

　つまり、図６に示すように、隣接して配置されている複数の筒電池１６，１６，・・・の上に接続板２３（図６では図示せず）を載置した後、接続板２３とそれぞれの筒電池１６の肩部との密着部２５と思われる予想位置を横切るように、レーザを照射する。 That is, as shown in FIG. 6, after placing the connection plate 23 (not shown in FIG. 6) on the plurality of adjacent

cylindrical batteries

16, 16,. Then, the laser is irradiated so as to cross an expected position which is considered to be a close contact portion 25 with the shoulder portion of each cylindrical battery 16.

　具体的には、複数の筒電池１６，１６，・・・の配列方向（矢印２８方向）に沿った軌跡Ｌ１，Ｌ２，Ｌ３，Ｌ４でレーザ走査し、各筒電池１６の密着部２５と接すると思われる、または各筒電池１６の密着部２５を横切ると思われる、直前から直後にわたるタイミングＴ１，Ｔ２，Ｔ３，Ｔ４，Ｔ５，Ｔ６にだけレーザ照射のパワーを溶接できるパワーに切り換えて、接続板２３と電池ケース８のかしめ部分の肩部２１ａの頂部を溶接して負極溶接部２４を形成する。このときの負極溶接部２４の形状は線状になる。５０は各筒電池１６の正極キャップ１１の中心を通る線である。なお、ここでは筒電池１６の正極の中心と正極キャップ１１の中心は一致している。 Specifically, laser scanning is performed along the trajectories L1, L2, L3, and L4 along the arrangement direction (the direction of the arrow 28) of the plurality of

tubular batteries

16, 16,. The laser irradiation power is switched to a power that can be welded only at the timings T1, T2, T3, T4, T5, and T6 from the immediately preceding to the immediately following, which seems to cross the close contact portion 25 of each cylindrical battery 16, and is connected. The negative electrode welded portion 24 is formed by welding the plate 23 and the top of the shoulder portion 21 a of the caulking portion of the battery case 8. At this time, the shape of the negative electrode welded portion 24 is linear. Reference numeral 50 denotes a line passing through the center of the positive electrode cap 11 of each cylindrical battery 16. Here, the center of the positive electrode of the cylindrical battery 16 and the center of the positive electrode cap 11 coincide.

　軌跡Ｌ１の走査が終了すると、複数の筒電池１６，１６，・・・の配列方向（矢印２８方向）とは交差する方向にレーザ照射位置を移動させて軌跡Ｌ２の走査を行って、各筒電池１６の密着部２５を横切ると思われる直前から直後にわたるタイミングＴ７，Ｔ８，Ｔ９，Ｔ１０，Ｔ１１，Ｔ１２にだけレーザ照射のパワーを溶接できるパワーに切り換えて、筒電池かしめ部分の頂部と接続板２３を溶接する。以下、同様に軌跡Ｌ３，Ｌ４の走査を行ってタイミングＴ１３～Ｔ１８，Ｔ１９～Ｔ２４にだけレーザ照射のパワーを溶接できるパワーに切り換えて、接続板２３と電池ケース８のかしめ部分の肩部２１ａの頂部を溶接する。 When the trajectory L1 is scanned, the trajectory L2 is scanned by moving the laser irradiation position in a direction crossing the direction of arrangement of the plurality of

cylindrical batteries

16, 16,. Switching the laser irradiation power to a power that can be welded only at the timings T7, T8, T9, T10, T11, and T12 immediately before and after the time when it seems to cross the contact portion 25 of the battery 16, the top part of the cylindrical battery caulking portion and the connection plate 23 is welded. Similarly, the trajectories L3 and L4 are similarly scanned to switch the laser irradiation power to a power that can be welded only at the timings T13 to T18 and T19 to T24, so that the connection plate 23 and the shoulder 21a of the caulking portion of the battery case 8 are switched. Weld the top.

　このように形成された各筒電池１６における負極溶接部２４の数は複数の８個所であって、各筒電池１６の正極キャップ１１の中心に対して何れも点対称である。線状の何れの負極溶接部２４もその延長線は、各筒電池１６の正極キャップ１１とは交差しない。また、この８つの負極溶接部２４が電池ケース８の周方向に分散して形成されているので、電流集中も無く、良好に電力を取り出せる。これらの点は以下の実施の形態においても同様である。 The number of the negative electrode welds 24 in each tubular battery 16 formed in this way is a plurality of eight places, and all are point-symmetric with respect to the center of the positive electrode cap 11 of each tubular battery 16. The extension line of any of the linear negative electrode welds 24 does not intersect the positive electrode cap 11 of each cylindrical battery 16. Further, since the eight negative electrode welded portions 24 are formed in a distributed manner in the circumferential direction of the battery case 8, there is no current concentration, and electric power can be taken out satisfactorily. These points are the same in the following embodiments.

　また、実施の形態２を示す図６では複数の負極溶接部２４を、複数の筒電池１６の正極キャップ１１の中心を通り、複数の筒電池１６の配列方向２８に沿った線５０に対して、線対称の形状に配置されている。 Further, in FIG. 6 showing the second embodiment, the plurality of negative electrode welded portions 24 are passed through the centers of the positive electrode caps 11 of the plurality of cylindrical batteries 16, with respect to the line 50 along the arrangement direction 28 of the plurality of cylindrical batteries 16. Are arranged in a line-symmetric shape.

　この溶接方法では、レーザ軌跡は必ず密着している部分を横断するため、位置合わせが不要になるという利点があり、また一直線に複数の筒電池１６をまとめて溶接するため短時間で溶接が可能である。さらに、溶接強度の偏りや溶接強度バラツキを無くして強度を均等化および安定化するとともに、溶接歪みを無くして溶接精度および機械精度を向上させることができる。 This welding method has the advantage that positioning is not required because the laser trajectory always crosses the closely contacted part. Also, since a plurality of cylindrical batteries 16 are welded together in a straight line, welding is possible in a short time. It is. Further, it is possible to equalize and stabilize the strength by eliminating welding strength unevenness and welding strength variation, and to improve welding accuracy and mechanical accuracy by eliminating welding distortion.

　また、複数の筒電池１６の配列方向２８に沿って走査してレーザ光線２６を照射して負極溶接部２４を形成しているので、一つの筒電池１６の接続板２３への溶接を完了してから次の筒電池１６の接続板２３への溶接を実施する場合に比べて、一つの筒電池１６への単位時間当たりに与える熱の影響が少なく、接続板２３の歪みも少ない。 Further, since the negative electrode welded portion 24 is formed by scanning along the arrangement direction 28 of the plurality of cylindrical batteries 16 and irradiating the laser beam 26, welding of the single cylindrical battery 16 to the connection plate 23 is completed. Compared to the case where the next battery cell 16 is welded to the connection plate 23, the influence of heat per unit time on the one battery cell 16 is small, and the distortion of the connection plate 23 is also small.

　このように複数の筒電池１６を共通の接続板２３で片側を溶接する場合に、接続板２３の歪みが少ないということは、接続された複数の筒電池１６を整列状態に維持できる点で非常に好ましく、多くの筒電池を限られたスペースに収めて車載用バッテリーなどを製造する場合に有効である。 In this way, when one side of the plurality of tubular batteries 16 is welded with the common connection plate 23, the distortion of the connection plate 23 is very small in that the connected plurality of tubular batteries 16 can be maintained in an aligned state. It is preferable, and it is effective when manufacturing a vehicle-mounted battery etc. by accommodating many cylindrical batteries in a limited space.

　　（実施の形態３）
　実施の形態２ではレーザ光線２６の走査を、複数の筒電池１６，１６，・・・の配列方向（矢印２８方向）の軌跡Ｌ１，Ｌ２，Ｌ３，Ｌ４で移動させたが、筒電池１６の円周方位角に対する接合強度や電池モジュール動作時の電流密度の均一性の観点から、図７に示すような矩形形状である例えば井桁状の溶接も好適に用いられる。ここで接合面積が小さいと、電池モジュール動作時に電流が流れた際の接合部の発熱が大きくなり、温度上昇が許容範囲内に収まらない場合があるが、その場合には図８に示すように溶接線を２重にすることにより接合面積や接合強度を向上させることができる。 (Embodiment 3)
In the second embodiment, the scanning of the laser beam 26 is moved along the trajectories L1, L2, L3, L4 in the arrangement direction (arrow 28 direction) of the plurality of

cylindrical batteries

16, 16,. From the viewpoint of the bonding strength with respect to the circumferential azimuth and the uniformity of the current density when the battery module operates, a rectangular shape as shown in FIG. Here, if the junction area is small, heat generation at the junction when current flows during battery module operation increases, and the temperature rise may not be within the allowable range. In that case, as shown in FIG. By making the weld line double, the joint area and joint strength can be improved.

　図７に示した実施例では、軌跡Ｌ１に沿ってレーザ走査位置を移動させて各筒電池１６の密着部２５と接すると思われる、または筒電池１６の密着部２５を横切ると思われる、直前から直後にわたるタイミングＴ１～Ｔ８にだけレーザ照射のパワーを溶接できるパワーに切り換えて、接続板２３と電池ケース８のかしめ部分の肩部２１ａの頂部を溶接する。溶接が終わった筒電池１６に隣接した溶接前の筒電池１６についても同様に溶接する。 In the embodiment shown in FIG. 7, it is assumed that the laser scanning position is moved along the locus L <b> 1 so as to come into contact with the contact portion 25 of each battery cell 16, or it is assumed that the contact portion 25 of the battery cell 16 is crossed. The power of the laser irradiation is switched to a power that can be welded only at timings T1 to T8 immediately after the welding, and the top of the shoulder 21a of the caulking portion of the battery case 8 is welded. The welding is performed in the same manner for the tubular battery 16 before welding adjacent to the tubular battery 16 after the welding.

　この場合にも、タイミングＴ１～Ｔ８にだけレーザ照射のパワーを溶接できるパワーに切り換えて、一つの筒電池の外周に沿って並んだ間欠的な複数の溶接点によって、接続板２３と電池ケース８の肩部２１ａとの負極溶接部２４が形成されているので、前記密着部２５に沿って連続してレーザ照射して溶接する場合に比べて、各筒電池１６および接続板２３に作用する熱影響が小さい。 Also in this case, the power of the laser irradiation is switched to a power that can be welded only at timings T1 to T8, and the connection plate 23 and the battery case 8 are formed by a plurality of intermittent welding points arranged along the outer periphery of one cylindrical battery. Since the negative electrode welded portion 24 with the shoulder portion 21a is formed, the heat acting on each of the battery cells 16 and the connecting plate 23 is compared with the case where welding is performed by laser irradiation continuously along the contact portion 25. The impact is small.

　図８に示した実施例では、軌跡Ｌ１に沿ってレーザ走査位置を移動させて図７と同様に溶接した後に、軌跡Ｌ１の内周側の軌跡Ｌ２にレーザ走査位置を移動して、前記密着部２５と接すると思われる、または筒電池１６の密着部２５を横切ると思われる、直前から直後にわたるタイミングＴ９～Ｔ１６にだけレーザ照射のパワーを溶接できるパワーに切り換えて、接続板２３と電池ケース８のかしめ部分の頂部を溶接する。溶接が終わった筒電池１６に隣接した溶接前の筒電池１６についても同様に溶接する。 In the embodiment shown in FIG. 8, after the laser scanning position is moved along the locus L1 and welding is performed in the same manner as in FIG. 7, the laser scanning position is moved to the locus L2 on the inner circumference side of the locus L1, and the contact The connection plate 23 and the battery case are switched to the power capable of welding the laser irradiation power only at the timings T9 to T16 from the immediately preceding to the immediately following which seems to be in contact with the portion 25 or cross the contact portion 25 of the cylindrical battery 16. The top of the caulking portion of 8 is welded. The welding is performed in the same manner for the tubular battery 16 before welding adjacent to the tubular battery 16 after the welding.

　　（実施の形態４）
　上記の各実施の形態では、レーザ溶接の形態が熱伝導型であった場合には、電池ケース８をレーザが貫通したり、電池ケース８の温度が上がりすぎたりしないようにレーザパワーを非常に高精度に調節することが必要であるが、レーザ溶接の形態として走査速度の高いキーホール溶接を各実施の形態に採用することによって、ガスケット９の応力緩和が起こらない範囲に電池ケース８の温度上昇を抑え、電解液が漏液しないように溶接を行うことができ、より簡単に、しかも短時間で、接続板２３と筒電池１６を溶接できる。 (Embodiment 4)
In each of the above-described embodiments, when the laser welding mode is a heat conduction type, the laser power is very low so that the laser does not penetrate the battery case 8 and the temperature of the battery case 8 does not rise too much. Although it is necessary to adjust with high accuracy, the temperature of the battery case 8 is within a range where stress relaxation of the gasket 9 does not occur by adopting keyhole welding with a high scanning speed as a laser welding mode in each embodiment. It is possible to perform welding so that the rise is suppressed and the electrolyte does not leak, and the connection plate 23 and the cylindrical battery 16 can be welded more easily and in a short time.

　キーホール溶接の際には、図１４に示すように、接続板２３を通して負極２１の表面付近までレーザ光線２６が届くように、熱伝導型レーザ溶接の場合よりも高出力のレーザ光線２６を使用する。このキーホール溶接では、レーザの熱によってレーザ照射位置の接続板２３と負極２１の肩部が部分的に溶融し、溶融金属の溜まりである溶融池４０が形成される。この溶融池４０の先端部分でレーザが接続板２３を貫通してキーホール４１が形成される。このキーホール溶接では、接続板２３の熱伝導によって溶融部を拡げる熱伝導型の溶接とは異なり、溶接される接続板２３の溶接個所以外の部分の温度上昇を抑えることができ、特に、レーザパワーによって走査速度の速いキーホール溶接を行うことによって、電池ケース８の温度上昇を熱伝導型レーザ溶接の場合よりも低く抑えることができる。図１４において矢印４２は溶接進行方向、矢印４３は溶融池４０での溶融の流れ、４４は気泡、４５はボイド、４６はスパッタである。 At the time of keyhole welding, as shown in FIG. 14, a laser beam 26 having a higher output than that in the case of heat conduction laser welding is used so that the laser beam 26 reaches the surface of the negative electrode 21 through the connection plate 23. To do. In this keyhole welding, the connection plate 23 at the laser irradiation position and the shoulder of the negative electrode 21 are partially melted by the heat of the laser to form a molten pool 40 that is a pool of molten metal. A laser penetrates the connecting plate 23 at the tip of the molten pool 40 to form a keyhole 41. In this keyhole welding, unlike the heat conduction type welding in which the melted portion is expanded by the heat conduction of the connection plate 23, the temperature rise of the portion other than the welded portion of the connection plate 23 to be welded can be suppressed. By performing keyhole welding with a high scanning speed by power, the temperature rise of the battery case 8 can be suppressed lower than that in the case of heat conduction laser welding. In FIG. 14, an arrow 42 indicates the welding progress direction, an arrow 43 indicates the flow of melting in the

molten pool

40, 44 indicates bubbles, 45 indicates voids, and 46 indicates spatter.

　レーザ光線２６の出力制御に際しては、キーホール深さ４７の変動とその溶接の際のプラズマ発光の発光量とには相関があるため、プラズマ発光量を計測し、計測によって得られたプラズマ発光量が目標キーホール深さの場合の目標プラズマ発光量に近付くように、レーザ光線２６の出力パワーを制御することによって、キーホール４１の細長い形状を安定にできる。 When controlling the output of the laser beam 26, since there is a correlation between the fluctuation of the keyhole depth 47 and the amount of plasma emission during welding, the amount of plasma emission is measured and the amount of plasma emission obtained by the measurement is measured. By controlling the output power of the laser beam 26 so as to approach the target plasma emission amount when is the target keyhole depth, the elongated shape of the keyhole 41 can be stabilized.

　　（実施の形態５）
　上記の各実施の形態におけるレーザ照射の具体例を図９に示す。 (Embodiment 5)
Specific examples of laser irradiation in each of the above embodiments are shown in FIG.

　この実施の形態５では、ファイバレーザ２９と半導体レーザ３０を重ね合わせたハイブリッドレーザが好適に用いられる。レーザ鏡筒３１はミラー３２，３３とレンズ３４を有している。レーザ鏡筒３１に入射したファイバレーザ２９は、ミラー３２で反射してミラー３３とレンズ３４を通過して負極溶接部に向けて照射される。レーザ鏡筒３１に入射した半導体レーザ３０は、ミラー３３で反射してレンズ３４を通過して負極溶接部に向けて照射される。ここでは、ファイバレーザ２９により溶込み深さを制御し、半導体レーザ３０によって溶接幅を確保することによって、電池ケースの厚みに対して寸止めの溶込み深さで十分な溶接幅を得ることができる。また、ハイブリッドレーザの特徴として、スパッタやブローホールの発生を抑止し、溶接品質を向上させることができる。 In the fifth embodiment, a hybrid laser in which the fiber laser 29 and the semiconductor laser 30 are overlapped is preferably used. The laser barrel 31 has

mirrors

32 and 33 and a lens 34. The fiber laser 29 incident on the laser barrel 31 is reflected by the mirror 32, passes through the mirror 33 and the lens 34, and is irradiated toward the negative electrode weld. The semiconductor laser 30 incident on the laser barrel 31 is reflected by the mirror 33, passes through the lens 34, and is irradiated toward the negative electrode weld. Here, by controlling the penetration depth with the fiber laser 29 and securing the welding width with the semiconductor laser 30, it is possible to obtain a sufficient welding width with a penetration depth that is a dimension stop relative to the thickness of the battery case. it can. Further, as a feature of the hybrid laser, it is possible to suppress the occurrence of spatter and blow holes and improve the welding quality.

　本発明は、高い性能および信頼性とともに省資源や省エネルギーが要求される、自動車などのモータ駆動用の電源に用いるための、電池を複数個搭載した電池モジュールおよびその溶接方法として有用である。 The present invention is useful as a battery module having a plurality of batteries mounted thereon and a welding method thereof for use in a power source for driving a motor of an automobile or the like, which requires high performance and reliability as well as resource saving and energy saving.

　８　　電池ケース
　９　　ガスケット
１０　　封口板
１１　　正極キャップ
１２　　電池モジュール
１３　　筐体
１４　　蓋体
１５　　配線基板
１６　筒電池
１７　　接続端子
１８　　接続板
１９　　絶縁体
２０　　正極溶接部
２１　　負極
２１ａ　　肩部
２２　　負極溶接部
２３　　接続板
２４　　負極溶接部
２５　　密着部
２６　　レーザ光線
２７　　レーザ軌跡
２８　　複数の筒電池１６の配列方向
Ｌ１，Ｌ２，Ｌ３，Ｌ４　　軌跡
Ｔ１～Ｔ６，Ｔ７～Ｔ１２，Ｔ１３～Ｔ１８，Ｔ１９～Ｔ２４　　溶接実行のタイミング
２９　　ファイバレーザ
３０　　半導体レーザ
３１　　レーザ鏡筒
３２，３３　ミラー
３４　　レンズ
8 Battery Case 9 Gasket 10 Sealing Plate 11 Positive Cap 12 Battery Module 13 Housing 14 Lid 15 Wiring Board 16 Tube Battery 17 Connection Terminal 18 Connection Plate 19 Insulator 20 Positive Electrode Welding Portion 21 Negative Electrode 21a Shoulder Portion 22 Negative Electrode Welding Portion 23 Connection Plate 24 Negative electrode welded portion 25 Adhering portion 26 Laser beam 27 Laser trajectory 28 Arrangement direction L1, L2, L3, L4 of a plurality of tubular batteries 16 Trajectories T1 to T6, T7 to T12, T13 to T18, T19 to T24 Timing of welding execution 29 Fiber laser 30 Semiconductor laser 31

Laser barrel

32, 33 Mirror 34 Lens

Claims

　複数の筒電池の電極を電気的に接続した電池モジュールであって、
　正極の突起部を配置した側の前記筒電池の端部で、前記筒電池の電池ケースの曲率を有した肩部と、接続板とを、負極溶接部にて接続した
電池モジュール。 A battery module in which electrodes of a plurality of cylindrical batteries are electrically connected,
The battery module which connected the shoulder part which had the curvature of the battery case of the said cylindrical battery, and the connection board in the edge part of the said cylindrical battery by the side which has arrange | positioned the projection part of a positive electrode in the negative electrode welding part.
　前記負極溶接部の形状が、前記接続板と前記電池ケースの肩部との密着部に交差する線状である
請求項１に記載の電池モジュール。 2. The battery module according to claim 1, wherein the shape of the negative electrode welded portion is a linear shape that intersects a close contact portion between the connection plate and a shoulder portion of the battery case.
　一つの前記筒電池毎に、複数の前記負極溶接部を有する
請求項１または請求項２に記載の電池モジュール。 The battery module according to claim 1, wherein each of the cylindrical batteries has a plurality of the negative electrode welds.
　一つの前記筒電池当たりに、複数の前記負極溶接部を有し、複数の前記負極溶接部は、前記正極の突起部の中心に対して点対称の形状となるよう配置されている
請求項１または請求項２に記載の電池モジュール。 The plurality of negative electrode welds are provided per one cylindrical battery, and the plurality of negative electrode welds are arranged so as to have a point-symmetric shape with respect to the center of the projection of the positive electrode. Or the battery module of Claim 2.
　複数の前記負極溶接部を、複数の筒電池の前記正極の突起部の中心を通り、前記複数の筒電池の配列方向に沿った線に対して、線対称の形状に配置した
請求項１または請求項２に記載の電池モジュール。 The plurality of negative electrode welds are arranged in a line-symmetric shape with respect to a line passing through the centers of the positive electrode protrusions of the plurality of tubular batteries and extending in the arrangement direction of the plurality of tubular batteries. The battery module according to claim 2.
　線状の前記負極溶接部の延長線が、正極の突起部に交差しない
請求項２～請求項５の何れかに記載の電池モジュール。 The battery module according to any one of claims 2 to 5, wherein an extension line of the linear negative electrode welded portion does not intersect with the protruding portion of the positive electrode.
　前記接続板と前記電池ケースの曲率を有した肩部との間がキーホール溶接されている
請求項１～請求項６の何れかに記載の電池モジュール。 The battery module according to any one of claims 1 to 6, wherein the connection plate and a shoulder portion having a curvature of the battery case are keyhole welded.
　電池ケースのかしめて封口され曲率を有した肩部を同一方向にして配置した複数の筒電池の前記肩部に接続板を載せ、
　前記接続板の前記電池ケースの肩部との密着部とは反対側の面からレーザ光線を照射して、前記レーザ光線が前記密着部の予想位置と接するまたは横切ると思われる直前から直後にわたるタイミングに、前記接続板と前記電池ケースが電気接続された負極溶接部を形成する
電池モジュール溶接方法。 Placing a connection plate on the shoulders of the plurality of tubular batteries arranged in the same direction with the shoulders that have been crimped and sealed in the battery case,
The laser beam is irradiated from the surface of the connection plate opposite to the contact portion with the shoulder portion of the battery case, and the timing immediately before and immediately after the laser beam is considered to contact or cross the expected position of the contact portion. And a battery module welding method for forming a negative electrode welded portion in which the connection plate and the battery case are electrically connected.
　複数の筒電池の配列方向に沿って走査してレーザ光線を照射して前記負極溶接部を形成する
請求項８に記載の電池モジュール溶接方法。 The battery module welding method according to claim 8, wherein the negative electrode welded portion is formed by scanning along a direction in which a plurality of cylindrical batteries are arranged and irradiating a laser beam.
　複数の前記筒電池ごとに、前記接続板と前記電池ケースとの密着部の予想位置と接するまたは横切る矩形形状の軌跡でレーザ光線を走査して前記負極溶接部を形成する
請求項８に記載の電池モジュール溶接方法。 9. The negative electrode welded portion according to claim 8, wherein the negative electrode welded portion is formed by scanning a laser beam with a rectangular trajectory that is in contact with or crosses the expected position of the contact portion between the connection plate and the battery case for each of the plurality of cylindrical batteries. Battery module welding method.
　キーホール溶接により前記負極溶接部を形成する
請求項８～請求項１０の何れかに記載の電池モジュール溶接方法。 11. The battery module welding method according to claim 8, wherein the negative electrode weld is formed by keyhole welding.
　ファイバレーザと半導体レーザを重ね合わせたハイブリッドレーザを前記接続板に向けて照射し、前記ファイバレーザにより前記負極溶接部の溶込み深さを制御し、前記半導体レーザによって溶接幅を確保して溶接する
請求項８～請求項１１の何れかに記載の電池モジュール溶接方法。 A hybrid laser in which a fiber laser and a semiconductor laser are superimposed is irradiated toward the connection plate, the penetration depth of the negative electrode weld is controlled by the fiber laser, and a welding width is secured by the semiconductor laser for welding. The battery module welding method according to any one of claims 8 to 11.
　キーホール溶接個所でのプラズマ発光量を計測し、計測によって得られたプラズマ発光量が目標キーホール深さの場合の目標プラズマ発光量に近付くように、前記レーザ光線の出力パワーを制御してキーホールの形状を制御する
請求項１１に記載の電池モジュール溶接方法。
The amount of plasma emitted at the keyhole weld is measured, and the output power of the laser beam is controlled so that the plasma emission obtained by the measurement approaches the target plasma emission when the target keyhole depth is reached. The battery module welding method according to claim 11, wherein the shape of the hole is controlled.