【０００１】
【発明の属する技術分野】
本発明は、リチウムイオン二次電池等の電池の正極側の絶縁気密端子等として使用される電池用端子に関する。
【０００２】
【従来の技術】
従来、電池から電気を取り出すための電池用端子を構成する端子部材や集電体には、導電性に優れること、電池内部で化学的に安定に存在すること、電池内部で占める体積が小さな小型化されたものであること、体積当たりの重量が小さいこと、実用的に十分な強度を有することといった種々の特性が要求されることから、このような特性を満たすニッケル（Ｎｉ）、ステンレス鋼、チタン（Ｔｉ）、アルミニウム（Ａｌ）等の金属が用いられていた。
【０００３】
また、二次電池では充電時に正極がアノード分極されるため、正極用の集電体となる金属には高い耐食性が要求される。さらに、リチウムイオン二次電池では有機電解液が用いられるため、正極用の集電体には有機電解液中での高い耐食性を有する金属としてＡｌが用いられていた。また、電池の筐体から外部に電気を取り出す電池用端子の端子部材としても上記と同様の理由でＡｌが用いられていた。
【０００４】
このような電池用端子において、端子部材と筐体とが電気的に絶縁されているとともに、端子部材と筐体との接合部から有機電解液が漏れることが無いように気密が確保されている必要がある。このような絶縁性および気密性を満足させるために、端子部材と筐体とは、ガラス層（ガラスフリットを焼結して成るもの）、樹脂接着剤、ゴム製のＯリング等の絶縁物を介して接合されていた。
【０００５】
また、リチウムイオン二次電池は、大きなエネルギー密度、優れたサイクル寿命、高い作動電圧、少ない自己放電、有害物質不使用、無メモリー効果などの優れた点が多いことから、近年、人工衛星用のバックアップ電源などとして用いられてきており、過酷な使用環境下でのより高い信頼性が要求されている。
【０００６】
しかしながら、このようなリチウムイオン二次電池の電池用端子にガラス、樹脂接着剤、ゴム製のＯリング等の絶縁物を用いると、環境の温度変化で絶縁物が劣化しひびや割れ等が発生して気密不良を起こしたり、また、有機電解液により絶縁物が腐食されて気密不良を起こすなどの問題が発生していた。
【０００７】
このような問題を解決するために、金属から成る端子部材を化学的に安定で耐腐食性の高いセラミック部材を介して電池の筐体にロウ付けすることで、気密性に対する高い信頼性を得ることが可能となった（例えば、下記の特許文献１参照）。
【０００８】
このような電池用端子の基本構成の断面図を図２に示す。図２において、２０はセラミックスから成る絶縁部材、２１は金属から成る環状部材、２２は金属から成る端子部材、２３は集電体であり、これら絶縁部材２０、環状部材２１、端子部材２２および集電体２３とで電池用端子が基本的に構成され、環状部材２１が電池の筐体にロウ材で接合されることで電池用端子として機能する。
【０００９】
絶縁部材２０は、アルミナ質焼結体（アルミナセラミックス）等のセラミックから成り、中央部に貫通孔を有する円筒形状の部材であり、その内周面にはＡｌからなる端子部材２２がＡｌを主成分として含むロウ材でロウ付けされ、外周面にはＡｌ等の金属からなる環状部材２１がＡｌを主成分として含むロウ材でロウ付けされている。端子部材２２の下端は、Ａｌから成る板状の集電体２３の円形状の開口に嵌着されてが溶接される。溶接による接合を強固なものとするため、端子部材２２の下端の接合部には鍔部２２ａが形成されている。セラミックスから成る絶縁部材２０はリチウムイオン二次電池の電池用端子に用いても、有機電解液による腐食をほとんど受けない。
【００１０】
このような電池用端子は、端子部材２２と絶縁部材２０、絶縁部材２０と環状部材２１をそれぞれ接合するロウ材は高融点（６００℃程度）であることから、広い温度範囲での使用が可能であり、人工衛星等で使用されても十分に気密性を保持することができる。
【００１１】
【特許文献１】
特開平１１−１６７９１５号公報
【００１２】
【発明が解決しようとする課題】
しかしながら、図２の従来の電池用端子においては、端子部材２２の鍔部２２ａの下面全面と集電体２３の開口とが密着しており、この密着部で熱容量が大きくなり溶接による熱が拡散しやすくなっているため、端子部材２２の外周面の下端の溶接起点部Ａ（図２）から鍔部２２ａの角部Ｂ（図２）へ向かって熱が伝わりにくいため、溶接による熱が小さい場合、溶接部の溶け込み（溶け合う部分の体積）が小さくなり十分な接合強度が確保できなかった。その結果、振動等により溶接部が破損したり、溶け込み不足によって端子部材２２から集電体２３へ電気が流れる導電経路が十分に形成されず、通電できる電気容量（電流値）が低下して、所望の電気容量が確保できないという問題点を有していた。
【００１３】
逆に溶接による熱が大きい場合、溶接起点部Ａと角部Ｂとに加わる熱応力の差によって、すなわち角部Ｂにより大きな熱応力が加わることによって、角部Ｂが起点となり溶接部が破損するといった問題点を有していた。
【００１４】
また、溶接時の熱が伝わり易いように、端子部材２２に鍔部２２ａを設けない構成とすることによって、溶接強度と電気容量を確保し、かつ熱応力の差によって角部Ｂが起点となり溶接部が破損することを防止できる。しかしながら、この構成では端子部材２２と集電体２３との位置決めがきわめて困難となり、製品として所定の正確な寸法や配置構造を有するものとならないといった問題点があった。
【００１５】
従って、本発明は上記従来の問題点に鑑みて完成されたものであり、その目的は、端子部材と集電体との溶接部が振動等により破損することがなく、端子部材と集電体との接合強度および導通性を向上させるとともに、端子部材と集電体とが正確な寸法および配置でもって接合された信頼性の高い電池用端子とすることである。
【００１６】
【課題を解決するための手段】
本発明の電池用端子は、外周面の下端部に全周にわたって鍔部が形成されたアルミニウムから成る円柱状の端子部材と、該端子部材がその両端が突出するように挿通され接合されたセラミックスから成る円筒状の絶縁部材と、該絶縁部材の外周面に内周面が接合された金属から成る環状部材とを具備しており、前記端子部材は、前記鍔部が前記端子部材の下端よりも高い位置に形成されており、前記鍔部の下面の内周端に全周にわたって溝が形成されていることを特徴とする。
【００１７】
本発明の電池用端子は、端子部材は、鍔部が端子部材の下端よりも高い位置に形成されており、鍔部の下面の内周端に全周にわたって溝が形成されていることから、溶接による熱は端子部材の外周面下端部と集電体の開口との嵌着部（溶接部）に集中しやすくなる。その結果、溶接による熱が小さくても、溶接部の溶け込みが十分となり大きな接合強度が確保できるため、振動等により溶接部が破損するのを防ぐことができ、また、端子部材から集電体へ電気が流れる導電経路が十分に形成されて、端子部材から集電体へ通電できる十分な電気容量を確保できる。
【００１８】
また、溶接による熱が大きい場合であっても、鍔部の付け根の角部は溶接部から離れているため、角部に大きな熱応力が加わるのを防ぐことができる。その結果、角部が起点となり溶接部が破損するようなことがなくなる。
【００１９】
さらに、鍔部によって端子部材と集電体との位置決めが容易になり、製品として所定の正確な寸法や配置構造を有するものとなる。
【００２０】
したがって、端子部材と集電体との接合強度および導通性が向上し、端子部材と集電体との接合部に破損が生じない信頼性の高い電池用端子となる。
【００２１】
【発明の実施の形態】
本発明の電池用端子について以下に詳細に説明する。図１は本発明の電池用端子について実施の形態の一例を示す断面図である。この図において、１０は絶縁部材、１１は環状部材、１２は端子部材、１２ａは端子部材の鍔部、１２ｂは鍔部１２ａの下面に形成された溝、１２ｃは鍔部の突出部、１３は集電体である。
【００２２】
本発明の電池用端子は、外周面の下端部に全周にわたって鍔部１２ａが形成されたＡｌから成る円柱状の端子部材１２と、端子部材１２がその両端が突出するように挿通され接合されたセラミックスから成る円筒状の絶縁部材１０と、絶縁部材１０の外周面に内周面が接合された金属から成る環状部材１１とを具備し、端子部材１２は、鍔部１２ａが端子部材１２の下端よりも高い位置に形成されており、鍔部１２ａの下面の内周端に全周にわたって溝１２ｂが形成されている。
【００２３】
このような構成により、端子部材１２の鍔部１２ａの下面に集電体１３との間に溝１２ｂが形成されて、溶接による熱は端子部材１２の外周面下端部と集電体１３の開口との嵌着部（溶接部）に集中しやすくなる。その結果、溶接による熱が小さくても、溶接部の溶け込みが十分となり大きな接合強度が確保できるため、振動等により溶接部が破損するのを防ぐことができ、また、端子部材１２から集電体１３へ電気が流れる導電経路が十分に形成されて、端子部材１２から集電体１３へ通電するための十分な電気容量を確保できる。また、溶接による熱が大きくても、鍔部１２ａの付け根の角部は、鍔部１２ａの下面の溝１２ｂ以外の部位に形成された突出部１２ｃによって溶接部から離れているため、角部に大きな熱応力が加わるのを防ぐことができ、角部が起点となり溶接部が破損するようなことがなくなる。さらに、鍔部１２ａによって端子部材１２と集電体１３との位置決めが容易になり、製品として所定の正確な寸法や配置構造を有するものとなる。
【００２４】
本発明におけるＡｌから成る端子部材１２は、Ａｌを９９重量％以上含有するものであるか、またはＡｌとＳｉ，Ｆｅ，Ｃｕ，Ｍｎ，Ｍｇ等とのＡｌ合金といったＡｌを主成分とする合金からなるものである。
【００２５】
また、セラミックスから成る絶縁部材１０は、酸化アルミニウム質焼結体（アルミナセラミックス），窒化アルミニウム（ＡｌＮ）質焼結体，ジルコニア（ＺｒＯ２）質焼結体，炭化珪素（ＳｉＣ）質焼結体，窒化珪素（Ｓｉ３Ｎ４）質焼結体等のセラミックスから成る。
【００２６】
金属から成る環状部材１１は、Ａｌを９９重量％以上含有するものであるか、またはＡｌとＳｉ，Ｆｅ，Ｃｕ，Ｍｎ，Ｍｇ等とのＡｌ合金といったＡｌを主成分とする合金からなるものである。
【００２７】
端子部材１２の鍔部１２ａの下面に形成された溝１２ｂの幅は、０．５〜２ｍｍが好ましい。０．５ｍｍ未満では、鍔部１２ａに対する溶接による熱の影響を小さくするのが難しくなり、溶接時の熱応力によって溶接部が破損し易くなる。また、２ｍｍを超えると、鍔部１２ａの外径が大きくなりすぎて、集電体１３との組み合わせで電池の筐体に収まりきらない場合が発生する。
【００２８】
また、溝１２ｂの深さは０．５〜２ｍｍが好ましい。０．５ｍｍ未満では、鍔部１２ａの付け根の角部に対する溶接による熱の影響を小さくするのが難しくなり、溶接時の熱応力によって溶接部が破損し易くなる。また、２ｍｍを超えると、鍔部１２ａの外径が大きくなりすぎて、集電体１３との組み合わせで電池の筐体に収まりきらない場合が発生する。
【００２９】
また、鍔部１２ａの厚みは３〜５ｍｍ程度、突出部１２ｃの厚みは０．５〜２ｍｍ程度であり、この程度の厚みであれば十分な強度および適度に変形して応力を緩和する効果を有するものとなる。
【００３０】
【実施例】
本発明の電池用端子の実施例について以下に説明する。
【００３１】
本発明の電池用端子として、図１に示す構成のものを以下のようにして製作した。内径１０ｍｍ、外径１５ｍｍ、長さ６ｍｍで、上部の３ｍｍの長さの部位を外径１２．５ｍｍとしたアルミナセラミックスから成る円筒状の絶縁部材１０を用意した。絶縁部材１０の下端面および下部の外周面に、モリブデン粉末とマンガン粉末と酸化ケイ素粉末とに有機バインダおよび溶剤を混合してなる金属ペーストを、１０μｍの厚さで印刷塗布し、乾燥後加湿したフォーミングガス中で１４００℃の温度で焼成して、メタライズ層を形成した。このメタライズ層の表面にニッケルメッキ層を電解メッキ法により約２μｍの厚さで被着した。
【００３２】
次に、絶縁部材１０の下端部の外径１５ｍｍより０．１ｍｍだけ大きい内径で、厚みが１ｍｍ、高さが５ｍｍ、外径が３０ｍｍで縦断面における断面形状がＵ字状（内周端の上方向に延びた突出部が外周端の突出部よりも高い形状）のＡｌ製の環状部材１１を用意した。
【００３３】
また、絶縁部材１０の内径より０．１ｍｍだけ小さい外径で、長さ１５ｍｍ、下部の長さ５ｍｍの部位の外径を１１ｍｍとし、外周面の下端から１乃至３ｍｍの部位に厚さ２ｍｍで直径１６ｍｍの鍔部１２ａを形成したＡｌ製の端子部材１２を用意した。その鍔部１２ａの下面の内周端に深さ１ｍｍ、幅０．５ｍｍの溝１２ｂを設け、さらに端子部材１２の下端面の中央部に直径９ｍｍで深さ１ｍｍの円形状の凹部を設けた。
【００３４】
円筒状の絶縁部材１０に端子部材１２を挿通させて配置し、また絶縁部材１０の外径１５ｍｍの下部を環状部材１１に嵌めこんで配置し、この状態で絶縁部材１０の下端面のメタライズ層および絶縁部材１０の下部の外周面のメタライズ層に接するように、端子部材１２と絶縁部材１０との隙間および絶縁部材１０と環状部材１１との隙間にＡｌからなる線状のロウ材のプリフォームを配置し、そのロウ材を約６２０℃に加熱して、端子部材１２と絶縁部材１０、および絶縁部材１０と環状部材１１とをロウ付けした。
【００３５】
次に、内径が端子部材１２の１１ｍｍの外径より０．１ｍｍだけ大きい内径で、外径が５０ｍｍ、厚さが１ｍｍのＡｌ製の、中央部に貫通した開口を有する円板状の集電体１３を用意した。端子部材１２の下端部を集電体１３の開口に嵌着させるとともに鍔部１２ａの突出部１２ｃの先端が集電体１３に当接するように配置し、端子部材１２の下端部と集電体１３の開口の内周面との嵌着部を溶接（ＴＩＧ溶接）した。これにより製作されたものをサンプルＡ（実施例１）とした。
【００３６】
また、鍔部１２ａの溝１２ｂの深さを０．３ｍｍ、幅を０．３ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＢとした。
【００３７】
また、鍔部１２ａの溝１２ｂの深さを０．５ｍｍ、幅を０．５ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＣとした。
【００３８】
また、鍔部１２ａの溝１２ｂの深さを１ｍｍ、幅を１ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＤとした。
【００３９】
また、鍔部１２ａの溝１２ｂの深さを１．５ｍｍ、幅を１．５ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＥとした。
【００４０】
また、鍔部１２ａの溝１２ｂの深さを２ｍｍ、幅を２ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＦとした。
【００４１】
また、鍔部１２ａの溝１２ｂの深さを２．５ｍｍ、幅を２．５ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＧとした。
【００４２】
比較例として、図２のように鍔部１２ａに溝１２ｂを設けず、それ以外は上記実施例と同様に製作したものをサンプルＨとした。
【００４３】
サンプルＡ〜Ｈについて、大気雰囲気中、常温で振動試験（ＭＩＬ−ＳＴＤ−２０２Ｆ ＭＥＴＨＯＤ２０１Ａ）を行い、その後溶接部を切断して切断部を双眼顕微鏡を用いて観察し、異常の有無を調べた結果を表１に示す。
【００４４】
【表１】
【００４５】
表１より、サンプルＡには異常は見られなかったが、サンプルＨでは端子部材１２の鍔部１２ａと集電体１３との溶接部にクラックの発生が確認された。
【００４６】
また、サンプルＢでは、鍔部１２ａの溝１２ｂが溶接の溶け込みにより埋まってしまい、鍔部１２ａと集電体１３との溶接部にクラックの発生がわずかに確認された。また、サンプルＣ，Ｄ，Ｅ，Ｆに異常は見られなかった。サンプルＧでは溶接部にクラックの発生は見られなかったが、鍔部１２ａの厚みが薄いため、溶接の熱による若干の変形が見られた。
【００４７】
以上より、サンプルＡ，Ｃ，Ｄ，Ｅ，Ｆが端子部材１２と集電体１３との溶接部において、破損の原因となるクラックおよび溶接の熱による変形が全く見られず、溶接構造において優れていることがわかった。
【００４８】
なお、本発明は上記実施の形態および実施例に限定されず、本発明の要旨を逸脱しない範囲内で種々の変更を施すことは何等差し支えない。例えば、本発明の電池用端子は、鍔部に設けた溝の断面形状が四角形状であるが、断面形状がＵ字のものであってもよい。
【００４９】
【発明の効果】
本発明の電池用端子は、端子部材は、鍔部が端子部材の下端よりも高い位置に形成されており、鍔部の下面の内周端に全周にわたって溝が形成されていることから、溶接による熱は端子部材の外周面下端部と集電体の開口との嵌着部（溶接部）に集中しやすくなる。その結果、溶接による熱が小さくても、溶接部の溶け込みが十分となり大きな接合強度が確保できるため、振動等により溶接部が破損するのを防ぐことができ、また、端子部材から集電体へ電気が流れる導電経路が十分に形成されて、端子部材から集電体へ通電できる十分な電気容量を確保できる。また、溶接による熱が大きい場合であっても、鍔部の付け根の角部は溶接部から離れているため、角部に大きな熱応力が加わるのを防ぐことができる。その結果、角部が起点となり溶接部が破損するようなことがなくなる。
【００５０】
さらに、鍔部によって端子部材と集電体との位置決めが容易になり、製品として所定の正確な寸法や配置構造を有するものとなる。
【００５１】
したがって、端子部材と集電体との接合強度および導通性が向上し、端子部材と集電体との接合部に破損が生じない信頼性の高い電池用端子となる。
【図面の簡単な説明】
【図１】本発明の電池用端子について実施の形態の例を示す断面図である。
【図２】従来の電池用端子の例を示す断面図である。
【付号の説明】
１０：絶縁部材
１１：環状部材
１２：端子部材
１２ａ：鍔部
１２ｂ：溝
１２ｃ：突出部
１３：集電体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery terminal used as an insulating hermetic terminal on the positive electrode side of a battery such as a lithium ion secondary battery.
[0002]
[Prior art]
Conventionally, terminal members and current collectors constituting battery terminals for extracting electricity from batteries have excellent conductivity, are chemically stable inside the battery, and occupy a small volume in the battery. Since various characteristics such as being made into a material, having a small weight per volume, and having sufficient strength for practical use are required, nickel (Ni), stainless steel, Metals such as titanium (Ti) and aluminum (Al) have been used.
[0003]
In addition, since the positive electrode of the secondary battery is anodically polarized at the time of charging, a metal serving as a current collector for the positive electrode is required to have high corrosion resistance. Furthermore, since an organic electrolyte is used in a lithium ion secondary battery, Al has been used as a metal having high corrosion resistance in the organic electrolyte for the positive electrode current collector. Also, Al has been used as a terminal member of a battery terminal for extracting electricity from the battery housing to the outside for the same reason as described above.
[0004]
In such a battery terminal, the terminal member and the housing are electrically insulated, and airtightness is ensured so that the organic electrolyte does not leak from the joint between the terminal member and the housing. There is a need. In order to satisfy such insulation properties and airtightness, the terminal member and the housing are made of an insulating material such as a glass layer (formed by sintering a glass frit), a resin adhesive, and a rubber O-ring. Had been joined through.
[0005]
In recent years, lithium-ion rechargeable batteries have many advantages such as large energy density, excellent cycle life, high operating voltage, low self-discharge, no harmful substances and no memory effect. It has been used as a backup power supply and the like, and higher reliability under a severe use environment is required.
[0006]
However, if insulators such as glass, resin adhesive, and rubber O-rings are used for battery terminals of such lithium ion secondary batteries, the insulators deteriorate due to environmental temperature changes, and cracks and cracks occur. This causes problems such as poor airtightness, and poor airtightness caused by corrosion of the insulator by the organic electrolyte.
[0007]
In order to solve such a problem, a high reliability for airtightness is obtained by brazing a metal terminal member to a battery housing via a chemically stable and highly corrosion-resistant ceramic member. (For example, see Patent Document 1 below).
[0008]
FIG. 2 is a cross-sectional view of the basic configuration of such a battery terminal. 2, reference numeral 20 denotes an insulating member made of ceramics, 21 denotes an annular member made of metal, 22 denotes a terminal member made of metal, and 23 denotes a current collector. These insulating member 20, annular member 21, terminal member 22, and collector A battery terminal is basically configured by the electric body 23, and the annular member 21 functions as a battery terminal by being joined to a battery housing with a brazing material.
[0009]
The insulating member 20 is made of a ceramic such as an alumina sintered body (alumina ceramics), and is a cylindrical member having a through hole at the center, and a terminal member 22 made of Al is formed mainly of Al on the inner peripheral surface. An annular member 21 made of a metal such as Al is brazed to the outer peripheral surface with a brazing material containing Al as a main component. The lower end of the terminal member 22 is fitted and welded to a circular opening of a plate-shaped current collector 23 made of Al. A flange 22a is formed at the joint at the lower end of the terminal member 22 in order to strengthen the joining by welding. The insulating member 20 made of ceramics is hardly corroded by the organic electrolyte even when used for a battery terminal of a lithium ion secondary battery.
[0010]
Such a battery terminal has a high melting point (approximately 600 ° C.) in the brazing material for joining the terminal member 22 and the insulating member 20, and the brazing material for joining the insulating member 20 and the annular member 21, respectively. Therefore, even when used in an artificial satellite or the like, sufficient airtightness can be maintained.
[0011]
[Patent Document 1]
JP-A-11-167915
[Problems to be solved by the invention]
However, in the conventional battery terminal of FIG. 2, the entire lower surface of the flange portion 22a of the terminal member 22 and the opening of the current collector 23 are in close contact with each other. Since the heat is not easily transmitted from the welding starting point A (FIG. 2) at the lower end of the outer peripheral surface of the terminal member 22 to the corner B (FIG. 2) of the flange 22a, the heat due to welding is small. In this case, the penetration of the welded portion (the volume of the fused portion) was small, and sufficient joining strength could not be secured. As a result, a welded portion is damaged by vibrations or the like, or a conduction path through which electricity flows from the terminal member 22 to the current collector 23 is not sufficiently formed due to insufficient penetration, and the electric capacity (current value) that can be energized decreases. There is a problem that a desired electric capacity cannot be secured.
[0013]
Conversely, if the heat generated by welding is large, the corner B becomes the starting point and the weld is broken due to the difference between the thermal stresses applied to the welding starting point A and the corner B, that is, the large thermal stress is applied to the corner B. There was such a problem.
[0014]
In addition, the terminal member 22 is not provided with the flange portion 22a so that heat during welding is easily transmitted, so that welding strength and electric capacity are ensured, and the corner portion B becomes a starting point due to a difference in thermal stress. It is possible to prevent the part from being damaged. However, in this configuration, it is extremely difficult to position the terminal member 22 and the current collector 23, and there has been a problem that the product does not have predetermined accurate dimensions and arrangement structure.
[0015]
Therefore, the present invention has been completed in view of the above-mentioned conventional problems, and an object of the present invention is to prevent a welded portion between a terminal member and a current collector from being damaged by vibration or the like, and to prevent the terminal member and the current collector from being damaged. And a highly reliable battery terminal in which the terminal member and the current collector are joined with accurate dimensions and arrangement.
[0016]
[Means for Solving the Problems]
The battery terminal according to the present invention includes a cylindrical terminal member made of aluminum having a flange formed at the lower end portion of the outer peripheral surface over the entire circumference, and a ceramic member which is inserted and joined so that the terminal member protrudes at both ends thereof. And a ring-shaped member made of metal whose inner peripheral surface is joined to the outer peripheral surface of the insulating member. Is formed at a higher position, and a groove is formed over the entire circumference at the inner peripheral end of the lower surface of the flange portion.
[0017]
In the battery terminal of the present invention, the terminal member has a flange formed at a position higher than the lower end of the terminal member, and a groove is formed over the entire inner peripheral end of the lower surface of the flange, Heat due to welding tends to concentrate on a fitting portion (welding portion) between the lower end portion of the outer peripheral surface of the terminal member and the opening of the current collector. As a result, even if the heat generated by welding is small, the penetration of the welded portion is sufficient and a large joint strength can be secured, so that it is possible to prevent the welded portion from being damaged by vibration or the like. A sufficient conduction path through which electricity flows is formed, and a sufficient electric capacity that allows current to flow from the terminal member to the current collector can be secured.
[0018]
Further, even when the heat due to welding is large, since the corner of the base of the flange is away from the weld, it is possible to prevent a large thermal stress from being applied to the corner. As a result, it is possible to prevent the welded portion from being broken at the corner.
[0019]
Further, the positioning of the terminal member and the current collector is facilitated by the flange portion, so that the product has predetermined accurate dimensions and arrangement structure.
[0020]
Therefore, the joining strength and conductivity between the terminal member and the current collector are improved, and a highly reliable battery terminal in which the joint between the terminal member and the current collector is not damaged.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
The battery terminal of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of the battery terminal of the present invention. In this figure, 10 is an insulating member, 11 is an annular member, 12 is a terminal member, 12a is a flange of the terminal member, 12b is a groove formed on the lower surface of the flange 12a, 12c is a protrusion of the flange, and 13 is a flange. It is a current collector.
[0022]
The battery terminal of the present invention is joined to a cylindrical terminal member 12 made of Al having a flange 12a formed at the lower end of the outer peripheral surface over the entire circumference, and the terminal member 12 is inserted and protruded at both ends. The terminal member 12 includes a cylindrical insulating member 10 made of ceramics, and an annular member 11 made of metal whose inner peripheral surface is joined to the outer peripheral surface of the insulating member 10. The groove 12b is formed at a position higher than the lower end, and a groove 12b is formed all around the inner peripheral end of the lower surface of the flange portion 12a.
[0023]
With such a configuration, a groove 12 b is formed between the lower surface of the flange 12 a of the terminal member 12 and the current collector 13, and the heat generated by welding causes the lower end of the outer peripheral surface of the terminal member 12 and the opening of the current collector 13 to open. It is easy to concentrate on the fitting portion (welded portion). As a result, even if the heat due to welding is small, penetration of the welded portion is sufficient and a large bonding strength can be secured, so that the welded portion can be prevented from being damaged by vibration or the like. The conductive path through which electricity flows to the current collector 13 is sufficiently formed, and a sufficient electric capacity for supplying electricity from the terminal member 12 to the current collector 13 can be secured. Also, even if the heat due to welding is large, the corner of the base of the flange 12a is separated from the weld by the protruding portion 12c formed at a portion other than the groove 12b on the lower surface of the flange 12a. It is possible to prevent a large thermal stress from being applied, and it is possible to prevent a corner portion from being a starting point and a welded portion from being damaged. Further, the positioning of the terminal member 12 and the current collector 13 is facilitated by the flange portion 12a, so that the product has predetermined accurate dimensions and arrangement structure.
[0024]
The terminal member 12 made of Al in the present invention contains 99% by weight or more of Al or is made of an alloy containing Al as a main component such as an Al alloy of Al and Si, Fe, Cu, Mn, Mg or the like. It becomes.
[0025]
The insulating member 10 made of ceramic is made of an aluminum oxide-based sintered body (alumina ceramics), an aluminum nitride (AlN) -based sintered body, a zirconia (ZrO 2 ) -based sintered body, or a silicon carbide (SiC) -based sintered body. And ceramics such as silicon nitride (Si 3 N 4 ) sintered body.
[0026]
The annular member 11 made of metal contains 99% by weight or more of Al or an alloy containing Al as a main component such as an Al alloy of Al and Si, Fe, Cu, Mn, Mg, or the like. is there.
[0027]
The width of the groove 12b formed on the lower surface of the flange 12a of the terminal member 12 is preferably 0.5 to 2 mm. If it is less than 0.5 mm, it is difficult to reduce the influence of heat due to welding on the flange 12a, and the weld is likely to be damaged by thermal stress during welding. On the other hand, if it exceeds 2 mm, the outer diameter of the flange portion 12a becomes too large, and the case where the outer diameter of the flange portion 12a cannot be accommodated in the battery case in combination with the current collector 13 may occur.
[0028]
Further, the depth of the groove 12b is preferably 0.5 to 2 mm. If it is less than 0.5 mm, it is difficult to reduce the influence of heat due to welding on the corner of the base of the flange 12a, and the weld is likely to be damaged by thermal stress during welding. On the other hand, if it exceeds 2 mm, the outer diameter of the flange portion 12a becomes too large, and the case where the outer diameter of the flange portion 12a cannot be accommodated in the battery case in combination with the current collector 13 may occur.
[0029]
The thickness of the flange 12a is about 3 to 5 mm, and the thickness of the protruding part 12c is about 0.5 to 2 mm. With such a thickness, sufficient strength and moderate deformation can be obtained to reduce stress. Will have.
[0030]
【Example】
Examples of the battery terminal of the present invention will be described below.
[0031]
As the battery terminal of the present invention, the battery terminal shown in FIG. 1 was manufactured as follows. A cylindrical insulating member 10 made of alumina ceramics having an inner diameter of 10 mm, an outer diameter of 15 mm, a length of 6 mm, and an upper portion having a length of 3 mm and an outer diameter of 12.5 mm was prepared. A metal paste obtained by mixing an organic binder and a solvent with a molybdenum powder, a manganese powder, and a silicon oxide powder was applied by printing to a thickness of 10 μm on the lower end surface and the lower outer peripheral surface of the insulating member 10, and then dried and humidified. The metallized layer was formed by firing at a temperature of 1400 ° C. in a forming gas. A nickel plating layer having a thickness of about 2 μm was applied to the surface of the metallized layer by electrolytic plating.
[0032]
Next, the inner diameter of the lower end portion of the insulating member 10 is larger than the outer diameter of 15 mm by 0.1 mm, the thickness is 1 mm, the height is 5 mm, the outer diameter is 30 mm, and the cross-sectional shape in the vertical cross section is U-shaped (the inner peripheral end). An annular member 11 made of Al having a shape in which the protruding portion extending upward is higher than the protruding portion at the outer peripheral end) was prepared.
[0033]
The outer diameter of the portion having a length of 15 mm and a lower length of 5 mm is set to 11 mm at an outer diameter smaller than the inner diameter of the insulating member 10 by 0.1 mm, and a thickness of 2 mm is set at a portion of 1 to 3 mm from the lower end of the outer peripheral surface. An Al terminal member 12 having a flange portion 12a having a diameter of 16 mm was prepared. A groove 12b having a depth of 1 mm and a width of 0.5 mm was provided at the inner peripheral end of the lower surface of the flange portion 12a, and a circular concave portion having a diameter of 9mm and a depth of 1mm was provided at the center of the lower end surface of the terminal member 12. .
[0034]
The terminal member 12 is inserted through the cylindrical insulating member 10 and disposed, and the lower part of the insulating member 10 having an outer diameter of 15 mm is inserted into the annular member 11 and disposed in this state. And a preform of a linear brazing material made of Al in a gap between the terminal member 12 and the insulating member 10 and in a gap between the insulating member 10 and the annular member 11 so as to be in contact with the metallized layer on the outer peripheral surface below the insulating member 10. , And the brazing material was heated to about 620 ° C. to braze the terminal member 12 and the insulating member 10, and the insulating member 10 and the annular member 11.
[0035]
Next, a disk-shaped current collector having an inner diameter 0.1 mm larger than the 11 mm outer diameter of the terminal member 12, an outer diameter of 50 mm, and a thickness of 1 mm made of Al and having an opening penetrating the center. A body 13 was prepared. The lower end of the terminal member 12 is fitted into the opening of the current collector 13 and the distal end of the protrusion 12 c of the flange 12 a is arranged so as to contact the current collector 13. The fitting of the thirteenth opening with the inner peripheral surface was welded (TIG welding). The sample manufactured in this manner was designated as Sample A (Example 1).
[0036]
Sample B was manufactured in the same manner as in the above example except that the depth of groove 12b of flange 12a was 0.3 mm and the width thereof was 0.3 mm.
[0037]
The sample C was manufactured in the same manner as in the above example except that the depth of the groove 12b of the flange portion 12a was 0.5 mm and the width thereof was 0.5 mm.
[0038]
Sample D was manufactured in the same manner as in the above example except that the depth of the groove 12b of the flange portion 12a was 1 mm and the width was 1 mm.
[0039]
The sample E was manufactured in the same manner as in the above example except that the depth of the groove 12b of the flange portion 12a was 1.5 mm and the width thereof was 1.5 mm.
[0040]
Sample F was manufactured in the same manner as in the above example except that the depth of the groove 12b of the flange portion 12a was 2 mm and the width was 2 mm.
[0041]
The sample G was manufactured in the same manner as in the above example except that the depth of the groove 12b of the flange portion 12a was 2.5 mm and the width thereof was 2.5 mm.
[0042]
As a comparative example, a sample H was manufactured in the same manner as in the above example except that the groove 12b was not provided in the flange portion 12a as shown in FIG.
[0043]
The samples A to H were subjected to a vibration test (MIL-STD-202F METHOD201A) at room temperature in an air atmosphere, and thereafter, the welded portion was cut, and the cut portion was observed using a binocular microscope to check for abnormalities. Are shown in Table 1.
[0044]
[Table 1]
[0045]
From Table 1, no abnormality was observed in Sample A, but in Sample H, cracks were confirmed at the weld between the flange 12a of the terminal member 12 and the current collector 13.
[0046]
In sample B, the groove 12b of the flange 12a was filled by the penetration of the welding, and cracks were slightly generated in the welded portion between the flange 12a and the current collector 13. No abnormalities were observed in Samples C, D, E, and F. In Sample G, no crack was observed in the welded portion, but slight deformation due to welding heat was observed because the thickness of the flange portion 12a was small.
[0047]
As described above, Samples A, C, D, E, and F showed no cracks or deformation due to welding heat at the welded portion between terminal member 12 and current collector 13, and were excellent in the welded structure. I understood that.
[0048]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and various changes may be made without departing from the spirit of the present invention. For example, in the battery terminal of the present invention, the cross-sectional shape of the groove provided in the flange portion is rectangular, but the cross-sectional shape may be U-shaped.
[0049]
【The invention's effect】
In the battery terminal of the present invention, the terminal member has a flange formed at a position higher than the lower end of the terminal member, and a groove is formed over the entire inner peripheral end of the lower surface of the flange, Heat due to welding tends to concentrate on a fitting portion (welding portion) between the lower end portion of the outer peripheral surface of the terminal member and the opening of the current collector. As a result, even if the heat generated by welding is small, the penetration of the welded portion is sufficient and a large joint strength can be secured, so that it is possible to prevent the welded portion from being damaged by vibration or the like. A sufficient conduction path through which electricity flows is formed, and a sufficient electric capacity that allows current to flow from the terminal member to the current collector can be secured. Further, even when the heat due to welding is large, since the corner of the base of the flange is away from the weld, it is possible to prevent a large thermal stress from being applied to the corner. As a result, it is possible to prevent the welded portion from being broken at the corner.
[0050]
Further, the positioning of the terminal member and the current collector is facilitated by the flange portion, so that the product has predetermined accurate dimensions and arrangement structure.
[0051]
Therefore, the joining strength and conductivity between the terminal member and the current collector are improved, and a highly reliable battery terminal in which the joint between the terminal member and the current collector is not damaged.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a battery terminal of the present invention.
FIG. 2 is a cross-sectional view showing an example of a conventional battery terminal.
[Description of numbering]
10: insulating member 11: annular member 12: terminal member 12a: flange portion 12b: groove 12c: projecting portion 13: current collector
