JP2004095217A - Laminated material for battery case, battery, its manufacturing method, battery pack, and battery pack module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery with a laminated film case, whereof waterproof performance is enhanced by covering a resin film by a metallic film at the side end of a laminated film. <P>SOLUTION: This battery is cased by the laminated film 20 wherein at least a resin film 21, a metal film 22, and a resin film 23 are laminated in this order and the metal film is longer than the resin film at its end, and it has a bonded part 25 formed by bonding the metallic films each other at the side end where the laminated films are bonded each other, and the inside resin films are covered by the metal films. <P>COPYRIGHT: (C)2004,JPO

Description

【００４１】
この表１からわかるとおり、ラミネートフィルム側端部において金属膜２２を接合した接合部２５の幅Ｓが０．５ｍｍ以上である場合に、水分の浸入をよく防止している。なお、接合部２５の幅Ｓの上限は、試験を行った試験サンプルでは２．０ｍｍとしているがもちろんこれ以上であってもよい。しかし、試験結果からは２．０ｍｍもあれば十分である。
【００４２】
以上のように、この実施例からも、ラミネートフィルム側端部を金属膜２２により覆い内側の樹脂膜２２が露出しないようにしたことで、水分の浸入を防止することができることがわかる。
【００４３】
なお、本第１の実施の形態において、電池外装のラミネートフィルムは、樹脂膜、金属膜、および樹脂膜をこの順序でそれぞれ１層を積層したものであるが、積層させる樹脂膜や金属膜は１層とは限らず、複数層が積層されたものであってもよい。
【００４４】
（電池要素）
なお、本第１の実施の形態における電池におけるラミネートフィルムの外装によって覆われた電池要素は、基本的にどのようなものでもよい。
【００４５】
一例をあげれば、下記のとおりである。
【００４６】
以下、本発明のラミネート電池がリチウムイオン二次電池である場合について簡単に記述する。ただし、本発明の電池は、リチウムイオン二次電池に限定されるわけではない。なお、電池要素１１とは、充放電に実質的に関与する正極、セパレータ、負極などが積層されてなる部分を意味する。
【００４７】
［正極］
正極は、アルミニウム等からなる正極集電体の両面に正極材料が結着した構造を有する。正極材料としては、種々の酸化物（ＬｉＭｎ_２Ｏ_４などのリチウムマンガン酸化物；二酸化マンガン；ＬｉＮｉＯ_２などのリチウムニッケル酸化物；ＬｉＣｏＯ_２などのリチウムコバルト酸化物；リチウム含有ニッケルコバルト酸化物；リチウムを含む非晶質五酸化バナジウムなど）や、カルコゲン化合物（二硫化チタン、二硫化モリブテンなど）等を挙げることができる。これらの中では、得られるリチウムイオン二次電池の出力特性を考慮すると、リチウムマンガン酸化物またはリチウムニッケル酸化物が好ましい。
【００４８】
正極集電体には、導電性を向上させるために、導電性材料を併せて結着させてもよい。導電性材料としては、たとえば、人造黒鉛、カーボンブラック（たとえばアセチレンブラックなど）、ニッケル粉末等が挙げられる。
【００４９】
正極集電体としては、たとえばアルミニウム製エキスパンドメタル、アルミニウム製メッシュ、アルミニウム製パンチドメタル等を用いることができる。なお、正極は正極集電体の片面に正極材料を結着させた構造であってもよい。
【００５０】
［負極］
負極は、銅などからなる負極集電体の両面に負極材料が結着した構造を有する。負極材料としては、リチウムイオンを吸蔵放出する炭素材料を用いることができる。このような炭素材料としては、天然黒鉛、人造黒鉛、カーボンブラック、活性炭、カーボンファイバー、コークス、有機前駆体（たとえば、フェノール樹脂、ポリアクリロニトリル、セルロース等）を不活性雰囲気中で熱処理して合成した炭素などが挙げられる。好ましくは、負極は非晶質カーボン系材料からなる。本願において「非晶質カーボン系材料」とは結晶構造を有さない炭素材料を意味し、換言すれば非晶質炭素材料を意味する。このような非晶質カーボン系材料は熱硬化性樹脂を炭素化することによって得られる。因みに、放電による電圧依存が大きい非晶質カーボン系材料を用いると、２以上のリチウムイオン二次電池を並列に接続した場合におけるリチウムイオン二次電池のサイクル特性を向上させることができる。
【００５１】
負極集電体としては、たとえば銅製エキスパンドメタル、銅製メッシュ、銅製パンチドメタル等を用いることができる。なお、負極は負極集電体の片面に負極材料を結着させた構造であってもよい。
【００５２】
［セパレータ］
セパレータは、ポリオレフィン系微多孔質セパレータ、たとえば、ポリエチレン、ポリプロピレンを用いることができ、セパレータ中には、非水電解液が含浸させられる。非水電解液は、非水溶媒に電解質を溶解することにより調製される。非水溶媒としては、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネート（ＢＣ）、ジメチルカーボネート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、エチルメチルカーボネート（ＥＭＣ）、γ−ブチロラクトン（γ−ＢＬ）、スルホラン、アセトニトリル、１，２−ジメトキシエタン、１，３−ジメトキシプロパン、ジメチルエーテル、テトラヒドロフラン（ＴＨＦ）、２−メチルテトラヒドロフラン等を挙げることができる。非水溶媒は、単独で使用しても、２種以上混合して使用しても良い。電解質としては、たとえば過塩素酸リチウム（ＬｉＣｌＯ_４）、六フッ化リン酸リチウム（ＬｉＰＦ_６）、四フッ化ホウ素リチウム（ＬｉＢＦ_４）、六フッ化砒素リチウム（ＬｉＡｓＦ_６）、トリフルオロメタンスルホン酸リチウム（ＬｉＣＦ_３ＳＯ_３）、ビストリフルオロメチルスルホニルイミドリチウム［ＬｉＮ（ＣＦ_３ＳＯ_３）_２］等のリチウム塩を挙げることができる。電解質の非水溶媒に対する溶解量は、通常は０．２ｍｏｌ／Ｌ〜２ｍｏｌ／Ｌ程度である。
【００５３】
非水電解液を保持するポリマーとしては、たとえば、ポリエチレンオキサイド誘導体、ポリプロピレンオキサイド誘導体、前記誘導体を含むポリマー、ビニリデンフロライド（ＶｄＦ）とヘキサフルオロプロピレン（ＨＦＰ）との共重合体等が挙げられる。
【００５４】
［タブ電極］
タブには、銅、鉄から選ばれる金属を用いることができるが、アルミニウム、ステンレス鋼といった金属またはこれらを含む合金材料も同様に使用可能である。また、表面被覆層にはニッケルが最も好適に使用できるが、銀、金といった金属材料も同様に使用可能である。
【００５５】
本発明のラミネート電池の製造は、当業者であれば想到するであろう公知技術を用いて行うことができる。たとえば、タブの所定の位置に、熱融着技術を用いてシート部材を配置する。このタブを電池要素と接続する。次に、タブが接続された電池要素をラミネートシートで包み込み、電解液を注入するための封口部を残して熱融着する。このとき、タブはラミネートシート外部に引き出され、所定の位置で熱融着されるようにする。続いて、封口部を通じて電解液を注入し、封口部を熱融着により閉じて、ラミネート電池を完成させる。このとき、前述したように、ラミネートフィルムの側端部を内側の樹脂膜が金属膜に覆われるように成型する。
【００５６】
（第２の実施の形態）
第２の実施の形態は、前述した第１の実施の形態とラミネートフィルム側端部の成型方法が異なるものである。したがって、電池としての形態や機能は前述した第１の実施の形態と同様であるので、それらの説明は省略する。
【００５７】
図４は、第２の実施の形態における電池の製造方法を説明するための図面である。
【００５８】
本第２の実施の形態では、まず、図４（ａ）に示すように、端部において金属膜２２ａおよび２２ｂが少なくとも樹脂膜２３よりも長いラミネートフィルムを用意する。このとき、電池を挟み込む２枚のラミネートフィルム２０のうち一方のラミネートフィルムの金属膜２２ａは他方のラミネートフィルム２０の金属膜２２ｂよりも長くしたものを用意する。
【００５９】
そして、電池要素（図４において不図示）を２枚のラミネートフィルム２０により挟み込む。
【００６０】
そして、ラミネートフィルム側端部をヒートプレス装置にセットし、プレス型を過熱しつつラミネートフィルム側端部を圧縮して熱加圧圧縮成型を行う。このとき、本第３の実施の形態においては、図４（ｂ）に示すように、一方よりも長くした金属膜２２ａをこれより短い金属膜２２ｂの方に折り曲げる。
【００６１】
その後、金属膜２２ａと金属幕２２ｂの接合部２６を溶接により封止する。
【００６２】
これにより、前述した第１の実施の形態と同様に、ラミネートフィルム側端部において、内側の樹脂膜２３が金属膜２２および２２ｂに覆われて、この部分からの水分の浸入を防止することができる。
【００６３】
なお、熱加圧圧縮成型を行う際には、熱加圧圧縮成型の前にラミネートフィルム側端部をあらかじめ加圧によって樹脂封止した後であってもよい。
【００６４】
（第３の実施の形態）
第３の実施の形態は、前述した第１の実施の形態による電池を複数個接続した組電池である。
【００６５】
図５は、第３の実施の形態による組電池の斜視図であり、図６は、内部構成を上方から見た図面である。
【００６６】
図示するようにこの組電池５０は、前述した第１の実施の形態による電池１を複数個直列に接続したものをさらに並列に接続したものである。電池１同士は、導電バー５３により各電池のタブ電極３および４が接続されている。この組電池５０には電極ターミナル５１および５２が、この組電池５０の電極として組電池５０の一側面に設けられている。
【００６７】
この組電池５０に用いる前述した第１の実施の形態による電池１の形状は、立方体であり、その電池１の幅をａ、長さをｂ、厚さをｃとした場合、ａ／ｂ比が０．３〜１．０の範囲であり、かつａ／ｃ比が５〜１００の範囲であることが好ましい。具体的には、電池１の幅が５０ｍｍ〜２００ｍｍの範囲、長さが５０ｍｍ〜３００ｍｍの範囲、厚さが２ｍｍ〜１０ｍｍの範囲であることがより好ましい。
【００６８】
電池１をこの大きさとすることで、組電池の製造工程上扱いやすく、また、パッケージングしやすい。さらに、組電池化した際トータルの容積を小さくすることができる
また、電池１から取り出されているそれぞれのタブ電極３および４の幅は、タブ電極取り出し面の幅の２０％〜９０％であることが好ましい。
【００６９】
これにより、必要な電池出力を保ちながら、電極部分のシール性を確保できる。
【００７０】
この組電池においては、電池１を直列に接続しさらに並列に接続する際の接続方法として、超音波溶接、熱溶接、レーザー溶接、リベット、かしめ、電子ビームなどを用いることができる。このような接続方法をとることで、長期的信頼性のある組電池を製造することができる。
【００７１】
以上のように本第３の実施の形態による組電池によれば、前述した第１の実施の形態による水の進入を防止することのできる電池を用いて組電池化することで、高容量、高出力と得ることができ、しかも一つひとつの電池の信頼性が高いため、組電池としての長期的信頼性を向上させることができる。
【００７２】
なお、組電池としての電池１の接続は、電池１を複数個全て並列に接続してもよいし、また、電池１を複数個全て直列に接続してもよい。
【００７３】
また、本第３の実施の形態では、前述し第１の実施の形態による電池１を用いて組電池としているが、当然に、前述した第２の実施に形態のようにラミネートフィルム側端部を成型した電池を用いて組電池としてもよい。この場合も本第３の実施の形態とまったく同じように、組電池としての長期的信頼性を向上させることができる。
【００７４】
（第４の実施の形態）
第４の実施の形態は、前述した第３の実施の形態による組電池を複数個接続した組電池モジュールである。
【００７５】
図７は、第３の実施の形態による組電池モジュールの斜視図である。
【００７６】
この組電池モジュール６０は、前述した第３の実施の形態による組電池５０を複数個積層し、各組電池５０の電極ターミナル５１、５２を導電バー６１および６２によって接続し、モジュール化したものである。
【００７７】
このように、組電池５０をモジュール化することによって、電池制御を容易にし、たとえば電気自動車やハイブリッド自動車などの車搭用として最適な組電池モジュールとなる。そして、この組電池モジュール６０は、前述した組電池を用いたものであるから防水性能が高く、長期の屋外での使用に際しても十分な防水性があり、長期的信頼性の高いものである向上させることができる。
【００７８】
（第５の実施の形態）
第５の実施の形態は、前述した第４の実施の形態による組電池モジュールを搭載してなる車両である。この組電池モジュールを用いる自動車としては、たとえば電気自動車、ハイブリッド自動車などである。
【００７９】
参考までに、図８に、組電池モジュール６０を搭載する車両（自動車）１００の概略図を示す。車両に搭載される組電池モジュール６０は、上記説明した特性を有する。このため、組電池モジュール６０を搭載してなる車両は高い耐久性を有し、長期間に渡って使用した後であっても充分な出力を提供しうる。
【図面の簡単な説明】
【図１】本発明を適用した第１の実施の形態における電池の概観構成を示す図面である。
【図２】上記電池のラミネートフィルム側端部の拡大断面図である。
【図３】上記電池の製造方法を説明するための図面である。
【図４】本発明を適用した第２の実施の形態における電池の製造方法を説明するための図面である。
【図５】本発明を適用した第３の実施の形態における組電池の概観構成を示す図面である。
【図６】第３の実施の形態における組電池を上方から見た内部構成を示す図面である。
【図７】本発明を適用した第４の実施の形態における組電池モジュールの概観構成を示す図面である。
【図８】本発明を適用した第５の実施の形態における車両を示す図面である。
【符号の説明】
１　電池、
２０　ラミネートフィルム、
２１、２３　樹脂膜、
２２、２２ａ、２２ｂ　金属膜、
２５　接合部、
３１　プレス型、
３２　突起部、
５０　組電池、
６０　組電池モジュール、
１００　車両。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery exterior laminate, a battery and a method for producing the same, and a battery pack and a battery pack module.
[0002]
[Prior art]
BACKGROUND ART A laminate film in which a resin film and a metal film are laminated is used as an exterior of a battery.
[0003]
By the way, the battery using this laminated film has a problem that the battery performance is deteriorated due to moisture permeation from the laminated film. This is because, as a characteristic of the laminate material, the laminate surface has excellent moisture penetration prevention performance, but the structure allows the penetration of moisture from the side edge where the laminated cross section of the laminate structure is exposed. It has become. This is because the laminate structure itself is not covered with metal at its side end, and the resin film is exposed, so that moisture penetrates or penetrates the resin film. .
[0004]
As a battery using such a laminate film as an exterior, for example, Japanese Patent Application Laid-Open No. 2001-357826 discloses a structure in which a margin for fusion is provided at an end of the laminate film and sealed.
[0005]
In addition, Japanese Patent Application Laid-Open No. 2000-223087 discloses a structure in which an end portion of a laminate film is further covered with a sealing auxiliary member.
[0006]
[Problems to be solved by the invention]
However, in these conventional structures, first, in the former case, even if a fusion allowance is provided, there is a problem that the laminated section of the laminated film which is most vulnerable to water intrusion is exposed in the sealing portion. .
[0007]
In the latter case, there is a problem that the manufacturing itself is difficult because the sealing auxiliary member is attached, and the manufacturing cost and the component cost are increased.
[0008]
Accordingly, an object of the present invention is to provide a battery having a laminated film exterior with improved waterproofness, and an object of the present invention is to provide a battery manufacturing method therefor.
[0009]
Still another object of the present invention is to provide an assembled battery using a battery in which moisture is prevented from entering from an end portion on the side of the laminated film, and in particular, to provide an assembled battery module for a vehicle.
[0010]
[Means for Solving the Problems]
The present invention is achieved by the following configurations.
[0011]
(1) A battery exterior laminate, wherein at least a resin film, a metal film, and a resin film are laminated in this order, and the metal film is longer than the resin film at an end.
[0012]
(2) A battery in which at least a resin film, a metal film, and a resin film are packaged in a laminated film in which the resin films are laminated in this order, and a joining portion in which the metal films are joined at a side end to which the laminated films are joined. Wherein the metal film covers the inside of the resin film.
[0013]
(3) A method for manufacturing a battery in which at least a resin film, a metal film, and a resin film are packaged with a laminated film in which the resin film is laminated in this order, wherein the metal film is longer than the resin film at an end of the laminated film. By using a film, a side end where the laminated films are joined to each other is formed by a heat press mold having a protrusion. And bonding the metal films to each other by bending the metal film.
[0014]
(4) A battery pack comprising a plurality of the batteries connected in parallel and / or series.
[0015]
(5) An assembled battery module, wherein a plurality of the assembled batteries are connected in parallel and / or series.
[0016]
【The invention's effect】
According to the present invention, the infiltration of water from this portion can be prevented by covering the resin film located on the inner side with the metal film constituting the laminate film at the end portion of the laminate film. For this reason, the waterproof performance from the laminate film exterior can be improved. Therefore, the long-term reliability of the battery can be improved.
[0017]
Further, since the battery pack of the present invention uses this battery, the long-term reliability of the battery pack can be improved.
[0018]
Further, since the battery module of the present invention uses the battery module, the long-term reliability of the battery module can be improved.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
(First Embodiment)
FIG. 1 is a drawing showing an overview of a battery to which the present invention is applied. In the drawings, (a) is a top view, (b) is a side view as viewed from the direction of arrow B in (a), and (c) is a side view as viewed from the direction of arrow C in (a). FIG. 2 is an enlarged cross-sectional view of the general non-laminate end of the battery, and is generally a partial cross-section along line AA in FIG. 1A.
[0021]
The battery 1 includes a battery element 5 housed inside a rectangular exterior 2 and tab electrodes 3 and 4 of the battery provided on both sides.
[0022]
The exterior 2 is a laminate film 20 having a three-layer structure in which a resin film 21, a metal film 22, and a resin film 23 are laminated in this order.
[0023]
As shown in FIG. 2, the side ends of the exterior 2 are joined by joining the metal films 22 constituting the laminated films 20 by hot-pressing and compressing the side ends to which the laminated films 20 are joined. A part 25 is formed. Thereby, the resin film 23 located inside the laminate film 20 is covered with the metal film 22.
[0024]
The width S of the joining portion 25 is preferably 0.5 mm or more from the example described later, and is preferably 0.5 to 2.0 mm according to the example.
[0025]
The laminate film 20 may be a general laminate film (sometimes referred to as a laminate sheet), for example, a polymer in which a heat-fusible resin film, a metal film, and a rigid resin film are laminated in this order. A metal composite film is used.
[0026]
As the heat-fusible resin, for example, polyethylene (PE), ionomer, ethylene vinyl acetate (EVA) and the like can be used. As the metal film, for example, an Al foil or a Ni foil can be used. As the resin having rigidity, for example, polyethylene terephthalate (PET), nylon or the like can be used. Specifically, a laminated film of PE / Al foil / PET laminated from the sealing surface side to the outer surface; a laminated film of PE / Al foil / Nylon; a laminated film of ionomer / Ni foil / PET; EVA / Al foil / A PET laminated film; an ionomer / Al foil / PET laminated film or the like can be used. The heat-fusible resin film functions as a seal layer when the battery element is housed inside. The metal film or the rigid resin film imparts moisture, air resistance, and chemical resistance to the exterior material. The laminate film can be easily and reliably joined by using ultrasonic fusion or the like.
[0027]
Next, a method for manufacturing such a battery will be described.
[0028]
FIG. 3 is a view illustrating a method of manufacturing the above-described battery.
[0029]
First, as shown in FIG. 3A, a resin film 21, a metal film 22, and a resin film 23 are laminated in this order, and a laminated film in which the metal film 22 is longer at least at the end than the resin film 23 is prepared. Then, a battery element (not shown in FIG. 3) is sandwiched between two laminated films 20.
[0030]
Then, as shown in FIG. 3B, the side end of the laminate film is set in a heat press device. Here, in the press die 31 of the heat press device, as shown in the drawing, a protrusion 32 is formed at a position in front of the end of the side end of the laminate film. The projection 32 has a rectangular shape in the drawing, but is not limited thereto, and the tip of the projection may have an arc shape.
[0031]
Subsequently, while the press mold 31 is overheated, the end portion on the laminate film side is compressed to perform hot press compression molding.
[0032]
Thereby, as shown in FIG. 3 (c), at the side end of the laminate film, the inner resin film 23 is thermocompression-bonded, and simultaneously, the metal films 22 projecting from the resin film 23 are also crimped, The inner resin film 23 is covered with the metal film 22.
[0033]
Thereafter, the joint 25 of the metal film 22 is sealed by welding as shown in FIG.
[0034]
Thus, the inner resin film 23 is covered with the metal film 22 at the end of the laminate film on the side of the laminate film where the lamination cross section of the laminate structure is exposed, thereby preventing intrusion of moisture from this portion. it can. In addition, the use of a laminate material for battery exterior in which the metal film is longer at the end than the resin film makes it possible to heat the laminate film side end by a heat press device using a press die having a projection as described above. Since it is only necessary to perform compression molding and then to weld the joined metal film portions, it can be easily manufactured without any need for an auxiliary member or the like.
[0035]
In addition, when performing heat-pressing compression molding, before the heat-pressing compression molding, it may be after resin-sealing the laminate film side end portion in advance by pressing.
[0036]
(Example)
Here, the results of the above-described battery waterproof test will be described.
[0037]
In the experiment, for the batteries shown in FIGS. 1 and 2, a battery was manufactured as a test sample in which the width S of the joining portion 25 formed by the metal film 22 on the side of the laminate film was changed. The battery was allowed to stand in a 100% constant temperature / humidity chamber for 3 months, and the moisture inside the battery was quantified by the Karl Fischer method.
[0038]
The test sample had a width S of 0.5 mm (Example 1), a width S of 1.0 mm (Example 2), a width S of 2.0 mm (Example 3), and a width S of 0.4 (Comparative Example 1). ), A test sample having no metal film bonded (that is, the width S is 0 mm) (Comparative Example 2).
[0039]
Table 1 shows the test results.
[0040]
[Table 1]

[0041]
As can be seen from Table 1, when the width S of the joint 25 where the metal film 22 is joined at the end of the laminate film is 0.5 mm or more, the penetration of moisture is well prevented. The upper limit of the width S of the joint 25 is set to 2.0 mm in the test sample subjected to the test, but may be more than 2.0 mm. However, from the test results, 2.0 mm is sufficient.
[0042]
As described above, also from this example, it can be seen that the infiltration of moisture can be prevented by covering the end portion on the laminate film side with the metal film 22 so as not to expose the inner resin film 22.
[0043]
In the first embodiment, the laminate film of the battery exterior is formed by laminating a resin film, a metal film, and one resin film in this order, respectively. The number of layers is not limited to one, and a plurality of layers may be stacked.
[0044]
(Battery element)
The battery element of the battery according to the first embodiment, which is covered with the laminate film, may be basically any type.
[0045]
An example is as follows.
[0046]
Hereinafter, the case where the laminated battery of the present invention is a lithium ion secondary battery will be briefly described. However, the battery of the present invention is not limited to a lithium ion secondary battery. In addition, the battery element 11 means a portion formed by laminating a positive electrode, a separator, a negative electrode, and the like that substantially participate in charge and discharge.
[0047]
[Positive electrode]
The positive electrode has a structure in which a positive electrode material is bonded to both surfaces of a positive electrode current collector made of aluminum or the like. Examples of the cathode material include various oxides (lithium manganese oxide such as LiMn ₂ O ₄ ; manganese dioxide; lithium nickel oxide such as LiNiO ₂ ; lithium cobalt oxide such as LiCoO ₂ ; lithium-containing nickel cobalt oxide; And chalcogen compounds (such as titanium disulfide and molybdenum disulfide). Among these, lithium manganese oxide or lithium nickel oxide is preferable in consideration of the output characteristics of the obtained lithium ion secondary battery.
[0048]
A conductive material may be bound to the positive electrode current collector in order to improve conductivity. Examples of the conductive material include artificial graphite, carbon black (eg, acetylene black), nickel powder, and the like.
[0049]
As the positive electrode current collector, for example, aluminum expanded metal, aluminum mesh, aluminum punched metal, or the like can be used. Note that the positive electrode may have a structure in which a positive electrode material is bound to one surface of a positive electrode current collector.
[0050]
[Negative electrode]
The negative electrode has a structure in which a negative electrode material is bonded to both surfaces of a negative electrode current collector made of copper or the like. As the negative electrode material, a carbon material that stores and releases lithium ions can be used. As such a carbon material, natural graphite, artificial graphite, carbon black, activated carbon, carbon fiber, coke, and an organic precursor (eg, phenol resin, polyacrylonitrile, cellulose, etc.) were synthesized by heat treatment in an inert atmosphere. Carbon and the like. Preferably, the negative electrode is made of an amorphous carbon-based material. In the present application, "amorphous carbon-based material" means a carbon material having no crystal structure, in other words, an amorphous carbon material. Such an amorphous carbon-based material is obtained by carbonizing a thermosetting resin. Incidentally, when an amorphous carbon-based material having a large voltage dependency due to discharge is used, the cycle characteristics of the lithium ion secondary battery when two or more lithium ion secondary batteries are connected in parallel can be improved.
[0051]
As the negative electrode current collector, for example, a copper expanded metal, a copper mesh, a copper punched metal, or the like can be used. Note that the negative electrode may have a structure in which a negative electrode material is bound to one surface of a negative electrode current collector.
[0052]
[Separator]
As the separator, a polyolefin-based microporous separator, for example, polyethylene or polypropylene can be used, and the separator is impregnated with a non-aqueous electrolyte. The non-aqueous electrolyte is prepared by dissolving the electrolyte in a non-aqueous solvent. Examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and γ-butyrolactone (γ-BL). ), Sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. The non-aqueous solvents may be used alone or as a mixture of two or more. Examples of the electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium boron tetrafluoride (LiBF ₄ ), lithium arsenic hexafluoride (LiAsF ₆ ), and lithium trifluoromethanesulfonate. (LiCF ₃ SO ₃ ) and lithium salts of lithium bistrifluoromethylsulfonylimide [LiN (CF ₃ SO ₃ ) ₂ ]. The amount of the electrolyte dissolved in the nonaqueous solvent is usually about 0.2 mol / L to 2 mol / L.
[0053]
Examples of the polymer holding the non-aqueous electrolyte include a polyethylene oxide derivative, a polypropylene oxide derivative, a polymer containing the derivative, a copolymer of vinylidene fluoride (VdF) and hexafluoropropylene (HFP), and the like.
[0054]
[Tab electrode]
A metal selected from copper and iron can be used for the tab, but a metal such as aluminum or stainless steel or an alloy material containing these can also be used. Nickel is most preferably used for the surface coating layer, but metal materials such as silver and gold can also be used.
[0055]
The production of the laminated battery of the present invention can be carried out by using a known technique that a person skilled in the art would conceive. For example, the sheet member is arranged at a predetermined position of the tab by using a heat fusion technique. This tab is connected to the battery element. Next, the battery element to which the tab is connected is wrapped with a laminate sheet, and heat-sealed while leaving a sealing portion for injecting the electrolyte. At this time, the tab is drawn out of the laminate sheet and is thermally fused at a predetermined position. Subsequently, an electrolytic solution is injected through the sealing portion, and the sealing portion is closed by heat fusion to complete a laminated battery. At this time, as described above, the side end of the laminate film is molded such that the inner resin film is covered with the metal film.
[0056]
(Second embodiment)
The second embodiment is different from the above-described first embodiment in the method of molding the laminate film side end. Therefore, the form and function of the battery are the same as those in the first embodiment, and a description thereof will be omitted.
[0057]
FIG. 4 is a drawing for explaining a method of manufacturing a battery according to the second embodiment.
[0058]
In the second embodiment, first, as shown in FIG. 4A, a laminate film in which the metal films 22a and 22b are longer at least at the ends than the resin film 23 is prepared. At this time, a metal film 22a of one of the two laminated films 20 sandwiching the battery is prepared to be longer than the metal film 22b of the other laminated film 20.
[0059]
Then, a battery element (not shown in FIG. 4) is sandwiched between two laminated films 20.
[0060]
Then, the laminate film side end is set in a heat press apparatus, and the laminate film side end is compressed while the press die is overheated to perform hot press compression molding. At this time, in the third embodiment, as shown in FIG. 4B, the metal film 22a longer than one is bent toward the shorter metal film 22b.
[0061]
Thereafter, the joint 26 between the metal film 22a and the metal curtain 22b is sealed by welding.
[0062]
As a result, similarly to the first embodiment described above, the inner resin film 23 is covered with the metal films 22 and 22b at the side of the laminate film, thereby preventing the infiltration of moisture from this portion. it can.
[0063]
In addition, when performing heat-pressing compression molding, before the heat-pressing compression molding, it may be after resin-sealing the laminate film side end portion in advance by pressing.
[0064]
(Third embodiment)
The third embodiment is an assembled battery in which a plurality of batteries according to the first embodiment are connected.
[0065]
FIG. 5 is a perspective view of the battery pack according to the third embodiment, and FIG. 6 is a view of the internal configuration as viewed from above.
[0066]
As shown, the battery pack 50 is obtained by connecting a plurality of the batteries 1 according to the first embodiment described above in series and further connecting them in parallel. In the batteries 1, the tab electrodes 3 and 4 of each battery are connected by the conductive bar 53. In the battery pack 50, electrode terminals 51 and 52 are provided on one side of the battery pack 50 as electrodes of the battery pack 50.
[0067]
The shape of the battery 1 according to the above-described first embodiment used for the battery pack 50 is a cube, and when the width of the battery 1 is a, the length is b, and the thickness is c, the a / b ratio Is preferably in the range of 0.3 to 1.0, and the a / c ratio is preferably in the range of 5 to 100. Specifically, it is more preferable that the battery 1 has a width in a range of 50 mm to 200 mm, a length in a range of 50 mm to 300 mm, and a thickness in a range of 2 mm to 10 mm.
[0068]
By setting the battery 1 to this size, it is easy to handle in the manufacturing process of the assembled battery, and it is easy to package. Further, the total volume can be reduced when the battery is assembled, and the width of each of the tab electrodes 3 and 4 extracted from the battery 1 is 20% to 90% of the width of the tab electrode extraction surface. Is preferred.
[0069]
As a result, the sealing performance of the electrode portion can be secured while maintaining the required battery output.
[0070]
In this assembled battery, ultrasonic welding, heat welding, laser welding, rivets, caulking, an electron beam, or the like can be used as a connection method when the batteries 1 are connected in series and further connected in parallel. By employing such a connection method, a battery pack having long-term reliability can be manufactured.
[0071]
As described above, according to the battery pack according to the third embodiment, by using the battery capable of preventing water from entering according to the above-described first embodiment, the battery pack is made into a battery pack, so that high capacity, Since a high output can be obtained and the reliability of each battery is high, the long-term reliability of the assembled battery can be improved.
[0072]
The connection of the batteries 1 as an assembled battery may be such that a plurality of batteries 1 are all connected in parallel, or a plurality of batteries 1 are all connected in series.
[0073]
Also, in the third embodiment, the battery 1 according to the first embodiment described above is used as an assembled battery. However, as a matter of course, as in the second embodiment described above, the laminated film side end portion is used. An assembled battery may be used by using a battery molded from. Also in this case, the long-term reliability of the battery pack can be improved just like in the third embodiment.
[0074]
(Fourth embodiment)
The fourth embodiment is an assembled battery module in which a plurality of assembled batteries according to the third embodiment are connected.
[0075]
FIG. 7 is a perspective view of the battery module according to the third embodiment.
[0076]
This assembled battery module 60 is obtained by stacking a plurality of assembled batteries 50 according to the third embodiment described above and connecting the electrode terminals 51 and 52 of each assembled battery 50 by conductive bars 61 and 62 to form a module. is there.
[0077]
By modularizing the assembled battery 50 in this way, battery control is facilitated, and an assembled battery module optimal for use in a vehicle such as an electric vehicle or a hybrid vehicle is obtained. And since this assembled battery module 60 uses the above-described assembled battery, it has high waterproof performance, has sufficient waterproofness even in long-term outdoor use, and has a long-term reliability. Can be done.
[0078]
(Fifth embodiment)
The fifth embodiment is a vehicle equipped with the battery module according to the fourth embodiment. Vehicles using this battery module include, for example, electric vehicles and hybrid vehicles.
[0079]
For reference, FIG. 8 shows a schematic diagram of a vehicle (automobile) 100 on which the battery pack module 60 is mounted. The assembled battery module 60 mounted on the vehicle has the characteristics described above. Therefore, the vehicle equipped with the battery module 60 has high durability, and can provide a sufficient output even after being used for a long period of time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a battery according to a first embodiment to which the present invention is applied.
FIG. 2 is an enlarged sectional view of a laminate film side end of the battery.
FIG. 3 is a view for explaining a method of manufacturing the battery.
FIG. 4 is a drawing for explaining a method of manufacturing a battery according to a second embodiment to which the present invention is applied.
FIG. 5 is a drawing showing an outline configuration of a battery pack according to a third embodiment to which the present invention is applied.
FIG. 6 is a diagram illustrating an internal configuration of a battery pack according to a third embodiment as viewed from above.
FIG. 7 is a diagram showing a schematic configuration of a battery module according to a fourth embodiment to which the present invention is applied.
FIG. 8 is a view showing a vehicle according to a fifth embodiment to which the present invention is applied.
[Explanation of symbols]
1 battery,
20 laminated film,
21, 23 resin film,
22, 22a, 22b metal film,
25 joints,
31 Press mold,
32 protrusions,
50 assembled batteries,
60 assembled battery modules,
100 vehicles.

Claims (11)

At least a resin film, a metal film, and a resin film are laminated in this order, and the metal film is longer at the end than the resin film at an end. At least a resin film, a metal film, and a battery covered with a laminated film in which the resin film is laminated in this order,
A battery comprising: a joining portion in which the metal films are joined to each other at a side end where the laminate films are joined; and the inside of the resin film is covered with the metal film. The battery according to claim 2, wherein the joint has a width of 0.5 to 2 mm. At least a resin film, a metal film, and a method for manufacturing a battery packaged with a laminate film in which a resin film is laminated in this order,
Using a laminated film in which the metal film is longer than the resin film at the end of the laminated film, the side end where the laminated films are joined to each other is formed by a heat press mold having a projected portion. A method for manufacturing a battery, comprising a step of bending a portion of a film protruding from the resin film to the resin film side coming inward to join the metal films. An assembled battery comprising a plurality of the batteries according to claim 2 connected in parallel and / or series. The battery has a cubic shape, and when the width of the battery is a, the length is b, and the thickness is c, the a / b ratio is 0.3 to 1.0, and a / b The battery pack according to claim 5, wherein the c ratio is 5 to 100. The battery pack according to claim 6, wherein the shape of the battery is such that the battery has a width of 50 mm to 200 mm, a length of 50 mm to 300 mm, and a thickness of 2 mm to 10 mm. The electrode of the battery has a width of 20% to 90% of a length of the electrode extraction surface on a surface from which the electrode of the exterior is extracted. An assembled battery according to one of the above. The electrode of the battery is connected by at least one of ultrasonic welding, heat welding, laser welding, rivet, caulking, and electron beam. The battery pack according to any one of the above. An assembled battery module comprising a plurality of the assembled batteries according to any one of claims 4 to 9, connected in parallel and / or in series. The assembled battery module according to claim 10, wherein the assembled battery module is for mounting on a vehicle.

Images