JP2008226695A - Manufacturing method of battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a possibility is increased that a positive electrode and a negative electrode are short-circuited due to shifting and damage of a separator when the electrode plate group is pulled out of a winding core, because of thinness of the separator accompanying a recent further high-energy trend of a battery. <P>SOLUTION: This is a manufacturing method of a battery in which an electrode plate group in which a belt-shape positive electrode plate and a negative electrode plate are wound round in a swirl shape through a separator using a winding core 8 and electrolytic liquid are housed in a bottomed case and the aperture of this bottomed case is sealed by a sealing plate. When the electrode group is pulled out of the winding core 8, the winding core 8 and the separator portion 9 at the winding start of the electrode group pinched by the winding core 8 are cooled to ≤10°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は渦巻き状に捲回してなる極板群を備えた電池の製造方法に関するものである。   The present invention relates to a method for manufacturing a battery including an electrode plate group wound in a spiral shape.

近年、電子機器の高性能化に伴ってそれら電子機器に搭載される電池への小型、高容量化の要望が強まっている。これら電池の形状としては、ボタン型、円筒型あるいは角型電池などがある。   In recent years, with the improvement in performance of electronic devices, there has been an increasing demand for small size and high capacity of batteries mounted on the electronic devices. As the shape of these batteries, there are a button type, a cylindrical type or a square type battery.

円筒型や角型電池などの捲回型と呼ばれる極板群を備えた電池の製造方法においては、一般的に正極板と負極板との間を隔てるセパレータを捲回機の捲芯に捲きつけた後、セパレータの両面にそれぞれ正極板と負極板とを配置して、捲回機がセパレータと両極板を同時に捲回することで渦巻状の極板群が構成される。捲回の終了時には、この極板群を捲回機の捲芯から抜き取り、有底ケースの内部に電解液とともに収納して、有底ケースの開口部を封口板により密閉することで電池が作製される。   In the manufacturing method of a battery having an electrode plate group called a winding type such as a cylindrical type or a square type battery, a separator that generally separates a positive electrode plate and a negative electrode plate is attached to the core of the winding machine. After that, a positive electrode plate and a negative electrode plate are arranged on both surfaces of the separator, respectively, and a winding machine winds the separator and both electrode plates at the same time to form a spiral electrode plate group. At the end of winding, the electrode plate group is removed from the winding core of the winding machine, stored together with the electrolyte in the bottomed case, and the battery is manufactured by sealing the bottomed case opening with a sealing plate. Is done.

上記の捲芯としては、角型電池の場合は平板状の捲芯が用いられ、これらはステンレス鋼やリボン鋼を加工したものであった。しかしながらこのような捲芯を用いた場合には、セパレータの代表的な材質であるポリエチレンやポリプロピレンなどとの摩擦抵抗が大きくなるため、渦巻状に捲回した極板群を捲芯から抜き取るときに抜き取りがスムーズに行えず、極板群がタケノコ状に型崩れするだけでなく、セパレータのズレや損傷により正・負極板間が短絡するおそれがあった。   As the above-mentioned core, in the case of a rectangular battery, a flat core is used, which is obtained by processing stainless steel or ribbon steel. However, when such a core is used, the frictional resistance with polyethylene, polypropylene, or the like, which is a typical separator material, increases, so when the spirally wound electrode plate group is removed from the core. Extraction could not be performed smoothly, and not only the electrode plate group was deformed into a bamboo shoot shape, but also there was a risk of short circuit between the positive and negative electrode plates due to the displacement or damage of the separator.

この課題を解決するため、セパレータと接触する捲芯の表面にポリエステルのテープを貼り付けたり、あるいは捲芯の表面にシリコンの離型剤を塗布したりする方法がとられていた。   In order to solve this problem, a method has been employed in which a polyester tape is attached to the surface of the core in contact with the separator, or a silicone release agent is applied to the surface of the core.

しかしながらこれらの方法では、捲芯とセパレータとの摩擦抵抗を十分に低減することができず、また、シリコンの離型剤を塗布する方法では捲回毎にセパレータと接触する捲芯の表面に塗布する必要があり、製造工程が煩雑になり好ましくない。そこで、セパレータと接触する捲芯の表面にフッ素樹脂層を設けたり、捲芯の表面に凹凸を設けることで捲芯とセパレータとの摩擦抵抗を低減する方法が開示されている（例えば、特許文献１参照）。
特開２００３−１７１１０号公報 However, in these methods, the frictional resistance between the core and the separator cannot be sufficiently reduced, and in the method of applying a silicon release agent, the coating is applied to the surface of the core that contacts the separator every time it is wound. This is not preferable because the manufacturing process becomes complicated. Therefore, a method for reducing the frictional resistance between the core and the separator by providing a fluororesin layer on the surface of the core that is in contact with the separator or by providing irregularities on the surface of the core is disclosed (for example, Patent Documents). 1).
JP 2003-17110 A

しかしながら上記従来の製造方法では、最近の電池の更なる高エネルギー密度化に伴うセパレータの薄膜化により、上記極板群を捲芯から抜き取るときにセパレータのズレや損傷によって正・負極板間が短絡する可能性が増していた。
本発明は上記課題を解決するためになされ、捲芯とセパレータとの磨耗抵抗を低減し、渦巻状の極板群を捲回機の捲芯からスムーズに抜き取り、極板群がタケノコ状に型崩れすることやセパレータのズレや損傷を低減して正・負極板間が短絡することのない電池の製造方法を提供することを目的とする。 However, in the above conventional manufacturing method, due to the thinning of the separator accompanying the further increase in energy density of recent batteries, the positive and negative electrodes are short-circuited due to the displacement or damage of the separator when the electrode plate group is removed from the core. The possibility of doing was increasing.
The present invention has been made to solve the above-mentioned problems, reduces the wear resistance between the core and the separator, smoothly removes the spiral electrode group from the core of the winding machine, and the electrode group is shaped like a bamboo shoot. An object of the present invention is to provide a method for producing a battery that does not collapse and reduces the displacement and damage of the separator so that the positive and negative electrode plates are not short-circuited.

上記の目的を達成するために本発明は、帯状の正極板と負極板とをセパレータを介して捲芯を用いて渦捲状に捲回してなる極板群と電解液を有底ケースに収納し、この有底ケー
スの開口部を封口板により密閉する電池の製造方法であって、前記捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を少なくとも極板群を捲芯から抜き取るときに１０℃以下に冷却することを特徴とする。 In order to achieve the above object, the present invention stores an electrode plate group formed by winding a strip-shaped positive electrode plate and a negative electrode plate in a spiral shape using a core through a separator, and an electrolyte in a bottomed case. A method for manufacturing a battery in which the opening of the bottomed case is sealed with a sealing plate, wherein at least the electrode plate group is cored with the separator part at the beginning of the electrode group held between the core and the core. It is characterized in that it is cooled to 10 ° C. or lower when it is extracted from the container.

この製造方法によれば、捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を少なくとも極板群を捲芯から抜き取るときに１０℃以下に冷却することにより、捲き始めのセパレータ部分と捲芯との摩擦抵抗を低減できるため、渦捲状に捲回した極板群を捲芯からスムーズに抜き取ることができる。   According to this manufacturing method, by separating at least the separator portion at the beginning of winding of the electrode plate group held between the core and the core by cooling to 10 ° C. or lower when extracting the electrode plate group from the core, Since the frictional resistance between the portion and the core can be reduced, the electrode plate group wound in a spiral shape can be smoothly extracted from the core.

本発明によれば、捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を少なくとも極板群を捲芯から抜き取るときに１０℃以下に冷却することにより、この捲き始めのセパレータ部分と捲芯との摩擦抵抗を低減できるため、渦捲状に捲回した極板群を捲芯からスムーズに抜き取ることができ、極板群がタケノコ状に型崩れすることなく、セパレータのズレや損傷による正・負極板間の短絡を抑制できる効果が得られる。   According to the present invention, the separator at the beginning of winding is cooled by cooling to 10 ° C. or less when at least the electrode group is removed from the core by separating the core and the separator portion at the beginning of winding of the electrode group held between the cores. Since the frictional resistance between the part and the iron core can be reduced, the electrode plate group wound in a vortex shape can be removed smoothly from the iron core, and the electrode plate group does not lose its shape like a bamboo shoot. The effect that the short circuit between the positive and negative electrode plates due to damage can be suppressed can be obtained.

本発明の形態においては、帯状の正極板と負極板とをセパレータを介して捲芯を用いて渦捲状に捲回してなる極板群と電解液を有底ケースに収納し、この有底ケースの開口部を封口板により密閉する電池の製造方法であって、前記捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を少なくとも極板群を捲芯から抜き取るときに１０℃以下に冷却することを特徴とする。   In the embodiment of the present invention, an electrode plate group formed by winding a belt-like positive electrode plate and a negative electrode plate in a spiral shape using a core through a separator and an electrolyte solution are housed in a bottomed case, and this bottomed A method of manufacturing a battery in which an opening of a case is sealed with a sealing plate, wherein at least the separator plate at the beginning of winding of the electrode plate group sandwiched between the iron core and the iron core is removed from the core core. It is characterized by cooling to below ℃.

この製造方法によれば、セパレータと捲芯との摩擦抵抗を低減できるため、捲芯から極板群をスムーズに抜き取ることができ、極板群がタケノコ状に型崩れすることや、セパレータのズレや損傷による正・負極板間での短絡の発生を抑制することができる。   According to this manufacturing method, since the frictional resistance between the separator and the core can be reduced, the electrode plate group can be smoothly extracted from the core, and the electrode plate group can be deformed into a bamboo shoot shape, and the separator can be displaced. It is possible to suppress the occurrence of a short circuit between the positive and negative electrode plates due to damage.

また、前記捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を、極板群を捲き取るときは常温であり、極板群を捲芯から抜き取るときに１０℃以下に冷却しても良い。   Further, when the electrode plate group is scraped off, the separator portion at the beginning of the electrode group held between the core and the core is at room temperature, and cooled to 10 ° C. or less when the electrode plate group is removed from the core. You may do it.

この製造方法によれば、極板群を捲き取るときはセパレータと捲芯との摩擦抵抗は特に低減されないためセパレータと捲芯とが滑ることなく安定して巻き取ることができ、極板群を捲芯から抜き取るときにのみセパレータと捲芯との摩擦抵抗を低減して極板群をスムーズに抜き取ることができる。また、極板群を捲芯から抜き取るときにのみ１０℃以下に冷却するため、極板群を巻き取るときにのみ冷却する方法や連続して冷却する方法と比べて効率的であり経済性にも優れる。   According to this manufacturing method, when the electrode plate group is scraped off, the frictional resistance between the separator and the core is not particularly reduced, so that the separator and the core can be stably wound without slipping. Only when extracting from the core, the frictional resistance between the separator and the core is reduced, and the electrode plate group can be extracted smoothly. Moreover, since the electrode plate group is cooled to 10 ° C. or less only when it is extracted from the core, it is more efficient and economical than the method of cooling only when the electrode plate group is wound up or the method of continuously cooling the electrode group. Also excellent.

また、前記捲芯にスポットクーラーの冷風を吹き付け、その熱伝導により捲き始めのセパレータ部分を冷却する方法が望ましい。   Further, it is desirable that a cold air of a spot cooler is blown on the core and the separator portion at the beginning of cooling is cooled by heat conduction.

この製造方法によれば、極板群を捲芯から抜き取るときにスポットクーラーの冷風を捲芯に容易に吹き付けることができるため、極板群を捲芯から抜き取るときに捲き始めのセパレータ部分を冷却する場合に適している。極板群を捲芯から抜き取るときに、捲き始めのセパレータ部分に冷風を直接吹き付ける方法と異なり、このように捲芯に吹き付ける方法であれば容易に実施できる。また、スポットクーラーの冷風を捲き始めのセパレータ部分に直接吹き付ける必要がないので、この冷風の吹き付けによって捲き始めのセパレータ部分の位置がずれた状態で極板群を構成し、極板群を捲芯から抜き取るときに極板群がタケノコ状に型崩れするという心配もない。   According to this manufacturing method, since the cool air of the spot cooler can be easily blown onto the core when the electrode plate group is extracted from the core, the separator portion at the beginning of cooling is cooled when the electrode plate group is extracted from the core. Suitable for you. Unlike the method in which cold air is blown directly onto the separator portion at the beginning of rolling when the electrode plate group is extracted from the core, this method can be easily implemented as long as it is sprayed on the core. In addition, since it is not necessary to blow the cool air of the spot cooler directly onto the separator part at the beginning of firing, the electrode plate group is configured with the position of the separator part at the beginning of firing being displaced by this blowing of cold air, and the electrode plate group is There is no worry that the electrode plate will be deformed into a bamboo shoot shape when it is removed.

また、前記捲き始めのセパレータ部分にスポットクーラーの冷風を吹き付ける方法でも良い。   Moreover, the method of spraying the cool air of a spot cooler to the said separator part of the beginning of burning may be used.

この製造方法によれば、スポットクーラーの冷風を捲き始めのセパレータ部分に直接吹き付けるので、このセパレータの温度を１０℃以下に効果的に短時間で冷却することができる。   According to this manufacturing method, since the cool air of the spot cooler is directly blown on the separator portion at the beginning of the burning, the temperature of the separator can be effectively cooled to 10 ° C. or less in a short time.

以下に本発明の実施例について、図面を参照して説明する。ただし、本発明は以下に説明する実施例に限定されるものではない。   Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the examples described below.

図１は本発明の角型リチウムイオン二次電池の一実施例を示した一部切欠斜視図、
図２、図３は本発明の実施例に用いた角型リチウムイオン二次電池の極板群の捲き始めの構成を示した模式図である。 FIG. 1 is a partially cutaway perspective view showing an embodiment of a prismatic lithium ion secondary battery of the present invention,
FIG. 2 and FIG. 3 are schematic views showing the structure at the beginning of the electrode plate group of the prismatic lithium ion secondary battery used in the examples of the present invention.

角型リチウムイオン二次電池の極板群１は、コバルト酸リチウムを正極活物質として導電剤と結着剤とを混合した正極合剤をアルミニウム箔集電体に塗工、乾燥、圧延し、所定の寸法に切断して作製した帯状の正極板と、黒鉛を負極活物質として導電剤と結着剤とを混合した負極合剤を銅箔集電体に塗工、乾燥、圧延し、所定の寸法に切断して作製した帯状の負極板とをセパレータを介して捲芯８を用いて捲回後、極板群１を捲芯８から抜き取る工程を経て構成する。   The electrode group 1 of the prismatic lithium ion secondary battery is coated with a positive electrode mixture in which a conductive agent and a binder are mixed using lithium cobalt oxide as a positive electrode active material, dried, rolled, A strip-like positive electrode plate produced by cutting to a predetermined size and a negative electrode mixture in which graphite and a negative electrode active material are mixed with a conductive agent and a binder are applied to a copper foil current collector, dried and rolled, and predetermined The strip-shaped negative electrode plate produced by cutting to the above dimensions is wound using a core 8 through a separator, and then the electrode plate group 1 is extracted from the core 8.

渦捲状の極板群１の捲き始めは正極板、負極板が存在しない捲き始めのセパレータ部分９が２枚重なり合って存在し、この２枚重なり合った捲き始めのセパレータ部分９を２枚の平板状の金属からなる捲芯８により挟持した状態で捲回を開始する。捲芯８の捲き始めは捲き始めのセパレータ部分９のみが数周捲回され、次いで正極板と負極板とをセパレータを介して捲回した後、捲き始めのセパレータ部分９の挟持を緩めて極板群１を捲芯８から抜き取っている。   At the beginning of whirling electrode group 1, there are two separator parts 9 at the beginning of firing, where there are no positive and negative electrode plates, and the two separator parts 9 at the beginning of the two overlapping parts are two flat plates. Winding is started in a state of being sandwiched between the cores 8 made of metal. At the beginning of winding of the core 8, only the separator portion 9 at the beginning of winding is wound several times, and then the positive electrode plate and the negative electrode plate are wound through the separator, and then the holding of the separator portion 9 at the beginning of rolling is loosened to form a pole. The plate group 1 is extracted from the core 8.

このように構成した極板群１は、正極リード２および負極リード３が各々正極板および負極板に電気的に接続されており、有底ケース４に収納した後、正極リード２と封口板５、および負極リード３と負極端子６を各々溶接する。   In the electrode plate group 1 configured as described above, the positive electrode lead 2 and the negative electrode lead 3 are electrically connected to the positive electrode plate and the negative electrode plate, respectively. , And the negative electrode lead 3 and the negative electrode terminal 6 are welded to each other.

その後、封口板５と有底ケース４をレーザー溶接する。次いで所定量の非水電解液を注入口７より有底ケース４内に注入し、注入口７に封栓を挿入、レーザー溶接して角型リチウムイオン二次電池を作製する。   Thereafter, the sealing plate 5 and the bottomed case 4 are laser welded. Next, a predetermined amount of non-aqueous electrolyte is injected into the bottomed case 4 from the inlet 7, a cap is inserted into the inlet 7, and laser welding is performed to produce a prismatic lithium ion secondary battery.

（実施例１）
図２に示すように、角型リチウムイオン二次電池用の捲芯８は、２枚の平板状の金属で構成されている。捲芯８の材質はステンレス鋼とし、表層部は厚さが１００μｍのポリテトラフルオロエチレン（ＰＴＦＥ）層とした。この捲芯８を備えた捲回機の捲回部付近にスポットクーラーの吹き出し口１０を取り付け、捲き始めのセパレータ部分９に冷風を直接吹き付けることにより、捲き始めのセパレータ部分９の表面温度を冷却した。なお、捲回機周辺の環境温度は約２５℃に設定した。捲芯８はモーターによって駆動し、極板群を約３０個／分のタクトで構成する捲回機を用いた。 (Example 1)
As shown in FIG. 2, the core 8 for a prismatic lithium ion secondary battery is composed of two flat metal plates. The material of the core 8 was stainless steel, and the surface layer portion was a polytetrafluoroethylene (PTFE) layer having a thickness of 100 μm. A spot cooler outlet 10 is attached to the vicinity of the winding part of the winding machine equipped with the core 8, and the surface temperature of the separator part 9 at the beginning of the rolling is cooled by directly blowing cool air to the separator part 9 at the beginning of the winding. did. The ambient temperature around the winding machine was set to about 25 ° C. The winding core 8 was driven by a motor, and a winding machine configured with a tactile plate group of about 30 / min was used.

このようにスポットクーラーの吹き出し口１０から捲き始めのセパレータ部分９に冷風を直接吹き付けるように設定した捲回機を捲回機Ａと称する。この捲回機Ａを用いて角型リチウムイオン電池を以下のように作製した。   The winding machine set so that the cold air is blown directly from the outlet 10 of the spot cooler to the separator portion 9 at the beginning of winding is referred to as a winding machine A. Using this winding machine A, a square lithium ion battery was produced as follows.

まず、ポリエチレン製の微多膜からなる捲き始めのセパレータ部分９の先端部を２枚の平板状のステンレス鋼からなる捲芯８によって挟持した状態で、スポットクーラーの吹き出し口１０から捲き始めのセパレータ部分９に冷風を直接吹き付けた。   First, in the state where the leading end portion of the separator portion 9 made of polyethylene made of a fine multi-layer film is sandwiched between two flat cores 8 made of stainless steel, the separator that starts rolling from the outlet 10 of the spot cooler Cold air was blown directly onto part 9.

捲き始めのセパレータ部分９の表面温度が設定した温度まで低下したことを検知してから捲回機Ａのモーターを駆動して捲芯８の捲回を開始し、捲芯８を約３回転した時点でスポットクーラーの吹き出しを停止した。このように捲芯８の捲き始めは捲き始めのセパレータ部分９のみを約３周捲回し、次いで正極板と負極板とをセパレータを介して捲回した。   After detecting that the surface temperature of the separator portion 9 at the beginning of the rolling has decreased to the set temperature, the winding machine A is driven to start the winding of the winding core 8, and the winding core 8 is rotated about 3 times. At that time, the spot cooler stopped blowing. Thus, at the beginning of winding of the core 8, only the separator portion 9 at the beginning of winding was wound about three times, and then the positive electrode plate and the negative electrode plate were wound through the separator.

所定の長さの正極板と負極板を捲回した後、両極板を切断し、外周をセパレータのみで約２周捲回してセパレータを切断し、この外周のセパレータを熱溶着して渦巻状の極板群１が解けないように固定した。   After winding a positive electrode plate and a negative electrode plate of a predetermined length, the both electrode plates are cut, the outer periphery is wound only about two times with a separator to cut the separator, and the outer peripheral separator is thermally welded to form a spiral shape. The electrode plate group 1 was fixed so as not to unravel.

次に、２枚の平板状の捲芯８によって挟持していた捲き始めのセパレータ部分９の挟持を緩めて極板群１を捲芯８から抜き取った。   Next, the electrode plate group 1 was removed from the core 8 by loosening the holding of the separator portion 9 that had been sandwiched between the two flat cores 8.

極板群１を捲き取るときに捲き始めのセパレータ部分９に直接吹き付けるスポットクーラーの吹き出し口１０から吹き出される冷風の温度は、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が５℃〜１０℃になるように設定した。   The temperature of the cold air blown from the outlet 10 of the spot cooler that blows directly on the separator portion 9 that starts to whip the electrode plate group 1 is such that the separator portion that starts to whip when the electrode plate group 1 is removed from the core 8. The surface temperature of 9 was set to 5 ° C to 10 ° C.

このように構成した極板群１を有底ケース４内に挿入し、非水電解液を注入した後、有底ケース４の開口部を封口板５で封口することにより作製した角型リチウムイオン二次電池を実施例１の電池Ａとした。   The thus-configured electrode plate group 1 is inserted into the bottomed case 4 and injected with a non-aqueous electrolyte, and then the rectangular lithium ion produced by sealing the opening of the bottomed case 4 with the sealing plate 5. The secondary battery was designated as battery A of Example 1.

（実施例２）
極板群１を捲き取るときに捲き始めのセパレータ部分９に直接吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−５℃〜０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例２の電池Ｂとした。 (Example 2)
The temperature of the cold air blown directly onto the separator portion 9 at the beginning of the electrode plate 1 when the electrode plate group 1 is removed, and the surface temperature of the separator portion 9 at the beginning of the operation when the electrode plate group 1 is removed from the core 8 is -5 ° C to 0 ° C. A square lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to 0 ° C. was designated as Battery B of Example 2.

（実施例３）
極板群１を捲き取るときに捲き始めのセパレータ部分９に直接吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−１５℃〜−１０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例３の電池Ｃとした。 (Example 3)
The temperature of the cold air blown directly onto the separator portion 9 at the beginning of the electrode plate 1 when the electrode plate group 1 is scraped, and the surface temperature of the separator portion 9 at the start of the electrode plate 1 when the electrode plate group 1 is removed from the core 8 is -15 ° C to- A prismatic lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to 10 ° C. was designated as Battery C of Example 3.

（実施例４）
極板群１を捲き取るときに捲き始めのセパレータ部分９に直接吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−２５℃〜−２０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例４の電池Ｄとした。 Example 4
The temperature of the cold air blown directly onto the separator part 9 at the beginning of the electrode plate 1 when the electrode plate group 1 is scraped off, and the surface temperature of the separator part 9 at the start of the electrode plate 1 when the electrode plate group 1 is removed from the core 8 A square lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to 20 ° C. was designated as Battery D of Example 4.

（比較例１）
極板群１を捲き取るときに捲き始めのセパレータ部分９に直接吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が１５℃〜２０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を比較例１の電池Ｍとした。 (Comparative Example 1)
The temperature of the cold air blown directly onto the separator portion 9 at the start of the electrode plate group 1 when the electrode plate group 1 is scraped, and the surface temperature of the separator portion 9 at the start of the electrode plate group 1 when the electrode plate group 1 is extracted from the core 8 The battery M of Comparative Example 1 was a prismatic lithium ion secondary battery produced in the same manner as in Example 1 except that the setting was made as follows.

（実施例５）
図３に示すように、スポットクーラーの吹き出し口１０から吹き出される冷風を捲芯８に吹き付け、その熱伝導により捲き始めのセパレータ部分９を冷却する構造の捲回機であって、極板群１を捲き取るときに冷風を吹き出すように設定した捲回機を捲回機Ｂと称する。 (Example 5)
As shown in FIG. 3, a winder having a structure in which cool air blown from a blowout port 10 of a spot cooler is blown to the core 8 and the separator portion 9 that starts to be blown by the heat conduction is cooled. A winding machine that is set to blow cold air when scraping 1 is referred to as winding machine B.

捲回機Ｂを用いて極板群１を捲き取るときに冷風を捲芯８に吹き付けた以外は実施例１と同様に、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が５℃〜１０℃になるように設定した。このように作製した角型リチウムイオン二次電池を実施例５の電池Ｅとした。   The separator portion at the beginning of winding when the electrode plate group 1 is removed from the core 8 in the same manner as in Example 1 except that cold air was blown onto the core 8 when the electrode plate group 1 was scraped off using the winding machine B The surface temperature of 9 was set to 5 ° C to 10 ° C. The square lithium ion secondary battery produced in this manner was designated as battery E of Example 5.

（実施例６）
捲回機Ｂを用いて極板群１を捲き取るときに捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−５℃〜０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例６の電池Ｆとした。 (Example 6)
When the electrode plate group 1 is scraped off using the winding machine B, the temperature of the cold air blown to the core 8 is removed, and when the electrode plate group 1 is extracted from the core 8, the surface temperature of the separator portion 9 at the beginning of winding is −5 A prismatic lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to 0 ° C. to 0 ° C. was designated as Battery F of Example 6.

（実施例７）
捲回機Ｂを用いて極板群１を捲き取るときに捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−１５℃〜−１０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例７の電池Ｇとした。 (Example 7)
The temperature of the cold air blown to the core 8 when the electrode plate group 1 is scraped using the winding machine B, and the surface temperature of the separator portion 9 at the beginning of the winding when the electrode plate group 1 is extracted from the core 8 is −15. A prismatic lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to be -10 ° C to -10 ° C was designated as Battery G of Example 7.

（実施例８）
捲回機Ｂを用いて極板群１を捲き取るときに捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−２５℃〜−２０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例８の電池Ｈとした。 (Example 8)
The temperature of the cold air blown to the core 8 when the electrode plate group 1 is scraped using the winding machine B, and the surface temperature of the separator portion 9 at the beginning of the winding when the electrode plate group 1 is extracted from the core 8 is −25. A prismatic lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to be -20 ° C to -20 ° C was designated as Battery H of Example 8.

（比較例２）
捲回機Ｂを用いて極板群１を捲き取るときに捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が１５℃〜２０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を比較例２の電池Ｎとした。 (Comparative Example 2)
The temperature of the cold air blown to the core 8 when the electrode plate group 1 is scraped off using the winding machine B, and the surface temperature of the separator portion 9 at the beginning of winding when the electrode plate group 1 is pulled out of the core 8 is 15 ° C. A rectangular lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to ˜20 ° C. was designated as Battery N of Comparative Example 2.

（実施例９）
図３に示すように、スポットクーラーの吹き出し口１０から吹き出される冷風を捲芯８に吹き付け、その熱伝導により捲き始めのセパレータ部分９を冷却する構造の捲回機であって、極板群１を捲き終えた後、極板群１を捲芯８から抜き取る直前にスポットクーラーの吹き出し口１０から冷風を吹き出すように設定した捲回機を捲回機Ｃと称する。 Example 9
As shown in FIG. 3, a winder having a structure in which cool air blown from a blowout port 10 of a spot cooler is blown to the core 8 and the separator portion 9 that starts to be blown by the heat conduction is cooled. A winding machine set to blow cold air from the air outlet 10 of the spot cooler immediately after pulling 1 and immediately before the electrode plate group 1 is extracted from the core 8 is referred to as a winding machine C.

捲回機Ｃを用いて極板群１を捲芯８から抜き取る直前に冷風を捲芯８に吹き付けた以外は実施例１と同様に、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が５℃〜１０℃になるように設定した。このように作製した角型リチウムイオン二次電池を実施例９の電池Ｉとした。   As in Example 1, except that the cold wind was blown onto the core 8 just before the electrode plate group 1 was extracted from the core 8 using the winding machine C, the electrode plate group 1 started to be extracted when extracted from the core 8. The surface temperature of the separator part 9 was set to 5 ° C to 10 ° C. The square lithium ion secondary battery produced in this way was designated as Battery I of Example 9.

（実施例１０）
捲回機Ｃを用いて極板群１を捲芯８から抜き取る直前に捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−５℃〜０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例１０の電池Ｊとした。 (Example 10)
The temperature of the cold air blown onto the core 8 immediately before the electrode plate group 1 is extracted from the core 8 using the winding machine C, and the surface temperature of the separator portion 9 at the beginning of the operation when the electrode plate group 1 is extracted from the core 8 Was set to be −5 ° C. to 0 ° C., and a prismatic lithium ion secondary battery produced in the same manner as in Example 1 was designated as Battery J of Example 10.

（実施例１１）
捲回機Ｃを用いて極板群１を捲芯８から抜き取る直前に捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−１５℃〜−１０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例１１の電池Ｋとした。 (Example 11)
The temperature of the cold air blown onto the core 8 immediately before the electrode plate group 1 is extracted from the core 8 using the winding machine C, and the surface temperature of the separator portion 9 at the beginning of the operation when the electrode plate group 1 is extracted from the core 8 Was set to be −15 ° C. to −10 ° C., and a prismatic lithium ion secondary battery produced in the same manner as in Example 1 was designated as Battery K of Example 11.

（実施例１２）
捲回機Ｃを用いて極板群１を捲芯８から抜き取る直前に捲芯８に吹き付ける冷風の温度を、極板群１を捲芯８から抜き取るときに捲き始めのセパレータ部分９の表面温度が−２５℃〜−２０℃になるように設定した以外は実施例１と同様に作製した角型リチウムイオン二次電池を実施例１２の電池Ｌとした。 (Example 12)
The temperature of the cold air blown onto the core 8 immediately before the electrode plate group 1 is extracted from the core 8 using the winding machine C, and the surface temperature of the separator portion 9 at the beginning of the operation when the electrode plate group 1 is extracted from the core 8 The battery L of Example 12 was a prismatic lithium ion secondary battery produced in the same manner as in Example 1 except that the temperature was set to −25 ° C. to −20 ° C.

（比較例３）
捲回機にスポットクーラーを取り付けなかった捲回機を捲回機Ｄと称する。 (Comparative Example 3)
A winding machine in which the spot cooler is not attached to the winding machine is referred to as a winding machine D.

捲回機Ｄを用いて捲き始めのセパレータ部分を冷却しなかった以外は実施例１と同様に作製した角型リチウムイオン二次電池を比較例３の電池Ｏとした。なお、捲回機周辺の環境温度は実施例１と同様に約２５℃に設定した。   A square lithium ion secondary battery produced in the same manner as in Example 1 was used as the battery O of Comparative Example 3, except that the separator portion at the beginning of rolling was not cooled using the winding machine D. The ambient temperature around the winding machine was set to about 25 ° C. as in Example 1.

＜評価＞
本発明の実施例１〜１２の電池Ａ〜Ｌ、および比較例１〜３の電池Ｍ〜Ｏを各１００個作製し、極板群がタケノコ状に型崩れしていないかを目視確認した。また、各極板群を捲芯から抜き取るために必要な力を調べた。 <Evaluation>
100 batteries A to L of Examples 1 to 12 of the present invention and 100 batteries M to O of Comparative Examples 1 to 3 were produced respectively, and it was visually confirmed whether or not the electrode plate group was out of shape in a bamboo shoot shape. In addition, the force required to extract each electrode plate group from the core was examined.

作製した各１００個の角型リチウムイオン二次電池は、環境温度２０℃において電圧４．２０Ｖまで定電流充電し、電圧４．２０Ｖに到達した後、充電時間の総計が２時間になるように定電圧４．２０Ｖで充電した。その後、６０℃の恒温槽に３日間保存し、６０℃の恒温槽から取り出した後、環境温度２０℃において電池温度が安定するまで６時間ほど保存した。電池温度が安定してから１回目の開路電圧を測定し、環境温度２０℃においてさらに２日間保存してから２回目の開路電圧を測定した。２回目の開路電圧が１回目の開路電圧より１００ｍＶ以上低下したものを開路電圧不良として判定した。   Each of the 100 prismatic lithium ion secondary batteries produced was charged at a constant current to a voltage of 4.20 V at an environmental temperature of 20 ° C., and after reaching the voltage of 4.20 V, the total charging time was 2 hours. The battery was charged at a constant voltage of 4.20V. Then, after storing in a 60 degreeC thermostat for 3 days, after taking out from a 60 degreeC thermostat, it preserve | saved for about 6 hours until battery temperature became stable in environmental temperature 20 degreeC. The first open-circuit voltage was measured after the battery temperature was stabilized, and the second open-circuit voltage was measured after storing for another two days at an environmental temperature of 20 ° C. A case where the second open circuit voltage was lower than the first open circuit voltage by 100 mV or more was determined as an open circuit voltage failure.

評価結果を（表１）に示す。   The evaluation results are shown in (Table 1).

この（表１）より明らかなように、本発明の実施例１〜１２の電池Ａ〜Ｌの各極板群を捲芯から抜き取るために必要な力は、比較例１〜３の電池Ｍ〜Ｏに比べて極めて小さくなった。特に捲き始めのセパレータ部分９の表面温度を、−２５℃〜−２０℃とした電池Ｄ、電池Ｈ、電池Ｌの各極板群を捲芯から抜き取るために必要な力は小さくなることがわかった。   As is clear from this (Table 1), the force required to pull out each electrode plate group of the batteries A to L of Examples 1 to 12 of the present invention from the core is the battery M to Comparative Examples 1 to 3. Compared with O, it became very small. In particular, it can be seen that the force required to extract the electrode plate groups of the battery D, the battery H, and the battery L from which the surface temperature of the separator portion 9 at the beginning of firing is −25 ° C. to −20 ° C. is reduced. It was.

また、実施例１〜１２の電池Ａ〜Ｌの各極板群はタケノコ状に型崩れすることなく、開路電圧不良の発生も皆無であった。一方、比較例１〜３の電池Ｍ〜Ｏの各極板群はタケノコ状に型崩れするものが１０〜１８％あり、開路電圧不良になるものが３〜５％あった。開路電圧不良となった角型リチウムイオン二次電池は、全て極板群がタケノコ状に型崩れしたものであり、電池を分解してセパレータを観察したところセパレータが大きくずれて損傷していることが確認できた。このセパレータの損傷により開路電圧不良になったと考えられる。   In addition, each electrode plate group of the batteries A to L of Examples 1 to 12 did not lose its shape like a bamboo shoot, and there was no occurrence of open circuit voltage failure. On the other hand, the electrode plate groups of the batteries M to O of Comparative Examples 1 to 3 had 10 to 18% of those that collapsed into a bamboo shoot shape, and 3 to 5% of those that became defective in open circuit voltage. All the square lithium ion secondary batteries with poor open circuit voltage are those in which the electrode plate group is deformed into a bamboo shoot shape.When the battery is disassembled and the separator is observed, the separator is greatly displaced and damaged. Was confirmed. It is considered that the open circuit voltage was defective due to the damage of the separator.

以上のように、捲き始めのセパレータ部分９の表面温度を１０℃以下に冷却すれば、極板群がタケノコ状に型崩れすることなく、セパレータのズレや損傷による正・負極板間の短絡を抑制できることがわかった。   As described above, if the surface temperature of the separator portion 9 at the beginning of cooling is cooled to 10 ° C. or less, the electrode plate group does not lose its shape like a bamboo shoot, and the short circuit between the positive and negative electrodes due to the displacement or damage of the separator can be achieved. It turned out that it can suppress.

これは捲き始めのセパレータ部分９と捲芯８との摩擦抵抗を低減できたため、渦捲状に捲回した極板群１を捲芯８からスムーズに抜き取ることができたと考えられる。   This is considered to be because the frictional resistance between the separator portion 9 at the beginning of rolling and the core 8 could be reduced, so that the electrode plate group 1 wound in a spiral shape could be smoothly extracted from the core 8.

本実施例はポリエチレン製の微多孔膜からなるセパレータを用いたが、このようなポリオレフィン系の微多孔膜からなるセパレータは低温で硬化するため、低温側での摩擦抵抗が小さくなったと考えられる。   In this example, a separator made of a polyethylene microporous film was used. However, such a separator made of a polyolefin-based microporous film is cured at a low temperature, so that the frictional resistance on the low temperature side is considered to be reduced.

なお、本実施例において角型リチウムイオン二次電池を例にとって説明したが、本発明はこれに限定されるものではなく、セパレータを介して正・負極板を捲回することにより得られる渦巻状の極板群からなる電池すべての製造方法に適応しうることは明らかである
。 In this embodiment, the prismatic lithium ion secondary battery has been described as an example. However, the present invention is not limited to this, and the spiral shape obtained by winding the positive and negative electrodes through a separator. It is obvious that the method can be applied to all the manufacturing methods of the battery made of the electrode plates.

本発明にかかる電池の製造方法は、渦捲状に捲回した極板群を捲芯からスムーズに抜き取ることができ、極板群がタケノコ状に型崩れすることなく、セパレータのズレや損傷による正・負極板間の短絡を抑制できる効果が得られ、小型、高容量の電池の製造に有用である。例えば、リチウムイオン二次電池やニカド電池、ニッケル水素電池、アルカリ乾電池などの製造に適している。   According to the battery manufacturing method of the present invention, the electrode plate group wound in a vortex shape can be smoothly extracted from the core, and the electrode plate group does not lose its shape like a bamboo shoot. The effect that the short circuit between the positive and negative electrode plates can be suppressed is obtained, and it is useful for the manufacture of a small and high capacity battery. For example, it is suitable for the production of lithium ion secondary batteries, nickel-cadmium batteries, nickel metal hydride batteries, alkaline batteries, and the like.

本発明の角型リチウムイオン二次電池の一実施例を示した一部切欠斜視図1 is a partially cutaway perspective view showing an embodiment of a prismatic lithium ion secondary battery of the present invention. 本発明の実施例に用いた角型リチウムイオン二次電池の極板群の捲き始めの構成を示した模式図The schematic diagram which showed the structure of the start of the electrode group of the square lithium ion secondary battery used for the Example of this invention 本発明の実施例に用いた角型リチウムイオン二次電池の極板群の捲き始めの他の構成を示した模式図The schematic diagram which showed the other structure of the start of the electrode group of the square lithium ion secondary battery used for the Example of this invention.

符号の説明Explanation of symbols

１ 極板群
２ 正極リード
３ 負極リード
４ 有底ケース
５ 封口板
６ 負極端子
７ 注入口
８ 捲芯
９ 捲き始めのセパレータ部分
１０ スポットクーラーの吹き出し口

DESCRIPTION OF SYMBOLS 1 Electrode plate group 2 Positive electrode lead 3 Negative electrode lead 4 Case with bottom 5 Sealing plate 6 Negative electrode terminal 7 Inlet 8 Core 9 Separator part which starts rolling 10 Spot cooler outlet

Claims (4)

帯状の正極板と負極板とをセパレータを介して捲芯を用いて渦捲状に捲回してなる極板群と電解液を有底ケースに収納し、この有底ケースの開口部を封口板により密閉する電池の製造方法であって、
前記捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を、少なくとも極板群を捲芯から抜き取るときに１０℃以下に冷却することを特徴とした電池の製造方法。 An electrode plate group formed by winding a strip-shaped positive electrode plate and a negative electrode plate in a spiral shape using a core through a separator and an electrolyte solution are stored in a bottomed case, and the opening of the bottomed case is sealed with a sealing plate A method of manufacturing a battery sealed by
A battery manufacturing method comprising cooling the core and the separator portion at the beginning of winding of the electrode group held between the cores to 10 ° C. or lower when removing at least the electrode group from the core. 前記捲芯および捲芯により挟持される極板群の捲き始めのセパレータ部分を、極板群を捲き取るときは常温であり、極板群を捲芯から抜き取るときに１０℃以下に冷却することを特徴とした請求項１に記載の電池の製造方法。   The core part and the separator part at the beginning of the electrode group held between the cores are at room temperature when the electrode group is scraped off and cooled to 10 ° C. or lower when the electrode group is removed from the core. The battery manufacturing method according to claim 1, wherein: 前記捲芯にスポットクーラーの冷風を吹き付けることを特徴とした請求項１〜２いずれかに記載の電池の製造方法。   The battery manufacturing method according to claim 1, wherein cold air of a spot cooler is blown onto the core. 前記捲き始めのセパレータ部分にスポットクーラーの冷風を吹き付けることを特徴とした請求項１〜２いずれかに記載の電池の製造方法。

The battery manufacturing method according to claim 1, wherein a cool air of a spot cooler is blown onto the separator portion at the beginning of firing.

Images