JP2004193402A - Solid electrolytic capacitor - Google Patents
Solid electrolytic capacitor Download PDFInfo
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- JP2004193402A JP2004193402A JP2002360695A JP2002360695A JP2004193402A JP 2004193402 A JP2004193402 A JP 2004193402A JP 2002360695 A JP2002360695 A JP 2002360695A JP 2002360695 A JP2002360695 A JP 2002360695A JP 2004193402 A JP2004193402 A JP 2004193402A
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- separator
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- electrolytic capacitor
- thermal decomposition
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- 238000004804 winding Methods 0.000 claims abstract description 23
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Images
Abstract
Description
【0001】
【発明の属する技術分野】
本発明は、固体電解コンデンサに関し、特に、陽極電極箔と陰極電極箔とをセパレータを介して巻き取ることにより巻回素子を作製し、該巻回素子内に固体電解質層を形成してなる固体電解コンデンサに関する。
【0002】
【従来の技術】
【0003】
【特許文献1】特開平2−15611号公報
【0004】
【特許文献2】特開平10−340829号公報
電解コンデンサは、表面に微細孔やエッチングピットを有するタンタル、アルミニウム等の弁作用金属からなる陽極電極の該表面に、誘電体となる酸化皮膜層を形成し、この酸化皮膜層から電極を引き出した構成からなる。そして、酸化皮膜層からの電極の引出しは、導電性を有する電解質層により行われる。したがって、電解コンデンサにおいては電解質層が真の陰極を担うことになる。このような真の陰極として機能する電解質層に対しては、酸化皮膜層との密着性、緻密性、均一性などが求められる。特に、陽極電極の微細孔やエッチングピットの内部における電解質との密着性が電気的な特性に大きな影響を及ぼしており、従来から数々の電解質層が提案されている。
【0005】
ところで、近年、電子機器のデジタル化、高周波化に伴い、小型大容量で高周波領域でのインピーダンスの低いコンデンサが要求されている。これらの要求に対して、陰極箔と陽極箔をセパレータを介して巻回してなる巻回素子を金属ケースに収納し、封口ゴムによって封止する巻回型の電解コンデンサが開発され、それによって、電解コンデンサを小型大容量化することが可能となった。そして、低インピーダンスの要求に対しては、電解質として固体電解質を用いることで対応することができ、このような固体電解質としては、二酸化マンガンや7、7、8、8−テトラシアノキノジメタン(TCNQ)錯体が知られている。しかしながら、これらの固体電解質は導電性が低く、これを用いた電解コンデンサはインピーダンス特性が十分であるとはいえない。
【0006】
そこで、この問題に対処すべく、ポリピロール、ポリチオフエン等の高導電性を有する導電性高分子を固体電解質として用いることが提案された。そして、最近、重合反応速度が緩やかで且つ陽極電極の酸化皮膜層との密着性に優れたポリエチレンジオキシチオフェン(PEDT)が固体電解質として着目されし(
【特許文献1】)、陽極電極箔と陰極電極箔とをセパレータを介して巻回してなる巻回素子に、エチレンジオキシチオフェン(EDT)モノマーと酸化剤とを含浸し、その後緩やかに起きるモノマーと酸化剤との化学重合反応を利用して固体電解質であるポリエチレンジオキシチオフェンを巻回素子内部で生成させることによ
り固体電解コンデンサを作製する方法が提案されている(
【特許文献2】)。
【0007】
ところが、上記提案の方法に従って巻回素子内に固体電解質層を形成せしめた固体電解コンデンサにおいては、導電性高分子を陰極材として用いることによるESR(等価直列抵抗)の低減効果が期待どおりに得られないことがある。
【0008】
【発明が解決しようとする課題】
本発明の目的は、陽極電極箔と陰極電極箔とをセパレータを介して巻き取ることにより巻回素子を作製し、該巻回素子内に固体電解質層を形成してなる固体電解コンデンサにける上記の如き問題点を解決することである。
【0009】
【課題を解決するための手段】
本発明者らは、上記の目的を達成すべく鋭意検討を重ねた結果、今回、陽極電極箔と陰極電極箔とをセパレータを介して巻回してなる巻回素子において、セパレータとして熱分解温度が異なる少なくとも2種の構成成分からなるものを使用し、且つ固体電解質層の形成に先立ち、巻回素子をセパレータの熱分解処理に付して該セパレータを減量すると、高度な固体電解質層保存量を有する固体電解コンデンサが得られることを見出し、本発明を完成するに至った。
【0010】
かくして、本発明は、陽極電極箔と陰極電極箔とをセパレータを介して巻き取ることにより巻回素子を作製し、該巻回素子内に固体電解質層を形成してなる固体電解コンデンサであって、セパレータとして熱分解温度が異なる少なくとも2種の構成成分からなるものを使用し、且つ該固体電解質層を形成する前に、該巻回素子を、セパレータの構成成分のうちの低熱分解温度成分の熱分解温度以上の温度に加熱して低熱分解温度成分の少なくとも一部を分解除去し、セパレータを減量してなることを特徴とする固体電解コンデンサを提供するものである。
【0011】
以下、本発明の固体電解コンデンサについてさらに詳細に説明する。
【0012】
【発明の実施の形態】
本発明の固体電解コンデンサは、基本的には、図1に示すように、陽極電極箔(1)と、陰極電極箔(2)とを、セパレータ(3)を介して巻回することにより巻回素子(6)を形成し、そして、この巻回素子(6)のセパレータ(3)に固体電解質を保持させてなるものである。陽極電極箔(1)は、アルミニウム、タンタル等の弁作用金属からなり、陽極電極箔(1)の表面には、通常、予めエッチング処理が施され表面積が拡大され、さらに、化成処理により、例えば、ホウ酸アンモニウム等の水溶液中で電圧を印加することにより、誘電体である酸化皮膜層が形成される。他方、陰極電極箔(2)は陽極電極箔(1)と同様にアルミニウム等の金属からなり、その表面には、通常、エッチング処理が施される。
【0013】
陽極電極箔(1)及び陰極電極箔(2)にはそれぞれの電極を外部に接続するための陽極引出し手段(4)及び陰極引出し手段(5)が、ステッチ、超音波溶接等の公知の手段により接続されている。これらの電極引出し手段(4)、(5)は、巻回素子(6)の端面から導出される。
【0014】
巻回素子(6)は、一般に、陽極電極箔(1)と陰極電極箔(2)とを、セパレータ(3)を間に挟むようにして巻き取ることにより形成される。両極電極箔(1)、(2)の寸法には、特に制限はなく、目的とする固体電解コンデンサの仕様等に応じて決定され、したがってセパレータ(3)の寸法も両極電極箔(1)、(2)の寸法に応じてこれよりやや大きい幅寸法に設定される。
【0015】
セパレータ(3)としては、相対的に熱分解温度が異なる少なくとも2種の構成成分からなるものが使用される。低熱分解温度成分としては、一般に、200〜500℃、特に250〜350℃の範囲内の温度で分解するものが好適であり、また、高熱分解温度成分としては、一般に、上記低熱分解温度成分よりも少なくとも10℃、特に50℃以上高い熱分解温度を有しているものが好適である。
【0016】
ここで「熱分解温度」とは、或る物質に熱を加えたときに、その物質が分解して質量の小さいものに変化する最低の温度であり、通常はTGA(熱重量分析装置)を使用し、一定の昇温速度で物質を加熱したときに、物質の質量の減少が開始する温度として測定される。
【0017】
かくして、本発明におけるセパレータを構成成分のうち、高熱分解温度成分としては、例えば、アラミド、ポリエステル、ポリフェニレンサルファイド、フッ素系樹脂、PBI(ポリベンゾイミダゾール)、PBO(ポリパラフェニレンベンゾビスオキサゾール)、ポリイミド、ガラス、ポリアクリロニトリル、酸化ポリアクリロニトリル、カーボンまたはその前駆体、アルミナなどが挙げられ、他方、低熱分解温度成分としては、例えば、セルロース、デンプン、ポリエチレン、ポリプロピレン、エポキシ、ナイロン、ポリビニルアルコール、アラミド、ポリエステル、ポリフェニレンサルファイド、フッ素系樹脂、PBI(ポリベンゾイミダゾール)、PBO(ポリパラフェニレンベンゾビスオキサゾール)、ポリイミドなどが挙げられ、これら各群の中から、上記の熱分解温度差条件を満たすものを選択し組み合わせて使用することができる。中でも、特に、アラミド繊維と木材パルプ(セルロース)とから湿式抄造法によって形成されたシートが好適である。
【0018】
高熱分解温度成分と低熱分解温度成分との構成割合は、厳密に制限されるものではなく、各成分の種類や巻回素子に望まれるセパレータの空隙率などに応じて変えることができるが、一般には、高熱分解温度成分/低熱分解温度成分の重量比は1/99〜99/1、特に10/90〜90/10の範囲内とすることができる。
【0019】
巻回素子(6)内に固体電解質層を形成することにより固体電解コンデンサが得られる。固体電解質としては、例えば、ポリチオフェン、ポリピロール、ポリアニリン、7,7,8,8−テトラシアノジメタン錯体及びそれらの誘導体などが挙げられるが、特に、ポリエチレンジオキシチオフェン(PEDT)を用いると、大容量、低ESR特性を有する固体電解コンデンサを得ることができるので好適である。このPEDTは、モノマーである3,4−エチレンジオキシチオフェン(EDT)を酸化剤であるp−トルエンスルホン酸第二鉄と反応させて重合させることにより得ることができる。固体電解質層の形成は、EDTまたはEDT溶液と酸化剤溶液(例えばブタノール溶液)をそれぞれ巻回素子に注入し、例えば約150℃で1時間程度加熱してEDTを重合させることにより行うことができ、或いは予め調製されたEDTと酸化剤の混合液を巻回素子に注入するかまたは該混合液に巻回素子を浸漬して含浸させ、例えば約150℃で1時間程度加熱することにより行うことができる。
【0020】
固体電解質層を形成せしめた巻回素子は、次いで、有底筒状の金属ケースに収納し、封口ゴム(例えば、イソブチレンとイソプレンとの共重合体からなるブチルゴムポリマーに加硫剤としてアルキルフェノール樹脂を添加したゴム)で加締め封止することにより固体電解コンデンサが形成される。これにより、例えば、定格が4WV−330μFの固体電解コンデンサを得ることができる。
【0021】
本発明においては、巻回素子に前記固体電解質層を形成するに先立ち、巻回素子を、セパレータの構成成分のうちの低熱分解温度成分の熱分解温度以上の温度に加熱して低熱分解温度成分の少なくとも一部を分解除去し、セパレータを減量する。この加熱分解処理は、減量後のセパレータ部分の空隙率が85%以上、特に、85〜95%の範囲内になるようにして行うのが好適である。減量後のセパレータ部分の空隙率は以下の式(1)または式(2)のいずれかより計算される値であって、本発明では、式(1)または式(2)の少なくともいずれか一方で算出される空隙率が85%以上であればよい。
[空隙率](%)= C/(C+D)×100・・・・式(2)
ここで
C=[巻回素子内の固体電解質の質量](g)/[固体電解質の密度](g/cm3)
D=[減量後のセパレータの質量](g)/A
加熱分解処理は、巻回素子を、該巻回素子中のセパレータの構成成分のうちの低熱分解温度成分の熱分解温度以上の温度、通常は該熱分解温度より少なくとも10℃高い温度で且つ高熱分解温度成分の熱分解温度より少なくとも20℃低い温度で、数分間ないし数時間加熱することによって、セパレータの構成成分のうちの低熱分解温度成分を部分的に又は実質的に完全に分解除去することにより行うことができる。加熱処理時の周囲の雰囲気は、低熱分解温度成分の熱分解が速やかに進行する限り、特に制限はなく、気体中、真空中、液体中のいずれであってもよいが、一般には、加熱分解処理は空気中で行うのが好ましい。
【0022】
巻回素子の加熱分解処理の好適条件は、例えば、巻回素子に使用されていると同じセパレータの試験片を用いた小規模実験により試行錯誤的に決定することができ、それによって、該試験片の空隙率が85%以上となるのに必要な温度及び時間条件を容易に決定することができる。
【0023】
かくして、本発明によれば、多量の固体電解質を安定に含有保持した、ESRの低減効果などの電気的特性に優れた固体電解コンデンサを提供することができる。
【0024】
【実施例】
次に実施例により本発明をさらに具体的に説明する。
実施例1
m−アラミド繊維(デュポン社製「ノーメックス」(登録商標)を6mmに切断したもの)とセルロース(木材パルプを叩解機で処理してカナダ標準濾水度を300mlに調節したもの)を湿式抄造法にてシート状に成形し紙を作製し、実施例用のセパレータとした。また、m−アラミド繊維(デュポン社製「ノーメックス」(登録商標)を6mmに切断したもの)とアラミドファイブリッド(特公昭52−151624号公報に記載のステーターとローターの組み合わせで構成される湿式沈殿機を用いる方法によって製造されたものを叩解機で処理してカナダ標準濾水度を105mlに調節したもの)を湿式抄造法にてシート状に成形しアラミド紙を作製し、比較例用のセパレータとした。
【0025】
表面に予めエッチング処理が施され且つ化成処理が施され表面に酸化アルミニウムからなる酸化皮膜層が形成されたアルミニウム箔からなる陽極電極箔と、アルミニウム箔からなる陰極電極箔を、上記で作製したセパレータを介して巻回し、2種の巻回素子を作製した。
【0026】
これら2種の巻回素子を恒温加熱炉に入れて、350℃で2時間加熱した。
【0027】
これらの巻回素子の質量の減少分からセパレータの密度、空隙率を計算した。その結果を下記表1に示す。なお、アラミドの素材密度は1.35g/cm3、セルロースの素材密度は1.55g/cm3して計算した。
【0028】
【表1】
【0029】
次いで、実施例1及び比較例1のそれぞれの巻回素子をエチレンジオキシチオフェン及びp−トルエンスルホン酸第二鉄のブタノール溶液中に浸漬し巻回素子内に該溶液を十分に含浸させた後、巻回素子を該溶液から取り出し、150℃で1時間加熱してエチレンジオキシチオフェンを重合させ、巻回素子内にポリエチレンジオキシチオフェンの固体電解質を形成した。その結果、実施例1の巻回素子は、比較例1の巻回素子に比べて、空隙率の増加に応じて、固体電解質の保存率が増加していることが確認された。
【図面の簡単な説明】
【図1】本発明で用いる巻回素子の分解斜視図である。
【符号の説明】
1 陽極電極箔
2 陰極電極箔
3 セパレータ
4 陽極引出し手段
5 陰極引出し手段
6 巻回素子[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solid electrolytic capacitor, in particular, a solid formed by winding a positive electrode foil and a negative electrode foil through a separator to produce a wound element, and forming a solid electrolyte layer in the wound element It relates to an electrolytic capacitor.
[0002]
[Prior art]
[0003]
[Patent Document 1] JP-A-2-15611
[Patent Document 2] Japanese Patent Application Laid-Open No. H10-340829 discloses an electrolytic capacitor in which an oxide film layer serving as a dielectric is formed on the surface of an anode electrode made of a valve metal such as tantalum or aluminum having fine holes or etching pits on the surface. And an electrode drawn out of the oxide film layer. The extraction of the electrode from the oxide film layer is performed by a conductive electrolyte layer. Therefore, in an electrolytic capacitor, the electrolyte layer serves as a true cathode. Such an electrolyte layer functioning as a true cathode is required to have adhesion, denseness, uniformity, and the like with an oxide film layer. In particular, the adhesiveness with the electrolyte inside the fine pores of the anode electrode and the inside of the etching pit has a great effect on the electrical characteristics, and a number of electrolyte layers have been proposed.
[0005]
By the way, in recent years, with the digitization and higher frequency of electronic devices, a capacitor having a small size, a large capacity, and a low impedance in a high frequency region has been required. In response to these demands, a wound type electrolytic capacitor in which a wound element formed by winding a cathode foil and an anode foil through a separator is housed in a metal case and sealed with a sealing rubber has been developed. This has made it possible to reduce the size and capacity of electrolytic capacitors. The demand for low impedance can be met by using a solid electrolyte as the electrolyte. As such a solid electrolyte, manganese dioxide, 7, 7, 8, 8-tetracyanoquinodimethane ( TCNQ) complexes are known. However, these solid electrolytes have low conductivity, and an electrolytic capacitor using such a solid electrolyte cannot be said to have sufficient impedance characteristics.
[0006]
In order to address this problem, it has been proposed to use a conductive polymer having high conductivity such as polypyrrole or polythiophene as a solid electrolyte. Recently, polyethylene dioxythiophene (PEDT), which has a slow polymerization reaction rate and excellent adhesion to the oxide film layer of the anode electrode, has been attracting attention as a solid electrolyte (
[Patent Document 1]) A wound element formed by winding an anode electrode foil and a cathode electrode foil via a separator is impregnated with an ethylenedioxythiophene (EDT) monomer and an oxidizing agent, and thereafter a monomer that gradually occurs There has been proposed a method for producing a solid electrolytic capacitor by generating polyethylene dioxythiophene, which is a solid electrolyte, inside a wound element by utilizing a chemical polymerization reaction of phenol and an oxidant (
[Patent Document 2]).
[0007]
However, in a solid electrolytic capacitor in which a solid electrolyte layer is formed in a wound element according to the method proposed above, the effect of reducing ESR (equivalent series resistance) by using a conductive polymer as a cathode material is obtained as expected. May not be possible.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to produce a wound element by winding an anode electrode foil and a cathode electrode foil through a separator, and to provide a solid electrolytic capacitor having a solid electrolyte layer formed in the wound element. It is to solve the problems as described above.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result, this time, in a wound element formed by winding an anode electrode foil and a cathode electrode foil via a separator, the thermal decomposition temperature as a separator is Using a material composed of at least two different components and subjecting the wound element to thermal decomposition treatment of the separator prior to formation of the solid electrolyte layer to reduce the amount of the separator, a high solid electrolyte layer storage amount can be obtained. It has been found that a solid electrolytic capacitor can be obtained, and the present invention has been completed.
[0010]
Thus, the present invention is a solid electrolytic capacitor in which a wound element is produced by winding an anode electrode foil and a cathode electrode foil through a separator, and a solid electrolyte layer is formed in the wound element. A separator composed of at least two types of components having different thermal decomposition temperatures is used as a separator, and before forming the solid electrolyte layer, the wound element is formed of a low thermal decomposition temperature component among the components of the separator. An object of the present invention is to provide a solid electrolytic capacitor characterized in that at least a part of a low pyrolysis temperature component is decomposed and removed by heating to a temperature equal to or higher than a pyrolysis temperature to reduce the number of separators.
[0011]
Hereinafter, the solid electrolytic capacitor of the present invention will be described in more detail.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The solid electrolytic capacitor of the present invention is basically formed by winding an anode electrode foil (1) and a cathode electrode foil (2) through a separator (3) as shown in FIG. The winding element (6) is formed, and the solid electrolyte is held by the separator (3) of the winding element (6). The anode electrode foil (1) is made of a valve metal such as aluminum or tantalum, and the surface of the anode electrode foil (1) is usually subjected to an etching treatment in advance to increase the surface area. By applying a voltage in an aqueous solution of ammonium borate or the like, an oxide film layer as a dielectric is formed. On the other hand, the cathode electrode foil (2) is made of a metal such as aluminum similarly to the anode electrode foil (1), and the surface thereof is usually subjected to an etching treatment.
[0013]
Anode extraction means (4) and cathode extraction means (5) for connecting the respective electrodes to the outside are provided on the anode electrode foil (1) and the cathode electrode foil (2) by known means such as stitching and ultrasonic welding. Connected by These electrode lead-out means (4) and (5) are led out from the end face of the winding element (6).
[0014]
The winding element (6) is generally formed by winding an anode electrode foil (1) and a cathode electrode foil (2) with a separator (3) interposed therebetween. The dimensions of the bipolar electrode foils (1) and (2) are not particularly limited, and are determined according to the specifications of the intended solid electrolytic capacitor. Therefore, the dimensions of the separator (3) are also determined. The width is set to a slightly larger width in accordance with the size of (2).
[0015]
As the separator (3), a separator composed of at least two types of components having relatively different thermal decomposition temperatures is used. As the low thermal decomposition temperature component, generally, those that decompose at a temperature in the range of 200 to 500 ° C, particularly 250 to 350 ° C, are preferable, and the high thermal decomposition temperature component is generally higher than the low thermal decomposition temperature component. Also, those having a high thermal decomposition temperature of at least 10 ° C, especially at least 50 ° C are suitable.
[0016]
Here, the “pyrolysis temperature” is the lowest temperature at which a substance decomposes and changes into a substance having a small mass when heat is applied to the substance. Usually, TGA (thermogravimetric analyzer) is used. Used to measure the temperature at which the mass of a substance begins to decrease when the substance is heated at a constant heating rate.
[0017]
Thus, among the constituent components of the separator of the present invention, examples of the high thermal decomposition temperature component include aramid, polyester, polyphenylene sulfide, fluororesin, PBI (polybenzimidazole), PBO (polyparaphenylenebenzobisoxazole), and polyimide , Glass, polyacrylonitrile, oxidized polyacrylonitrile, carbon or its precursor, alumina and the like, on the other hand, as the low thermal decomposition temperature component, for example, cellulose, starch, polyethylene, polypropylene, epoxy, nylon, polyvinyl alcohol, aramid, Polyester, polyphenylene sulfide, fluororesin, PBI (polybenzimidazole), PBO (polyparaphenylenebenzobisoxazole), polyimide, etc. From among each of these groups, it can be used in combination with selecting the thermal decomposition temperature difference condition is satisfied. Among them, a sheet formed from aramid fiber and wood pulp (cellulose) by a wet papermaking method is particularly preferable.
[0018]
The composition ratio of the high thermal decomposition temperature component and the low thermal decomposition temperature component is not strictly limited, and can be changed according to the type of each component and the porosity of the separator desired for the wound element, but generally, The weight ratio of the high thermal decomposition temperature component to the low thermal decomposition temperature component can be in the range of 1/99 to 99/1, especially 10/90 to 90/10.
[0019]
By forming a solid electrolyte layer in the winding element (6), a solid electrolytic capacitor is obtained. Examples of the solid electrolyte include polythiophene, polypyrrole, polyaniline, 7,7,8,8-tetracyanodimethane complex and derivatives thereof. Particularly, when polyethylenedioxythiophene (PEDT) is used, This is preferable because a solid electrolytic capacitor having a capacity and low ESR characteristics can be obtained. This PEDT can be obtained by reacting 3,4-ethylenedioxythiophene (EDT), which is a monomer, with ferric p-toluenesulfonate, which is an oxidizing agent, and polymerizing it. The solid electrolyte layer can be formed by injecting EDT or an EDT solution and an oxidizing agent solution (for example, a butanol solution) into the wound element and polymerizing the EDT by heating at about 150 ° C. for about 1 hour, for example. Alternatively, by injecting a previously prepared mixture of EDT and an oxidizing agent into the wound element, or by immersing the wound element in the mixed solution and impregnating the same, for example, by heating at about 150 ° C. for about 1 hour. Can be.
[0020]
The wound element having the solid electrolyte layer formed thereon is then housed in a bottomed cylindrical metal case, and a sealing rubber (for example, an alkylphenol resin as a vulcanizing agent is added to a butyl rubber polymer made of a copolymer of isobutylene and isoprene). The solid electrolytic capacitor is formed by caulking and sealing with added rubber. Thereby, for example, a solid electrolytic capacitor having a rating of 4 WV-330 μF can be obtained.
[0021]
In the present invention, prior to forming the solid electrolyte layer on the wound element, the wound element is heated to a temperature equal to or higher than the thermal decomposition temperature of the low thermal decomposition temperature component among the constituent components of the separator, and the low thermal decomposition temperature component is heated. Is decomposed and removed, and the separator is reduced in weight. This thermal decomposition treatment is preferably carried out so that the porosity of the separator portion after the weight reduction is at least 85%, particularly within the range of 85 to 95%. The porosity of the separator portion after the weight loss is a value calculated from any of the following formulas (1) and (2), and in the present invention, at least one of the formulas (1) and (2) It is sufficient that the porosity calculated by is not less than 85%.
[Porosity] (%) = C / (C + D) × 100 Formula (2)
Here, C = [mass of solid electrolyte in wound element] (g) / [density of solid electrolyte] (g / cm 3 )
D = [mass of separator after weight loss] (g) / A
The thermal decomposition treatment is performed by heating the wound element at a temperature higher than the thermal decomposition temperature of the low thermal decomposition temperature component of the components of the separator in the wound element, usually at a temperature at least 10 ° C. higher than the thermal decomposition temperature and at a high heat. By partially or substantially completely decomposing and removing the low pyrolysis temperature component among the components of the separator by heating at a temperature at least 20 ° C. lower than the pyrolysis temperature of the decomposition temperature component for several minutes to several hours. Can be performed. The surrounding atmosphere during the heat treatment is not particularly limited as long as the thermal decomposition of the low thermal decomposition temperature component proceeds promptly, and may be any of a gas, a vacuum, and a liquid. The treatment is preferably performed in air.
[0022]
Suitable conditions for the thermal decomposition treatment of the wound element can be determined by trial and error, for example, by a small-scale experiment using a test piece of the same separator as that used for the wound element. The temperature and time conditions necessary for the porosity of the piece to be 85% or more can be easily determined.
[0023]
Thus, according to the present invention, it is possible to provide a solid electrolytic capacitor stably containing a large amount of solid electrolyte and having excellent electrical characteristics such as an ESR reduction effect.
[0024]
【Example】
Next, the present invention will be described more specifically with reference to examples.
Example 1
m-aramid fiber (DuPont "Nomex" (registered trademark) cut to 6 mm) and cellulose (wood pulp treated with a beater to adjust Canadian standard freeness to 300 ml) by wet papermaking Was formed into a sheet to prepare paper, which was used as a separator for Examples. In addition, m-aramid fiber (a product obtained by cutting “Nomex” (registered trademark) manufactured by DuPont into 6 mm) and aramid fibrid (wet precipitation comprising a combination of a stator and a rotor described in Japanese Patent Publication No. 52-151624). Produced by the method using a disintegrator and processed with a beater to adjust Canadian standard freeness to 105 ml) into a sheet by wet papermaking to produce aramid paper, and a separator for a comparative example. And
[0025]
An anode electrode foil made of an aluminum foil having a surface previously subjected to an etching treatment and a chemical conversion treatment and an oxide film layer made of aluminum oxide formed on the surface, and a cathode electrode foil made of an aluminum foil, the separator prepared above. To form two types of wound elements.
[0026]
These two types of wound elements were placed in a constant temperature heating furnace and heated at 350 ° C. for 2 hours.
[0027]
The density and porosity of the separator were calculated from the decrease in the mass of these wound elements. The results are shown in Table 1 below. The calculation was performed with the material density of aramid being 1.35 g / cm 3 and the material density of cellulose being 1.55 g / cm 3 .
[0028]
[Table 1]
[0029]
Next, the wound elements of Example 1 and Comparative Example 1 were immersed in a butanol solution of ethylenedioxythiophene and ferric p-toluenesulfonate to sufficiently impregnate the wound elements with the solution. The wound element was taken out of the solution and heated at 150 ° C. for 1 hour to polymerize ethylenedioxythiophene, thereby forming a solid electrolyte of polyethylenedioxythiophene in the wound element. As a result, it was confirmed that the wound element of Example 1 had a higher storage rate of the solid electrolyte in accordance with the increase in the porosity than the wound element of Comparative Example 1.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a winding element used in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Anode electrode foil 2 Cathode electrode foil 3 Separator 4 Anode extraction means 5 Cathode extraction means 6 Winding element
Claims (5)
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JP2002360695A JP3975161B2 (en) | 2002-12-12 | 2002-12-12 | Solid electrolytic capacitor |
CNB2003801056733A CN100538942C (en) | 2002-12-12 | 2003-12-05 | Solid electrolytic capacitor |
PCT/JP2003/015597 WO2004053903A1 (en) | 2002-12-12 | 2003-12-05 | Solid electrolytic capacitor |
AU2003289294A AU2003289294A1 (en) | 2002-12-12 | 2003-12-05 | Solid electrolytic capacitor |
TW92134878A TWI235392B (en) | 2002-12-12 | 2003-12-10 | Solid-state electrolytic capacitor |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2008159941A (en) * | 2006-12-25 | 2008-07-10 | Nichicon Corp | Method for manufacturing solid electrolytic capacitor |
KR100965043B1 (en) * | 2007-03-19 | 2010-06-21 | 니치콘 가부시키가이샤 | Method of manufacturing solid electrolytic capacitor |
JPWO2008139619A1 (en) * | 2007-05-14 | 2010-07-29 | 旭化成せんい株式会社 | Power storage device separator and power storage device |
JP4726794B2 (en) * | 2004-08-25 | 2011-07-20 | 三洋電機株式会社 | Solid electrolytic capacitor |
WO2024062720A1 (en) * | 2022-09-22 | 2024-03-28 | エルナー株式会社 | Electrolytic capacitor and method for manufacturing same |
Families Citing this family (2)
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CN104900404A (en) * | 2015-03-22 | 2015-09-09 | 深圳江浩电子有限公司 | Low-impedance electrolytic capacitor core cladding and manufacturing method thereof |
CN110993353A (en) * | 2020-01-06 | 2020-04-10 | 深圳市兴创嘉技术有限公司 | Winding method of electrolytic capacitor core cladding |
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2002
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Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
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JP4726794B2 (en) * | 2004-08-25 | 2011-07-20 | 三洋電機株式会社 | Solid electrolytic capacitor |
JP2008159941A (en) * | 2006-12-25 | 2008-07-10 | Nichicon Corp | Method for manufacturing solid electrolytic capacitor |
JP4486636B2 (en) * | 2006-12-25 | 2010-06-23 | ニチコン株式会社 | Manufacturing method of solid electrolytic capacitor |
KR100965043B1 (en) * | 2007-03-19 | 2010-06-21 | 니치콘 가부시키가이샤 | Method of manufacturing solid electrolytic capacitor |
US7948740B2 (en) | 2007-03-19 | 2011-05-24 | Nichicon Corporation | Solid electrolytic capacitor and method of manufacturing the same |
JPWO2008139619A1 (en) * | 2007-05-14 | 2010-07-29 | 旭化成せんい株式会社 | Power storage device separator and power storage device |
WO2024062720A1 (en) * | 2022-09-22 | 2024-03-28 | エルナー株式会社 | Electrolytic capacitor and method for manufacturing same |
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JP3975161B2 (en) | 2007-09-12 |
CN100538942C (en) | 2009-09-09 |
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LAPS | Cancellation because of no payment of annual fees |