JP2000007314A - Solid active carbon and electric double layer capacitor using the same - Google Patents
Solid active carbon and electric double layer capacitor using the sameInfo
- Publication number
- JP2000007314A JP2000007314A JP10175914A JP17591498A JP2000007314A JP 2000007314 A JP2000007314 A JP 2000007314A JP 10175914 A JP10175914 A JP 10175914A JP 17591498 A JP17591498 A JP 17591498A JP 2000007314 A JP2000007314 A JP 2000007314A
- Authority
- JP
- Japan
- Prior art keywords
- activated carbon
- electric double
- active carbon
- double layer
- layer capacitor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/13—Energy storage using capacitors
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、電気二重層コンデ
ンサやリチウムイオン電池をはじめとする小型大容量の
コンデンサや、バックアップ電源、車両用電源、補助電
源等の各種電池に用いられる電極材料、あるいはガス吸
着材や上水用、食品精製用、排水浄化用等の濾材に用い
られる多孔質の活性炭焼結体として一般に広く適用し得
る固形状活性炭及びそれを用いた電気二重層コンデンサ
に関するもので、とりわけ静電容量が大きく、エネルギ
ー密度が大きな電力用蓄電システムを実現可能とする固
形状活性炭及びそれを非水系電解液の分極性電極として
用いた電気二重層コンデンサに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode material used for various large-capacity capacitors such as electric double-layer capacitors and lithium ion batteries, backup power supplies, vehicle power supplies, auxiliary power supplies, and the like. For solid activated carbon that can be generally widely used as a porous activated carbon sintered body used as a filter medium for gas adsorbents, water purification, food purification, wastewater purification, and the like, and an electric double-layer capacitor using the same, In particular, the present invention relates to a solid activated carbon capable of realizing a power storage system having a large capacitance and a large energy density, and an electric double layer capacitor using the same as a polarizable electrode of a non-aqueous electrolyte.
【０００２】[0002]
【従来の技術】近年、活性炭はその特性に着目した各種
応用分野への適用が検討されているが、特に、小型大容
量のコンデンサや、各種電池の電極材料用の多孔性炭素
材として活性炭が取り上げられ、種々検討されている。2. Description of the Related Art In recent years, application of activated carbon to various application fields focusing on its characteristics has been studied. In particular, activated carbon has been used as a porous carbon material for electrode materials of small and large-capacity capacitors and various batteries. It has been taken up and variously studied.
【０００３】かかる活性炭等の炭素質を主体とする分極
性電極は、該分極性電極間に電解質を含有させ、両者の
界面で形成される電気二重層を利用した、従来のコンデ
ンサに比較して単位体積当たり数千倍にも及ぶ静電容量
を有する電気二重層コンデンサ用として多用され、かか
る電気二重層コンデンサはコンデンサと電池の両方の機
能を有することから、小型のメモリーバックアップ電源
や自動車の駆動源として搭載される大容量のモーター等
の補助電源に適用される等、エレクトロニクス分野の発
展と共に急速にその需要が伸びている。[0003] Such a polarizable electrode mainly composed of carbonaceous material such as activated carbon has an electrolyte contained between the polarizable electrodes, and is compared with a conventional capacitor using an electric double layer formed at the interface between the two. It is often used for electric double-layer capacitors with a capacitance several thousand times per unit volume. Such electric double-layer capacitors have the functions of both capacitors and batteries, so they can be used to drive small memory backup power supplies and automobiles. The demand is rapidly growing with the development of the electronics field, such as application to an auxiliary power supply such as a large-capacity motor mounted as a power source.
【０００４】当初、前記電極材料としては、一般に広く
適用される多孔質の固形状活性炭が用いられており、そ
のような固形状活性炭としては、例えば、活性炭やカー
ボンブラック等の炭素質と、含フッ素重合体等の有機樹
脂を混練してロール成形法等の公知の成形手段でシート
状に成形したもの等が用いられていた。[0004] Initially, porous solid activated carbon which is generally widely used is used as the electrode material. Examples of such solid activated carbon include carbonaceous materials such as activated carbon and carbon black. A sheet formed by kneading an organic resin such as a fluoropolymer and forming the sheet by a known forming means such as a roll forming method has been used.
【０００５】しかしながら、前述のようなコンデンサや
電池の電極材料としては、とりわけ高い静電容量と低い
内部抵抗という性能を満足し、かつ昨今の電子部品の小
型化の要求を満足するために、所定容量に対する体積の
極小化、及び電解液の含浸性を考慮した多孔体構造で亀
裂や破損等を起こし難いことと共に、一般の用途として
もより耐久性と機械的特性に優れたものであること等が
要求されるようになっていた。[0005] However, as the electrode material of the above-mentioned capacitor or battery, in order to satisfy the performance of particularly high capacitance and low internal resistance, and to satisfy the recent demand for miniaturization of electronic components, it is necessary to use a predetermined material. Minimizing the volume relative to the capacity, and having a porous structure that takes into account the impregnating properties of the electrolytic solution, so that cracks and breakage are unlikely to occur, as well as being superior in durability and mechanical properties for general use, etc. Was being requested.
【０００６】特に、電気二重層コンデンサの静電容量
は、電気二重層が形成される分極性電極の表面積や単位
体積当たりの静電容量、電極の抵抗等に支配されるが、
電気二重層を形成する電解液中のイオンの大きさと密接
な関係があり、微細孔の比表面積が静電容量を左右する
と考えられている。In particular, the capacitance of an electric double layer capacitor is governed by the surface area of the polarizable electrode on which the electric double layer is formed, the capacitance per unit volume, the resistance of the electrode, and the like.
There is a close relationship with the size of the ions in the electrolyte forming the electric double layer, and it is considered that the specific surface area of the micropores determines the capacitance.
【０００７】従って、電極単位体積当たりの静電容量を
増すために、耐久性や機械的強度を損なわない範囲で比
表面積を大きくした多孔質の活性炭であることが必要と
されていた。[0007] Therefore, in order to increase the capacitance per unit volume of the electrode, it has been required that the porous activated carbon has a large specific surface area without impairing the durability and mechanical strength.
【０００８】そこで、前記諸要求を満足するために、活
性炭微粒子やカーボン繊維等を混合して加圧焼結した
り、あるいは活性炭粉末と粉末状フェノール樹脂の混合
物を射出成形して熱処理したり、活性炭繊維にパルプ繊
維等を加えて抄造したり、活性炭粉末とセルロース繊維
等を主成分とするプリプレグシートを圧着、焼成した
り、又は活性炭粉末とフェノール樹脂の混合物を基板状
に成膜し、非酸化性雰囲気中で熱処理を行ったり、硬化
型球状フェノール樹脂を炭化して得た球状炭化物と熱反
応型球状フェノール樹脂との混合物を加熱硬化させ、不
活性雰囲気で熱処理した後、賦活処理する等、各種製造
方法による固形状活性炭が提案されている（特開平８−
１１９６１４号公報、特開平６−６９０７５号公報、特
開平５−１２９１５７号公報、特開平３−２０１５１６
号公報参照）。Therefore, in order to satisfy the above requirements, activated carbon fine particles and carbon fibers are mixed and sintered under pressure, or a mixture of activated carbon powder and powdery phenol resin is injection-molded and heat-treated. Pulp fiber or the like is added to the activated carbon fiber to form a paper, a prepreg sheet containing activated carbon powder and cellulose fiber as main components is pressed and calcined, or a mixture of activated carbon powder and a phenol resin is formed into a film on a substrate. Heat-treating in a oxidizing atmosphere, or heating and curing a mixture of a spherical carbide obtained by carbonizing a curable spherical phenolic resin and a heat-reactive spherical phenolic resin, heat-treating in an inert atmosphere, and then performing an activation treatment. In addition, solid activated carbon produced by various production methods has been proposed (Japanese Patent Application Laid-Open No. Hei 8-
JP-A-119614, JP-A-6-69075, JP-A-5-129157, JP-A-3-201516
Reference).
【０００９】[0009]
【発明が解決しようとする課題】しかしながら、前記固
形状活性炭は、とりわけ電気二重層コンデンサの分極性
電極として適用した場合、該電気二重層コンデンサの電
解質として用いられる非水系電解液は水系電解液より耐
電圧が高く、理論的には非水系電解液の方が数倍高いエ
ネルギー密度が得られると共に、小型化に有利ではある
ものの、非水系電解液を用いた電気二重層コンデンサは
内部抵抗が高くなることから、その静電容量を定電流放
電法で測定した場合、活性炭と各種有機樹脂との割合か
ら予測される静電容量より低くなり、例えば、３ｍＡ／
ｃｍ2 程度の低電流で放電すると２０Ｆ／ｇ未満の静電
容量しか得られず、高い静電容量が必要な電気二重層コ
ンデンサの分極性電極の材料としては適用できないとい
う課題があった。However, when the solid activated carbon is used as a polarizable electrode of an electric double layer capacitor, the non-aqueous electrolyte used as an electrolyte of the electric double layer capacitor is more than an aqueous electrolyte. Although non-aqueous electrolytes have a higher withstand voltage and can theoretically achieve several times higher energy density and are advantageous for miniaturization, electric double-layer capacitors using non-aqueous electrolytes have higher internal resistance. Therefore, when the capacitance is measured by the constant current discharge method, the capacitance is lower than the capacitance predicted from the ratio of activated carbon to various organic resins, for example, 3 mA /
When discharged at a low current of about 2 cm 2, only a capacitance of less than 20 F / g is obtained, and there is a problem that it cannot be applied as a material of a polarizable electrode of an electric double layer capacitor requiring a high capacitance.
【００１０】[0010]
【発明の目的】本発明は、前記課題を解消せんとして成
されたもので、その目的は、活性炭と各種有機樹脂との
割合から予測される静電容量を充分に引き出し、実用的
な高い静電容量を有し、機械的強度の大きい耐久性に優
れた各種用途に適用可能な固形状活性炭、とりわけ電気
二重層コンデンサや補助電源用各種電池の電極材料とし
て好適な固形状活性炭を得ることにある。SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems. The purpose of the present invention is to sufficiently extract the capacitance expected from the ratio between activated carbon and various organic resins to achieve a practically high static capacitance. To obtain solid activated carbon having electric capacity and high mechanical strength and being applicable to various applications with excellent durability, particularly solid activated carbon suitable as an electrode material for electric double layer capacitors and various batteries for auxiliary power supplies. is there.
【００１１】[0011]
【課題を解決するための手段】本発明者等は、前記課題
に対して鋭意研究の結果、耐久性や機械的強度を損なわ
ない範囲で比表面積を大きくした多孔質の各種活性炭材
料と炭化性樹脂から成る混合物を成形し、該成形体を非
酸化性雰囲気中で炭化一体化した後に大気中で更に賦活
処理し、固形状活性炭の細孔分布を制御することによ
り、特に電気二重層コンデンサの電解質に非水系電解液
を用いても低電流放電時の静電容量が高く、実用的な静
電容量を有すると共に、機械的強度と耐久性に優れた固
形状活性炭が得られることを見いだした。Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above-mentioned problems, and have found that various activated carbon materials having a large specific surface area as long as durability and mechanical strength are not impaired are obtained. By molding a mixture comprising a resin, carbonizing and unifying the molded body in a non-oxidizing atmosphere, further activating in the air, and controlling the pore distribution of the solid activated carbon, particularly for an electric double layer capacitor. It has been found that even when a non-aqueous electrolyte is used as the electrolyte, solid activated carbon with high capacitance at low current discharge, practical capacitance, and excellent mechanical strength and durability can be obtained. .
【００１２】即ち、本発明の固形状活性炭は、Ｈｏｒｖ
ａｔｈ−Ｋａｗａｚｏｅ法（以下、ＨＫ法と記す）によ
るアルゴン吸着等温線から求める細孔分布測定におい
て、１０Å以下の細孔径が占める細孔の容積の割合が
０．３５〜０．７０ｃｃ／ｇであり、かつかかる固形状
活性炭を分極性電極とし、電解質として非水系電解液を
用いて対向する電極間で３ｍＡ／ｃｍ2 の定電流放電法
で静電容量を測定した場合、該静電容量は、２０Ｆ／ｇ
以上を示すものであることを特徴とするものである。That is, the solid activated carbon of the present invention comprises Horv
In the pore distribution measurement determined from the argon adsorption isotherm by the ath-Kawazoe method (hereinafter referred to as the HK method), the ratio of the volume of the pores occupied by the pore diameter of 10 ° or less is 0.35 to 0.70 cc / g. When the solid activated carbon is used as a polarizable electrode, and a capacitance is measured by a constant current discharge method of 3 mA / cm 2 between opposing electrodes using a non-aqueous electrolyte as an electrolyte, 20F / g
It is characterized by the above.
【００１３】また、前記固形状活性炭は、該固形状活性
炭を分極性電極とする非水系電解液を用いた電気二重層
コンデンサに最適なものである。[0013] The solid activated carbon is most suitable for an electric double layer capacitor using a non-aqueous electrolytic solution using the solid activated carbon as a polarizable electrode.
【００１４】[0014]
【作用】本発明の固形状活性炭は、アルゴン吸着等温線
から求める細孔分布における１０Å以下の細孔径が占め
る容積の割合が０．３５〜０．７０ｃｃ／ｇで、かつか
かる固形状活性炭を分極性電極とした場合、非水系電解
液を用いて３ｍＡ／ｃｍ2 の定電流放電法で測定した静
電容量が２０Ｆ／ｇ以上であることから、非水系電解液
中の過塩素酸リチウムイオンあるいはトリエチルメチル
アンモニウムイオン等がトラップされる部分が多く、し
かも、前記細孔径が１０Åというのは、前記過塩素酸イ
オンあるいはトリエチルメチルアンモニウムイオン等の
イオンの大きさが約５Åであることから、効率よくトラ
ップするのに適度な大きさであり、高い静電容量を有す
ると考えられ、その結果、低電流放電時の静電容量が大
きい、機械的強度及び耐久性に優れた多目的の固形状活
性炭とすることができる。The solid activated carbon of the present invention has a volume ratio occupied by pore diameters of 10 ° or less in the pore distribution determined from the argon adsorption isotherm of 0.35 to 0.70 cc / g. When the polar electrode is used, since the capacitance measured by a constant current discharge method of 3 mA / cm 2 using a non-aqueous electrolyte is 20 F / g or more, lithium perchlorate ion in the non-aqueous electrolyte or There are many portions where triethylmethylammonium ions and the like are trapped, and the pore diameter is 10 ° because the size of the ions such as the perchlorate ion or the triethylmethylammonium ion is about 5 °, It is considered to be moderately sized to trap and has high capacitance, resulting in high capacitance during low current discharge, mechanical strength It can be an excellent multi-purpose solid activated carbon to a fine durability.
【００１５】一方、前記固形状活性炭を非水系電解液を
用いた電気二重層コンデンサの分極性電極とした場合、
活性炭の比率が大きくなり実用的な静電容量を有し、簡
単な構造で効率の良い、耐久性に優れた小型の電気二重
層コンデンサが得られる。On the other hand, when the solid activated carbon is used as a polarizable electrode of an electric double layer capacitor using a non-aqueous electrolyte,
The ratio of activated carbon is increased, and a small-capacity electric double-layer capacitor having practical capacitance, having a simple structure, being efficient, and having excellent durability can be obtained.
【００１６】[0016]
【発明の実施の形態】以下、本発明の固形状活性炭及び
それを用いた電気二重層コンデンサについて詳述する。
本発明の固形状活性炭は、活性炭粉末又は活性炭繊維、
あるいは活性炭粉末及び活性炭繊維と、バインダとして
添加される公知の炭化性樹脂とを熱処理した炭化物とか
ら成るものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS The solid activated carbon of the present invention and an electric double layer capacitor using the same will be described in detail below.
Solid activated carbon of the present invention, activated carbon powder or activated carbon fiber,
Alternatively, it is composed of activated carbon powder and activated carbon fiber and a carbide obtained by heat-treating a known carbonizable resin added as a binder.
【００１７】本発明において、アルゴン吸着等温線（Ｈ
Ｋ法）から求めた固形状活性炭の細孔分布における１０
Å以下の細孔径が占める容積の割合が０．３５ｃｃ／ｇ
未満の場合には、非水系電解液中の過塩素リチウムイオ
ンあるいはトリエチルメチルアンモニウムイオン等をト
ラップする部分が少なくなるため、電極表面と電解質と
の界面に形成される電気二重層が少なく成ることから、
静電容量が２０Ｆ／ｇ未満となり、高い静電容量が必要
となる電気二重層コンデンサの分極性電極の材料として
適用できなくなる。In the present invention, the argon adsorption isotherm (H
K in the pore distribution of solid activated carbon determined by the K method)
割 合 The ratio of the volume occupied by the pore diameters of 0.35 cc / g or less is
If the value is less than the above, the number of trapping portions of perchloric lithium ions or triethylmethylammonium ions in the non-aqueous electrolytic solution is reduced, so that the electric double layer formed at the interface between the electrode surface and the electrolyte is reduced. ,
The capacitance becomes less than 20 F / g, so that it cannot be applied as a material of a polarizable electrode of an electric double layer capacitor requiring a high capacitance.
【００１８】又、前記細孔容積の割合が、０．７０ｃｃ
／ｇを越えると、固形状活性炭中の細孔が多いために、
機械的強度が極端に悪くなり、ハンドリングができなく
なることから、０．３５〜０．７０ｃｃ／ｇに特定さ
れ、安定したハンドリングと３０Ｆ／ｇ以上の高い静電
容量を有し、他分野への広い適用を考慮すると０．４０
〜０．６０ｃｃ／ｇの範囲が特に望ましい。The ratio of the pore volume is 0.70 cc.
/ G, there are many pores in the solid activated carbon,
Since the mechanical strength becomes extremely poor and handling becomes impossible, it is specified to be 0.35 to 0.70 cc / g, has stable handling and a high capacitance of 30 F / g or more, and is suitable for other fields. 0.40 considering wide application
A range of .about.0.60 cc / g is particularly desirable.
【００１９】又、前記固形状活性炭を非水系電解液を用
いて３ｍＡ／ｃｍ2 の定電流放電法で静電容量を測定し
た場合、該静電容量が２０Ｆ／ｇ未満の場合には、固形
状活性炭の細孔容積が小さいために、限られた種類のガ
ス吸着剤等の用途に限定されてしまい、多目的の固形状
活性炭として適用できず、上水用や食品精製用、排水浄
化用に適用する場合には濾過効果が少なく、モジュール
が大型化してしまい、特に、電気二重層コンデンサの分
極性電極としては、小電力蓄電型のボタン型電気二重層
コンデンサ等に使用が限定されてしまい、エネルギー密
度が大きな電力用蓄電システムを実現することが不可能
となる。When the capacitance of the solid activated carbon is measured by a constant current discharge method of 3 mA / cm 2 using a non-aqueous electrolyte, if the capacitance is less than 20 F / g, Due to the small pore volume of activated carbon, it is limited to applications of a limited type of gas adsorbents and cannot be used as multipurpose solid activated carbon, and is used for water purification, food purification, and wastewater purification. When applied, the filtration effect is small, the module becomes large, and in particular, as the polarizable electrode of the electric double layer capacitor, the use is limited to a small power storage type button type electric double layer capacitor, etc. It becomes impossible to realize a power storage system with a large energy density.
【００２０】従って、本発明の固形状活性炭としては、
アルゴン吸着等温線（ＨＫ法）から求めた細孔分布にお
ける１０Å以下の細孔径の細孔容積は０．３５ｃｃ／ｇ
以上で、かつ分極性電極として非水系電解液を用いて３
ｍＡ／ｃｍ2 の低電流放電法で測定した静電容量が２０
Ｆ／ｇ以上であることが必要となる。Accordingly, the solid activated carbon of the present invention includes:
The pore volume with a pore diameter of 10 ° or less in the pore distribution determined from the argon adsorption isotherm (HK method) is 0.35 cc / g.
Above, and using a non-aqueous electrolyte as a polarizable electrode
The capacitance measured by a low current discharge method of mA / cm 2 is 20
It is necessary to be F / g or more.
【００２１】又、本発明の固形状活性炭において、原料
である前記活性炭粉末や活性炭繊維は特に限定するもの
ではなく、ヤシ殻系や石炭系、木質系等のいずれでも良
く、コストと吸着能力の点ではヤシ殻系が最も望まし
い。In the solid activated carbon of the present invention, the activated carbon powder and activated carbon fiber as raw materials are not particularly limited, and may be coconut shell type, coal type, wood type, etc. In terms of point, coconut shell system is most desirable.
【００２２】尚、前記原料の活性炭粉末は、目的とする
静電容量によってその比表面積を選択すれば良く、特に
電気二重層コンデンサ用の分極性電極に用いる場合に
は、静電容量の観点からは、その比表面積が１５００〜
２５００ｍ2 ／ｇであるものが好適であり、又、活性炭
繊維を用いる場合には、バインダとの混合性や表面の平
滑性からは繊維径が６〜１８μｍで、静電容量の観点か
らは、比表面積が１０００〜２５００ｍ2 ／ｇであるも
のが好適である。The specific surface area of the activated carbon powder as the raw material may be selected depending on the desired capacitance. In particular, when the activated carbon powder is used for a polarizable electrode for an electric double layer capacitor, it is preferable from the viewpoint of the capacitance. Has a specific surface area of 1500 to
2500 m 2 / g is preferable, and when activated carbon fiber is used, the fiber diameter is 6 to 18 μm from the viewpoint of mixing with a binder and smoothness of the surface, and from the viewpoint of capacitance, Those having a specific surface area of 1000 to 2500 m 2 / g are preferred.
【００２３】次に、バインダとして添加される炭化性樹
脂は、公知の有機性樹脂であればいずれでも適用でき、
特に限定するものではないが、例えば、フェノールやテ
フロン、コールタール、ポリビニルブチラール（ＰＶ
Ｂ）、ポリビニルホルマール（ＰＶＦＭ）等のポリビニ
ルアセタール、酢酸ビニル等が上げられ、とりわけ成形
性あるいは得られる固形状活性炭の強度の点からは、ポ
リビニルブチラール（ＰＶＢ）が好適である。Next, as the carbonizable resin added as a binder, any known organic resin can be used.
Although not particularly limited, for example, phenol, Teflon, coal tar, polyvinyl butyral (PV
B), polyvinyl acetal such as polyvinyl formal (PVFM), vinyl acetate, etc., and polyvinyl butyral (PVB) is particularly preferable from the viewpoint of moldability or strength of the obtained solid activated carbon.
【００２４】更に、得られた固形状活性炭の比表面積
は、前記原料の活性炭の比表面積によりその上限は決定
されるが、比表面積が５００ｍ2 ／ｇ未満では電解液と
電極との界面に生じる電気二重層が少なくなるため、静
電容量が小さくなって実用性に欠け、少なくとも前記比
表面積は、５００ｍ2 ／ｇ以上を有するように調整する
ことが肝要である。Further, the upper limit of the specific surface area of the obtained solid activated carbon is determined by the specific surface area of the activated carbon as the raw material. If the specific surface area is less than 500 m 2 / g, the specific surface area occurs at the interface between the electrolyte and the electrode. Since the number of the electric double layers is reduced, the capacitance is reduced and the practicability is lacking. It is important to adjust at least the specific surface area to be 500 m 2 / g or more.
【００２５】従って、かかる固形状活性炭であれば、非
水系電解液に浸漬しても固形状活性炭自体が非水系電解
液に侵されて強度劣化を生じることもなく、又、大きな
比表面積は、電解液と電極との界面に生じる電気二重層
が多く形成されることから、前記固形状活性炭を分極性
電極とし、電解質として非水系電解液を用いて電気二重
層コンデンサとした場合に最適なものが得られることに
なる。Therefore, if the solid activated carbon is immersed in a non-aqueous electrolyte, the solid activated carbon itself is not eroded by the non-aqueous electrolyte and the strength is not deteriorated. Since the electric double layer generated at the interface between the electrolyte and the electrode is formed in a large amount, the solid activated carbon is used as a polarizable electrode, and when the electric double layer capacitor is used as a non-aqueous electrolyte as an electrolyte, it is optimal. Is obtained.
【００２６】次に、本発明の固形状活性炭の製造方法の
一例を述べる。先ず、活性炭粉末及び／又は活性炭繊維
１００重量部に対して、フェノール又はテフロン、コー
ルタール、ポリビニルブチラール（ＰＶＢ）等、公知の
炭化性樹脂の少なくとも一種を２０〜２００重量部の割
合で混合し、該混合物から泥漿又は造粒体を調製して成
形用材料を作製した後、ドクターブレード法やテープ成
形法、又は加圧成形法やロール成形法、あるいはそれら
を組み合わせた成形法等の公知の成形法で成形した成形
体を炭化熱処理に先立ち、大気中、１５０〜３００℃の
温度でエージング処理を行う。Next, an example of the method for producing the solid activated carbon of the present invention will be described. First, with respect to 100 parts by weight of activated carbon powder and / or activated carbon fiber, at least one kind of a known carbonizable resin such as phenol or Teflon, coal tar, polyvinyl butyral (PVB) is mixed at a ratio of 20 to 200 parts by weight, After preparing a material for molding by preparing a slurry or granules from the mixture, a known molding method such as a doctor blade method, a tape molding method, a pressure molding method, a roll molding method, or a combination method thereof is used. Prior to the carbonization heat treatment, the molded body formed by the method is subjected to an aging treatment at a temperature of 150 to 300 ° C. in the air.
【００２７】かかるエージング処理は、炭化性樹脂が少
量で固形状活性炭の強度を高く保持することができると
共に、活性炭自体の細孔を塞ぎ難くしてその表面積を低
減せず、活性炭の特性を最大限に引き出すことを目的と
するものである。This aging treatment can maintain the strength of the solid activated carbon at a high level with a small amount of the carbonizable resin, make it difficult to close the pores of the activated carbon itself, reduce its surface area, and maximize the properties of the activated carbon. It is intended to draw out to the limit.
【００２８】次いで、非酸化性雰囲気中で炭化熱処理
し、成形体中の炭化性樹脂を炭化すると共に、前記活性
炭粉末及び／又は活性炭繊維と炭化性樹脂の炭化物とを
焼成一体化して固形状活性炭を得る。Next, a carbonization heat treatment is performed in a non-oxidizing atmosphere to carbonize the carbonized resin in the molded body, and the activated carbon powder and / or the activated carbon fiber and the carbide of the carbonizable resin are calcined and integrated to form solid activated carbon. Get.
【００２９】前記炭化熱処理温度は、炭化性樹脂の炭化
を充分に進行させるとともに、活性炭粉末や活性炭繊維
のネック部の焼結を進行させて充分な強度を保持させる
ためには８００〜１２００℃の温度が望ましく、特に８
００〜１０００℃の温度が最適である。The carbonization heat treatment temperature is set to 800 to 1200 ° C. in order to sufficiently promote the carbonization of the carbonizable resin and to advance the sintering of the neck portion of the activated carbon powder or the activated carbon fiber to maintain a sufficient strength. Temperature is preferred, especially 8
Temperatures between 00 and 1000 ° C. are optimal.
【００３０】又、前記炭化処理は、温度を高くしたり、
炭化時間を長くすれば強度は向上するものの、全細孔容
積が低下して低電流放電時の静電容量が低下してしまう
ため、用途に合わせて強度と静電容量との兼ね合いか
ら、好適な細孔分布を有するように炭化処理条件を選択
することが肝要である。In the carbonization treatment, the temperature may be increased,
If the carbonization time is lengthened, the strength is improved, but the total pore volume is reduced and the capacitance at the time of low current discharge is reduced, so from the balance between the strength and the capacitance according to the application, it is preferable. It is important to select carbonization conditions so as to have a fine pore distribution.
【００３１】更に、前記非酸化性雰囲気下で炭化熱処理
した固形状活性炭を大気中で賦活処理することにより、
細孔を制御した固形状活性炭を得ることができるが、該
賦活処理で未分解のバインダを分解させ細孔を復元する
と共に、活性炭の炭素と反応して新たな細孔の形成を行
わせるためには、処理温度は４００〜５５０℃の範囲が
望ましく、４００〜４５０℃の温度が最適である。Further, by activating the solid activated carbon subjected to the carbonization heat treatment in the non-oxidizing atmosphere in the air,
Although it is possible to obtain solid activated carbon with controlled pores, the activation treatment decomposes the undecomposed binder to restore the pores and reacts with the carbon of the activated carbon to form new pores. In this case, the processing temperature is preferably in the range of 400 to 550 ° C., and the temperature of 400 to 450 ° C. is optimal.
【００３２】又、前記賦活処理は、処理温度を高くした
り、処理時間を長くすれば細孔容積が増加し、静電容量
は向上するものの、強度の低下を招くため、用途に合わ
せ強度と静電容量の兼ね合いから、好適な細孔分布を有
するように賦活処理条件を選択することが肝要である。In the activation treatment, if the treatment temperature is increased or the treatment time is increased, the pore volume increases and the capacitance is improved, but the strength is reduced. It is important to select the activation treatment conditions so as to have a suitable pore distribution in consideration of the capacitance.
【００３３】尚、本発明の固形状活性炭は、ドクターブ
レード法やカレンダーロール法等によりシート状に成形
して活性炭基板としたり、各種プレス成形法でブロック
状に成形したり、あるいは押出成形法により棒状や筒状
としたり、それらを組み合わせたりしてさまざまな形状
とすることができる。The solid activated carbon of the present invention can be formed into a sheet by a doctor blade method, a calendar roll method, or the like to form an activated carbon substrate, formed into a block by various press molding methods, or formed by an extrusion molding method. Various shapes can be obtained by making the shape of a rod or a tube, or by combining them.
【００３４】更に、前記シート状成形体を複数積層した
後、非酸化性雰囲気下で熱処理することも可能であり、
複数のシート状成形体を積層し、熱圧着したり、あるい
は密着液や接着剤等で接合することにより、互いの反り
方向を相殺して熱処理時の反りの発生を低減することも
可能となる。Further, after laminating a plurality of the sheet-shaped molded bodies, it is possible to perform a heat treatment in a non-oxidizing atmosphere.
By laminating a plurality of sheet-like molded bodies and bonding them by thermocompression bonding or with an adhesive liquid or an adhesive, it becomes possible to offset the warping directions of each other and reduce the occurrence of warpage during heat treatment. .
【００３５】[0035]
【実施例】本発明の固形状活性炭を以下のようにして評
価した。先ず、ＢＥＴ値が１０００ｍ2 ／ｇ、１５００
ｍ2 ／ｇ、及び２０００ｍ2 ／ｇのヤシ殻活性炭粉末１
００重量部に対して、ＰＶＢを１００重量部及びメソフ
ェーズを２０重量部調合して高速混合撹拌機にて撹拌
し、得られた粉体を４０メッシュの篩いで篩別して成形
用原料を作製した。EXAMPLES The solid activated carbon of the present invention was evaluated as follows. First, the BET value is 1000 m 2 / g, 1500
m 2 / g and 2000 m 2 / g coconut shell activated carbon powder 1
With respect to 00 parts by weight, 100 parts by weight of PVB and 20 parts by weight of mesophase were mixed and stirred by a high-speed mixing stirrer, and the obtained powder was sieved with a 40-mesh sieve to prepare a raw material for molding.
【００３６】次に、得られた成形用原料をプレス成形、
あるいはロール成形して平板状の成形体を得た後、該成
形体を大気中、２００℃の温度で４８時間保持してエー
ジング処理を行い、次いで、真空中、表１及び表２に示
す炭化熱処理条件で炭化処理を行い、ＰＶＢ及びメソフ
ェーズを炭化させて活性炭とカーボンの複合体を作製し
た後、該複合体に表１及び表２に示す賦活処理条件を施
して縦７０ｍｍ、横５０ｍｍ、厚さ１ｍｍの評価用の活
性炭基板を作製した。Next, the obtained molding material is press-molded,
Alternatively, after a flat molded body is obtained by roll molding, the molded body is kept at a temperature of 200 ° C. in the air for 48 hours to perform an aging treatment, and then the carbonized material shown in Tables 1 and 2 is vacuumed. After performing carbonization under heat treatment conditions and carbonizing PVB and mesophase to produce a composite of activated carbon and carbon, the composite was subjected to the activation treatment conditions shown in Tables 1 and 2 to be 70 mm long, 50 mm wide, and 50 mm thick. An activated carbon substrate for evaluation having a thickness of 1 mm was prepared.
【００３７】かくして得られた評価用の活性炭基板につ
いて、島津−マイクロメリティックス製アサップ２０１
０Ｍ型を用いたアルゴン吸着等温線（ＨＫ法）から細孔
分布を測定し、前記活性炭基板試料の重量から細孔径が
１０Å以下の細孔容積の割合を求めた。With respect to the activated carbon substrate for evaluation thus obtained, ASAP 201 manufactured by Shimadzu-Micromeritics was used.
The pore distribution was measured from an argon adsorption isotherm (HK method) using a 0M type, and the ratio of the pore volume having a pore diameter of 10 ° or less was determined from the weight of the activated carbon substrate sample.
【００３８】図１に本発明の代表的な固形状活性炭であ
る試料番号２のアルゴン吸着等温曲線から求めた細孔分
布を示す。FIG. 1 shows a pore distribution obtained from an argon adsorption isotherm of Sample No. 2, which is a typical solid activated carbon of the present invention.
【００３９】又、前記評価用の活性炭基板を電気二重層
コンデンサの分極性電極とし、炭酸プロピレン１リット
ルに対して１ｍｏｌのＬｉＣｌＯ4 を含有した非水系電
解液中で、２．５Ｖの電圧にて３０分間充電した後、３
ｍＡ／ｃｍ2 の定電流放電法で電極単位重量当たりの静
電容量（Ｆ／ｇ）を求めた。Further, the activated carbon substrate for evaluation was used as a polarizable electrode of an electric double layer capacitor, and a voltage of 2.5 V was applied in a non-aqueous electrolyte containing 1 mol of LiClO 4 per liter of propylene carbonate. After charging for 30 minutes, 3
The capacitance per unit weight of the electrode (F / g) was determined by a constant current discharge method of mA / cm 2 .
【００４０】一方、前記評価用の活性炭基板を用いてＪ
ＩＳ−Ｒ−１６０１規格に準じ、３点曲げ強度を測定し
た。On the other hand, using the activated carbon substrate for evaluation
The three-point bending strength was measured according to the IS-R-1601 standard.
【００４１】[0041]
【表１】 [Table 1]
【００４２】[0042]
【表２】 [Table 2]
【００４３】表１及び表２から明らかなように、本発明
の請求範囲外である試料番号１、７、１２、１６は、１
０Å以下の細孔容積が０．３５ｃｃ／ｇ以上であるにも
かかわらず、３ｍＡ／ｃｍ2 の低電流放電時に静電容量
の測定ができず、かつ曲げ強度も１９０ｇ／ｍｍ2 未満
と低く、同じく試料番号３３、３４、３６、４１、４
３、４５では、１０Å以下の細孔容積が０．３５ｃｃ／
ｇ未満となって低電流放電時の静電容量が２０Ｆ／ｇ未
満と低く、電気二重層コンデンサの分極性電極をはじめ
とする多目的な固形状活性炭として不適当であるのに対
して、本発明では、いずれも低電流放電時の静電容量が
２０Ｆ／ｇ以上と高く、曲げ強度も２９１ｇ／ｍｍ2 以
上を示している。As is clear from Tables 1 and 2, Sample Nos. 1, 7, 12, and 16, which are out of the scope of the present invention, are 1
Despite the pore volume of 0 ° or less being 0.35 cc / g or more, the capacitance cannot be measured at a low current discharge of 3 mA / cm 2 , and the bending strength is as low as less than 190 g / mm 2 , Similarly, sample numbers 33, 34, 36, 41, 4
For 3, 45, the pore volume of 10 ° or less is 0.35 cc /
g, which is less than 20 F / g at the time of low current discharge, which is unsuitable as a versatile solid activated carbon including a polarizable electrode of an electric double layer capacitor. In each case, the capacitance at the time of low current discharge is as high as 20 F / g or more, and the bending strength is also 291 g / mm 2 or more.
【００４４】尚、本発明は前記実施例に限定されるもの
ではなく、本発明の主旨を満足するものであれば良いこ
とはいうまでもない。It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention satisfies the gist of the invention.
【００４５】[0045]
【発明の効果】以上詳述したように、本発明の固形状活
性炭及びそれを用いた電気二重層コンデンサによれば、
非水系電解液を用いても低電流放電時の静電容量が２０
Ｆ／ｇ以上と高く、かつ機械的強度も大きいことから、
耐久性に優れた各種用途に適用可能な多目的の固形状活
性炭が得られ、静電容量に対する体積の小型化が実現で
き、とりわけ電気二重層コンデンサや補助電源用各種電
池の電極材料として好適なものである。As described above in detail, according to the solid activated carbon of the present invention and the electric double layer capacitor using the same,
Even when a non-aqueous electrolyte is used, the capacitance at the time of low current discharge is 20%.
F / g or more and high mechanical strength,
A versatile solid activated carbon applicable to various applications with excellent durability can be obtained, and the volume can be reduced with respect to the capacitance. Particularly suitable as an electrode material for electric double layer capacitors and various batteries for auxiliary power supply It is.
【００４６】従って、本発明の固形状活性炭を分極性電
極として使用した場合には、電極として電解液に接する
表面積が増大し、電荷の通過する電路も増加するため、
非水系電解液を電解質とする実用的な静電容量を有する
簡単な構造で効率の良い、耐久性に優れた小型の電気二
重層コンデンサを得ることができる。Therefore, when the solid activated carbon of the present invention is used as a polarizable electrode, the surface area of the electrode in contact with the electrolyte increases, and the number of electric paths through which electric charges pass increases.
It is possible to obtain a small-sized electric double-layer capacitor that is efficient and has excellent durability with a simple structure having a practical capacitance using a non-aqueous electrolyte as an electrolyte.
【図１】本発明の代表的な固形状活性炭のアルゴン吸着
等温曲線（ＨＫ法）から求めた細孔分布図である。FIG. 1 is a pore distribution diagram of a typical solid activated carbon of the present invention obtained from an argon adsorption isotherm (HK method).
Claims (2)
おいて、細孔径が１０Å以下の細孔容積が０．３５〜
０．７０ｃｃ／ｇを占め、かつ非水系電解液を用いて分
極性電極として対向する電極間で３ｍＡ／ｃｍ2 の定電
流放電法で測定した静電容量が２０Ｆ／ｇ以上であるこ
とを特徴とする固形状活性炭。In a pore distribution obtained from an argon adsorption isotherm, a pore volume having a pore diameter of 10 ° or less is 0.35 to 0.35.
It occupies 0.70 cc / g and has a capacitance of 20 F / g or more measured by a constant current discharge method of 3 mA / cm 2 between opposing electrodes as a polarizable electrode using a non-aqueous electrolyte. Solid activated carbon.
電解液を用いた分極性電極としたことを特徴とする電気
二重層コンデンサ。2. An electric double layer capacitor comprising the solid activated carbon according to claim 1 as a polarizable electrode using a non-aqueous electrolyte.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10175914A JP2000007314A (en) | 1998-06-23 | 1998-06-23 | Solid active carbon and electric double layer capacitor using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10175914A JP2000007314A (en) | 1998-06-23 | 1998-06-23 | Solid active carbon and electric double layer capacitor using the same |
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| Publication Number | Publication Date |
|---|---|
| JP2000007314A true JP2000007314A (en) | 2000-01-11 |
Family
ID=16004464
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10175914A Pending JP2000007314A (en) | 1998-06-23 | 1998-06-23 | Solid active carbon and electric double layer capacitor using the same |
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| Country | Link |
|---|---|
| JP (1) | JP2000007314A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003067690A1 (en) * | 2002-02-08 | 2003-08-14 | Ketchen Black International Company | Carbon black for electrode of cell or electric double-layer capacitor |
| CN108962620A (en) * | 2018-06-25 | 2018-12-07 | 蓝霆(大连)科技有限公司 | Micro- energy storage super capacitor device |
-
1998
- 1998-06-23 JP JP10175914A patent/JP2000007314A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003067690A1 (en) * | 2002-02-08 | 2003-08-14 | Ketchen Black International Company | Carbon black for electrode of cell or electric double-layer capacitor |
| JP2003234104A (en) * | 2002-02-08 | 2003-08-22 | Ketjen Black International Co | Carbon black for electrode of battery or electric double layer-type capacitor |
| CN108962620A (en) * | 2018-06-25 | 2018-12-07 | 蓝霆(大连)科技有限公司 | Micro- energy storage super capacitor device |
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