JPH11145011A - Electric double layer capacitor - Google Patents

Electric double layer capacitor

Info

Publication number
JPH11145011A
JPH11145011A JP9308207A JP30820797A JPH11145011A JP H11145011 A JPH11145011 A JP H11145011A JP 9308207 A JP9308207 A JP 9308207A JP 30820797 A JP30820797 A JP 30820797A JP H11145011 A JPH11145011 A JP H11145011A
Authority
JP
Japan
Prior art keywords
activated carbon
electric double
double layer
layer capacitor
electrode
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.)
Granted
Application number
JP9308207A
Other languages
Japanese (ja)
Other versions
JP3837880B2 (en
Inventor
Satoshi Hirahara
聡 平原
Mitsuo Suzuki
光雄 鈴木
Kohei Okuyama
公平 奥山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Chemical Corp
Original Assignee
Mitsubishi Chemical Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Chemical Corp filed Critical Mitsubishi Chemical Corp
Priority to JP30820797A priority Critical patent/JP3837880B2/en
Priority to EP98112660A priority patent/EP0890963A3/en
Priority to US09/111,765 priority patent/US6094338A/en
Publication of JPH11145011A publication Critical patent/JPH11145011A/en
Application granted granted Critical
Publication of JP3837880B2 publication Critical patent/JP3837880B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/58—Liquid electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/58—Liquid electrolytes
    • H01G11/62—Liquid electrolytes characterised by the solute, e.g. salts, anions or cations therein
    • 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

PROBLEM TO BE SOLVED: To provide an electric double layer capacitor having excellent durability and charge and discharge durability, when a high voltage of >=3.35 V is impressed upon the capacitor and a large energy density. SOLUTION: An electric double layer capacitor using a nonaqueous electrolyte and activated carbon electrodes for both poles has such a special feature that the solute of the electrolyte is composed of a salt prepared by combining quaternary-onium cations with anions composed of BF4 <-> , PF6 <-> , ClO4 <-> , or CF3 SO3 <-> and the solvent of the electrolyte is composed mainly of a mixture of propylene carbonate and ethylene carbonate, and then, the natural potential of the activated carbon electrode bodies in the electrolyte falls within the range of 1.7-2.5 V when the counter electrode is composed of Li/Li<+> . Therefore, such an electric double layer capacitor that its impressed voltage can be raised to >=3.35 V and its energy density is remarkably improved can be obtained.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、耐電圧、エネルギ
ー密度が大きく、急速充放電でき、耐久性に優れた電気
二重層キャパシターに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric double layer capacitor which has a high withstand voltage, a high energy density, can be rapidly charged and discharged, and has excellent durability.

【０００２】[0002]

【従来の技術】大電流で充放電できる電気二重層キャパ
シターは、電気自動車、補助電源等の用途に有望であ
る。そのために、エネルギー密度が高く、急速充放電が
可能であり、高電圧印加時の耐久性及び充放電サイクル
耐久性に優れた電気二重層キャパシターの実現が望まれ
ている。2. Description of the Related Art Electric double layer capacitors which can be charged and discharged with a large current are promising for applications such as electric vehicles and auxiliary power supplies. Therefore, it is desired to realize an electric double layer capacitor having a high energy density, capable of rapid charge / discharge, and having excellent durability when a high voltage is applied and charge / discharge cycle durability.

【０００３】キャパシターのセルに蓄積されるエネルギ
ーは、１／２・Ｃ・Ｖ2 で算出され、Ｃはセル当たりの
容量（Ｆ）、Ｖはセルに印加可能な電圧（Ｖ）である。
印可可能電圧Ｖは、その値の二乗がエネルギーに反映さ
れるため、エネルギー密度の向上にはキャパシターに印
加する電圧を上げるの効果的であるが、大きな電圧では
電解液の分解が起こる。The energy stored in a capacitor cell is calculated by ・ · C · V 2 , where C is the capacity per cell (F) and V is the voltage (V) that can be applied to the cell.
Since the square of the value of the applicable voltage V is reflected in the energy, it is effective to increase the voltage applied to the capacitor to improve the energy density. However, at a large voltage, the decomposition of the electrolytic solution occurs.

【０００４】そのため、従来の電気二重層キャパシター
では使用する電解液の溶媒と溶質の種類にもよるが、単
位セルあたりの耐電圧は、非水系電解液の電気二重層キ
ャパシターの場合、約２．４Ｖであり（特開平７−１４
５００１号公報）、２．５Ｖ以上の高電圧で使用する
と、内部直列抵抗の増加あるいは静電容量の減少が短時
間で発生する。そこで、正負側の電極、セパレータ、電
解液、容器等を詳細に検討し、２．５Ｖ〜２．８Ｖの電
圧を印加することが試みられている。例えば、フェノー
ル樹脂、石油コークス等をＫＯＨ 賦活して得られる活
性炭を用いた電極を不活性雰囲気中で熱処理して耐久性
は向上するさせる方法や、原料を選定した結果、フェノ
ール樹脂、フラン樹脂、ポリアクリロニトリル樹脂の場
合に耐久性がわずかに向上したこと（特開平８−１６２
３７５号公報）、キャパシターの集電体に多孔質アルミ
ニウムを用いて耐久性向上を図る手法（特開平８−３３
９９４１号公報）等が知られている。[0004] For this reason, the withstand voltage per unit cell of a conventional electric double layer capacitor depends on the type of the solvent and the solute of the electrolytic solution used. 4 V (Japanese Unexamined Patent Publication No. 7-14)
If the battery is used at a high voltage of 2.5 V or more, an increase in internal series resistance or a decrease in capacitance occurs in a short time. Therefore, positive and negative electrodes, separators, electrolytes, containers, and the like have been examined in detail, and attempts have been made to apply a voltage of 2.5 V to 2.8 V. For example, phenolic resin, petroleum coke or the like is activated by KOH activation, and an electrode using activated carbon is heat-treated in an inert atmosphere to improve durability. As a result of selecting raw materials, phenolic resin, furan resin, The durability was slightly improved in the case of polyacrylonitrile resin (Japanese Patent Laid-Open No. 8-162).
375), a method of improving durability by using porous aluminum as a current collector of a capacitor (Japanese Patent Laid-Open No. 8-33)
No. 9941) and the like.

【０００５】エネルギー密度を大きくするため、印加電
圧を３Ｖ以上にする方法としては、特開平８−１０７０
４８号公報にリチウム箔を接触させてリチウムを吸蔵さ
せた黒鉛電極を負極に、活性炭を正極に、リチウムイオ
ンを溶質に含んだ電解液を用いたキャパシターや特開平
９−２３２１９０号公報では、活性炭粉末を含む分極性
電極材料にステンレス鋼繊維の集電体が混在状態で組み
合わしたものを正極としたキャパシターが提案されてい
る。また、特開平９−２０５０４１号公報では、電解液
に２−メチルスルホランを溶媒の主体とする電解液を用
いて、耐電圧の向上を図っている。As a method of increasing the applied voltage to 3 V or more in order to increase the energy density, Japanese Patent Application Laid-Open No.
JP-A-9-232190 discloses a capacitor using an electrolytic solution containing lithium ion as a solute, a graphite electrode having lithium foil in contact with a lithium foil and activating carbon as a positive electrode, and JP-A-9-232190 discloses an activated carbon. A capacitor has been proposed in which a polarizable electrode material containing powder and a stainless steel fiber current collector combined in a mixed state are used as a positive electrode. In JP-A-9-205041, the withstand voltage is improved by using an electrolytic solution mainly composed of 2-methylsulfolane as a solvent for the electrolytic solution.

【０００６】[0006]

【発明が解決すべき課題】しかしながらこれらの例は、
いずれの程度の差こそあれ満足すべきものではなかっ
た。例えば前述の、フェノール樹脂、石油コークス等を
ＫＯＨ 賦活して得られる活性炭を用いた電極を不活性
雰囲気中で熱処理する方法では、同時に初期静電容量も
小さくなるという問題があった。また、特開平８−１６
２３７５号公報、特開平８−３３９９４１号公報の方法
では、根本的には耐久性を改善することはできないと言
ってよい。印加電圧を３Ｖ以上にすることによるエネル
ギー密度向上策として、特開平９−２３２１９０号公
報、特開平９−２０５０４１号公報は、最大の印加電圧
は３．３Ｖであり、それより大きい電圧を印加すること
ができない。また、特開平８−１０７０４８号公報の方
法では、電極−電解液間で酸化還元反応を伴うため、耐
久性が問題がある。また、負極（非分極性電極）にリチ
ウムを含有するため、未充電の状態ですでに正極（分極
性電極）は約３Ｖであり、記載の実施例のように４．３
Ｖまで電圧を印加した場合の充電による電位変化は１．
３Ｖ程度となる。従って、キャパシターとして使用した
場合のエネルギー密度は通常のキャパシターより小さく
なる。However, these examples are:
Any difference was not satisfactory. For example, in the above-described method of heat-treating an electrode using activated carbon obtained by activating a phenol resin, petroleum coke, or the like with KOH in an inert atmosphere, there is a problem that the initial capacitance is also reduced at the same time. Also, JP-A-8-16
It can be said that the methods of 2375 and JP-A-8-339941 cannot fundamentally improve the durability. As measures for improving the energy density by increasing the applied voltage to 3 V or more, JP-A-9-232190 and JP-A-9-205041 disclose that the maximum applied voltage is 3.3 V, and a higher voltage is applied. Can not do. In the method disclosed in Japanese Patent Application Laid-Open No. H08-107048, there is a problem in durability because an oxidation-reduction reaction is involved between the electrode and the electrolytic solution. Further, since the negative electrode (non-polarizable electrode) contains lithium, the positive electrode (polarizable electrode) is already about 3 V in an uncharged state.
The potential change due to charging when a voltage is applied up to V is 1.
It is about 3V. Therefore, the energy density when used as a capacitor is smaller than that of a normal capacitor.

【０００７】従来の電気二重層キャパシターに用いたら
れた活性炭電極では、２．５Ｖを越える高電圧の連続印
加によって、ガス発生あるいは分極性電極上への反応生
成物の付着が発生していた。これが、原因となって、著
しい内部抵抗の増加あるいは静電容量の減少を起こすと
いう欠点を有していた。そこで、本発明者らは、特願平
９−１８３６７０号公報において、炭素質電極の自然電
位を任意に調節して充電時の電位を、電解液の高電位側
（酸化側）の実質的な分解開始電圧以下にすることによ
り、電解液の分解が抑制され、電気二重層キャパシター
の印加可能電圧、及び耐久性が改善できることを提案し
てる。In the activated carbon electrode used in the conventional electric double layer capacitor, continuous application of a high voltage exceeding 2.5 V generates gas or deposits of a reaction product on the polarizable electrode. This has the disadvantage of causing a significant increase in internal resistance or a decrease in capacitance. In view of this, the present inventors have disclosed in Japanese Patent Application No. 9-183670 that the natural potential of a carbonaceous electrode is arbitrarily adjusted so that the potential at the time of charging is substantially higher on the high potential side (oxidation side) of the electrolytic solution. It is proposed that by setting the voltage to be equal to or lower than the decomposition start voltage, decomposition of the electrolytic solution is suppressed, and the applicable voltage and durability of the electric double layer capacitor can be improved.

【０００８】これについて、簡単に説明する。代表的な
非水系の電解液である４級アルキルアンモニウム塩のプ
ロピレンカーボネート溶液の実質的に炭素質物質からな
る電極を用いた場合、電解液の酸化側の分解開始電圧は
４．４Ｖ（対Ｌｉ／Ｌｉ+ ）付近であると言われてい
る。一方、通常の活性炭電極の自然電位は３Ｖ（対Ｌｉ
／Ｌｉ+ ）付近であり、キャパシターの印加電圧が２．
８Ｖの場合、充電後の正極側の分極は約１．４Ｖとな
り、酸化側の電位は４．４Ｖ（対Ｌｉ／Ｌｉ+ ）以上を
示し、電解液の電気化学的分解がおこると考えられる。
その結果、従来の活性炭電極を用いた場合、その電解液
の分解により発生するガス等により容量は低下するた
め、長期間使用した場合に耐久性が問題であった。従っ
て、特願平９−１８３６７０号の発明では活性炭電極の
自然電位を下げて充電後の正極側の電位が電解液の酸化
分解開始電圧以下とすることによて、キャパシターの実
質的な印加可能電圧が大幅に増加し、エネルギー密度を
向上できることを提案している。しかしながら、耐久性
を確保しつつ高いエネルギー密度を有する電気二重層キ
ャパシターの電解液組成と活性炭電極の自然電位との最
適な組合せについては不明であった。[0008] This will be described briefly. When an electrode substantially consisting of a carbonaceous substance of a propylene carbonate solution of a quaternary alkylammonium salt, which is a typical non-aqueous electrolyte, is used, the decomposition start voltage on the oxidation side of the electrolyte is 4.4 V (vs. Li). / Li + ). On the other hand, the natural potential of a normal activated carbon electrode is 3 V (vs. Li
/ Li + ) and the voltage applied to the capacitor is 2.
In the case of 8 V, the polarization on the positive electrode side after charging is about 1.4 V, the potential on the oxidation side is 4.4 V (vs. Li / Li + ) or more, and it is considered that electrochemical decomposition of the electrolytic solution occurs.
As a result, when a conventional activated carbon electrode is used, the capacity is reduced due to a gas or the like generated by the decomposition of the electrolytic solution, and thus there has been a problem of durability when used for a long period of time. Therefore, in the invention of Japanese Patent Application No. 9-183670, the potential of the capacitor can be substantially applied by lowering the natural potential of the activated carbon electrode so that the potential on the positive electrode side after charging is lower than the oxidative decomposition starting voltage of the electrolytic solution. It proposes that the voltage can be greatly increased and the energy density can be improved. However, the optimal combination of the electrolyte composition of the electric double layer capacitor having a high energy density while ensuring the durability and the natural potential of the activated carbon electrode was unknown.

【０００９】[0009]

【発明が解決するための手段】そこで、本発明者らは、
上記の課題を検討すべく鋭意検討した結果、従来の電極
の不純物を低減させたりするなどという方法とは異なる
抜本的解決方法として、特定の非水系溶液を電解液と
し、自然電位を調節した活性炭電極体を用いることによ
り、高エネルギー密度かつ耐久性に優れた電気二重層キ
ャパシターが得られることを見出し、本発明に到達し
た。すなわち、本発明の目的は、３．３５Ｖ以上の高電
圧印加時の耐久性及び充放電耐久性に優れ，かつエネル
ギー密度の大きい電気二重層キャパシターを提供するこ
とにあり、かかる目的は、非水系電解液と活性炭電極を
両極に用いた電気二重層キャパシターにおいて、電解液
の溶質が第４級オニウムカチオンとＢＦ4 - 、Ｐ
Ｆ6 - 、ＣｌＯ4 - 、またはＣＦ3 ＳＯ3 - なるアニオ
ンとを組み合わせた塩であり、溶媒がプロピレンカーボ
ネートとエチレンカーボネートの混合物を主体としたも
のであり、かつ、活性炭電極体の両極の自然電位を１．
７Ｖ以上２．５Ｖ以下（対Ｌｉ／Ｌｉ+ ）にすることに
より容易に達成される。Means for Solving the Problems Accordingly, the present inventors have
As a result of intensive studies to study the above problems, as a drastic solution different from the conventional method of reducing impurities in electrodes, etc., a specific non-aqueous solution was used as an electrolytic solution and activated carbon with adjusted natural potential. The present inventors have found that an electric double layer capacitor having high energy density and excellent durability can be obtained by using an electrode body, and arrived at the present invention. That is, an object of the present invention is to provide an electric double layer capacitor which is excellent in durability and charge / discharge durability when a high voltage of 3.35 V or more is applied and has a large energy density. In an electric double layer capacitor using an electrolyte and an activated carbon electrode for both electrodes, the solute of the electrolyte contains quaternary onium cations and BF 4 − , P
A salt in which an anion such as F 6 − , ClO 4 − , or CF 3 SO 3 − is combined; the solvent is mainly a mixture of propylene carbonate and ethylene carbonate; Set the potential to 1.
It is easily achieved by setting the voltage between 7 V and 2.5 V (relative to Li / Li + ).

【００１０】[0010]

【発明の実施の形態】以下、本発明を詳細に説明する。
本発明の最大の特徴は、電解液の溶質が第４級オニウム
塩で、溶媒がプロピレンカーボネートとエチレンカーボ
ネートの混合物を主体としたものであり、かつ、活性炭
電極体の両極の自然電位を１．７Ｖ以上２．５Ｖ以下
（対Ｌｉ／Ｌｉ+）にすることにより、特に３．３５Ｖ
以上の高電圧印加時に，高いエネルギー密度を示し，か
つ長時間電圧印加時の耐久性及びサイクル耐久性が大幅
に改善される点にある。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The most significant feature of the present invention is that the solute of the electrolyte is a quaternary onium salt, the solvent is mainly a mixture of propylene carbonate and ethylene carbonate, and the natural potential of both electrodes of the activated carbon electrode is 1. By setting the voltage to 7 V or more and 2.5 V or less (vs. Li / Li + ), especially 3.35 V
The point is that when the high voltage is applied as described above, a high energy density is exhibited, and the durability and the cycle durability when the voltage is applied for a long time are greatly improved.

【００１１】具体的には、本発明は、非水系電解液と両
極に活性炭を実質的に主とする電極体を用いた電気二重
層キャパシターであって、該電解液に溶質が好ましくは
Ｒ4Ｎ+ 、Ｒ4 Ｐ+ （ただし、ＲはＣn Ｈ2n+1で示され
るアルキル基）、トリエチルメチルアンモニウムイオン
等でなる第４級オニウムカチオンとＢＦ4 - 、Ｐ
Ｆ6 - 、ＣｌＯ4 - 、またはＣＦ3 ＳＯ3 - なるアニオ
ンとを組み合わせた塩であり、溶媒がプロピレンカーボ
ネートとエチレンカーボネートの混合物を主体としたも
のを用い、好ましくは電解液中の溶質濃度が１．０モル
／リットル以上２．１モル／リットル以下で、かつ、活
性炭電極体の両極の自然電位を１．７Ｖ以上２．５Ｖ以
下（対Ｌｉ／Ｌｉ+ ）とするものであり、特に、活性炭
電極体の自然電位を調節する物質として、該電極体中に
リチウム等のアルカリ金属、アルカリ土類金属、または
希土類金属を含有するものである。Specifically, the present invention relates to a non-aqueous electrolyte
Electric double with an electrode body consisting essentially of activated carbon at the poles
A layer capacitor, wherein a solute is preferably present in the electrolyte.
RFourN+, RFourP+(However, R is CnH2n + 1Indicated by
Alkyl group), triethylmethylammonium ion
Quaternary onium cation and BFFour -, P
F6 -, ClOFour -Or CFThreeSOThree -Naru Anio
And propylene carbonate as the solvent.
Mainly composed of a mixture of carboxylate and ethylene carbonate
Preferably, the solute concentration in the electrolyte is 1.0 mol
/ L to 2.1 mol / l and active
The natural potential of both electrodes of the charcoal electrode body is 1.7 V or more and 2.5 V or less
Below (vs. Li / Li+), Especially activated carbon
As a substance that regulates the spontaneous potential of the electrode body,
Alkali metals such as lithium, alkaline earth metals, or
It contains a rare earth metal.

【００１２】本発明における活性炭電極体の自然電位の
測定は、通常の電気化学的手法を用いて行われる。非水
系での電位測定は、水溶液での標準水素電極のような電
位基準は厳密には定義されていないが、実際には、銀−
塩化銀電極、白金電極、リチウム電極等の電極を用いて
一般に広く行われている。本発明においても同様な方法
で測定可能である。The measurement of the spontaneous potential of the activated carbon electrode body in the present invention is carried out by using a usual electrochemical technique. In the measurement of potential in a non-aqueous system, a potential reference such as a standard hydrogen electrode in an aqueous solution is not strictly defined, but in practice, silver-
It is generally widely used using electrodes such as a silver chloride electrode, a platinum electrode, and a lithium electrode. In the present invention, it can be measured by a similar method.

【００１３】本発明で用いる分極性電極体の実質的に主
な材料である活性炭だけでは、自然電位が１．７Ｖ以上
２．５Ｖ以下（対Ｌｉ／Ｌｉ+ ）の範囲にならないた
め、何らかの調節が必要となる。活性炭電極の自然電位
を１．７Ｖ以上２．５Ｖ以下（対Ｌｉ／Ｌｉ+ ）に調節
する手法は特に限定するものではないが、アルカリ金
属、アルカリ土類金属、希土類金属から選ばれる少なく
とも一つ以上の物質を、電気化学的手法、化学的手法、
物理的手法等により電極体に添加すること好ましい。例
えば、簡便な方法の一つとして、非常に卑な金属である
金属リチウムまたはリチウムを含む物質からなるリチウ
ム含有電極、活性炭を主とする炭素質電極、セパレータ
及び非水系電解液で構成される電気化学セルにおいて、
リチウム含有電極と炭素質電極を短絡またはリチウム含
有電極を正極、炭素質電極を負極として充電することに
より活性炭電極中にリチウムを導入させることができ
る。リチウムを含む物質としては、特に限定するもので
はないが、例えば、リチウム−アルミニウム合金、リチ
ウム−マグネシウム合金等のリチウムを含む合金、リチ
ウム金属間化合物、リチウムを含むマンガン酸化物、コ
バルト酸化物、ニッケル酸化物、バナジウム酸化物等の
複合酸化物、リチウムを含む硫化チタン、セレン化ニオ
ブ、硫化モリブデン等のカルコゲナイト、リチウムを含
む炭素から選ばれる少なくとも１つ以上の物質を用いる
ことが好ましい。卑な電位をもつ金属として、リチウム
以外に、ナトリウム、カリウム等のアルカリ金属、カル
シウム、マグネシウム等のアルカリ土類金属、イットリ
ウム、ネオジウム等の希土類金属または、これらの金属
を含む物質をリチウムの場合と同様に自然電位を下げる
物質として用いてもよい。電極電位を下げすぎて１．７
Ｖ未満にすると、印加電圧３．３５Ｖ以上の場合、電解
液の分解が起こるため初期エネルギー密度及び耐久性が
低下する場合があり好ましくない。The activated carbon alone, which is substantially the main material of the polarizable electrode body used in the present invention, does not have a natural potential in the range of 1.7 V or more and 2.5 V or less (vs. Li / Li + ). Is required. The method of adjusting the natural potential of the activated carbon electrode to 1.7 V or more and 2.5 V or less (vs. Li / Li + ) is not particularly limited, but at least one selected from alkali metals, alkaline earth metals, and rare earth metals. The above substances can be used in electrochemical, chemical,
It is preferable to add to the electrode body by a physical method or the like. For example, as one of the simple methods, there is a lithium-containing electrode made of a substance containing lithium or lithium, which is a very noble metal, a carbonaceous electrode mainly composed of activated carbon, a separator and a non-aqueous electrolyte. In a chemical cell,
By short-circuiting the lithium-containing electrode and the carbonaceous electrode or charging the lithium-containing electrode as the positive electrode and the carbonaceous electrode as the negative electrode, lithium can be introduced into the activated carbon electrode. Examples of the substance containing lithium include, but are not particularly limited to, an alloy containing lithium such as a lithium-aluminum alloy and a lithium-magnesium alloy, a lithium intermetallic compound, a manganese oxide containing lithium, a cobalt oxide, and nickel. It is preferable to use at least one substance selected from oxides, composite oxides such as vanadium oxide, lithium-containing titanium sulfide, niobium selenide, chalcogenite such as molybdenum sulfide, and lithium-containing carbon. As a metal having a low potential, in addition to lithium, an alkali metal such as sodium and potassium, an alkaline earth metal such as calcium and magnesium, a rare earth metal such as yttrium and neodymium, or a substance containing these metals is referred to as lithium. Similarly, it may be used as a substance that lowers the natural potential. 1.7 too low electrode potential
When the applied voltage is less than V, when the applied voltage is 3.35 V or more, the decomposition of the electrolytic solution occurs, so that the initial energy density and the durability may decrease, which is not preferable.

【００１４】こうして自然電位を調節した活性炭電極を
両極に用いて、電気二重層キャパシターを組み立てる。
活性炭電極両極間の自然電位の差が大きすぎると、動作
が不安定になるため好ましくない。電極中のリチウムの
含有量は、活性炭の嵩密度、比表面積、表面性状等によ
り若干異なるが、０．０２重量％以上２重量％以下程度
となる。An electric double layer capacitor is assembled by using the activated carbon electrode whose natural potential has been adjusted as described above for both electrodes.
If the difference in the natural potential between the two electrodes of the activated carbon electrode is too large, the operation becomes unstable, which is not preferable. The content of lithium in the electrode slightly varies depending on the bulk density, specific surface area, surface properties, etc. of the activated carbon, but is about 0.02% by weight or more and 2% by weight or less.

【００１５】自然電位を調節する前の活性炭は、電気二
重層キャパシターを大容量とするために比表面積の大き
な活性炭を用いるのが好ましい。活性炭の比表面積は大
きすぎると嵩密度が低下してエネルギー密度が低下する
ので、２００〜３０００ｍ2／ｇが好ましく、さらに好
ましくは３００〜２３００ｍ2 ／ｇである。活性炭の原
料としては、植物物系の木材、のこくず、ヤシ殻、パル
プ廃液、化石燃料系の石炭、石油重質油、あるいはそれ
らを熱分解した石炭および石油系ピッチ、タールピッチ
を紡糸した繊維、合成高分子、フェノール樹脂、フラン
樹脂、ポリ塩化ビニル樹脂、ポリ塩化ビニリデン樹脂、
ポリイミド樹脂、ポリアミド樹脂、液晶高分子、プラス
チック廃棄物、廃タイヤ等多種多用である。これらの原
料を炭化後、賦活するが、賦活法は、ガス賦活と薬品賦
活に大別される。ガス賦活法は、薬品賦活が化学的な活
性化であるのに対して、物理的な活性化ともいわれ、炭
化された原料を高温で水蒸気、炭酸ガス、酸素、その他
の酸化ガスなどと接触反応させて、活性炭が得られる。
薬品賦活法は、原料に賦活薬品を均等に含侵させて、不
活性ガス雰囲気中で加熱し、薬品の脱水および酸化反応
により活性炭を得る方法である。使用される薬品として
は、塩化亜鉛、りん酸、りん酸ナトリウム、塩化カルシ
ウム、硫化カリウム、水酸化カリウム、水酸化ナトリウ
ム、炭酸カリウム、炭酸ナトリウム、硫酸ナトリウム、
硫酸カリウム、炭酸カルシウム等がある。活性炭の製法
に関しては、上記に各種あげたが、特に問わない。活性
炭はの形状は、破砕、造粒、顆粒、繊維、フェルト、織
物、シート状等各種の形状があるが、いずれも本発明に
使用することができる。これらの活性炭のうち、ＫＯＨ
を用いた薬品賦活で得られる活性炭は、水蒸気賦活品と
比べて容量が大きい傾向にあることから、特に好まし
い。更に水蒸気賦活後に薬品賦活したものは、表面積が
大きいのみならず、賦活によって得られた孔の形状がキ
ャパシタ用として適切なものに成りやすいので、好まし
い。As the activated carbon before adjusting the natural potential, it is preferable to use activated carbon having a large specific surface area in order to increase the capacity of the electric double layer capacitor. Since the specific surface area of the activated carbon is decreased is too large the bulk density energy density decreases, 200~3000m 2 / g are preferred, more preferably 300~2300m 2 / g. The raw materials of activated carbon were spun wood, wood, sawdust, coconut husk, pulp waste liquid, fossil fuel coal, petroleum heavy oil, or thermally decomposed coal, petroleum pitch, and tar pitch. Fiber, synthetic polymer, phenolic resin, furan resin, polyvinyl chloride resin, polyvinylidene chloride resin,
Polyimide resin, polyamide resin, liquid crystal polymer, plastic waste, waste tire, etc. These carbonized materials are activated after carbonization. Activation methods are roughly classified into gas activation and chemical activation. In the gas activation method, chemical activation is chemical activation, whereas physical activation is also called physical activation, and the carbonized raw material is contact-reacted with steam, carbon dioxide, oxygen, and other oxidizing gases at high temperatures. Then, activated carbon is obtained.
The chemical activation method is a method in which a raw material is uniformly impregnated with an activation chemical, heated in an inert gas atmosphere, and activated carbon is obtained by a dehydration and oxidation reaction of the chemical. The chemicals used include zinc chloride, phosphoric acid, sodium phosphate, calcium chloride, potassium sulfide, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, sodium sulfate,
There are potassium sulfate, calcium carbonate and the like. Various methods for producing activated carbon have been described above, but are not particularly limited. Activated carbon has various shapes such as crushed, granulated, granulated, granular, fiber, felt, woven, and sheet shapes, and any of them can be used in the present invention. Of these activated carbons, KOH
Activated carbon obtained by chemical activation using is particularly preferable because it tends to have a larger capacity than a steam activated product. Further, those activated with water vapor and then activated with a chemical are preferred because not only the surface area is large, but also the shape of the holes obtained by the activation tends to be suitable for a capacitor.

【００１６】更に賦活処理後の活性炭を、窒素、アルゴ
ン、ヘリウム、キセノン等の不活性雰囲気下で、５００
〜２５００℃、好ましくは７００〜１５００℃で熱処理
し、不要な表面官能基を除去したり、炭素の結晶性を発
達させて電子伝導性を増加させ留ことも好ましい。粒状
の活性炭の場合、電極の嵩密度の向上、内部抵抗の低減
という点で、平均粒子径は３０μｍ以下が好ましい。Further, the activated carbon after the activation treatment is treated under an inert atmosphere of nitrogen, argon, helium, xenon, etc. for 500 hours.
It is also preferable to remove the unnecessary surface functional groups by heat treatment at 2500 ° C., preferably 700-1500 ° C., or to improve the crystallinity of carbon to increase the electron conductivity, and to retain. In the case of granular activated carbon, the average particle diameter is preferably 30 μm or less from the viewpoint of improving the bulk density of the electrode and reducing the internal resistance.

【００１７】活性炭を主体とする分極性電極は、活性
炭、導電剤とバインダーから構成される。分極性電極
は、従来より知られている方法により成形することが可
能である。例えば、活性炭とアセチレンブラックの混合
物に、ポリテトラフルオロエチレンを添加・混合した
後、プレス成形して得られる。また、導電剤、バインダ
ーを用いず、活性炭のみを焼結して分極性電極とするこ
とも可能である。電極は、薄い塗布膜、シート状または
板状の成形体、さらには複合物からなる板状成形体のい
ずれであっても良い。The polarizable electrode mainly composed of activated carbon is composed of activated carbon, a conductive agent and a binder. The polarizable electrode can be formed by a conventionally known method. For example, it is obtained by adding and mixing polytetrafluoroethylene to a mixture of activated carbon and acetylene black, followed by press molding. Further, it is also possible to form a polarizable electrode by sintering only activated carbon without using a conductive agent and a binder. The electrode may be any of a thin coating film, a sheet-like or plate-like molded body, and a plate-like molded body made of a composite.

【００１８】分極性電極に用いられる導電剤として、ア
セチレンブラック、ケッチェンブラック等のカーボンブ
ラック、天然黒鉛、熱膨張黒鉛、炭素繊維、酸化ルテニ
ウム、酸化チタン、アルミニウム、ニッケル等の金属フ
ァイバーからなる群より選ばれる少なくとも一種の導電
剤が好ましい。少量で効果的に導電性が向上する点で、
アセチレンブラック及びケッチェンブラックが特に好ま
しく、活性炭との配合量は、活性炭の嵩密度により異な
るが多すぎると活性炭の割合が減り容量が減少するた
め、活性炭の重量の５〜５０％、特には１０〜３０％程
度が好ましい。The conductive agent used for the polarizable electrode is a group consisting of carbon black such as acetylene black and Ketjen black, natural graphite, thermally expanded graphite, carbon fiber, and metal fiber such as ruthenium oxide, titanium oxide, aluminum and nickel. At least one kind of conductive agent selected from the above is preferable. In terms of improving conductivity effectively with a small amount,
Acetylene black and Ketjen black are particularly preferred, and the amount of the activated carbon varies depending on the bulk density of the activated carbon. However, if the amount is too large, the proportion of the activated carbon is reduced and the capacity is reduced. About 30% is preferable.

【００１９】バインダーとしては、ポリテトラフルオロ
エチレン、ポリフッ化ビニリデン、カルボキシメチルセ
ルロース、フルオロオレフィン共重合体架橋ポリマー、
ポリビニルアルコール、ポリアクリル酸、ポリイミド、
石油ピッチ、石炭ピッチ、フェノール樹脂のうち少なく
とも１種類以上用いるのが好ましい。集電体は電気化学
的及び化学的に耐食性があればよく、特に限定するもの
ではないが、例えば、正極ではステンレス、アルミニウ
ム、チタン、タンタルがあり、負極では、ステンレス、
ニッケル、銅等が好適に使用される。Examples of the binder include polytetrafluoroethylene, polyvinylidene fluoride, carboxymethylcellulose, a fluoroolefin copolymer crosslinked polymer,
Polyvinyl alcohol, polyacrylic acid, polyimide,
It is preferable to use at least one or more of petroleum pitch, coal pitch, and phenol resin. The current collector is not particularly limited as long as it has electrochemical and chemical corrosion resistance.Examples include, but are not limited to, stainless steel, aluminum, titanium, and tantalum for the positive electrode, and stainless steel for the negative electrode.
Nickel, copper and the like are preferably used.

【００２０】非水系電解液の溶質は、Ｒ4 Ｎ+ 、Ｒ4 Ｐ
+ （ただし、ＲはＣn Ｈ2n+1で示されるアルキル基）、
トリエチルメチルアンモニウムイオン等でなる第４級オ
ニウムカチオンと、ＢＦ4 - 、ＰＦ6 - 、ＣｌＯ4 - 、
またはＣＦ3 ＳＯ3 - なるアニオンとを組み合わせた塩
を使用するのが好ましい。これらの塩の非水系電解液中
の濃度は電気二重層キャパシターの特性が十分引き出せ
るように、１．０〜２．１モル／リットルが好ましい。
また、非水系電解液の溶媒はプロピレンカーボネートと
エチレンカーボネートの混合溶媒を主体とするものを使
用する。プロピレンカーボネートとエチレンカーボネー
トの混合比は特に限定しないが、プロピレンカーボネー
トの体積１に対し、エチレンカーボネートは体積０．１
以上４以下が好ましい。また、電解液の電気伝導性、電
気化学的安定性、及び化学的安定性を向上させるため
に、プロピレンカーボネートとエチレンカーボネートの
混合溶媒に、ブチレンカーボネート、ジメチルカーボネ
ート、メチルエチルカーボネート、ジエチルカーボネー
ト、スルホラン、メチルスルホラン、γ−ブチロラクト
ン、γ−バレロラクトン、Ｎ−メチルオキサゾリジノ
ン、ジメチルスルホキシド、トリメチルスルホキシド、
アセトニトリル、プロピオニトリル、ＬｉＢＦ4、Ｌｉ
ＰＦ6 、ＬｉＣｌＯ4 から選ばれる１種類以上の物質を
添加してもよい。また、高い耐電圧を維持できように、
非水系電解液中の水分は２００ｐｐｍ以下、さらには５
０ｐｐｍ以下が好ましい。The solute of the non-aqueous electrolyte is R 4 N + , R 4 P
+ (Where R is an alkyl group represented by C n H 2n + 1 ),
A quaternary onium cation such as triethylmethylammonium ion, and BF 4 − , PF 6 − , ClO 4 − ,
Alternatively, it is preferable to use a salt in combination with an anion CF 3 SO 3 — . The concentration of these salts in the non-aqueous electrolyte is preferably 1.0 to 2.1 mol / liter so that the characteristics of the electric double layer capacitor can be sufficiently obtained.
The solvent of the non-aqueous electrolyte is mainly a mixed solvent of propylene carbonate and ethylene carbonate. The mixing ratio of propylene carbonate and ethylene carbonate is not particularly limited, but the volume of propylene carbonate is 1 and the volume of ethylene carbonate is 0.1
It is preferably at least 4 and at most 4. Further, in order to improve the electrical conductivity, electrochemical stability, and chemical stability of the electrolytic solution, butylene carbonate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, sulfolane, and the like in a mixed solvent of propylene carbonate and ethylene carbonate. , Methylsulfolane, γ-butyrolactone, γ-valerolactone, N-methyloxazolidinone, dimethylsulfoxide, trimethylsulfoxide,
Acetonitrile, propionitrile, LiBF 4 , Li
One or more substances selected from PF 6 and LiClO 4 may be added. Also, to maintain high withstand voltage,
The water content in the non-aqueous electrolyte is 200 ppm or less,
0 ppm or less is preferable.

【００２１】[0021]

【実施例】以下、本発明を具体的な実施例で説明する
が、本発明はその要旨を超えない限り以下の実施例によ
り限定されるものではない。EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to the following examples unless it exceeds the gist.

【００２２】（実施例１）はじめに、活性炭電極へのリ
チウムの添加方法について述べる。ＫＯＨ賦活処理して
得られたフェノール樹脂系活性炭粉末（比表面積１９０
０ｍ2 ／ｇ、平均粒子径１０μｍ）８０重量％、アセチ
レンブラック１０重量％、ポリテトラフルオロエチレン
１０重量％からなる混合物を混練した後、日本分光製錠
剤成型器を用い、油圧プレスで直径１０ｍｍ，厚さ０．
５ｍｍとなるように５０ｋｇｆ／ｃｍ2 の圧力で加圧成
形して円盤状の成型体を得た。この成型体を０．１ｔｏ
ｒｒ以下の真空中、３００℃で３時間乾燥し電極体とし
た。この方法で作製した２枚の電極の間に三菱化学製ポ
リエチレン製セパレータを入れた後、集電体に使う白金
板２枚で全体を挟み込み、さらに集電体、活性炭電極、
セパレータがよく接触するように一番外側から２枚の厚
さ５ｍｍで４個のボルト孔をもつテフロン板で挟み込ん
で、オープンセル型キャパシターを組み立てた。こうし
て得たオープンセル型キャパシターと白金板の先端に金
属リチウム箔を圧着することにより作製したリチウム極
をビーカー内の１モル／リットルの濃度のＬｉＢＦ４の
プロピレンカーボネート溶液中に浸漬させた。次に、リ
チウム極と活性炭電極をリード線でつなぎ、約１時間短
絡させた。その後、電極部を分解して活性炭電極体２枚
を取り出した。次に、リチウム極と活性炭電極をリード
線でつなぎ、約１時間短絡させた。短絡させた後、活性
炭電極とリチウム極との間に電圧計を接続して測定した
活性炭電極の自然電位は、２．２０Ｖ（対Ｌｉ／Ｌ
ｉ+ ）であった。(Example 1) First, a method of adding lithium to an activated carbon electrode will be described. Phenol resin-based activated carbon powder (specific surface area 190
0 m 2 / g, average particle diameter 10 μm) After kneading a mixture consisting of 80% by weight, acetylene black 10% by weight, and polytetrafluoroethylene 10% by weight, using a tablet press made by JASCO, a 10 mm diameter oil-press was used. Thickness 0.
Pressure molding was performed at a pressure of 50 kgf / cm 2 so as to be 5 mm to obtain a disk-shaped molded body. 0.1 to
The electrode was dried at 300 ° C. for 3 hours in a vacuum of rr or less. After inserting a polyethylene separator made by Mitsubishi Chemical between the two electrodes produced by this method, the whole is sandwiched between two platinum plates used for the current collector, and the current collector, activated carbon electrode,
An open-cell capacitor was assembled by sandwiching the two outermost Teflon plates having a thickness of 5 mm and four bolt holes so that the separators were in good contact with each other. The thus-obtained open cell capacitor and a lithium electrode produced by pressing metal lithium foil on the tip of a platinum plate were immersed in a 1 mol / liter LiBF4 propylene carbonate solution in a beaker. Next, the lithium electrode and the activated carbon electrode were connected by a lead wire, and short-circuited for about 1 hour. Thereafter, the electrode portion was disassembled and two activated carbon electrode bodies were taken out. Next, the lithium electrode and the activated carbon electrode were connected by a lead wire, and short-circuited for about 1 hour. After the short circuit, the natural potential of the activated carbon electrode measured by connecting a voltmeter between the activated carbon electrode and the lithium electrode was 2.20 V (vs. Li / L).
i + ).

【００２３】次に、電気二重層キャパシターの作製方法
について述べる。上記の方法で得た自然電位２．２０Ｖ
の活性炭電極２枚に１モル／リットルの濃度の（Ｃ2 Ｈ
5 ） 4 ＮＢＦ4 のプロピレンカーボネート＋エチレンカ
ーボネート（体積混合比１＋１）溶液を充分に含浸させ
たものを各々正極２、負極５とし、ポリエチレンセパレ
ータ４を両極間に配置して図１に示すようなコイン型セ
ル型電気二重層キャパシターを得た。Next, a method for manufacturing an electric double layer capacitor
Is described. 2.20 V of the natural potential obtained by the above method
(C) at a concentration of 1 mol / liter on two activated carbon electrodesTwoH
Five) FourNBFFourPropylene carbonate + ethylene carbonate
-Carbonate solution (volume mixing ratio 1 + 1)
These were used as positive electrode 2 and negative electrode 5, respectively.
And a coin-shaped cell as shown in FIG.
A double-type electric double layer capacitor was obtained.

【００２４】得られた電気二重層キャパシターに、北斗
電工製充放電装置「ＨＪ２０１−Ｂ」を用いて、室温下
で３．４Ｖの電圧を１時間印加した後、１．１６ｍＡで
１．０Ｖまで定電流放電して求めた初期のエネルギー密
度は、１１．６Ｗｈ／ｌであった。同様に３．８Ｖを印
加したときのエネルギー密度は、１３．０Ｗｈ／ｌであ
った。電圧印加条件下におけるキャパシターの長期的な
作動信頼性を評価するため、このキャパシターを３．４
Ｖの電圧を印加し、５００時間経過後のエネルギー密度
の変化率は−１０％となり殆ど低下はなかった。また、
印加電圧３．８Ｖの場合の５００時間経過後のエネルギ
ー密度変化率は、−１６％を示した。A voltage of 3.4 V was applied to the obtained electric double layer capacitor at room temperature for 1 hour at room temperature using a charging / discharging apparatus “HJ201-B” manufactured by Hokuto Denko, and then increased to 1.0 V at 1.16 mA. The initial energy density determined by constant current discharge was 11.6 Wh / l. Similarly, the energy density when 3.8 V was applied was 13.0 Wh / l. In order to evaluate the long-term operational reliability of the capacitor under voltage application conditions,
When a voltage of V was applied, the change rate of the energy density after lapse of 500 hours was -10%, and there was almost no decrease. Also,
The energy density change rate after 500 hours when the applied voltage was 3.8 V was -16%.

【００２５】（実施例２）活性炭粉末を石炭ピッチをＫ
ＯＨ賦活して得られたもの（比表面積５６０ｍ2／ｇ、
平均粒子径１０μｍ）とし、調節した活性炭電極体の自
然電位を２．１１Ｖとした以外は実施例１と同様な電気
二重層キャパシターを構成した。得た電気二重層キャパ
シターの初期のエネルギー密度は、印加電圧３．４Ｖの
場合では１６．６Ｗｈ／ｌ、印加電圧３．８Ｖの場合で
は、２３．３Ｗｈ／ｌを示した。５００時間後のエネル
ギー密度は、印加電圧３．４Ｖの場合では−７％、印加
電圧３．８Ｖの場合では、−１１％を示した。(Example 2) Activated carbon powder was converted to coal pitch K
What was obtained by OH activation (specific surface area: 560 m 2 / g,
An electric double layer capacitor was formed in the same manner as in Example 1 except that the average particle diameter was 10 μm) and the adjusted natural potential of the activated carbon electrode body was 2.11 V. The initial energy density of the obtained electric double layer capacitor was 16.6 Wh / l when the applied voltage was 3.4 V, and 23.3 Wh / l when the applied voltage was 3.8 V. The energy density after 500 hours was -7% when the applied voltage was 3.4 V, and -11% when the applied voltage was 3.8 V.

【００２６】（実施例３）活性炭粉末を石油コークスを
ＫＯＨ賦活して得られたもの（比表面積１５５０ｍ2 ／
ｇ、平均粒子径１０μｍ）とし、調節した活性炭電極体
の自然電位を１．７１Ｖ（対Ｌｉ／Ｌｉ＋）とした以外
は実施例１と同様な電気二重層キャパシターを構成し
た。得た電気二重層キャパシターの初期のエネルギー密
度は、印加電圧３．４Ｖの場合では１５．１Ｗｈ／ｌ、
印加電圧３．８Ｖの場合では、１９．２Ｗｈ／ｌを示し
た。５００時間後のエネルギー密度は、印加電圧３．４
Ｖの場合では−４％、印加電圧３．８Ｖの場合では、−
５％を示した。Example 3 Activated carbon powder obtained by activating petroleum coke with KOH (specific surface area: 1550 m 2 /
g, average particle diameter 10 μm), and the same electric double layer capacitor as in Example 1 was configured except that the adjusted natural electrode potential of the activated carbon electrode was 1.71 V (vs. Li / Li +). The initial energy density of the obtained electric double layer capacitor was 15.1 Wh / l when the applied voltage was 3.4 V,
In the case of an applied voltage of 3.8 V, 19.2 Wh / l was shown. After 500 hours, the energy density was 3.4 applied voltage.
In the case of V, -4%, and in the case of the applied voltage of 3.8 V,-
5%.

【００２７】（比較例１）リチウム極と活性炭極の短時
間の短絡処理により自然電位を２．８Ｖに調節した以外
は実施例１と同様な電気二重層キャパシターを構成し
た。得た電気二重層キャパシターの初期のエネルギー密
度は、印加電圧３．４Ｖの場合では１１．５Ｗｈ／ｌ、
印加電圧３．８Ｖの場合では、１２．８Ｗｈ／ｌを示し
た。５００時間後のエネルギー密度は、印加電圧３．４
Ｖの場合では−２７％、印加電圧３．８Ｖの場合では、
−３７％を示した。Comparative Example 1 An electric double layer capacitor similar to that of Example 1 was constructed except that the natural potential was adjusted to 2.8 V by short-circuiting the lithium electrode and the activated carbon electrode for a short time. The initial energy density of the obtained electric double layer capacitor was 11.5 Wh / l when the applied voltage was 3.4 V,
When the applied voltage was 3.8 V, 12.8 Wh / l was shown. After 500 hours, the energy density was 3.4 applied voltage.
In the case of V, -27%, and in the case of an applied voltage of 3.8 V,
-37%.

【００２８】（比較例２）リチウムを活性炭極中へ該充
放電装置を用いて導入することにより、活性炭電極の自
然電位を１．０Ｖ（対Ｌｉ／Ｌｉ+ ) に調節したこと以
外は実施例１と同様な電気二重層キャパシターを構成し
た。得た電気二重層キャパシターに３．４Ｖ及び３．８
Ｖの電圧を印加したところ１時間以内に電圧降下が起こ
りエネルギー密度を測定することができなかった。試験
後のコインセルは電解液の分解によるガス発生のために
大きく膨らんでいた。(Comparative Example 2) Example 2 was repeated except that the natural potential of the activated carbon electrode was adjusted to 1.0 V (vs. Li / Li + ) by introducing lithium into the activated carbon electrode using the charging / discharging device. The same electric double-layer capacitor as in No. 1 was constructed. 3.4 V and 3.8 were applied to the obtained electric double layer capacitor.
When a voltage of V was applied, a voltage drop occurred within one hour, and the energy density could not be measured. The coin cell after the test was largely swollen due to gas generation due to decomposition of the electrolytic solution.

【００２９】（比較例３）電気二重層キャパシターの電
解液を１モル／リットルの濃度の（Ｃ2 Ｈ5 ）4ＮＢＦ
4 のプロピレンカーボネート溶液とした以外は実施例１
と同様な電気二重層キャパシターを構成した。得た電気
二重層キャパシターの初期のエネルギー密度は、印加電
圧３．４Ｖの場合では１０．５Ｗｈ／ｌ、印加電圧３．
８Ｖの場合では、１１．９Ｗｈ／ｌを示した。５００時
間後のエネルギー密度は、印加電圧３．４Ｖの場合では
−１４％、印加電圧３．８Ｖの場合では、−２１％を示
した。(Comparative Example 3) The electrolytic solution of the electric double layer capacitor was prepared at a concentration of 1 mol / liter of (C 2 H 5 ) 4 NBF.
Except for using 4 propylene carbonate solution of Example 1
An electric double layer capacitor similar to the above was constructed. The initial energy density of the obtained electric double layer capacitor was 10.5 Wh / l when the applied voltage was 3.4 V, and the applied energy was 3.
In the case of 8V, 11.9 Wh / l was shown. The energy density after 500 hours was -14% when the applied voltage was 3.4 V, and -21% when the applied voltage was 3.8 V.

【００３０】（比較例４）電気二重層キャパシターの電
解液の溶質濃度を０．５モル／リットルとした以外は実
施例１と同様な電気二重層キャパシターを構成した。得
た電気二重層キャパシターの初期のエネルギー密度は、
印加電圧３．４Ｖの場合では７．３Ｗｈ／ｌ、印加電圧
３．８Ｖの場合では、７．８Ｗｈ／ｌを示し、溶質濃度
が１．０モル／リットルの場合よりかなり小さい値を示
した。Comparative Example 4 An electric double layer capacitor was constructed in the same manner as in Example 1 except that the solute concentration of the electrolytic solution of the electric double layer capacitor was 0.5 mol / l. The initial energy density of the obtained electric double layer capacitor is
When the applied voltage was 3.4 V, the value was 7.3 Wh / l, and when the applied voltage was 3.8 V, the value was 7.8 Wh / l, which was much smaller than that when the solute concentration was 1.0 mol / liter.

【００３１】[0031]

【発明の効果】本発明により、従来に比べ、印可電圧を
高くでき、エネルギー密度が大幅に向上した電気二重層
キャパシターを得ることができる。According to the present invention, it is possible to obtain an electric double layer capacitor in which the applied voltage can be increased and the energy density can be greatly improved as compared with the prior art.

【図面の簡単な説明】[Brief description of the drawings]

【図１】図１は、本発明の実施例１にて用いた電気二重
層キャパシターの説明図である。FIG. 1 is an explanatory diagram of an electric double layer capacitor used in Example 1 of the present invention.

【符号の説明】[Explanation of symbols]

１：ステンレス製容器のケース ２：活性炭成型体 ３：ガスケット ４：セパレータ ５：活性炭成型体 ６：ステンレス製容器の上蓋 1: Case of stainless steel container 2: Activated carbon molded body 3: Gasket 4: Separator 5: Activated carbon molded body 6: Top cover of stainless steel container

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】非水系電解液と両極に活性炭電極を用いた
電気二重層キャパシターにおいて、該電解液の溶質が、
第４級オニウムカチオンとＢＦ4 - 、ＰＦ6 - 、ＣｌＯ
4 -、またはＣＦ3 ＳＯ3 - なるアニオンとを組み合わ
せた塩であり、該電解液の溶媒がプロピレンカーボネー
トとエチレンカーボネートの混合物を主体したもでであ
り、かつ、活性炭電極体の該電解液中での自然電位がＬ
ｉ／Ｌｉ+ を対極とした場合，１．７Ｖ以上２．５Ｖ以
下であること特徴とする電気二重層キャパシター。In an electric double layer capacitor using a non-aqueous electrolyte and an activated carbon electrode for both electrodes, the solute of the electrolyte is:
Quaternary onium cation and BF 4 -, PF 6 -, ClO
4 − , or a salt in combination with an anion of CF 3 SO 3 −, wherein the solvent of the electrolytic solution is mainly a mixture of propylene carbonate and ethylene carbonate, and the electrolytic solution of the activated carbon electrode is in the electrolytic solution. The natural potential at L
An electric double layer capacitor having a voltage of 1.7 V or more and 2.5 V or less when i / Li + is used as a counter electrode. 【請求項２】該第４級オニウムカチオンが、Ｒ4 Ｎ+ 、
Ｒ4 Ｐ+ （ただし、ＲはＣn Ｈ2n+1で示されるアルキル
基）、トリエチルメチルアンモニウムイオンからなる群
のいずれかであって、電解液中の溶質の濃度が１．０モ
ル／リットル以上２．１モル／リットル以下であること
を特徴とする請求項１記載の電気二重層キャパシター。2. The method according to claim 1, wherein the quaternary onium cation is R 4 N + ,
R 4 P + (where R is an alkyl group represented by C n H 2n + 1 ) and triethylmethylammonium ion, wherein the concentration of the solute in the electrolytic solution is 1.0 mol / liter. 2. The electric double layer capacitor according to claim 1, wherein the content is not less than 2.1 mol / liter. 【請求項３】活性炭電極体にアルカリ金属、アルカリ土
類金属、及び希土類金属から選ばれる少なくとも１つ以
上の物質を含む請求項１又は２のいずれか記載の電気二
重層キャパシター。3. The electric double layer capacitor according to claim 1, wherein the activated carbon electrode body contains at least one substance selected from alkali metals, alkaline earth metals, and rare earth metals. 【請求項４】活性炭電極体にリチウムを含むことを特徴
とする請求項１乃至３のいずれか記載の電気二重層キャ
パシター。4. The electric double layer capacitor according to claim 1, wherein the activated carbon electrode body contains lithium.
JP30820797A 1997-07-09 1997-11-11 Electric double layer capacitor Expired - Fee Related JP3837880B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP30820797A JP3837880B2 (en) 1997-11-11 1997-11-11 Electric double layer capacitor
EP98112660A EP0890963A3 (en) 1997-07-09 1998-07-08 Electric double-layer capacitor
US09/111,765 US6094338A (en) 1997-07-09 1998-07-08 Electric double-layer capacitor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30820797A JP3837880B2 (en) 1997-11-11 1997-11-11 Electric double layer capacitor

Publications (2)

Publication Number Publication Date
JPH11145011A true JPH11145011A (en) 1999-05-28
JP3837880B2 JP3837880B2 (en) 2006-10-25

Family

ID=17978216

Family Applications (1)

Application Number Title Priority Date Filing Date
JP30820797A Expired - Fee Related JP3837880B2 (en) 1997-07-09 1997-11-11 Electric double layer capacitor

Country Status (1)

Country Link
JP (1) JP3837880B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006351915A (en) * 2005-06-17 2006-12-28 Japan Carlit Co Ltd:The Electric-double-layer capacitor and electrolyte therefor
JP2011502096A (en) * 2007-10-31 2011-01-20 コーニング インコーポレイテッド High energy density ultracapacitor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006351915A (en) * 2005-06-17 2006-12-28 Japan Carlit Co Ltd:The Electric-double-layer capacitor and electrolyte therefor
JP2011502096A (en) * 2007-10-31 2011-01-20 コーニング インコーポレイテッド High energy density ultracapacitor

Also Published As

Publication number Publication date
JP3837880B2 (en) 2006-10-25

Similar Documents

Publication Publication Date Title
US6094338A (en) Electric double-layer capacitor
JP3800799B2 (en) Electric double layer capacitor
EP1843362B1 (en) Lithium ion capacitor
JP4202334B2 (en) Electrochemical devices
US7625839B2 (en) Activated carbon for use in electric double layer capacitors
US6414837B1 (en) Electrochemical capacitor
JP4618929B2 (en) Activated carbon for electric double layer capacitors
JP5931326B2 (en) Activated carbon for electric double layer capacitors
US20110043968A1 (en) Hybrid super capacitor
JPH097896A (en) Electric double-layer capacitor
US6038123A (en) Electric double layer capacitor, and carbon material and electrode therefor
JP2009205918A (en) Power storage device
JP3812098B2 (en) Electric double layer capacitor
JPH1131637A (en) Electric double-layer capacitor, carbon material for it and electrode
JP2000208372A (en) Electrolytic solution and electric double-layer capacitor using the same
JP3837866B2 (en) Electric double layer capacitor
JP3807854B2 (en) Electric double layer capacitor
JP3800810B2 (en) Electric double layer capacitor
JP4503134B2 (en) Activated carbon for electric double layer capacitors
JP4066506B2 (en) A method for producing a carbonaceous material.
JP3837880B2 (en) Electric double layer capacitor
JP3541476B2 (en) Electric double layer capacitor
JPH11297580A (en) Electric double-layer capacitor
JP3991566B2 (en) Electrochemical capacitor
JP3843558B2 (en) Electric double layer capacitor

Legal Events

Date Code Title Description
A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20041001

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20050329

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050525

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060509

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20060621

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060711

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20060724

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100811

Year of fee payment: 4

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100811

Year of fee payment: 4

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110811

Year of fee payment: 5

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120811

Year of fee payment: 6

FPAY Renewal fee payment (prs date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130811

Year of fee payment: 7

LAPS Cancellation because of no payment of annual fees