JP4044295B2 - Batteries, electric double layer capacitors and methods for producing them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize inside resistance and reduce its dispersion in a battery or an electric double layer capacitor structured to decompress and seal an element made up of a basic cell structured to previously seal a battery constitutional material or an electric double layer capacitor constitutional material in a gasket in an outer package. SOLUTION: An electrolytic solution injection hole 9 to communicate inside and outside of a basic cell to each other and a gas permeable and non-liquid permeable filter 10 to close the electrolytic solution injection hole 9 from the outside of the basic cell are provided on the basic cell 2A to constitute the element 3A. As the inside of the element 3A is decompressed in the same atmospheric pressure as the inside of a flexible film in a decompressing process to decompress and seal it in the flexible film, pressure applied on the element 3A by a difference with the atmospheric pressure becomes larger than the conventional case where the inside of the element is the atmospheric pressure. Leakage of the electrolytic solution in the basic cell 2A into the flexible film is prevented by non-liquid permeability of the filter 10.

Description

【００７０】
表１及び図７を参照して、実施例１と比較例１とは、ガスケット７側面の電解液注入孔９を通気撥水性フィルター１０で塞ぐ（実施例１：図１参照）か、通気性のない封止栓１２で塞ぐ（比較例１：図４参照）かが違っているだけである。然るに、実施例１の方が比較例１に比べ、ＥＳＲの初期値では約１／３、ばらつきでは１／５と小さく、充放電サイクル性能は１０倍も良い値を示している。これは、素子をラミネートフィルム製の外装パッケージ中に減圧封止する（図３参照）とき、実施例１においては、基本セル２Ａ内が通気撥水性フィルター１０を介して、外装パッケージと同時に、同じ真空度に減圧されるのに対し、比較例１においては、電解液注入孔９が通気性のない封止栓１２で予め塞がれていることから、基本セル２Ｃの内部は大気圧を保ったままであるという違いよるものであり、素子に係る圧力は実施例１の方が比較例１より大きいことを示すものであると考えられる。
【００７１】
次に、比較例１と比較例２とを比べると、比較例２の方が、ＥＳＲの初期値では１／２、ばらつきでは約１／２．５と小さく、充放電サイクル試験では５倍の良い性能を示している。この結果は、素子をラミネート製の外装パッケージ内に減圧封止する（図３参照）とき、基本セルの内部が大気圧のまま（比較例１：図４参照）であるか、予め減圧されている（比較例２：図５参照）かの相違に基づくものであり、素子に加わる圧力は、基本セル内を予め減圧に封止してからその基本セルを外装パッケージ内に減圧封止するという方法を採用した比較例２の方が、比較例１より大きいことを示しているものと考えられる。
【００７２】
しかしながら、実施例１と比較例２とを比較すると、実施例１の方が、ＥＳＲの初期値では約１／１．６、ばらつきでは約１／２と小さく、充放電サイクル性能は２倍の良い性能を示している。以上のことから、素子をラミネート製の外装パッケージ内に減圧封止するとき、基本セル内を予め減圧しておく比較例２の方法は、基本セル内が大気圧のままで減圧封止する比較例１の方法に比べ、基本セルに加わる圧力の点で改善効果が認められるものの、外装パッケージと基本セルとを同時に、同じ真空度に減圧する実施例１の方法に比べ、効果は限定的であるといえる。このことは、実施例５と比較例３とを比べた結果からも支持される。
【００７３】
すなわち、実施例５と比較例３とは、素子をラミネートフィルム製の外装パッケージ内に減圧封止する際、実施例５では外装パッケージ内と基本セルの内部とを、通気撥水性フィルターを介して、同時に、同じ真空度に減圧するのに対し、比較例３は、基本セル内を予め減圧にして封止してから、その減圧した基本セルを外装パッケージ内に減圧封止する点で異なっているのであるが、実施例５の方が、ＥＳＲの初期値の点でも、ばらつきの点でも、充放電サイクル性能の点でも優れた性能を示している。
【００７４】
次に、実施例３と実施例４とを比較すると、両者は、電解液注入孔９をガスケット７の側面に設ける（実施例３：図１参照）か上側の集電体６Ａに設ける（実施例４：図２参照）かの点で異なっているが、ＥＳＲの初期値及びばらつき、充放電サイクル性能とも同じ性能を示している。このことから、本発明において、基本セルに設ける電解液注入孔９及び通気撥水性フィルター１０は、ガスケットの側面に設けても集電体に設けても、基本セルに加わる圧力の点で、どちらでも同じ効果を示すと言える。
【００７５】
次に、実施例１、２、３を比較すると通気撥水性フィルター１０のガーレ数が小さくなるのに伴って、ＥＳＲの初期値も、ばらつきも小さくなってゆき、充放電サイクル性能は向上してゆく。これは、素子をラミネートフィルム性の外装パッケージ内に減圧封止する（図３参照）とき、チャンバー２１内を一定の排気能力の真空ポンプで一定の時間（実施例の場合は、ロータリーポンプで、１分間）で打ち切っていることから、基本セル内の真空度はフィルター１０のガーレ数が小さい方がより良くなり、その結果、ラミネートフィルムへの減圧封止が完了した後に基本セルに加わる圧力が大きくなるからであると考えられる。
【００７６】
次に、実施例４と実施例５とを比較すると、実施例５の方が、ＥＳＲの初期値も、ばらつきも約１／２と小さく、充放電サイクル性能は約２．５倍の良い値を示している。これは、集電体６Ｔ、６６Ｂ（図２参照）に用いる材料の体積固有抵抗値が、実施例４においては０．０１２Ω・ｍであるのに対し、実施例５においては０．００２Ω・ｍであって、実施例５の方が集電体自体の抵抗が小さいことによるものであると考えられる。このことは、集電体の導電率だけが異なる比較例２と比較例３と比べた場合、集電体の導電率が良い比較例３の方がＥＳＲの初期値、ばらつき、充放電サイクル性能とも優れた特性を示していることでも支持される。
【００７７】
ここで、上に述べた実施例は全て、素子が単セル構造の電池の例であるが、本発明は、これに限られるものではない。回路が要求する電圧に応じて、図１に示す実施例１〜３に係る基本セル（電解液注入孔をガスケットの側面に設けた構造の基本セル）を、図６（ａ）に示すように複数個直列に積層した積層セル構造の素子に対しても、実施例と同様の作用効果が得られる。図２に示す実施例４、５に係る基本セル（電解液注入孔を集電体に設けた構造の基本セル）を複数個直列に積層した（図６（ｂ））場合は、紙面下側の基本セルの電解液注入孔の上に、上側の基本セルの集電体６６Ｂが載ることになるが、ラミネートフィルム内に減圧封止する前では、上側の基本セルは単に下側の基本セルに載せてあるだけで、空気の流通という観点からすれば、上下の基本セルどうしの間のわずかな隙間が空気の流通路として働くので、本発明の作用原理発現には何ら支障はない。
【００７８】
尚、これまでの実施例においてはいずれの場合も、電解液に硫酸水溶液を用いたが、本発明はこれに限定されない。金属腐食性の電解質には、例えば硫酸、塩酸、硝酸、リン酸、ホウ酸等の無機酸、p-トルエンスルホン酸、トリフルオロ酢酸、テトラフルオロホウ酸、クエン酸、ポリビニルスルホン酸、ポリスチレンスルホン酸等の有機酸、硫酸水素アンモニウム、硫酸水素リチウム、硫酸水素ナトリウム、硫酸水素カリウム、テトラフルオロホウ酸ナトリウムなどの無機酸塩、有機酸塩を含む電解液が挙げられ、また溶媒も水に限らず有機溶媒であることもあるが、どのような電解液であっても構わない。更には、本発明が、腐食性の有無に限らず、電解液全般に適用できることは明らかであろう。
【００７９】
尚また、本発明は電池に限らず、電気二重層コンデンサに対しても適用可能である。これまでの説明から明らかなように、実施例１〜５は、電池構成材を予めガスケットに収納した構造の基本セルを用いる電池に対し、基本セルに通気非液体透過性のフィルターを設けることによって、電池の内部抵抗とそのばらつきを小さくし、充放電サイクル性能を向上させた例であり、本発明の作用効果は上記通気非液体透過性のフィルターで、基本セル内の気体に対してはセル外部への透過を許す一方で、電解液に対してはセル外部への漏出を許さないという、気体と液体とを分けるフィルター作用によって得られるところ、電池と電気二重層コンデンサとは、電池にあっては正極と負極とを用い、電気二重層コンデンサにあっては２つの分極性電極を用いるという相違はあるものの、基本セルの内部の空間に電解液を内包しているという点で、上記本発明の作用原理から見た場合、構造が同一であると言えるからである。
【００８０】
また、電気二重層コンデンサの分極性電極には、よく知られているような、活性炭の粉末と電解液とを混練したペースト状の分極性電極や、実施例で述べたような、粉末活性炭とバインダー樹脂とを含む混合粉末を熱プレス機で加圧成形したものや、更には、特開平４―２８８３６１号公報に開示されているような、活性炭の粉末又は繊維とフェノール樹脂との混合物を不活性ガス雰囲気注で高温度に熱し、炭化したフェノール樹脂で活性炭粉末（または繊維）どうしを結合させて得られる固体材料を用いるものなどがあるが、本発明はいずれの分極性電極を用いた場合でも、電解液を含む限り同じ作用効果を奏する。
【００８１】
【発明の効果】
以上説明したように、本発明によれば、素子をフレキシブルなフィルムからなる外装パッケージ内に減圧状態で封止した構造の電池又は電気二重層コンデンサで、特に電池構成材又は電気二重層コンデンサ構成材を予めガスケット内に封止した構造の基本セルを単独で又は複数個積層して素子とし、その素子を外装パッケージ内に減圧封止してなる電池又は電気二重層コンデンサにおいて、内部抵抗を小さくし、またそのばらつきも小さくなるようにすることができる。
【図面の簡単な説明】
【図１】本発明の実施例１〜３に係る電池の基本セルの平面図及び断面図図である。
【図２】本発明の実施例４、５に係る電池の基本セルの平面図及び断面図図である。
【図３】実施例及び比較例の電池を外装パッケージ内に減圧封止する方法を示す図である。
【図４】比較例１に係る電池の基本セルの断面を、製造工程順に示す図である。
【図５】比較例２、３に係る電池の基本セルを製造する方法を示す図である。
【図６】実施例１〜３に係る電池の基本セルを積層した積層セル構造の素子の断面図及び、実施例４、５に係る電池の基本セルを積層した積層セル構造の素子の断面図である。
【図７】実施例１〜５に係る電池の充放電サイクル試験の結果を示す図及び、比較例１〜３に係る電池の充放電サイクル試験の結果を示す図である。
【図８】ラミネートフィルム内に減圧封止した電池の一例の断面図である。
【図９】ラミネートフィルム内に減圧封止した電気二重層コンデンサの一例の平面図及び断面図並びに、コンデンサ素子の断面図である。
【符号の説明】
１Ａ 電池
２Ａ，２Ｂ，２Ｃ，２Ｄ 基本セル
３Ａ，３Ｂ，３Ｃ，３Ｄ 素子
４Ｔ 正極
４Ｂ 負極
５ セパレータ
６Ｔ 集電体
７ ガスケット
８Ｔ、８Ｂ 端子板
９ 電解液注入孔
１０ フィルター
１１Ｔ，１１Ｂ ラミネートフィルム
１２ 封止栓
１４Ｔ，１４Ｂ 分極性電極
１５ 外装パッケージ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery, an electric double layer capacitor, and a method of manufacturing the same, and more particularly, a battery and an electric double layer capacitor having a structure in which the battery element or the electric double layer capacitor element is sealed in a package made of a flexible film in a reduced pressure state. And a manufacturing method thereof.
[0002]
[Prior art]
In recent years, various electronic devices have been remarkably reduced in size and power saving, and accordingly, batteries and capacitors mounted on devices as power supply sources are strongly required to be reduced in size, weight and performance. ing.
[0003]
One of the items showing the performance as a power supply source of a battery or a capacitor is the value of the internal resistance. As a method for improving the internal resistance (reducing the resistance value), a battery or capacitor element has been conventionally used. A technique for sealing and packaging in a reduced pressure state in a flexible film such as a laminate film is known. For example, Japanese Patent Laid-Open No. 8-083596 discloses a thin card battery having a structure in which a battery constituent material is accommodated in a sealed outer package made of a flexible film. A battery with low resistance is disclosed.
[0004]
FIG. 8 shows again FIG. 1 of the above publication. For convenience of explanation, the reference numerals and names of the respective parts in FIG. 8 may be indicated by using different signs and names from those used in the above publication. Referring to FIG. 8, a battery 51 shown in this figure is a thin battery having a thickness of 200 μm, and is manufactured as follows. First, a flexible laminate film having a thickness of 30 μm and having a laminated structure of polyethylene / aluminum / polyethylene is used as the exterior material. After housing the positive electrode 4T, the separator 5, the negative electrode 4B, the electrolyte (not shown), the terminal plates 8T and 8B formed in advance in the exterior package 15 made of this laminate film, the inside of the package 15 is vacuum pumped. Connect to and depressurize. Then, after reducing the pressure inside the package for 10 seconds, the end of the laminate film as the exterior material is heat sealed with a heater at a temperature of 120 ° C., and the inside of the package 15 is sealed with the pressure reduced.
[0005]
In the battery 51 thus obtained, since the inside of the laminate film forming the outer package 15 is in a reduced pressure state, a uniform pressure is applied between the electrode current collectors by the atmospheric pressure. Thereby, since the adhesiveness between electrodes improves and contact resistance becomes small, the internal resistance of a battery is restrained low.
[0006]
The above is an example in which a vacuum sealing technique using a flexible film is applied to a battery, and an electric double layer capacitor is known in addition to a battery as a power supply source of an electronic device. An electric double layer capacitor is a capacitor that can easily realize a very large capacitance not found in other capacitors, such as a Farad (F) order, and because of its large capacity, an IC memory, a microprocessor, etc. It is also used as an alternative to batteries such as backup power supplies.
[0007]
An electric double layer capacitor is a dielectric layer that uses an electric double layer formed at a solid-liquid interface between a solid and a liquid as a dielectric layer, and has a principle of developing a capacitance. Although the electric double layer thickness is about the same as the molecular diameter and is much smaller than other capacitors, a large capacity can be obtained, but from the aspect of the structure to make the above principle practical. And an electrode that is electrochemically stable with respect to the electrolytic solution (polarizable electrode), and two such polarizable electrodes are placed opposite each other with an electrically insulating and ion-permeable porous separator interposed therebetween, A basic structure is a structure similar to a battery in which an electrolyte is included in a polarizable electrode or a separator. From the viewpoint of the present invention, it will be apparent from the following description that the basic structure of the electric double layer capacitor is equivalent to the basic structure of the battery.
[0008]
An example of an electric double layer capacitor to which a reduced pressure sealing technique using a laminate film is applied is described in Japanese Patent Application No. 2000-174266 by the same applicant as the present invention. FIG. 9A shows a plan view of an example of this type of electric double layer capacitor, and FIG. 9B shows a cross-sectional view taken along line A3-A3. Further, FIG. 9C shows a cross-sectional view of the sealed capacitor element.
[0009]
Referring to FIG. 9, in the illustrated electric double layer capacitor 61 as well, in the same way as in the battery described above, the capacitor element 63 is sealed in a vacuum state in the outer package 15 made of a flexible laminate film. . Referring to FIG. 9C showing a cross section of the capacitor element 63, the capacitor element 63 is an element having a stacked cell structure in which two basic cells 62 are stacked in series. Each basic cell 62 has its own charge storage function. The reason why the two basic cells 62 are stacked to form the element 63 is that the withstand voltage of the entire capacitor satisfies the withstand voltage required from the circuit side. Therefore, in general, the number of basic cells constituting the capacitor element is not limited to two and may be more than that. In addition, a single basic cell may be an element as it is. Terminal plates 8T and 8B with lead terminals are provided on the top and bottom surfaces of the element 63, respectively.
[0010]
Each basic cell 62 includes an electrically insulating and ion-permeable porous separator 5, a pair of polarizable electrodes 14 T and 14 B disposed so as to be in contact with the separator across the separator 5, and the two A pair of conductive current collectors 66T and 66B arranged so as to be in contact with the surface opposite to the separator 5 with respect to the polarizable electrode, and the polarizable electrodes 14T and 14B are surrounded by the current collectors 66T and 66B. An electrically insulating gasket 67 interposed between the gasket 67 and the upper and lower current collectors 66T and 66B in a state in which an electrolyte solution (not shown) is contained therein is sealed and sealed. . For example, a sulfuric acid aqueous solution is used as the electrolytic solution.
[0011]
For the current collectors 66T and 66B, for example, conductive rubber in which carbon is dispersed in butyl rubber to provide conductivity, or conductive plastic film in which carbon is dispersed in olefin-based resin to provide conductivity are used. . The gasket 67 is made of electrically insulating butyl rubber or olefin resin (without carbon dispersion).
[0012]
The basic cell 62 generally includes the polarizable electrode 14B, the separator 5 and the polarizable electrode 14T in a gasket 67, injects an electrolytic solution, and is covered with current collectors 66T and 66B. By heating while applying pressure between the bodies 66T and 66B, the current collector 66T and the gasket 67 and the current collector 66B and the gasket 67 are sealed by thermocompression bonding.
[0013]
Here, comparing the cross-sectional view of the battery 51 shown in FIG. 8 with the cross-sectional view of the element 63 of the electric double layer capacitor shown in FIG. 9C, in the case of the battery 51, the terminal plate is included in the exterior package 15. 8B, the negative electrode 4B, the separator 5, the positive electrode 4T, the terminal plate 8T, and the electrolytic solution are all exposed, whereas in the case of an electric double layer capacitor, the two polarizability 14T, 14B, the separator 5 and the electrolytic solution are The gasket 67 and the current collectors 66T and 66B above and below the gasket 67 are sealed and sealed, and are different in structure in that they are not directly exposed in the exterior package.
[0014]
The structural difference between the battery and the electric double layer capacitor is that the electric double layer capacitor 61 uses an aqueous sulfuric acid solution as an electrolytic solution. That is, when a corrosive electrolytic solution is used in addition to the sulfuric acid aqueous solution, if the electrolytic solution is exposed in the outer package 15, an electrode plate mainly made of a highly conductive metal such as copper or aluminum. 8T and 8B are corroded by the electrolytic solution. Therefore, the electrolytic solution must be once sealed in the gasket 67 and then accommodated in the exterior package 15. In the electric double layer capacitor 61 described above, a material that is not affected by an aqueous sulfuric acid solution such as butyl rubber or olefin resin is used for the gasket 67 and the current collectors 66T and 66B constituting the basic cell 62 for the same reason. The same is true for batteries if a corrosive electrolyte is used. In other words, whether it is a battery or an electric double layer capacitor, and a corrosive electrolyte is used, the battery component (positive electrode, negative electrode, separator and electrolyte) or the electric double layer capacitor component (two polarizable electrodes) The separator and the electrolytic solution) must be sealed once by some method and then stored in the outer package.
[0015]
[Problems to be solved by the invention]
As described above, in a battery or an electric double layer capacitor, by sealing the element in a flexible film in a reduced pressure state, pressure is applied to the element by atmospheric pressure to reduce the internal resistance, and the performance as a power supply source can be reduced. Can be improved. In that case, in a battery or an electric double layer capacitor using a corrosive material such as a sulfuric acid aqueous solution as an electrolyte, the structure of a basic cell constituting the element is, for example, as shown in FIG. The material or capacitor constituent material must be sealed in the gasket 67 in advance, and due to this, the effect of reducing internal resistance cannot be obtained sufficiently. This will be described below. In the following, in this section, in order to simplify the explanation and make it easy to understand, the electric double layer capacitor element 63 shown in FIG. 9C is mainly used, and the capacitor element 63 is formed from one basic cell 62. It is assumed that
[0016]
With reference to FIGS. 9B and 9C, the pressure applied between the current collectors 66T and 66B above and below the element 63, that is, the basic cell 62 is substantially determined by the difference between the atmospheric pressure and the atmospheric pressure in the basic cell 62. . Therefore, in order to increase the pressure applied to the basic cell 62, it is important to increase the degree of vacuum in the basic cell (lower the atmospheric pressure). In the case of the conventional electric double layer capacitor described above, when the basic cell 62 is manufactured, the gasket 67 and the current collectors 66T and 66B are thermocompression bonded at atmospheric pressure, so that the basic cell 62 is at atmospheric pressure. You can think about it. Therefore, in order to make the inside of the basic cell 62 lower than the atmospheric pressure, the thermocompression bonding between the gasket 67 and the current collectors 66T and 66B is performed not under atmospheric pressure but under reduced pressure and before sealing in the flexible film. In addition, it may be possible to reduce the pressure in the basic cell to atmospheric pressure or less in advance.
[0017]
However, in the case of this method, a basic cell forming step for sealing the capacitor constituent material in the gasket 67 under reduced pressure, and an outer packaging step for sealing the obtained basic cell, that is, the element 63 in the outer package 15 under reduced pressure. Since these are separate processes, generally, the atmospheric pressure in the basic cell 62 and the atmospheric pressure in the exterior package 15 are different. Therefore, the adhesion between the gasket 67 and the current collectors 66T and 66B, that is, the sealing performance of the basic cells varies due to variations in conditions when the gasket 67 and the current collectors 66T and 66B are thermocompression bonded. In the long term, the degree of vacuum in the basic cell 62 varies from one basic cell to another due to variations in the gas permeability of the conductive rubber that is the material of the current collectors 66T and 66B. In other words, the pressure applied to the basic cell 62 varies from capacitor to capacitor. This tendency increases the amount of carbon (conductive filler) in the conductive rubber or conductive plastic film, which is the material of the current collectors 66T and 66B, or reduces the film thickness in order to reduce the internal resistance of the basic cell. Then it becomes even more prominent. By doing so, the gas permeability of the current collectors 66T and 66B is further increased, so that the degree of vacuum in the basic cell 62 is likely to decrease in a short period of time, and accordingly the vacuum in the basic cell is reduced. This is because the variation in the degree will expand in a short period of time.
[0018]
When the pressure applied to the basic cell 62 varies as described above, the internal resistance of the battery or the electric double layer capacitor also varies, and as a result, the capacity of the battery or the capacitor varies. Moreover, charge / discharge cycle performance deteriorates. For example, in the case of a battery, the capacity (ampere hour) is determined by the discharge current (A) × discharge time (h) depending on the time required to discharge from a certain initial voltage to a certain voltage with a certain constant discharge current. However, if the basic cell resistance is large, the capacity decreases. As an example, let us consider a case where the discharge current is 100 mA, the discharge voltage range is 1.0 to 0 V, and the basic cell resistance is 1Ω and 10Ω. In this case, in the basic cell having a resistance of 1Ω, the voltage decreases by 100 mV (1Ω × 100 mA) in 1 second, and thus the discharge time is 10 seconds. On the other hand, in a basic cell having a resistance of 10Ω, the voltage decreases by 1 V in 1 sec. That is, if the basic cell resistance is large, the capacity decreases. Further, the resistance variation is reflected in the capacitance variation.
[0019]
On the other hand, the charge / discharge cycle performance of a battery or an electric double layer capacitor is defined by the number of charge / discharge cycles until the capacity drops to a certain constant value of the initial value when charge / discharge with a constant current is repeated. . In a battery or an electric double layer capacitor, when the charge / discharge cycle is repeated, some gas is generated in the basic cell. This generated gas reduces the pressure applied to the basic cell from the inside, and as a result, increases the resistance of the basic cell. And if resistance increases, since capacity | capacitance will reduce as mentioned above, cycle performance of charging / discharging will fall. If the basic cell is not sufficiently pressurized in the initial state, even a small amount of gas causes an increase in resistance, and the cycle performance is significantly deteriorated.
[0020]
As described above, the magnitude or variation of the internal resistance in the battery or the electric double layer capacitor influences the capacitance and the variation, and is an important characteristic item having a great influence on the charge / discharge cycle performance. In a battery or electric double layer capacitor having a structure in which a battery constituent material or an electric double layer capacitor constituent material as shown in (c) is previously sealed in a gasket and sealed in a flexible film in a reduced pressure state, It is difficult to reduce the internal resistance and its variation.
[0021]
Therefore, the present invention is a battery or electric double layer capacitor having a structure in which an element is sealed in an external package made of a flexible film in a reduced pressure state. In a battery or electric double layer capacitor in which a double cell capacitor component is sealed in a gasket in advance or a plurality of basic cells are used to form an element, and the element is sealed under reduced pressure in an exterior package The purpose is to reduce the internal resistance and to reduce the variation.
[0022]
[Means for Solving the Problems]
  In the battery of the present invention, a battery constituent material including at least a separator, a positive electrode and a negative electrode, and an electrolyte solution that are opposed to each other is surrounded by a cylindrical gasket and a current collector that covers both upper and lower surfaces thereof. A single cell or a plurality of basic cells stacked in series to form an element, and the element is stored in a sealed package made of a flexible exterior film together with an electrode plate with lead terminals. In a battery in which the inside of the package is in a decompressed state,Each of the basic cells has a through-hole that passes through the inside and outside of the basic cell, and a gas-permeable and non-liquid-permeable filter that closes the through-hole from the outside of the basic cell,The interior of each basic cell constituting the element and the space in the package made of the exterior filmSimultaneous decompressionIt is characterized by that.
[0023]
  In the battery described above, a battery constituent material including a separator, a positive electrode and a negative electrode that are opposed to each other, and an electrolyte solution is accommodated in a space surrounded by a cylindrical gasket and a current collector that covers both upper and lower surfaces thereof. A basic cell forming process for forming a basic cell, an element forming process for forming an element by stacking the basic cells individually or in series, and lead terminals on each of the two outermost current collectors of the element And a sealing process of sealing in a reduced pressure state in a sealed package made of a flexible film after disposing the attached electrode plate, in the sealing process, in the package and in the package Simultaneously within each basic cell constituting the elementReduced toIt is manufactured by a method for manufacturing a battery, wherein the package is sealed in a pressed state.
[0024]
  In addition, the electric double layer capacitor of the present invention is composed of a cylindrical gasket and both upper and lower surfaces of the electric double layer capacitor constituent material including at least two polarizable electrodes and an electrolyte solution facing each other across the separator. A basic cell housed in a space surrounded by a current collector to be closed is formed as an element by laminating alone or in series, and the element is composed of a flexible exterior film together with an electrode plate with lead terminals. An electric double layer capacitor having a structure housed in a sealed package, wherein the inside of the package is in a decompressed state,Each of the basic cells has a through-hole that passes through the inside and outside of the basic cell, and a gas-permeable and non-liquid-permeable filter that closes the through-hole from the outside of the basic cell,The interior of each basic cell constituting the element and the space in the package made of the exterior filmSimultaneous decompressionIt is characterized by that.
[0025]
  In the electric double layer capacitor described above, an electric double layer capacitor constituent material including a separator, a positive electrode and a negative electrode facing each other, and an electrolyte is surrounded by a cylindrical gasket and a current collector that covers both upper and lower surfaces thereof. A basic cell forming process for forming a basic cell accommodated in a space, an element forming process for forming an element by stacking the basic cells individually or in series, and two outermost current collectors of the element In the method of manufacturing an electric double layer capacitor, the method further includes: a sealing process in which an electrode plate with a lead terminal is disposed on each of the bodies, and then sealed in a sealed package made of a flexible film in a reduced pressure state. In the stopping process, the inside of the package and the inside of each basic cell constituting the element are simultaneouslyReduced toSeal the package under pressureRukoIt is manufactured by the manufacturing method of the electric double layer capacitor characterized by these.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings, using five examples and three comparative examples. In FIG. 1, the top view of the basic cell used for the battery which concerns on Example 1, 2, 3 of this invention, and sectional drawing in an A1-A1 cutting line are shown. In FIG. 2, the top view of the basic cell used for the battery which concerns on Example 4, 5 and sectional drawing in A2-A2 cutting line are shown. FIG. 4B shows a cross-sectional view of the basic cell used in the battery according to Comparative Example 1. FIG. 5D shows a cross-sectional view of the basic cell used in the batteries according to Comparative Examples 2 and 3. In Examples 1 to 5 and Comparative Examples 1 to 3, a single basic cell shown in each of the above figures was used as an element, and the element of the single cell structure was sealed in a package 15 made of a flexible laminate film under reduced pressure. . The materials and methods for sealing under reduced pressure in the outer package 15 are the same in any of the examples and comparative examples.
[0027]
1 and 2 showing the basic cell of the embodiment and FIGS. 4 and 5 showing the basic cell of the comparative example, the battery or electric double layer capacitor according to the present invention has the electrolyte injection hole 9 in the basic cell. There is a structural feature in that it is provided and a ventilation non-liquid permeable filter 10 that closes the electrolyte injection hole 9 from the outside of the basic cell is provided. Below, each Example and a comparative example are demonstrated in detail.
[0028]
Example 1
With reference to FIG. 1, the basic cell 2A of the battery according to Example 1 was produced as follows. First, the positive electrode 4T is produced. Polyindole is used as the positive electrode active material and vapor growth carbon is used as the conductive auxiliary agent. The mixture is mixed at a weight ratio of 4: 1, and the mixture is weighted with polyvinylidene fluoride (average molecular weight: 1100) as a binder resin. The ratio was adjusted by adding 8 wt%. The mixed powder was sufficiently stirred with a blender and formed into a square sheet of a predetermined size using a hot press machine to obtain a positive electrode.
[0029]
Separately, the negative electrode 4B is produced. Polyphenylquinoxaline was used as the negative electrode active material, vapor phase growth carbon was used as the conductive auxiliary agent, and the weight ratio was adjusted to 3: 1. This mixed powder was sufficiently stirred with a blender and formed into a square of a predetermined size using a hot press machine to obtain a negative electrode.
[0030]
Separately from the positive electrode 4T and the negative electrode 4B, a conductive butyl rubber sheet is cut into a square to prepare current collectors 66T and 66B. The conductive butyl rubber, which is a material of these current collectors, is obtained by dispersing carbon in a base butyl rubber and imparting conductivity.₂ Gas permeability coefficient: 5.3 × 10^{- 14} m^Three / M² / S · Pa, volume resistivity: 0.012 Ω · m.
[0031]
Further, an insulating butyl rubber sheet is cut into a rectangular frame shape to prepare a gasket 7. The gasket 7 has an outer size that is the same as that of the current collectors 66T and 66B described above, and an inner size that is slightly larger than the positive electrode 4T and the negative electrode. A part of the side surface is provided with a through hole (electrolyte injection hole) 9 through the outside and inside of the frame.
[0032]
In addition, a separator 5 is prepared by cutting a porous insulating sheet based on polypropylene resin into a square. The size of the separator 5 is smaller than the inner size of the gasket 7 and larger than the positive electrode 4T and the negative electrode 4B.
[0033]
And after mounting the said frame-shaped gasket 7 on the electrical power collector 66B, the negative electrode 4B, the separator 5, and the positive electrode 4T are accommodated in the gasket 7, and also the electrical power collector 66T is covered. Then, thermocompression bonding was performed at a temperature of 120 ° C. for 3 hours while applying pressure between the current collectors 66T and 66B from above and below, and between the current collector 66T and the gasket 7 and between the current collector 66B and the gasket 7 The vulcanization was adhered between the two.
[0034]
After cooling, a sulfuric acid aqueous solution (electrolytic solution) is injected into the basic cell under reduced pressure and pressure from the electrolytic solution injection hole 9 provided on the side surface of the gasket 7. After the injection, the basic cell 2A is completed by adhering an air-repellent water-repellent filter 10 having a Gurley number (a value representing the time until 100 cc of air escapes) to the electrolyte injection hole 9 from the outside of the gasket 7. To do. In this example, the element 3A is completed. As the filter 10, a sheet having a continuous porous structure made of polytetrafluoroethylene (manufactured by Japan Gore-Tex Co., Ltd., trade name: GORE-TEX (R) vent filter) was used. The filter 10 has water repellency and air permeability, and has a property of allowing gas to pass but not water.
[0035]
After the element 3A is completed, it is depressurized and sealed in an exterior package 15 made of a flexible laminate film as follows. Referring to FIG. 3 which shows a cross section of the element when sealed in a package in the order of operation, as shown in FIG. 3A and FIG. Copper terminal plates 8T and 8B with lead terminals are placed on the outside of the electric bodies 66T and 66B, respectively, and sandwiched between two upper and lower flexible laminate films 11T and 11B. For the laminate films 11T and 11B, a film having a three-layer structure of ionomer / aluminum / nylon was used. In addition, a four-layer structure of ionomer / polyethylene / aluminum / nylon can be used, but is not particularly limited to the one containing an aluminum core. Any film may be used as long as it is flexible and has a high air barrier property and can be heat-sealed.
[0036]
Thereafter, as shown in FIG. 3C, the laminate film is put together in the chamber 21 that can be evacuated, and the chamber 21 is decompressed. A vacuum pump (not shown) was used for decompression, and the chamber was evacuated for 1 minute. By this exhaust, the basic cell 2A is exhausted and depressurized through the filter 10. After predetermined evacuation, the ends of the two upper and lower laminate films 11T and 11B sandwiching the element and the terminal plate are heat-sealed and sealed in the decompressed chamber 21. By this series of exhaust and sealing operations, the inside of the basic cell 2A and the inside of the package 15 are sealed with the same degree of vacuum. On the other hand, due to the water repellency of the filter 10, the sulfuric acid aqueous solution (electrolytic solution) in the basic cell 2A does not leak out of the cell 2A.
[0037]
Finally, the chamber 21 is returned to atmospheric pressure to obtain the battery 1A of the present example whose sectional view is shown in FIG.
[0038]
In Example 1, 1000 batteries each having a single cell structure were manufactured by the above-described method, and the initial value and variation of the equivalent series resistance (ESR) of the battery and the charge / discharge cycle performance were evaluated. ESR was measured at AC 1 kHz. 10 mA / cm for charge / discharge cycle test² The charge / discharge cycle performance was evaluated by repeating the constant current charge / discharge of 1.2 V with the number of cycles until 80% of the initial capacity was reached. The results are shown in Table 1 and FIG. The average value of the initial value of ESR was 30 mΩ, and the variation was 3σ = 8 mΩ. The charge / discharge cycle performance was 10,000 times.
[0039]
(Example 2)
In Example 2, 1000 batteries having the same material and the same structure as Example 1 were produced by the same method except that the vented water-repellent filter 10 having the Gurley number of 30 sec was used in Example 1, and the same method was used. 1 was used to evaluate the initial values and variations of ESR and charge / discharge cycle performance. The results are shown in Table 1 and FIG. The average value of the initial value of ESR was 20 mΩ, and the variation was 3σ = 4 mΩ. The charge / discharge cycle performance was 50000 times.
[0040]
Example 3
In Example 3, 1000 batteries having the same material and the same structure as Example 1 were produced by the same method except that the vent water-repellent filter 10 having a Gurley number of 1 sec in Example 1 was used. The initial value and variation of ESR and charge / discharge cycle performance were evaluated by the same method as in. The results are shown in Table 1 and FIG. The average value of the initial value of ESR was 10 mΩ, and the variation was 3σ = 1 mΩ. The charge / discharge cycle performance was 200000 times.
[0041]
Example 4
This Example 4 is a battery different from Example 3 in that the air-permeable water repellent filter 10 is provided on the current collector. Compared with Examples 1-3 so far, there is an advantage that the ventilated water-repellent filter 10 can be provided even for a thin basic cell.
[0042]
To produce a battery according to Example 4 with reference to FIG. 2 showing a plan view of a basic cell 2B used in the battery according to Example 4 and a cross-sectional view taken along the line A2-A2, A positive electrode 4T and a negative electrode 4B are prepared using the same material and method as in Examples 1 to 3.
[0043]
Further, current collectors 6T and 66B are prepared using the same material and the same method as in Examples 1 to 3. However, unlike in the first to third embodiments, only one current collector 6T of the two current collectors has a part of a region along one side of the quadrangle (in this example, on the left side of the page). An electrolytic solution injection hole 9 is provided in the central part of the side.
[0044]
In addition, a frame-shaped gasket 67 is prepared using the same material and the same method as in the first to third embodiments. However, unlike the gaskets used in the first to third embodiments, the gasket 67 of this embodiment has a simple frame shape with no through holes provided on the side surfaces.
[0045]
Separately, the separator 5 is prepared with the same material and the same method as in the first to third embodiments.
[0046]
Then, after mounting the frame-shaped gasket 67 on the current collector 66B in the same manner as in Examples 1 to 3, the negative electrode 4B, the separator 5, and the positive electrode 4T are accommodated in the gasket 67, and Mount the current collector 6T. Then, thermocompression bonding is performed at a temperature of 120 ° C. for 3 hours while applying pressure between the current collectors 6T and 66B from above and below, and between the current collector 6T and the gasket 67 and between the current collector 66B and the gasket 67. And vulcanized and bonded.
[0047]
After cooling, a sulfuric acid aqueous solution is pressure-injected under reduced pressure into the basic cell from the electrolyte injection hole 9 provided in the upper current collector 6T. After the injection, an air-repellent water-repellent filter (this is the same filter used in Example 3) 10 having a Gurley number of 1 sec is adhered to the electrolyte injection hole 9 from the outside of the current collector 6T. The cell 2B, that is, the element 3B is completed.
[0048]
After the completion of the element 3B, the same material as that of the vacuum sealing in Examples 1 to 3 shown in FIG. 3 is used, and the element 3A in FIG. 3 is replaced by the element 3B shown in FIG. The inside of 3B and the inside of the exterior package 15 are depressurized to the same atmospheric pressure, and the laminate film is sealed in the depressurized state to complete the battery of this example. The completed battery is different from Example 3 in that the electrolyte injection hole 9 is provided not in the gasket but in the upper current collector 6T.
[0049]
In Example 4, 1000 batteries having a single cell structure were prepared, and the initial value and variation of ESR and charge / discharge cycle performance were evaluated by the same method as in Example 1. The results are shown in Table 1 and FIG. The average value of the initial value of ESR was 10 mΩ, and the variation was 3σ = 8 mΩ. The charge / discharge cycle performance was 200000 times.
[0050]
(Example 5)
In Example 5, a battery having the same material and the same structure as in Example 4 except that the material of the current collectors 6T and 66B in Example 4 is changed from conductive butyl rubber to a conductive plastic film having higher conductivity. 1000 were manufactured by the same method, and the initial value and variation of ESR and charge / discharge cycle performance were evaluated by the same method as in Example 1. The conductive plastic film, which is the material of the current collectors 6T and 66B of this example, is obtained by dispersing carbon in a base ethylene-styrene-butylene copolymer resin to provide conductivity.₂ Gas permeation coefficient: 6.8 × 10^-12 m^Three / M² / S · Pa, volume resistivity: 0.002 Ω · m. In the fifth embodiment, the ESR can be further reduced by increasing the conductivity of the current collectors 6T and 66B as compared with the fourth embodiment.
[0051]
The performance evaluation results are shown in Table 1 and FIG. The average value of the initial value of ESR was 20 mΩ, and the variation was 3σ = 4 mΩ. The charge / discharge cycle performance was 50000 times.
[0052]
(Comparative Example 1)
In this comparative example, the same material and the same structure as in Example 1 except that the electrolyte injection hole 9 on the side surface of the gasket was blocked with a breathable water-repellent filter instead of being sealed with a non-breathable sealing plug. 1000 batteries were produced by the same method, and the initial value and variation of ESR and charge / discharge cycle performance were evaluated by the same method as in Example 1.
[0053]
In order to manufacture a battery according to Comparative Example 1 with reference to FIG. 4 showing the cross-sectional views of the basic cell 2C in this comparative example in the order of the manufacturing process, first, the positive electrode with the same material and the same method as in Example 1 is used. 4T and the negative electrode 4B are prepared.
[0054]
Further, current collectors 66T and 66B are prepared using the same material and the same method as in the first embodiment. The current collectors 66T and 66B are made of conductive butyl rubber and are made of CO.₂ Gas permeability coefficient is 5.3 × 10^{- 14} m^Three / M² / S · Pa, and the volume resistivity is 0.012 Ω · m.
[0055]
In addition, a frame-shaped gasket 7 having an electrolyte injection hole 9 formed in the side surface is prepared by the same material and method as in the first embodiment.
[0056]
Separately, the separator 5 is prepared using the same material and method as in the first embodiment.
[0057]
Then, after mounting the frame-shaped gasket 7 on the current collector 66B in the same manner as in Example 1, the negative electrode 4B, the separator 5, and the positive electrode 4T are accommodated in the gasket 7, and the current collector is further collected. Cover the body 66T. Then, thermocompression bonding is performed while applying pressure between the current collectors 66T and 66B from above and below to vulcanize and bond between the current collector 66T and the gasket 7 and between the current collector 66B and the gasket 7.
[0058]
After cooling, a sulfuric acid aqueous solution is injected into the basic cell under reduced pressure and pressure from the electrolyte injection hole 9 provided on the side surface of the gasket 7. Next, after the electrolyte solution is injected, a sealing plug 12 having no air permeability is filled in the injection hole 9 and fixed with an adhesive to complete the basic cell 2C, that is, the element 3C.
[0059]
After the completion of the element 3C, the same method is used by using the same material as the reduced pressure sealing in the first to third embodiments shown in FIG. 3 (however, the element 3A in FIG. 3 is replaced with the element 3C shown in FIG. 4B). Thus, the outer package 15 is sealed under reduced pressure. The battery of Comparative Example 1 produced in this way is different from the battery of Example 1 in that the electrolyte injection hole 9 on the side surface of the gasket 7 is closed with a non-breathable sealing plug 12. Will be. In Comparative Example 1, since the electrolyte injection hole 9 on the side surface of the gasket is closed with a non-breathable sealing plug 12, when the element 3C is sealed in the laminate package 15 under reduced pressure, the basic cell 2C The interior is not evacuated and remains at atmospheric pressure.
[0060]
In this comparative example, 1000 batteries having a single cell structure were prepared, and the initial value and variation of ESR and charge / discharge cycle performance were evaluated by the same method as in Example 1. The results are shown in Table 1 and FIG. The average value of the initial value of ESR was 100 mΩ, and the variation was 3σ = 40 mΩ. The charge / discharge cycle performance was 1000 times.
[0061]
(Comparative Example 2)
The comparative example 2 differs from the comparative example 1 in the method of injecting the electrolytic solution when producing the basic cell and the method of containing the injected electrolytic solution in the basic cell.
[0062]
Referring to FIG. 5 showing the cross section of the basic cell of Comparative Example 2 in the order of the manufacturing process, first, using the same material as in Comparative Example 1, positive electrode 4T, negative electrode 4B, separator 5, gasket 67, current collector by the same method. 66T and 66B are prepared. However, in this comparative example 2, a simple frame-like gasket having no electrolyte injection hole on the side surface is used as the gasket 67.
[0063]
Next, the gasket 67 without the electrolyte injection hole is placed on the lower current collector 66B, and after the negative electrode 4B, the separator 5, and the positive electrode 4T are accommodated therein, as shown in FIG. A sulfuric acid aqueous solution is injected as an electrolytic solution. Next, as shown in FIG. 5B, the whole is put into a chamber 23 that can be evacuated as it is, the chamber 23 is evacuated and decompressed, and the upper current collector 66T is covered.
[0064]
Then, as shown in FIG. 5 (c), thermocompression bonding is performed at 120 ° C. for 3 hours while applying pressure between the upper and lower current collectors 66T and 66B in the decompressed chamber 23 to collect the current. The basic cell 2D, that is, the element 3D is completed by vulcanizing and bonding between the body 66T and the gasket 67 and between the current collector 66B and the gasket 67.
[0065]
After the completion of the element 3D, the same material as that of the vacuum sealing in Examples 1 to 3 shown in FIG. 3 is used in the same manner (however, the element 3A in FIG. 3 is replaced with the element 3D shown in FIG. 5D). Replace), and seal in the outer package 15 under reduced pressure. The battery of Comparative Example 2 and the battery of Comparative Example 1 manufactured in this way are different from each other in Comparative Example 1 in that the inside of the basic cell constituting the element 3C is atmospheric pressure. The difference is that the inside of the basic cell 3D is decompressed in advance before being sealed in the exterior package 15 under reduced pressure.
[0066]
In Comparative Example 2, 1,000 batteries having a single cell structure were produced by the manufacturing method described above, and the initial value and variation of ESR and charge / discharge cycle characteristics were evaluated by the same method as in Example 1. did. The results are shown in Table 1 and FIG. The average value of the initial value of ESR was 50 mΩ, and the variation was 3σ = 15 mΩ. The charge / discharge cycle performance was 5000 times.
[0067]
(Comparative Example 3)
In this comparative example, compared to Comparative Example 2, the current collectors 66T and 66B are made of conductive plastic based on ethylene-styrene-butylene copolymer resin, and the volume specific resistance values of the current collectors 66T and 66B are set as follows. 1000 batteries having the same material and the same structure as Comparative Example 2 were produced by the same method except that the difference was lowered. And the initial value and dispersion | variation of ESR, and charging / discharging cycling performance were evaluated by the same method as in Example 1. The current collectors 66T and 66B used in this comparative example 3 are made of CO.₂ Gas permeability coefficient is 6.8 × 10^-12 m^Three / M² It is made of an ethylene-styrene-butylene copolymer resin-based conductive plastic having a volume resistivity of 0.002 Ω · m, and is the same as the current collector used in Example 5 described above.
[0068]
The performance evaluation results are shown in Table 1 and FIG. The average value of the initial value of ESR was 30 mΩ, and the variation was 3σ = 11 mΩ. The charge / discharge cycle performance was 10,000 times.
[0069]
[Table 1]

[0070]
Referring to Table 1 and FIG. 7, in Example 1 and Comparative Example 1, the electrolyte injection hole 9 on the side surface of the gasket 7 is closed with a ventilation water-repellent filter 10 (Example 1: see FIG. 1) or air permeability. The only difference is whether or not it is sealed with a sealing plug 12 having no gap (Comparative Example 1: see FIG. 4). However, compared with Comparative Example 1, Example 1 has a smaller ESR initial value of about 1/3 and a variation of 1/5, and the charge / discharge cycle performance is 10 times as good. This is because when the element is sealed under reduced pressure in an exterior package made of a laminate film (see FIG. 3), in Example 1, the inside of the basic cell 2A is the same as the exterior package via the ventilated water-repellent filter 10. While the pressure is reduced to a degree of vacuum, in Comparative Example 1, the electrolyte injection hole 9 is previously closed with a non-breathable sealing plug 12, so that the inside of the basic cell 2C is kept at atmospheric pressure. It is considered that the pressure applied to the element indicates that Example 1 is larger than Comparative Example 1.
[0071]
Next, when comparing Comparative Example 1 and Comparative Example 2, Comparative Example 2 has a smaller ESR initial value of 1/2, a variation of about 1 / 2.5, and a charge / discharge cycle test of 5 times. Shows good performance. As a result, when the device is sealed under reduced pressure in a laminate outer package (see FIG. 3), the inside of the basic cell remains at atmospheric pressure (Comparative Example 1: see FIG. 4), or the pressure is reduced in advance. (Comparative Example 2: refer to FIG. 5), the pressure applied to the element is that the basic cell is sealed in advance under reduced pressure and then the basic cell is sealed under reduced pressure in the exterior package. It is considered that Comparative Example 2 employing the method is larger than Comparative Example 1.
[0072]
However, when Example 1 and Comparative Example 2 are compared, Example 1 has a smaller ESR initial value of about 1 / 1.6 and variation of about 1/2, and the charge / discharge cycle performance is doubled. Shows good performance. From the above, when the device is sealed under reduced pressure in a laminate outer package, the method of Comparative Example 2 in which the pressure in the basic cell is reduced in advance is a comparison in which the pressure in the basic cell is kept at atmospheric pressure. Although an improvement effect is recognized in terms of pressure applied to the basic cell compared to the method of Example 1, the effect is limited compared to the method of Example 1 in which the exterior package and the basic cell are simultaneously decompressed to the same degree of vacuum. It can be said that there is. This is also supported from the result of comparing Example 5 and Comparative Example 3.
[0073]
That is, in Example 5 and Comparative Example 3, when the element was sealed under reduced pressure in an outer package made of a laminate film, in Example 5, the inside of the outer package and the inside of the basic cell were passed through a ventilation water repellent filter. At the same time, while the pressure is reduced to the same degree of vacuum, the comparative example 3 is different in that the basic cell is previously reduced in pressure and sealed, and then the reduced basic cell is reduced in pressure and sealed in the exterior package. However, Example 5 shows better performance in terms of the initial value of ESR, variation, and charge / discharge cycle performance.
[0074]
Next, when Example 3 and Example 4 are compared, both of them provide the electrolyte injection hole 9 on the side surface of the gasket 7 (Example 3: refer to FIG. 1) or the upper current collector 6A (implementation). Example 4: Refer to FIG. 2). However, the initial value and variation of ESR and charge / discharge cycle performance are the same. Therefore, in the present invention, the electrolyte injection hole 9 and the air permeable water repellent filter 10 provided in the basic cell are either provided on the side surface of the gasket or provided on the current collector, in terms of the pressure applied to the basic cell. But the same effect can be said.
[0075]
Next, when Examples 1, 2, and 3 are compared, as the Gurley number of the ventilated water-repellent filter 10 decreases, the initial value of ESR also decreases, and the charge / discharge cycle performance improves. go. This is because when the element is sealed under reduced pressure in a laminated film package (see FIG. 3), the inside of the chamber 21 is fixed with a vacuum pump having a constant exhaust capacity (in the case of the embodiment, with a rotary pump, 1 degree), the degree of vacuum in the basic cell is better when the Gurley number of the filter 10 is smaller. As a result, the pressure applied to the basic cell after the vacuum sealing to the laminate film is completed This is thought to be because it grows.
[0076]
Next, when Example 4 and Example 5 are compared, Example 5 has a smaller initial value of ESR and variation of about 1/2, and charge / discharge cycle performance is a good value of about 2.5 times. Is shown. This is because the volume specific resistance value of the material used for the current collectors 6T and 66B (see FIG. 2) is 0.012 Ω · m in the fourth embodiment and 0.002 Ω · m in the fifth embodiment. Thus, it is considered that Example 5 is due to the lower resistance of the current collector itself. This is because, when compared with Comparative Example 2 and Comparative Example 3 in which only the electrical conductivity of the current collector is different, Comparative Example 3 having a better electrical conductivity of the current collector has an ESR initial value, variation, and charge / discharge cycle performance. Both are also supported by their excellent properties.
[0077]
Here, all of the embodiments described above are examples of a battery having a single cell structure, but the present invention is not limited to this. As shown in FIG. 6 (a), basic cells (basic cells having a structure in which an electrolyte injection hole is provided on the side surface of the gasket) according to Examples 1 to 3 shown in FIG. 1 according to the voltage required by the circuit are obtained. The same effects as those of the embodiment can be obtained for a device having a stacked cell structure in which a plurality of devices are stacked in series. When a plurality of basic cells (basic cells having a structure in which an electrolyte injection hole is provided in a current collector) according to Examples 4 and 5 shown in FIG. 2 are stacked in series (FIG. 6B), the lower side of the page The current collector 66B of the upper basic cell is placed on the electrolyte injection hole of the basic cell, but the upper basic cell is simply the lower basic cell before being sealed under reduced pressure in the laminate film. From the viewpoint of air flow, a slight gap between the upper and lower basic cells acts as an air flow path, and there is no problem in the expression of the operation principle of the present invention.
[0078]
In any of the embodiments described so far, the sulfuric acid aqueous solution is used as the electrolytic solution in any case, but the present invention is not limited to this. Examples of metal corrosive electrolytes include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and boric acid, p-toluenesulfonic acid, trifluoroacetic acid, tetrafluoroboric acid, citric acid, polyvinyl sulfonic acid, and polystyrene sulfonic acid. Examples include organic acids such as ammonium hydrogensulfate, lithium hydrogensulfate, sodium hydrogensulfate, potassium hydrogensulfate, sodium tetrafluoroborate, and other electrolytes containing organic acid salts, and the solvent is not limited to water. Although it may be an organic solvent, any electrolyte may be used. Furthermore, it will be apparent that the present invention is applicable not only to the presence or absence of corrosiveness, but to all electrolytes.
[0079]
In addition, the present invention is not limited to a battery but can be applied to an electric double layer capacitor. As is apparent from the above description, in Examples 1 to 5, the battery using the basic cell having a structure in which the battery constituent material is previously stored in the gasket is provided with a ventilation non-liquid permeable filter in the basic cell. This is an example in which the internal resistance of the battery and its variation are reduced, and the charge / discharge cycle performance is improved, and the operational effect of the present invention is the above-mentioned air-permeable non-liquid permeable filter. The battery and electric double-layer capacitor are suitable for the battery because it is obtained by the filter action that separates gas and liquid while allowing permeation to the outside but not allowing leakage of electrolyte to the outside of the cell. Although there is a difference between using a positive electrode and a negative electrode and using two polarizable electrodes in an electric double layer capacitor, the electrolyte is contained in the space inside the basic cell. Cormorants in that, when viewed from the working principle of the present invention, because it can be said that the structure is the same.
[0080]
In addition, the polarizable electrode of the electric double layer capacitor includes a well-known paste-like polarizable electrode obtained by kneading activated carbon powder and an electrolyte, and powdered activated carbon as described in the examples. The mixture powder containing the binder resin is pressure-molded with a hot press machine, and further, a mixture of activated carbon powder or fiber and phenol resin as disclosed in JP-A-4-288361 is not used. There are those that use a solid material obtained by bonding activated carbon powder (or fibers) with carbonized phenol resin heated to high temperature in an active gas atmosphere injection, but the present invention uses any polarizable electrode However, as long as the electrolytic solution is included, the same effect is obtained.
[0081]
【The invention's effect】
As described above, according to the present invention, a battery or an electric double layer capacitor having a structure in which an element is sealed in an external package made of a flexible film in a reduced pressure state, particularly a battery component or an electric double layer capacitor component. In a battery or electric double layer capacitor in which a basic cell having a structure sealed in advance in a gasket is singly or laminated to form an element and the element is sealed under reduced pressure in an exterior package, the internal resistance is reduced. In addition, the variation can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view and a cross-sectional view of a basic cell of a battery according to Examples 1 to 3 of the present invention.
FIG. 2 is a plan view and a cross-sectional view of a basic cell of a battery according to Examples 4 and 5 of the present invention.
FIG. 3 is a view showing a method for sealing the batteries of Examples and Comparative Examples in an outer package under reduced pressure.
4 is a view showing cross sections of basic cells of a battery according to Comparative Example 1 in the order of manufacturing steps; FIG.
FIG. 5 is a diagram showing a method for manufacturing a basic cell of a battery according to Comparative Examples 2 and 3;
6 is a cross-sectional view of an element having a stacked cell structure in which basic cells of batteries according to Examples 1 to 3 are stacked, and a cross-sectional view of an element having a stacked cell structure in which basic cells of batteries according to Examples 4 and 5 are stacked. It is.
7 is a diagram showing results of charge / discharge cycle tests for batteries according to Examples 1 to 5 and a diagram showing results of charge / discharge cycle tests for batteries according to Comparative Examples 1 to 3. FIG.
FIG. 8 is a cross-sectional view of an example of a battery sealed under reduced pressure in a laminate film.
FIG. 9 is a plan view and a cross-sectional view of an example of an electric double layer capacitor sealed under reduced pressure in a laminate film, and a cross-sectional view of a capacitor element.
[Explanation of symbols]
1A battery
2A, 2B, 2C, 2D basic cells
3A, 3B, 3C, 3D element
4T positive electrode
4B negative electrode
5 Separator
6T current collector
7 Gasket
8T, 8B terminal board
9 Electrolyte injection hole
10 Filter
11T, 11B Laminate film
12 Sealing stopper
14T, 14B Polarized electrode
15 Exterior package

Claims (8)

A battery constituent material including a separator, a positive electrode and a negative electrode facing each other, and an electrolyte, a cylindrical gasket that accommodates the battery constituent material therein, and a current collector that covers both upper and lower surfaces of the gasket A basic cell comprising a single element or a plurality of elements stacked in series, an electrode plate with a lead terminal for electrically connecting the element to the outside, and a flexible exterior housing the element and the electrode plate A battery comprising a sealed package made of a film for use, wherein the package has a reduced pressure inside.
Each of the basic cells includes a through-hole that passes through the inside and outside of the basic cell, and a gas-permeable and non-liquid-permeable filter that closes the through-hole from the outside of the basic cell. An electric double layer capacitor component comprising a separator, two polarizable electrodes opposed to each other, and an electrolyte; a cylindrical gasket containing the electric double layer capacitor component; and upper and lower portions of the gasket A basic cell composed of a current collector that covers both surfaces, a single element or a plurality of elements stacked in series, an electrode plate with a lead terminal for electrically connecting the element to the outside, the element and In an electric double layer capacitor containing an electrode plate, which is a sealed package made of a flexible exterior film, and the inside of the package is in a reduced pressure state,
Each of the basic cells has a through-hole that passes through the inside and outside of the basic cell, and a gas-permeable and non-liquid-permeable filter that closes the through-hole from the outside of the basic cell. . The through hole, characterized in that provided in the gasket constituting the basic cell, an electric double layer capacitor according to the battery or claim 2 of claim 1. The through hole, characterized in that provided in the current collector constituting the basic cell, an electric double layer capacitor according to the battery or claim 2 of claim 1. From across the separator and this as opposed positive and negative electrodes and the battery structure material containing an electrolyte solution, a cylindrical gasket for housing said battery constituting material therein, the current collector for closing both sides of and below the gasket A basic cell forming process for forming a basic cell, an element forming process for forming an element by stacking the basic cells individually or in series, and lead terminals on each of the two outermost current collectors of the element In the battery manufacturing method including the sealing process of sealing in a reduced pressure state in a sealed package made of a flexible film after disposing the attached electrode plate,
Each of the basic cells includes a through-hole that passes through the inside and outside of the basic cell, and a gas-permeable and non-liquid-permeable filter that closes the through-hole from the outside of the basic cell. In the sealing process, method for producing a battery, characterized in that the in each basic cell that constitutes the the package element, for sealing the package in a state of pressure reduction at the same time. An electric double layer capacitor constituent material including a separator, two polarizable electrodes opposed to each other and an electrolyte , a cylindrical gasket containing the electric double layer capacitor constituent material, and both upper and lower surfaces thereof are closed a basic cell forming process of forming a basic cell consisting of a current collector, an element formation step of forming an element overlapping said basic cells alone or a plurality in series, the two outermost current collectors of the element In the manufacturing method of the electric double layer capacitor including the sealing step of sealing in a reduced pressure state in a sealed package made of a flexible film after disposing an electrode plate with lead terminals in each,
Each of the basic cells includes a through-hole that passes through the inside and outside of the basic cell, and a gas-permeable and non-liquid-permeable filter that closes the through-hole from the outside of the basic cell. In the sealing process, method for producing an electric double layer capacitor to feature that the in each basic cell that constitutes the the package element, for sealing the package in a state of pressure reduction at the same time. In the manufacturing method of the battery according to claim 5 or the manufacturing method of the electric double layer capacitor according to claim 6 ,
The through hole is provided in gasket constituting the basic cell, in the basic cell formation process, the through holes with using a gasket provided on the side surface, the said through-hole of the gasket side surface after the basic cell formation Provide a process of plugging with a gas permeable and non-liquid permeable filter,
In the sealing process, the package containing the element and the electrode plate is disposed in a container that can be evacuated, and then the container is evacuated and depressurized. pressure reduced to the same time, the manufacturing method of the battery manufacturing process or electric double layer capacitor, characterized in that for sealing an opening part of the package in its decompressed state. In the manufacturing method of the battery according to claim 5 or the manufacturing method of the electric double layer capacitor according to claim 6 ,
The through hole is, the provided on the current collector constituting the basic cell, in the basic cell formation process, the use of a current collector wherein the through hole is provided, is provided on the current collector after the basic cell formation the step of closing the through hole by the gas permeable in a non-liquid-permeable filter is provided with,
In the sealing process, the package containing the element and the electrode plate is disposed in a container that can be evacuated, and then the container is evacuated and depressurized. pressure reduced to the same time, the manufacturing method of the battery manufacturing process or electric double layer capacitor, characterized in that for sealing an opening part of the package in its decompressed state.

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