JPH088100B2 - Method for manufacturing hydrogen storage electrode - Google Patents

Method for manufacturing hydrogen storage electrode

Info

Publication number
JPH088100B2
JPH088100B2 JP1002524A JP252489A JPH088100B2 JP H088100 B2 JPH088100 B2 JP H088100B2 JP 1002524 A JP1002524 A JP 1002524A JP 252489 A JP252489 A JP 252489A JP H088100 B2 JPH088100 B2 JP H088100B2
Authority
JP
Japan
Prior art keywords
electrode
hydrogen
hydrogen storage
powder
alloy
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.)
Expired - Lifetime
Application number
JP1002524A
Other languages
Japanese (ja)
Other versions
JPH02183964A (en
Inventor
哲男 境
博 石川
信宏 栗山
徳一 狭間
静男 坂本
弘之 川島
景三 坂口
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.)
Kurimoto Ltd
Original Assignee
Kurimoto Ltd
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 Kurimoto Ltd filed Critical Kurimoto Ltd
Priority to JP1002524A priority Critical patent/JPH088100B2/en
Publication of JPH02183964A publication Critical patent/JPH02183964A/en
Publication of JPH088100B2 publication Critical patent/JPH088100B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/24—Electrodes for alkaline accumulators
    • H01M4/242—Hydrogen storage electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • 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
    • Y02E60/10—Energy storage using batteries

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、水素吸蔵合金を負極とし、酸化ニッケル電
極を正極とするニッケル−水素二次電池に関するもので
あり、特に、合金負極の製造と活性化を同時に行うこと
により、電池の製造コストの低減を図るとともに、その
後の電気化学的な水素の吸蔵・放出に伴う電極の変形を
防止することで電池寿命を向上させる新しい水素吸蔵電
極の製造方法に関するものである。The present invention relates to a nickel-hydrogen secondary battery in which a hydrogen storage alloy is used as a negative electrode and a nickel oxide electrode is used as a positive electrode, and particularly to the production of an alloy negative electrode. By activating at the same time, the manufacturing cost of the battery is reduced, and at the same time, the production of a new hydrogen storage electrode that improves the battery life by preventing the electrode from being deformed due to electrochemical storage and release of hydrogen. It is about the method.

〔従来技術とその課題〕 ホットプレスなどで作成したマイクロカプセル化水素
吸蔵電極は、これを酸化ニッケル極、セパレータと組み
合わせて電池を構成する前に合金に水素を吸収させる活
性化処理が必要である。従来、この活性化処理は、電極
をオートクレーブ中に入れ十分真空排気後、10〜30気圧
の水素雰囲気下で150℃まで昇温し、１時間程度保持し
た後、放冷する工程によって行っていた。[Prior art and its problems] A microencapsulated hydrogen storage electrode made by hot pressing requires an activation treatment to absorb hydrogen in the alloy before it is combined with a nickel oxide electrode and a separator to form a battery. . Conventionally, this activation treatment has been carried out by a step in which an electrode is put in an autoclave, sufficiently evacuated, heated to 150 ° C. in a hydrogen atmosphere of 10 to 30 atmospheres, held for about 1 hour, and then allowed to cool. .

この場合、電極面積が大きくなると活性化処理に伴う
合金の水素吸蔵によって電極が変形し、コンパクト・高
容量に電池を組み立てることを困難にし、また変形した
電極のエッジによってセパレータを破損し、短絡が生じ
やすいといった問題点があった。また、特開昭54-13938
号公報の従来技術は、水素吸蔵合金の粉末と有機高分子
結着剤との混合物を電極支持体に保持させ、水素雰囲気
中において、前記結着剤の融点以上でかつ分解温度以下
の温度で圧縮成形して水素吸蔵合金を電極支持体に一体
的に結合することを要旨とした発明を提示している。す
なわち、従来の水素吸蔵合金粉末を使用した電極は合金
が活性化されていないために電気化学的な水素吸蔵（充
電）、水素放出（放電）の容量が少ない上に、電極の充
放電を繰り返すと水素吸蔵合金の微細化が起こり、電極
の膨張、合金粉末の脱落のあったことを課題として促
え、水素吸蔵合金の水素活性化と電極体の成形とを同時
に行なって、この課題を解決したと謳っている。In this case, if the electrode area becomes large, the electrode will be deformed due to the hydrogen absorption of the alloy accompanying the activation treatment, making it difficult to assemble the battery into a compact and high capacity, and the edge of the deformed electrode will damage the separator, resulting in a short circuit. There was a problem that it was likely to occur. Also, JP-A-54-13938
In the prior art of the publication, a mixture of powder of a hydrogen storage alloy and an organic polymer binder is held on an electrode support, and in a hydrogen atmosphere, at a temperature not lower than the melting point of the binder and not higher than the decomposition temperature. An invention is presented which is characterized in that compression molding is performed to integrally bond a hydrogen storage alloy to an electrode support. That is, in the electrode using the conventional hydrogen storage alloy powder, since the alloy is not activated, the capacity of electrochemical hydrogen storage (charge) and hydrogen release (discharge) is small, and the electrode is repeatedly charged and discharged. And the miniaturization of the hydrogen storage alloy caused the expansion of the electrode and the dropping of the alloy powder as a problem, and this problem was solved by simultaneously activating the hydrogen storage alloy with hydrogen and forming the electrode body. It is said to have been done.

しかし、この従来技術の実施例を検討すれば、水素吸
蔵合金粉末とフッ素樹脂粉末の混合粉末を電極支持体の
ニッケル製発泡金属内に充填する手順を示しているか
ら、ホットプレスによって支持体に加温加圧作用が加わ
っても、加圧の主たる対象は定形を保つ支持体に向けら
れ、この押圧作用が水素吸蔵合金同士の結着には直接的
にさほど有効に働くとも考え難いし、微小な気孔内に占
める少量の粉末材料同士が結着したところで、他の気孔
を占める粉末との結着が緊密強固な状態に成形されると
は到底信じ難い。したがって、このように各気孔内の粉
末が単独に近い状態で少量ずつ分散されているから、電
極として使用すれば充電、放電の繰り返しに遭って早急
に結着状態が崩壊し、微粉化、脱落の経過を辿る基本的
な懸念は依然未解決の課題として残る。However, studying this example of the prior art shows a procedure for filling the mixed powder of hydrogen storage alloy powder and fluororesin powder into the nickel foam metal of the electrode support, so that the support is hot-pressed onto the support. Even if a heating and pressurizing action is applied, the main target of pressurization is directed to a support that maintains a fixed shape, and it is unlikely that this pressing action directly and so effectively acts on the binding of hydrogen storage alloys. It is hard to believe that when a small amount of powder material occupies the inside of the minute pores, the powder materials occupying the other pores are tightly and firmly bonded. Therefore, since the powder in each pore is dispersed little by little in a state similar to that of a single substance in this way, if it is used as an electrode, it will be repeatedly charged and discharged and the binding state will quickly collapse and become fine powder and fall off. The basic concerns that keep track of are still unresolved issues.

また、実施例では、加温、加圧の条件下で電極を成形
後、容器内をアルゴンガスで置換して電極を取り出しす
手順を明記している。しかし、電極用水素吸蔵合金が水
素を安定に吸蔵できる温度域は150℃付近を限界とし、
それ以上の高温度において水素雰囲気内で成形すること
は、いわゆる「活性化」であって、水素の存在によって
酸化されている合金表面のニッケルを水素還元して活性
化する作用は発現しても、水素の吸蔵自体は起こり得な
いことが技術的に確認された事実である。すなわち、引
用例の電極材はアルゴンガス雰囲気内で常温まで冷却さ
れるから、空気との接触による再度の酸化は阻止できる
が、常温に至った水素吸蔵電極は水素を吸蔵した状態で
はない。したがって電極が充電されるに当って水素の吸
蔵に伴い20％近い体積膨張をする性質を本来的には失っ
ていないから、電極の変形は起こりやすく如何に結着性
を向上させたと主張しても、なお本質的な課題の解決に
は至っていないと見るのが正しい。本願発明は上記の課
題を解決するために変形の生じ難い水素吸蔵電極を簡素
化したプロセスで製造する方法の提供を目的とする。In addition, in the examples, the procedure of forming the electrode under the conditions of heating and pressurization, replacing the inside of the container with argon gas, and taking out the electrode is specified. However, the temperature range in which the hydrogen storage alloy for electrodes can store hydrogen stably is limited to around 150 ° C,
Forming in a hydrogen atmosphere at a higher temperature than that is so-called "activation", and even if an action of reducing nickel on the alloy surface oxidized by the presence of hydrogen to hydrogen and activating it is exhibited. However, it is technically confirmed that hydrogen storage itself cannot occur. That is, since the electrode material of the reference example is cooled to room temperature in an argon gas atmosphere, it is possible to prevent re-oxidation due to contact with air, but the hydrogen storage electrode reaching room temperature is not in a state of storing hydrogen. Therefore, as the electrode is charged, it does not inherently lose the property of undergoing a volume expansion of about 20% due to the absorption of hydrogen, so it is argued that the electrode is easily deformed and the binding property is improved. However, it is correct to see that the essential issues have not yet been resolved. An object of the present invention is to provide a method for manufacturing a hydrogen storage electrode which is hard to be deformed by a simplified process in order to solve the above problems.

〔課題を解決するための手段〕[Means for solving the problem]

本発明に係る水素吸蔵電極の製造方法は、水素吸蔵合
金粉末の表面を銅又はニッケルで被覆したマイクロカプ
セル化合金を電極支持体の切り抜き部内へ充填し、該充
填材表面上を集電体である金属製金網で被覆してホット
プレス内へ装入し、先ず真空排気後に１気圧〜10気圧の
水素ガス雰囲気内で100〜350℃の温度域に維持して１To
n/cm2以下のホットプレス圧で加圧成形を行ない、完全
に成形後、前記水素ガス雰囲気を持続したままでホット
プレス圧を５〜50kgf/cm2の範囲に減圧して常温まで徐
冷し、該水素吸蔵状態に活性化した成形体と該成形体表
面を被覆する集電体とを一体化することによって前記の
課題を解決した。The method for producing a hydrogen storage electrode according to the present invention is a method for filling a microencapsulated alloy in which the surface of a hydrogen storage alloy powder is coated with copper or nickel into a cutout portion of an electrode support, and the filler surface is a collector. It is covered with a metal wire mesh and charged into a hot press, and after evacuation, it is maintained in a temperature range of 100 to 350 ° C in a hydrogen gas atmosphere of 1 to 10 atmospheres for 1 To.
Pressure molding is performed at a hot press pressure of n / cm 2 or less, and after complete molding, the hot press pressure is reduced to 5 to 50 kgf / cm 2 while maintaining the hydrogen gas atmosphere and gradually cooled to room temperature. Then, the above-mentioned problem was solved by integrating the molded body activated to the hydrogen storage state and the current collector covering the surface of the molded body.

また、このこのマイクロカプセル化を単独で用いる
他、これに粘結剤として銅粉末、ニッケル粉末、四フッ
化エチレン（PTFE）、四フッ化エチレン・フッ化プロピ
レン共重合体（FEP）、ポリエチレン、ポリプロピレ
ン、ナイロンよりなる群から選んだ少なくとも１種を、
その量が電極に対して10％重量以下になるよう混合して
用いる実施態様がきわめて望ましい。In addition to using this microencapsulation alone, copper powder, nickel powder, ethylene tetrafluoride (PTFE), tetrafluoroethylene / fluorinated propylene copolymer (FEP), polyethylene, etc. At least one selected from the group consisting of polypropylene and nylon,
An embodiment in which the amount is 10% by weight or less with respect to the electrode and used as a mixture is highly desirable.

〔作用〕[Action]

本願方法で製造された電極は水素吸蔵状態で平滑な形
状となっているため、水素放出時でもその形状が維持さ
れる。そこで、ニッケル正極、セパレータを組み合わせ
て電池を構成する際に、電池ケース内にコンパクト・高
密度に充填することができ、また、電気化学的な水素の
吸蔵・放出サイクルの長期繰り返しにおいても、電極の
変形に伴う電極間の短絡や合金粉末の脱落を防止でき、
電池寿命を大幅に改善することができる。Since the electrode manufactured by the method of the present application has a smooth shape in a hydrogen storage state, the shape is maintained even when hydrogen is released. Therefore, when a battery is constructed by combining a nickel positive electrode and a separator, the battery can be compactly and densely packed in the battery case, and the electrode can be used for long-term repeated electrochemical hydrogen storage / release cycles. It is possible to prevent short circuit between electrodes and drop of alloy powder due to deformation of
The battery life can be greatly improved.

〔実施例〕〔Example〕

ホットプレス温度は、マイクロカプセル化合金を単独
で用いる場合や、粘結剤として銅粉末、ニッケル粉末、
PTFE,FEPなどを用いる場合には、250〜350℃が好まし
く、粘結剤としてポリエチレンやポリプロピレン、ナイ
ロンなどを用いる場合には80〜140℃が好ましい。一
方、合金電極を水素化活性化するためには100℃以上に
温度が必要である。したがって、ホットプレス温度は10
0℃以上300℃以下の範囲がよい。また、水素圧について
は常温で１気圧以上あればよいが、10気圧を越えると耐
圧容器の基準が厳しくなるので、１気圧以上10気圧以下
の範囲が好ましい。プレス圧については、粘結剤を使用
する場合には、100〜400kg/cm2で十分であるが、マイク
ロカプセル化合金を単独で用いる場合には300kg/cm2以
上の圧力が好ましい。しかし、１t/cm2以上の圧力でプ
レスすると電極が圧密化しすぎて、これに水素を吸蔵さ
せる活性化処理が円滑に進行しなくなるため、100kg/cm
2以上１t/cm2以下の範囲が好適である。また、電極を冷
却する際にはそのプレス圧を合金の水素吸蔵時の膨張圧
力以下にすることが必要である。すなわち、プレス圧を
200kg/cm2以下、好ましくは５kg/cm2〜50kg/cm2の範囲
で行うと電極にその変形を防ぎながら水素を完全に吸蔵
させることができる。この活性化処理によって水素吸蔵
状態の電極を、ニッケル正極、セパレータと組み合わせ
て正極規制の半密閉型電池を構成すると、１回の充放電
サイクルで電池の公称容量を得ることができる。活性化
処理を施さない電極については、充電効率が悪いためガ
ス発生が多く、電池セルを開放状態にして10〜30回充放
電サイクルを繰り返す電気化学的活性化処理が必要であ
り装置的、時間的なロスが大きい。銅又はニッケルによ
るマイクロカプセル化合金の場合は、被覆金属が水素化
物と酸素との直接接触を防ぐため水素吸蔵状態で大気中
に取り出しても酸化による合金の劣化はほとんど進行し
ない。一方、裸の合金を用いた場合は、水素化物表面で
大気中の酸素との反応による酸化が進行するため、大気
中に取り出す前に再度150℃程度まで昇温し、水素を放
出させる脱気処理が必要となり、工程が煩雑となる。そ
こで、本発明の方法は、特にカプセル化合金を用いる電
極製造法及び活性化処理法として実用的価値が大きい。Hot pressing temperature, when using the microencapsulated alloy alone, as a binder copper powder, nickel powder,
When using PTFE, FEP, etc., it is preferably 250 to 350 ° C., and when using polyethylene, polypropylene, nylon, etc. as a binder, 80 to 140 ° C. is preferable. On the other hand, a temperature of 100 ° C. or higher is required to activate the alloy electrode by hydrogenation. Therefore, the hot press temperature is 10
The range of 0 ° C to 300 ° C is preferable. The hydrogen pressure may be 1 atm or more at room temperature, but if it exceeds 10 atm, the standard of the pressure-resistant container becomes strict, so the range of 1 atm or more and 10 atm or less is preferable. With regard to the pressing pressure, when using a binder, 100 to 400 kg / cm 2 is sufficient, but when using the microencapsulated alloy alone, a pressure of 300 kg / cm 2 or more is preferable. However, if pressed at a pressure of 1 t / cm 2 or more, the electrode will be too compacted and the activation process for absorbing hydrogen will not proceed smoothly.
2 above 1t / cm 2 or less in the range are preferred. Further, when cooling the electrode, it is necessary to set the pressing pressure to be equal to or lower than the expansion pressure at the time of hydrogen absorption of the alloy. That is, press pressure
When the pressure is 200 kg / cm 2 or less, preferably 5 kg / cm 2 to 50 kg / cm 2 , hydrogen can be completely absorbed while preventing the electrode from being deformed. When the electrode in the hydrogen storage state is combined with the nickel positive electrode and the separator by this activation treatment to form a positive electrode regulated semi-enclosed battery, the nominal capacity of the battery can be obtained by one charge / discharge cycle. Electrodes that are not subjected to activation treatment generate a lot of gas due to poor charging efficiency, and require electrochemical activation treatment that repeats 10 to 30 charge / discharge cycles with the battery cells left open. Loss is large. In the case of a copper- or nickel-microencapsulated alloy, the coating metal prevents direct contact between the hydride and oxygen, so that even if the coating metal is taken out into the atmosphere in a hydrogen-absorbed state, the deterioration of the alloy due to oxidation hardly progresses. On the other hand, when a bare alloy is used, the surface of the hydride is oxidized by the reaction with oxygen in the atmosphere, so the temperature is raised to about 150 ° C again before taking it out into the atmosphere to release hydrogen. Processing is required and the process becomes complicated. Therefore, the method of the present invention has great practical value especially as an electrode manufacturing method and an activation treatment method using an encapsulated alloy.

電極用材料としてはLaNi2.5Co2.4Al0.1水素吸蔵合金
粉末（粒径:150μｍ以下）に無電解銅メッキ（銅メッキ
量:20wt％相当）を施したものを使用し、第１表の実施
例ならびに比較例にも示すようにそれぞれ活性化方法等
を変えて電極を作製した。この合金の初期放電容量は26
5mAh/g程度である。なお、また、電極支持体として用い
た発泡ニッケル金属は、一辺56mm、厚さ1.6mm、多孔率9
5％、空孔径350〜500μｍのものであり、面内四カ所に
それぞれ一辺20mm四方の切り抜き部を設けた格子状のも
のである。As the electrode material, LaNi 2.5 Co 2.4 Al 0.1 hydrogen storage alloy powder (particle size: 150 μm or less) plated with electroless copper (copper plating amount: 20 wt% equivalent) was used. Also, as shown in Comparative Examples, electrodes were prepared by changing the activation method and the like. The initial discharge capacity of this alloy is 26
It is about 5 mAh / g. The foamed nickel metal used as the electrode support had a side of 56 mm, a thickness of 1.6 mm, and a porosity of 9 mm.
It is 5% and has a pore size of 350 to 500 μm, and it is a grid-like one with cutouts of 20 mm square on each side at four locations in the plane.

第１表は本願実施例及び対照のための比較例である。 Table 1 is a comparative example for the examples of the present application and a control.

表における実施例の電極は、本発明の製造方法による
ところのもので、この発泡ニッケル電極支持体の切り抜
き部に合金粉末を充填してこの表面を集電体である銅製
金網でおおい、これをホットプレス装置中100℃で十分
真空排気して、これに水素ガスを３気圧で導入して温度
300℃、プレス圧400kg/cm2で１時間保持することでホッ
トプレスを行った後、プレス圧を10kg/cm2まで下げて室
温まで冷却することで作製したものである。 The electrodes of the examples in the table are according to the manufacturing method of the present invention, the cutout portion of the foamed nickel electrode support is filled with alloy powder, and the surface is covered with a copper wire mesh which is a current collector. Evacuate well at 100 ℃ in a hot press machine, and introduce hydrogen gas at 3 atm into it.
After hot pressing by holding at 300 ° C. and a press pressure of 400 kg / cm 2 for 1 hour, the press pressure was lowered to 10 kg / cm 2 and cooled to room temperature.

また、表における比較例の電極は、温度300℃、プレ
ス圧400kg/cm2で真空下でホットプレス成形した後、こ
れをオートクレーブ中に入れ、温度150℃、水素圧10気
圧で１時間保持し、合金中に強制的に水素を吸蔵させる
ことにより活性化処理を行ったものである。The electrodes of the comparative examples in the table were hot-press molded under vacuum at a temperature of 300 ° C. and a pressing pressure of 400 kg / cm 2 , and then placed in an autoclave, and kept at a temperature of 150 ° C. and a hydrogen pressure of 10 atm for 1 hour. The alloy was subjected to activation treatment by forcibly absorbing hydrogen in the alloy.

前記いずれの電極においても、銅メッキ重量を除いた
合金自体の重量を約2.5g（約660mAhの容量）となるよう
にした。これらの水素吸蔵電極を負極とし、正極に焼結
型の酸化ニッケル電極を、セパレーターとしてナイロン
不織布を用い、5N水酸化カリウムと1N水酸化リチウム混
合溶液を電解液とし、公称容量をおよそ450mAhとする正
極規制の開放型電池を組み立てた。これらの試験用電池
を温度20℃で恒温室内に置いて、充電電流250mAで2.5時
間充電し、0.5時間休止した後、放電電流225mAで電圧が
0.8Vに低下するまで放電するといったサイクルで長時間
放電繰り返し試験を行った。この試験の結果を、電極活
性化処理時の変形量とともに表に示す。In each of the above electrodes, the weight of the alloy itself excluding the weight of copper plating was set to about 2.5 g (capacity of about 660 mAh). These hydrogen storage electrodes are used as negative electrodes, sintered nickel oxide electrodes are used as positive electrodes, nylon non-woven fabric is used as separators, and a mixed solution of 5N potassium hydroxide and 1N lithium hydroxide is used as an electrolytic solution, with a nominal capacity of approximately 450 mAh. An open battery regulated by the positive electrode was assembled. These test batteries were placed in a temperature-controlled room at a temperature of 20 ° C, charged with a charging current of 250 mA for 2.5 hours, and then rested for 0.5 hours.
A long-time repeated discharge test was conducted in a cycle of discharging until it dropped to 0.8V. The results of this test are shown in the table together with the amount of deformation during the electrode activation treatment.

両電極とともに活性化処理が終了しているため、１サ
イクル目から450mAhの放電容量を得ることができた。実
施例の電池については500サイクル以上の寿命が得られ
たが、比較例の電池については300サイクル付近で電池
の短絡が起こった。この原因は変形した合金負極を、正
極であるニッケル極とセパレータをはさんで強制的に圧
着させたため、変形した合金電極のエッジ部分がセパレ
ータにくい込み、正極と短絡を引き起こしたものと分か
った。Since the activation treatment was completed for both electrodes, a discharge capacity of 450 mAh could be obtained from the first cycle. The battery of the example obtained a life of 500 cycles or more, but the battery of the comparative example caused a short circuit of the battery at around 300 cycles. It was found that the cause was that the deformed alloy negative electrode was forcibly pressed by sandwiching the nickel electrode, which is the positive electrode, and the separator, so that the edge portion of the deformed alloy electrode was hard to enter into the separator, causing a short circuit with the positive electrode.

電極の変形に関しては、実施例の電極が成形後あるい
は電池の充放電過程においても全く平滑な形状を維持し
ているのに対して、比較例の電極は活性化処理段階で既
にお碗状に変形しており、この変形量を電極の４つのコ
ーナーで形成される面とお碗の頂点との間の距離で表す
と２〜3mmであった。Regarding the deformation of the electrode, the electrode of the example maintains a completely smooth shape even after molding or during the charging / discharging process of the battery, whereas the electrode of the comparative example is already bowl-shaped at the activation treatment stage. It was deformed, and this deformation amount was 2 to 3 mm when expressed by the distance between the surface formed by the four corners of the electrode and the apex of the bowl.

以上に示してきたように、新たに開発した製造方法で
作製された水素吸蔵電極は、水素の吸蔵状態で平滑な形
状となっているため、平板型電池を高密度に組み立てる
のが容易であり、またその後の長期にわたる水素吸蔵・
放出サイクルを経ても変形することはないため電極間の
短絡も起こりにくく、電池の寿命を顕著に改善すること
ができた。As shown above, since the hydrogen storage electrode manufactured by the newly developed manufacturing method has a smooth shape in the hydrogen storage state, it is easy to assemble a flat battery at high density. , And the long-term storage of hydrogen thereafter
Since it does not deform even after the discharging cycle, a short circuit between electrodes is unlikely to occur, and the battery life could be significantly improved.

〔発明の効果〕〔The invention's effect〕

電極の製造と活性化を同時に行う本発明の電極製造法
により、製造プロセスが簡素化されるとともに、合金の
水素吸蔵・放出を伴う変形を生じにくい平板型水素吸蔵
電極を製造することができ、より安価で高エネルギー密
度、長寿命のニッケル／水素吸蔵合金二次電池が製造で
きるようになった。先に引用した従来技術（特開昭54-1
3938号公報）と比較してみても、本発明ではプレスの押
圧力は集電体と共に切り抜き部に充填された合金粉末自
体の集合体に直接掛かって合金同士を緊密に圧着した一
体的な電極体を成形し、その強固な相互の結着力が引用
例の比でないことは、何人も理解できることであるし、
この要素に加えて合金粉末自体がそれぞれマイクロカプ
セル化されているから、一体の電極として結着されてい
るだけでなく、各粉末自体の表面も空気との接触が断絶
され酸化現象の発生を極度に抑止するという二重の保護
要件を具備しているのである。By the electrode manufacturing method of the present invention in which the production and activation of the electrode are performed at the same time, the manufacturing process is simplified, and it is possible to manufacture a flat plate hydrogen storage electrode that is less likely to cause deformation accompanied by hydrogen storage / release of the alloy, It has become possible to manufacture nickel / hydrogen storage alloy secondary batteries that are cheaper, have high energy density, and have a long life. The prior art cited above (JP-A-54-1)
3938), in the present invention, the pressing force of the press is directly applied to the aggregate of the alloy powder itself filled in the cutout portion together with the current collector, and the integrated electrodes in which the alloys are tightly pressure-bonded to each other. It is understandable to everyone that the body is shaped and its strong cohesive strength is not the ratio of the cited examples.
In addition to this element, the alloy powder itself is microencapsulated, so it is not only bound as an integral electrode, but also the surface of each powder itself is cut off from contact with air and the occurrence of oxidation phenomena is extremely high. It has the double protection requirement of deterrent.

また、本発明では高温高圧による成形後、水素雰囲気
中で成形圧力だけを軽減することで水素吸蔵を容易にし
て降温して常温に至る。すなわち、本発明は前記の従来
技術とは異なり常温における水素吸蔵電極は水素を吸蔵
した状態で電極として提供される。既に冷却の過程にお
いて水素との反応が終了した格子構造の変化に伴う変形
分も吸収しているから、あらためて電極として使用され
るときには、初期における活性化の立ち上がりが円滑か
つ迅速であり、その充放電も容量も大きい上、充放電の
繰り返しによる電極の変形は殆ど発生せず、多数のサイ
クルの繰り返しに十分に耐えて優れた機能を持続すると
いう顕著な特徴を具えているという差が現れる。Further, in the present invention, after molding by high temperature and high pressure, only the molding pressure is reduced in the hydrogen atmosphere to facilitate hydrogen absorption, and the temperature is lowered to normal temperature. That is, the present invention is different from the above-mentioned prior art in that the hydrogen storage electrode at room temperature is provided as an electrode in the state of storing hydrogen. Since it also absorbs the deformation caused by the change in the lattice structure, which has already reacted with hydrogen in the cooling process, when it is used as an electrode again, the activation in the initial stage is smooth and quick. The difference is that the discharge and the capacity are large, the electrode is hardly deformed due to repeated charging and discharging, and it has a remarkable feature that it sufficiently withstands the repetition of many cycles and maintains an excellent function.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 坂本 静男 大阪府大阪市西区北堀江１丁目12番19号 株式会社栗本鐵工所内 (72)発明者 川島 弘之 大阪府大阪市西区北堀江１丁目12番19号 株式会社栗本鐵工所内 (72)発明者 坂口 景三 大阪府大阪市西区北堀江１丁目12番19号 株式会社栗本鐵工所内 審査官 鈴木 正紀 (56)参考文献 特開 昭61−138459（ＪＰ，Ａ) 特開 昭54−13938（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shizuo Sakamoto 1-12-19 Kitahori, Nishi-ku, Osaka City, Osaka Prefecture Kurimoto Iron Works Co., Ltd. (72) Hiroyuki Kawashima 1-12 Kitahori, Nishi-ku, Osaka City, Osaka Prefecture No. 19 Kurimoto Iron Works Co., Ltd. (72) Inventor Keizo Sakaguchi 1-12-19 Kitahori, Nishi-ku, Osaka City Osaka Prefecture Examiner Kurimoto Iron Works Co., Ltd. Masanori Suzuki (56) References JP-A-61- 138459 (JP, A) JP-A-54-13938 (JP, A)

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】水素吸蔵合金粉末の表面を銅又はニッケル
で被覆したマイクロカプセル化合金を電極支持体の切り
抜き部内へ充填し、該充填材表面上を集電体である金属
製金網で被覆してホットプレス内へ装入し、先ず真空排
気後に１気圧〜10気圧の水素ガス雰囲気内で100〜350℃
の温度域に維持して１Ton/cm2以下のホットプレス圧で
加圧成形を行ない、完全に成形後、前記水素ガス雰囲気
を持続したままでホットプレス圧を５〜50kgf/cm2の範
囲に減圧して常温まで徐冷し、該水素吸蔵状態に活性化
した成形体と該成形体表面を被覆する集電体とを一体化
することを特徴とする水素吸蔵電極の製造方法。1. A microencapsulated alloy obtained by coating the surface of a hydrogen-absorbing alloy powder with copper or nickel is filled in a cutout portion of an electrode support, and the surface of the filling material is covered with a metal wire mesh serving as a current collector. And put it into a hot press, and first evacuate it to 100-350 ° C in a hydrogen gas atmosphere of 1-10 atm.
While maintaining the temperature range of 1 ton / cm 2 and press forming at a hot press pressure of 1 Ton / cm 2 or less, the hot press pressure is kept within the range of 5 to 50 kgf / cm 2 with the hydrogen gas atmosphere maintained. A method for producing a hydrogen storage electrode, comprising decompressing and gradually cooling to room temperature to integrate a molded body activated to the hydrogen storage state and a current collector covering the surface of the molded body. 【請求項２】前記マイクロカプセル化合金粉末を単独で
用いるか、あるいはこれに粘結剤として、銅粉末、ニッ
ケル粉末、四フッ化エチレン（PTFE）、四フッ化エチレ
ン・フッ化プロピレン共重合体（FEP）、ポリエチレ
ン、ポリプロピレン、ナイロンよりなる群から選んだ少
なくとも１種を、その量が電極に対して10％重量以下に
なるよう混合して用いる特許請求の範囲第１項記載の水
素吸蔵電極の製造方法。2. The microencapsulated alloy powder is used alone or as a binder for the powder, copper powder, nickel powder, tetrafluoroethylene (PTFE), tetrafluoroethylene / fluorinated propylene copolymer. The hydrogen storage electrode according to claim 1, wherein at least one selected from the group consisting of (FEP), polyethylene, polypropylene and nylon is mixed and used in an amount of 10% by weight or less with respect to the electrode. Manufacturing method.
JP1002524A 1989-01-09 1989-01-09 Method for manufacturing hydrogen storage electrode Expired - Lifetime JPH088100B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1002524A JPH088100B2 (en) 1989-01-09 1989-01-09 Method for manufacturing hydrogen storage electrode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1002524A JPH088100B2 (en) 1989-01-09 1989-01-09 Method for manufacturing hydrogen storage electrode

Publications (2)

Publication Number Publication Date
JPH02183964A JPH02183964A (en) 1990-07-18
JPH088100B2 true JPH088100B2 (en) 1996-01-29

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Country Link
JP (1) JPH088100B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0824040B2 (en) * 1989-09-11 1996-03-06 工業技術院長 Method for manufacturing hydrogen storage electrode
JPH0644966A (en) * 1992-07-21 1994-02-18 Agency Of Ind Science & Technol Manufacture of hydrogen storage electrode
JP5636965B2 (en) * 2011-01-05 2014-12-10 トヨタ自動車株式会社 Method for producing electrode body for lithium ion secondary battery and method for producing lithium ion secondary battery

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5413938A (en) * 1977-07-04 1979-02-01 Matsushita Electric Ind Co Ltd Method of making hydrogen occlusion electrode
JPS61138459A (en) * 1984-12-11 1986-06-25 Asahi Glass Co Ltd Electrode for cell

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