JPS61264672A - Manufacture of cadmium negative electrode - Google Patents

Manufacture of cadmium negative electrode

Info

Publication number
JPS61264672A
JPS61264672A JP60107407A JP10740785A JPS61264672A JP S61264672 A JPS61264672 A JP S61264672A JP 60107407 A JP60107407 A JP 60107407A JP 10740785 A JP10740785 A JP 10740785A JP S61264672 A JPS61264672 A JP S61264672A
Authority
JP
Japan
Prior art keywords
electrode
nickel
negative electrode
discharge
cadmium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP60107407A
Other languages
Japanese (ja)
Other versions
JPH0654662B2 (en
Inventor
Yoshimasa Inaba
稲葉　▲吉▼尚
Hideo Kaiya
英男 海谷
Osamu Takahashi
収 高橋
Minoru Yamaga
山賀　実
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP60107407A priority Critical patent/JPH0654662B2/en
Publication of JPS61264672A publication Critical patent/JPS61264672A/en
Publication of JPH0654662B2 publication Critical patent/JPH0654662B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • H01M4/26—Processes of manufacture
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

PURPOSE:To lengthen the life of a battery at high temperature by forming a thin nickel layer on the active material surface of an electrode in a specified solution by electrical plating. CONSTITUTION:A thin nickel layer is formed by electrical plating on the active material surface of an electrode in a solution containing 0.05-0.2mol/l nickel salt at a current density of 20-500mA/cm<2>. By this method, very fine metallic nickel particles are densely deposited on the electrode surface layer, and since the formed thin layer has conductivity and catalytic activity, discharge reaction and gas absorbing reaction in a negative electrode are accelerated. Charge- discharge cycle life of the alkaline storage battery at high temperature is remarkably increased without decrease in charge-discharge performance and storage life.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、アルカリ蓄電池に用いられるカドミウム負極
の製造法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a cadmium negative electrode for use in alkaline storage batteries.

従来の技術 アルカリ蓄電池用カドミウム負極には、ニッケル焼結基
板に活物質を充填した焼結式カドミウム負極、活物質と
導電材との混合成型体をニッケル多孔性容器内に入れ被
覆したポケット式負極、活物質を結着材とともに練合し
、導電性支持体の両側に塗布したペースト式負極などが
ある。いずれもアルカリ蓄電池用負極としては優れた充
放電特性を示すが、高温領域（４０″Ｃ以上）では高濃
度アルカリ溶液中での水酸化カドミウムの溶解度が高く
なり、充放電サイクルのくり返しによりカドミウムの溶
解析出がくり返され、負極の変形、利用率の低下、デ／
ドライドの成長等によシ、比較的短寿命になυやずいと
いう欠点を有していた。Conventional technology Cadmium negative electrodes for alkaline storage batteries include a sintered cadmium negative electrode in which a nickel sintered substrate is filled with an active material, and a pocket-type negative electrode in which a molded mixture of active material and conductive material is placed in a porous nickel container and coated. There are also paste-type negative electrodes in which an active material is kneaded with a binder and coated on both sides of a conductive support. Both exhibit excellent charge and discharge characteristics as negative electrodes for alkaline storage batteries, but in the high temperature range (above 40"C), the solubility of cadmium hydroxide in highly concentrated alkaline solutions increases, and repeated charge and discharge cycles cause cadmium to dissolve. Repeated melt deposition may cause deformation of the negative electrode, decrease in utilization rate, and
It had the disadvantage of a relatively short lifespan due to the growth of dried, etc.

中でもペースト式カドミウム負極については、焼結式カ
ドミウム負極のように活物質を保持する導電性骨格がな
いために、この傾向は著しく、高温での寿命が特に短か
いという欠点を有していた。Among these, paste-type cadmium negative electrodes have the drawback of having a particularly short service life at high temperatures because they do not have a conductive skeleton that holds the active material like sintered-type cadmium negative electrodes.

このような問題を解決するために、特開昭５８−３２３
６３号特開昭５５−１０９３７１　　号にみられるよう
に、負極活物質中に変形防止の機能を有する添加剤を混
入したり、表面に樹脂膜を形成することが提案されてい
た。In order to solve such problems, Japanese Patent Application Laid-Open No. 58-323
As seen in JP-A No. 63, JP-A-55-109371, it has been proposed to mix an additive with a function of preventing deformation into the negative electrode active material or to form a resin film on the surface.

発明が解決しようとする問題点 このような構成の電極では、結晶の粗大化や利用率の低
下についてはある程度防止することはできるが、カドミ
ウムの溶解および電解液中への拡散を防止することは出
来ず、特に高温領域では効果はほとんど得られなかった
。Problems to be Solved by the Invention Although it is possible to prevent the coarsening of crystals and the decrease in utilization rate to some extent with an electrode having such a structure, it is impossible to prevent cadmium from dissolving and diffusing into the electrolyte. Especially in the high temperature range, almost no effect was obtained.

また、特公昭４８−２５１４９号に見られるように、無
電解メッキまたは電解メッキにより電極の表面に金属の
ニッケル層を設けることが提案されているが、水溶液中
でニッケルを析出させる場合に、不純物やニッケル塩お
よびニッケル以外の電解主成物が、多孔性電極の内部に
入り込み、自己放電が増大するなどの悪影響が認められ
、実用的ではなかった。Furthermore, as seen in Japanese Patent Publication No. 48-25149, it has been proposed to provide a metallic nickel layer on the surface of the electrode by electroless plating or electrolytic plating, but when depositing nickel in an aqueous solution, impurities The main electrolytic components other than nickel, nickel salts, and nickel entered the inside of the porous electrode, resulting in negative effects such as increased self-discharge, making it impractical.

本発明は、以上のような問題を解決し、充放電特性の低
下なしに、高温領域でも長寿命を有するアルカリ蓄電池
用カドミウム負極を得ることを目的とする。The object of the present invention is to solve the above-mentioned problems and to obtain a cadmium negative electrode for alkaline storage batteries that has a long life even in a high temperature range without deteriorating charge/discharge characteristics.

問題点を解決するための手段 本発明は、０．０６〜０．２ｍｏｌ／ｌのニッケル塩を
含む水溶液中で、２０〜６００　ｍＡ／ｃｍ３の電流密
度により電極の活物質表面層に、電気メッキをすること
により、金属ニッケルの薄膜層を形成することを特徴と
するアルカリ蓄電池用カドミウム負・極の製造法を提供
するものである。Means for Solving the Problems The present invention provides electroplating on the active material surface layer of an electrode with a current density of 20 to 600 mA/cm3 in an aqueous solution containing 0.06 to 0.2 mol/l of nickel salt. The present invention provides a method for producing a cadmium negative electrode for an alkaline storage battery, which is characterized in that a thin film layer of metallic nickel is formed by the following steps.

作用 アルカリ蓄電池用カドミウム負極は、先にも述べたよう
に、優れた充放電特性を示すが、高温領域（４０″Ｃ以
上・）では高濃度アルカリ溶液中での水酸化カドミウム
の溶解度が高くなり、比較的短寿命になりやすいという
欠点を有する。高温領域において負極を放電した場合、
放電生成物がカドミ酸イオンとして溶出し、アルカリ電
解液中を拡散し、次に充電したときに元に戻らずに析出
する。As mentioned above, the cadmium negative electrode for alkaline storage batteries exhibits excellent charge and discharge characteristics, but in the high temperature range (40"C or higher), the solubility of cadmium hydroxide in a highly concentrated alkaline solution increases. , has the disadvantage that it tends to have a relatively short life.When the negative electrode is discharged in a high temperature region,
Discharge products elute as cadmate ions, diffuse in the alkaline electrolyte, and precipitate without returning to their original state when the battery is next charged.

これは充放電サイクルのくり返しにより促進され、負極
は著しく変形し利用率が低下したり、デンドライト等の
成長によりセパレータ中を活物質が浸透し短絡を引き起
こしたりし、寿命を短かくする原因となる。This is accelerated by repeated charge/discharge cycles, and the negative electrode is significantly deformed, reducing its utilization rate, and the growth of dendrites causes the active material to penetrate into the separator, causing short circuits, shortening its lifespan. .

本発明では、電極表面層に、０．０６〜０．２ｍｏ　Ｌ
／ｌのニッケル塩を含む水溶液中で、２０〜５００ｍＡ
／ｃｄの電流密度で電気メッキをすることにより、金属
ニッケルの薄膜層を形成せしめることにより、以上のよ
うな問題を解決しようとするものである。In the present invention, the electrode surface layer contains 0.06 to 0.2 mo L
20-500 mA in an aqueous solution containing /l of nickel salt
The present invention attempts to solve the above problems by forming a thin film layer of metallic nickel by electroplating at a current density of /cd.

前記方法により、極めて微細な金属ニッケル粒子を電極
表面層に緻密に形成させることができるので、高温領域
での放電主成物の溶解、拡散を防止することが可能とな
り、充放電サイクル寿命が大幅に向上する。一方、電極
表面に薄膜層を形成させた場合、水酸イオンの拡散が阻
害されたり、ガス透過性が低下したシして、充放電特性
を低下させる場合があるが、本発明における方法により
得た負極では、薄膜が導電性を有するとともに、触媒機
能を果たすために、放電反応、ガス吸収反応を共に促進
することになるので、充放電特性に対しては、悪影響を
あたえない。またニッケル塩水溶液中で陰電解すること
によっても、ニッケルの薄膜層を形成させることができ
るが、この方法の場合、原因は明確ではないが、ニッケ
ル塩水溶液中の不純物または金属ニッケル以外の電解生
成物が電極活物質中に残留し、自己放電が著しく増大す
るという欠点があった。The method described above allows extremely fine metallic nickel particles to be densely formed on the electrode surface layer, making it possible to prevent the main components of discharge from dissolving and diffusing in high-temperature regions, significantly extending the charge-discharge cycle life. improve. On the other hand, when a thin film layer is formed on the electrode surface, diffusion of hydroxide ions may be inhibited or gas permeability may be reduced, resulting in a decrease in charge/discharge characteristics. In the case of the negative electrode, the thin film has conductivity and functions as a catalyst, thereby promoting both the discharge reaction and the gas absorption reaction, so that the charge and discharge characteristics are not adversely affected. A thin nickel film layer can also be formed by negative electrolysis in a nickel salt aqueous solution, but in this method, impurities in the nickel salt aqueous solution or electrolytic formation of metals other than metallic nickel may occur, although the cause is not clear. However, there was a drawback in that substances remained in the electrode active material, resulting in a significant increase in self-discharge.

特に特開昭５５−１０９３７１　　号にあるように、電
流密度１０Ａ／ｄｉ以下、１ｍｏｌ／ｌの硫酸ニッケル
溶液中で陰電解する場合には、メッキ条件としては最適
であるが、被メッキ物が多孔体であるために、ニッケル
イオンが細孔内に拡散し易く、前記の金属ニッケル以外
の電解生成物が入り込みやすく、自己放電を大きくして
いた。これに対して本発明における負極では、電解液濃
度を通常のメッキ液濃度の％、すなわち０　、０６−０
．２ｍ　Ｏｌ　／１３に低くシ、電流密度を通常の条件
より大きくし２０’　〜５００　ｍＡ／ｃｉにすること
により、電解中のニッケルイオンの拡散を遅らせ、電極
の細孔内部に金属ニッケルの電解生成物等が生成しない
ようにしているので、自己放電などの特性を低下なしに
長寿命化を図ることができる。In particular, as described in JP-A-55-109371, when negative electrolysis is performed in a 1 mol/l nickel sulfate solution at a current density of 10 A/di or less, the plating conditions are optimal; Because it is a solid body, nickel ions easily diffuse into the pores, and electrolysis products other than the metal nickel easily enter, increasing self-discharge. On the other hand, in the negative electrode of the present invention, the electrolyte concentration is set to % of the normal plating solution concentration, that is, 0.06-0.
．． By setting the current density as low as 2mOl/13 and increasing the current density to 20' to 500 mA/ci, which is higher than normal conditions, the diffusion of nickel ions during electrolysis is delayed and the electrolytic formation of metallic nickel inside the pores of the electrode is achieved. Since this prevents the generation of substances, it is possible to extend the lifespan without degrading characteristics such as self-discharge.

実施例 平均粒径約１μの酸化カドミウム粉末にポリビニルアル
コールのエチレンクリコール？ｉＩ［全加工、混練して
ペースト状にする。このペーストを導電性支持体である
厚さ０．１圏のニッケルメッキした開孔鋼板に塗着し、
約１４０″Ｃで３０分間乾燥し、厚さ約０．５＋＋ａ＋
＋の電極を得た。次にこの電極を、ＰＨ３，液温約２６
°Ｃに調整した硫酸ニッケルと塩化ニッケルの０．１　
ｍｏ　１　／ｌの混合液中で、ニッケルを対極として、
電流密度１５０　ｍＡ／ｄ　　で１分間電気メツキを行
なった後、水洗、乾燥した。Example: Cadmium oxide powder with an average particle size of about 1μ and polyvinyl alcohol ethylene glycol? iI [All processing, kneading to form a paste. Apply this paste to a nickel-plated perforated steel plate with a thickness of about 0.1 mm, which is a conductive support.
Dry at about 140″C for 30 minutes to a thickness of about 0.5++a+
A + electrode was obtained. Next, connect this electrode to a liquid with a pH of 3 and a liquid temperature of approximately 26
0.1 of nickel sulfate and nickel chloride adjusted to °C.
In a mixed solution of mo 1 /l, with nickel as a counter electrode,
After electroplating was performed for 1 minute at a current density of 150 mA/d, it was washed with water and dried.

続いて、この電極をアルカリ溶液中で理論容量の約４０
％充電し、水洗、乾燥後、所定の寸法に切断してアルカ
リ蓄電池用カドミウム負極を得た。This electrode is then heated to about 40% of its theoretical capacity in an alkaline solution.
%, washed with water, dried, and then cut into predetermined dimensions to obtain a cadmium negative electrode for an alkaline storage battery.

この負極をａとする。Let this negative electrode be a.

一方、上記の電気メッキにより電極表面に金属ニッケル
薄膜を形成させない他は同様の構成による比較例のカド
ミウム負極を用意した。これをｂとする。On the other hand, a cadmium negative electrode of a comparative example having the same structure was prepared except that a metal nickel thin film was not formed on the electrode surface by the above electroplating. Let this be b.

さらに、一般的な電解メッキの条件である濃度１ｍｏｌ
／ｌ、液温２６’Ｃ％ＰＨ３の硫酸ニッケルと塩化ニッ
ケルの混合水溶液中で、３０　ｍＡ／ｃｍ３の電流密度
で２０分間この電極を陰電解して比較例の負極Ｃを得た
。Furthermore, the concentration is 1 mol, which is the general electrolytic plating condition.
This electrode was subjected to negative electrolysis for 20 minutes at a current density of 30 mA/cm3 in a mixed aqueous solution of nickel sulfate and nickel chloride with a liquid temperature of 26'C% PH3 and a liquid temperature of 26'C% PH3 to obtain a negative electrode C of a comparative example.

上記、３種類のカドミウム負極を焼結式ニッケル正極と
組み合わせて、密閉形蓄電池を試作し、サイクル寿命試
験と、放電率特性試験および過充電時の電池内圧試験、
自己放電試験を行なった。A sealed storage battery was prototyped by combining the above three types of cadmium negative electrodes with a sintered nickel positive electrode, and was subjected to cycle life tests, discharge rate characteristics tests, and battery internal pressure tests during overcharging.
A self-discharge test was conducted.

サイクル寿命特性は、６０″Ｃで、％Ｃ相当の電流で４
．６　時間充電し、１Ｃ相当の抵抗負荷で完全放電をす
る充放電をくり返し、サイクルによる容量低下で評価し
た。放電率特性は、電池を２０”Ｃで０゜１Ｃ相当の電
流で１６時間充電し、１〜６Ｃ相当の電流で放電したと
きの放電容量と、０．２Ｃ相当の電流で放電したときの
放電容量との比率で評価した。また過充電時の電池内圧
特性は、２゜°Ｃで３ＡＣ〜３Ｃ相当の電流で過充電し
たときの電池内圧のピーク値で評価した。The cycle life characteristics are 4 at 60″C and a current equivalent to %C.
．． The battery was charged for 6 hours and then completely discharged under a resistive load equivalent to 1 C. The battery was then repeatedly charged and discharged, and the capacity drop due to the cycles was evaluated. The discharge rate characteristics are the discharge capacity when the battery is charged at 20"C with a current equivalent to 0°1C for 16 hours and discharged with a current equivalent to 1 to 6C, and the discharge capacity when discharged with a current equivalent to 0.2C. The battery internal pressure characteristics during overcharging were evaluated based on the peak value of the battery internal pressure when overcharging at 2°C with a current equivalent to 3AC to 3C.

自己放電特性は、２０°Ｃで０．１０相当の電流で１６
時間充電した後、４５°Ｃの温度で放置したときの自己
放電量で評価した。Self-discharge characteristics are 16 at a current equivalent to 0.10 at 20°C.
After charging for an hour, the self-discharge amount was evaluated when the battery was left at a temperature of 45°C.

第１図は、１サイクル目の容量を１ｏｏとした場合の容
量維持率と充放電サイクル数の関係を示す。ａは本発明
による負極を用いた電池、ｂは比較の負極すを用いた従
来例の電池、Ｃは比較の負極Ｃを用いた従来例の電池を
示す。この結果から明らかなように、比較例の従来から
の負極す、ｃを用いた電池に比べて大幅にサイクル寿命
特性が向上している。各々の電池について、６００サイ
クル経過後分解し、負極の外観の変化を調べたところ、
比較例の負極すでは著しく変形が進み、活物質がセパレ
ータ中に浸透している状態にあった。FIG. 1 shows the relationship between the capacity retention rate and the number of charge/discharge cycles when the capacity at the first cycle is 1oo. A shows a battery using the negative electrode according to the present invention, b shows a conventional battery using a comparative negative electrode, and C shows a conventional battery using a comparative negative electrode C. As is clear from this result, the cycle life characteristics are significantly improved compared to the comparative example of the battery using conventional negative electrodes S and C. Each battery was disassembled after 600 cycles and changes in the appearance of the negative electrode were examined.
The negative electrode of the comparative example was significantly deformed, and the active material had penetrated into the separator.

比較例の負極、Ｃでは、ｂはどではないが、やや変形が
進んでいる状態にあった。ところが、本発明による負極
ａではほぼ初期の状態が保たれていた。In the negative electrode C of the comparative example, deformation was slightly advanced, although b was not the same. However, in the negative electrode a according to the present invention, almost the initial state was maintained.

このことから本発明による負極では、高温での充放電サ
イクルによっても、表面層に金属ニッケルの微細な結晶
粒子が緻密に密着することで、活物質の溶解、析出によ
る著しい変形を防止できるものと考えられる。従来例の
負極Ｃも、金属ニッケルを電極に形成させることには変
わりはないが、電解ニッケル、メッキ条件に近い条件で
、実施例におけるような多孔性電極に適用した場合、電
極の細孔内にまでニッケルイオンが円滑に拡散してしま
い、電極表面よりも細孔内に金属ニッケルが形成され易
くなるので、表面層には緻密なメッキ層は形成されにく
いと考えられる。これに対し、本発明による負極ａでは
、ニッケルイオンの拡散が良好には行なわれない条件な
ので、多孔性電極の表面のみに金属ニッケルが緻密に形
成されるものと思われる。したがって寿命特性が大幅に
向上するものと考えられる。From this, in the negative electrode according to the present invention, even during high-temperature charge-discharge cycles, the fine crystal particles of metallic nickel are tightly adhered to the surface layer, thereby preventing significant deformation due to dissolution and precipitation of the active material. Conceivable. In the conventional negative electrode C, metal nickel is formed on the electrode, but when applied to a porous electrode like the one in the example under conditions similar to electrolytic nickel and plating conditions, the inside of the pores of the electrode It is thought that a dense plating layer is difficult to form on the surface layer because nickel ions diffuse smoothly and metal nickel is more likely to be formed in the pores than on the electrode surface. In contrast, in the negative electrode a according to the present invention, the conditions do not allow good diffusion of nickel ions, so it is thought that metallic nickel is densely formed only on the surface of the porous electrode. Therefore, it is considered that the life characteristics are significantly improved.

第２図は、放電容量比率と放電レートとの関係を示す。FIG. 2 shows the relationship between discharge capacity ratio and discharge rate.

ａとす、ｃではほとんど差がないことがわかる。電極表
面層に薄膜が存在する場合、水酸イオンの供給が妨げら
れ、放電特性を著しく低下させることが考えられるが、
本発明による負極では、電極表面に導電ネットワークが
形成されているために、速やかに放電反応が起きると考
えられる。It can be seen that there is almost no difference between a and c. If a thin film exists on the electrode surface layer, it is thought that the supply of hydroxide ions will be hindered and the discharge characteristics will be significantly reduced.
It is thought that in the negative electrode according to the present invention, a conductive network is formed on the electrode surface, so that a discharge reaction occurs quickly.

第３図は充電レートと電池内圧のピーク値との関係を示
す。これについても、ａとす、ｃではほとんど差がなく
、むしろ本発明による負極の方が良好である。これも放
電特性と同様に、電極表面層に薄膜が存在する場合、酸
素ガスの透過が妨げ□られ、電池内圧を著しく上昇させ
ることが考えられるが、本発明による負極では表面に導
電ネットワークが形成されているために、充電時に正極
から発生する酸素ガスを効率的に吸収するためと考関係
の図である。比較例の負極Ｃは著しく自己放電が大きい
。従来のこの現象は明らかにされてい電極中に不純物ま
たは金属ニッケル以外の電解生成物が入り込み自己放電
を大きくしているものと考えられる。この負極Ｃに対し
て本発明による負極ａでは、このようなことはなく比較
例の負極すと同等の自己放電量であり問題はない。これ
は本発明による負極の場合、負極Ｃに比べてニッケルイ
オン濃度が低く、電流密度が大きいためにニッケルイオ
ンの拡散が遅れ電極の細孔内までニッケルが浸透せず、
電極中に不純物または金属ニッケル以外の電解生成物が
入り込むことがないからと考えられる。FIG. 3 shows the relationship between the charging rate and the peak value of the battery internal pressure. In this regard, there is almost no difference between a and c, and the negative electrode according to the present invention is actually better. Similarly to the discharge characteristics, when a thin film exists on the electrode surface layer, it is thought that the permeation of oxygen gas is blocked and the internal pressure of the battery increases significantly, but in the negative electrode according to the present invention, a conductive network is formed on the surface. This is a diagram considering the relationship between the positive electrode and the oxygen gas, which is used to efficiently absorb oxygen gas generated from the positive electrode during charging. The negative electrode C of the comparative example had a significantly large self-discharge. This phenomenon has not been clarified in the past, but it is thought that impurities or electrolytic products other than metal nickel enter the electrode and increase self-discharge. In contrast to this negative electrode C, the negative electrode a according to the present invention does not have this problem, and has the same amount of self-discharge as the negative electrode of the comparative example, so there is no problem. This is because in the case of the negative electrode according to the present invention, the nickel ion concentration is lower than that of negative electrode C, and the current density is high, so the diffusion of nickel ions is delayed, and nickel does not penetrate into the pores of the electrode.
This is thought to be because impurities or electrolysis products other than metal nickel do not enter the electrode.

本発明による金属ニッケルの薄膜の厚みは０．５〜５μ
の範囲に規制することが望ましく、Ｏ，Ｓμ以下の場合
、本発明における効果は認められるものの、膜に存在す
る多数の孔の孔径が大きくなり、放電時に溶出するカド
ミ酸イオンを電極の外へ拡散しやすくしてしまうために
、０．６μ以上の膜に比べてサイクル寿命の効果は顕著
ではなかった。The thickness of the metal nickel thin film according to the present invention is 0.5 to 5μ
It is desirable to regulate the value within the range of O, Sμ or less, although the effect of the present invention is recognized, the pore diameter of the many pores existing in the membrane becomes large, and cadmate ions eluted during discharge are forced out of the electrode. Because of the ease of diffusion, the effect on cycle life was not as significant as in films with a thickness of 0.6μ or more.

また５μ以上になると、極めて微細な金属ニッケルの粒
子が、電極の表面に緻密に厚く覆ってしまうので、孔が
塞がってしまい、放電特性および電池内圧に対して影響
が認められた。また、実施例ではペースト式カドミウム
負極を用いているが、他の焼結式カドミウム負極におい
ても同様であった。ただペースト式カドミウム負極自体
、他の方式に比べて、高温領域での充放電サイクルによ
る負極の変形、利用率の低下、デンドライトの発生が著
しいので、効果としては最も大きかった。Moreover, when the particle size exceeds 5μ, the surface of the electrode is densely and thickly covered with extremely fine particles of metallic nickel, so that the pores are clogged, which has an effect on the discharge characteristics and the internal pressure of the battery. Further, although a paste-type cadmium negative electrode was used in the example, other sintered-type cadmium negative electrodes were also used. However, compared to other methods, the paste-type cadmium negative electrode itself was more susceptible to deformation of the negative electrode, lower utilization rate, and generation of dendrites due to charging and discharging cycles in high-temperature regions, so it was the most effective.

ニッケル塩水溶液は、通常ニッケルメッキを行なう場合
には１　ｍｏ　ｌ　／ｌ程度であるが、本発明において
は、０．０６〜０．２ｍｏ　ｌ　／ｌ　　ノ範囲ｆ行な
’）必要がある。多孔質電極の表面にニッケルメッキを
する場合、ニッケル塩水溶液の濃度が高いと、ニッケル
の拡散、供給が円滑に行なわれ電極の表面よりも細孔内
にメッキされてしまい、表面層にはメッキが十分ではな
くなる。本発明のように０、０６〜０．２　ｍ　ｏ　１
　／ｌ　の範囲にすると、ニラＩｆ　／Ｉ／イオンの拡
散の遅れが生じて、表面層のみにメッキが行なわれる。The nickel salt aqueous solution is usually about 1 mol/l when performing nickel plating, but in the present invention, it is required to be in the range of 0.06 to 0.2 mol/l. When nickel plating is applied to the surface of a porous electrode, if the concentration of the nickel salt aqueous solution is high, the diffusion and supply of nickel will occur smoothly, and the pores will be plated rather than the surface of the electrode, leaving the surface layer unplated. is no longer sufficient. As in the present invention, 0.06 to 0.2 m o 1
If it is in the range of /l, the diffusion of chive If /I/ ions will be delayed, and only the surface layer will be plated.

メッキ電流密度についても同様であり、表面のみメッキ
をするには、２０〜５００ｍＡ／ｄ　　の範囲で行なう
必要がある。The same applies to the plating current density, and in order to plate only the surface, it is necessary to conduct plating in the range of 20 to 500 mA/d.

発明の効果 以上のように、本発明によれば、充放電特性。Effect of the invention As described above, according to the present invention, the charging and discharging characteristics.

保存特性を低下させることなくアルカリ蓄電池の高温に
おける充放電サイクル寿命を大幅に向上させることが可
能となり、その工業的価値は犬なるものがある。　　・It has become possible to significantly improve the charge/discharge cycle life of alkaline storage batteries at high temperatures without deteriorating their storage characteristics, and this has great industrial value.・

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は、ニッケルーカドミウム蓄電池の容量維持率と
充放電サイクル数との関係を示す図、第２図は放電容量
比率と放電レートとの関係を示す図、第３図は電池内圧
のピーク値と充電レートとめ関係を示す図、第４図は容
量残存率と保存期間との関係を示す図である。 ａは、本発明における負極を用いた電池、ｂは比較例に
おける負極すを用いた電池、Ｃは比較例における負極Ｃ
を用いた電池。 代理人の氏名　弁理士　中　尾　敏　男　ほか１名第１
図 友九（／Ｉｔ、對クル＆（ν〕 第２図 鉄／！ｔシード（Ｃ１］ 第３図 死ノ元Ｌ−１−ＣＣｍＡ） 第４図 Ｊ米０−ｖｉ　朋　ζ〜５ノFigure 1 shows the relationship between the capacity retention rate and the number of charge/discharge cycles of a nickel-cadmium storage battery, Figure 2 shows the relationship between the discharge capacity ratio and the discharge rate, and Figure 3 shows the peak of battery internal pressure. FIG. 4 is a diagram showing the relationship between the remaining capacity rate and the storage period. a is a battery using a negative electrode according to the present invention, b is a battery using a negative electrode according to a comparative example, and C is a negative electrode C according to a comparative example.
A battery using Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 9 (/It, 對くる&(ν)) Figure 2 Tetsu/!t Seed (C1) Figure 3 Death L-1-CCmA) Figure 4 J rice 0-vi Tomo ζ~5ノ

Claims (3)

【特許請求の範囲】[Claims] （１）０．０６〜０．２ｍｏｌ／ｌのニッケル塩を含む
水溶液中で、２０〜５００ｍＡ／ｃｍ＾３の電流密度に
より、電極の活物質表面層に電気メッキをすることによ
り、金属ニッケルの薄膜層を形成することを特徴とする
アルカリ蓄電池用カドミウム負極の製造法。(1) By electroplating the surface layer of the active material of the electrode at a current density of 20 to 500 mA/cm^3 in an aqueous solution containing 0.06 to 0.2 mol/l of nickel salt, metallic nickel is removed. A method for producing a cadmium negative electrode for alkaline storage batteries, characterized by forming a thin film layer. （２）金属ニッケル薄膜層の厚みが、０．５〜５μであ
る特許請求の範囲第１項記載のアルカリ蓄電池用カドミ
ウム負極の製造法。(2) The method for producing a cadmium negative electrode for an alkaline storage battery according to claim 1, wherein the thickness of the metal nickel thin film layer is 0.5 to 5 μm. （３）電極が、酸化カドミウムまたは水酸化カドミウム
を主体とする活物質粉末をペースト状もしくはシート状
として導電性支持体の両側に塗布するペースト式電極で
ある特許請求の範囲第１項記載のアルカリ蓄電池用カド
ミウム負極の製造法。(3) The alkali according to claim 1, wherein the electrode is a paste type electrode in which active material powder mainly composed of cadmium oxide or cadmium hydroxide is applied in paste or sheet form on both sides of a conductive support. A method for producing cadmium negative electrodes for storage batteries.
JP60107407A 1985-05-20 1985-05-20 Cadmium negative electrode manufacturing method Expired - Lifetime JPH0654662B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60107407A JPH0654662B2 (en) 1985-05-20 1985-05-20 Cadmium negative electrode manufacturing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60107407A JPH0654662B2 (en) 1985-05-20 1985-05-20 Cadmium negative electrode manufacturing method

Publications (2)

Publication Number Publication Date
JPS61264672A true JPS61264672A (en) 1986-11-22
JPH0654662B2 JPH0654662B2 (en) 1994-07-20

Family

ID=14458363

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60107407A Expired - Lifetime JPH0654662B2 (en) 1985-05-20 1985-05-20 Cadmium negative electrode manufacturing method

Country Status (1)

Country Link
JP (1) JPH0654662B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01146270A (en) * 1987-12-01 1989-06-08 Matsushita Electric Ind Co Ltd Sealed alkaline storage battery

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55109371A (en) * 1979-02-15 1980-08-22 Matsushita Electric Ind Co Ltd Method of producing cadmium negative electrode for alkaline battery

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55109371A (en) * 1979-02-15 1980-08-22 Matsushita Electric Ind Co Ltd Method of producing cadmium negative electrode for alkaline battery

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01146270A (en) * 1987-12-01 1989-06-08 Matsushita Electric Ind Co Ltd Sealed alkaline storage battery

Also Published As

Publication number Publication date
JPH0654662B2 (en) 1994-07-20

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