JP3815511B2

JP3815511B2 - Nickel / metal hydride sealed alkaline storage battery

Info

Publication number: JP3815511B2
Application number: JP02597496A
Authority: JP
Inventors: 克哉七元
Original assignee: GS Yuasa Corp
Current assignee: GS Yuasa Corp
Priority date: 1996-01-18
Filing date: 1996-01-18
Publication date: 2006-08-30
Anticipated expiration: 2016-01-18
Also published as: JPH09199162A

Description

【０００１】
【発明の属する技術分野】
本発明は、負極活物質を多孔性の電極基体の両面に担持してなる負極板と、セパレータと、正極活物質を電極基体に担持する正極板と、アルカリ電解液と電池容器を具備してなるニッケル・金属水素化物密閉形アルカリ蓄電池に関するものである。
【０００２】
【従来の技術】
密閉形アルカリ蓄電池、とりわけ水素吸蔵合金やカドミウムを主体とする負極板と、水酸化ニッケルを主活物質とする正極板とを備える密閉形ニッケル・水素化物アルカリ蓄電池は、エネルギー密度が高いことから、ポータブル機器や電気自動車の電源として、近年賞用されている。
【０００３】
これらの密閉形アルカリ蓄電池は、過充電時に、水素ガスが負極から発生する前に、酸素ガスが正極から発生するように、充電末期に未充電の活物質（これは「充電リザーブ」とよばれる。）が残るように電池を構成する。そして、正極から発生した酸素ガスを負極において還元吸収することによって、電池内へのガスの蓄積を防止し、密閉化を達成している。
【０００４】
【発明が解決しようとする課題】
このような密閉形アルカリ蓄電池では、電池のエネルギー密度を大きくしょうとして、充放電に関与しない充電リザーブ量を少なくしょうとすると、充電末期に負極からの水素ガス発生が起こりやすくなり、電池の安全弁が開いて、電池内のガスや電解液が放出され、電解液涸れが起こって、電池寿命が短くなるという課題があった。この課題は、負極に水素吸蔵合金を用いる場合に、その水素過電圧が小さく水素が発生しやすいことから、深刻であった。
【０００５】
【課題を解決するための手段】
本発明は、上記した課題を解決するために、負極活物質を耐アルカリ性金属からなるパンチングメタルである多孔性の電極基体の両面に担持してなる水素吸蔵合金を主体とした負極板と、セパレータと、水酸化ニッケルを主体とする正極活物質を電極基体に担持する正極板と、アルカリ電解液と電池容器を具備してなるニッケル・金属水素化物密閉形アルカリ蓄電池であって、前記正極板が前記セパレータを介して前記負極板と対向し、両側の面において前記正極板と対向する前記負極板の部分（Ａ）と、片側の面において前記正極板と対向する前記負極板の部分（Ｂ）とを具備し、前記負極板の部分（Ａ）の単位面積に担持される活物質の量が、前記負極板の部分（Ｂ）の単位面積に担持される活物質の量を１００％として、１０％以上多いニッケル・金属水素化物密閉形アルカリ蓄電池を提供する。
【０００８】
【発明の実施の形態】
本発明の構成すなわち、ニッケル・金属水素化物密閉形アルカリ蓄電池において、負極活物質を耐アルカリ性金属からなるパンチングメタルである多孔性の電極基体の両面に担持してなる水素吸蔵合金を主体とした負極板と、セパレータと、水酸化ニッケルを主体とする正極活物質を電極基体に担持する正極板と、アルカリ電解液と電池容器を具備してなるニッケル・金属水素化物密閉形アルカリ蓄電池であって、前記正極板が前記セパレータを介して前記負極板と対向し、両側の面において前記正極板と対向する前記負極板の部分（Ａ）と、片側の面において前記正極板と対向する前記負極板の部分（Ｂ）とを具備し、前記負極板の部分（Ａ）の単位面積に担持される活物質の量が、前記負極板の部分（Ｂ）単位面積に担持される活物質の量よりも多くすることにより、充電時の内圧の上昇が効果的に抑制され、電池のサイクル寿命が向上する。
【０００９】
具体的には、帯状電極を捲回して構成した円筒形や長円形電池では、最外周や最内周の部分の負極板が、片側の面において前記正極板と対向する前記負極板の部分（Ｂ）に相当し、平板状電極を積層して構成した角形電池では、最外側の部分の負極板が、片側の面において前記正極板と対向する前記負極板の部分（Ｂ）に相当する。
【００１０】
また、電池内圧を著しく上昇させることなく、大電流の充電が可能となるので、より短時間の急速充電が可能となる。
【００１１】
このような電池の内圧上昇が抑制される機構については明確ではないが、両側の面において正極板と対向する負極板は、充放電反応が良好に進むときに、充電終期に正極から発生した酸素ガスをスムーズに吸収することができる。
【００１２】
しかし、片側の面において正極板と対向する負極板では、正極に対向していない側の負極活物質は、とくに負極板の電極基体がパンチングメタルの場合に、パンチングメタルの無孔部の影になる部分の面積が大きいので、その負極活物質の多くが、充電反応に関与しにくいと推定される。
【００１４】
よって、両側の面において前記正極板と対向する前記負極板の部分（Ａ）と、片側の面において前記正極板と対向する前記負極板の部分（Ｂ）とを具備し、前記負極板の部分（Ａ）の単位面積に担持される活物質の量が、前記負極板の部分（Ｂ）の単位面積に担持される活物質の量よりも多くすることにより、前記負極板の部分（Ｂ）において、負極板の電極基体の影になる負極活物質の量が減少し、そのことによって、電池内に占める負極の体積、および見かけのリザーブ量は同じであっても、有効なリザーブ量が大きくなるためと考えられる。
【００１５】
このような効果は、前記負極板の部分（Ａ）の単位面積に担持される活物質の量が、前記負極板の部分（Ｂ）の単位面積に担持される活物質の量を１００％として、１０％以上多い場合に顕著である。
【００１６】
【実施例】
本発明を好適な実施例によって詳しく説明する。
【００１７】
負極はつぎの方法で製作した。
ミッシュメタル（原料はバストネサイト）、ニッケル、コバルト、マンガン、およびアルミニウムの金属材料をＭｍＮｉ３．５Ｃｏ０．８Ｍｎ０．３ＡＡｌ０．４のなるようにアルゴン雰囲気にした高周波誘導炉で溶解し、この溶湯をモールドに流し込んで鋳込み、この合金塊を、ジョークラッシャーで粗粉砕してからボールミルで微粉砕するという方法で機械的に粉砕し、篩掛けして、水素吸蔵合金粉末を得た。
【００１８】
次に、この水素吸蔵合金粉末を主体とし、結着剤を分散した分散液ととともに混練りしてペースト状混合物を調整した。このペースト状混合物を、厚さが０．０５μｍで開口率が約０．５のニッケルメッキした鉄製パンチングメタルの両面に塗布し、乾燥した後プレスし、所定の寸法に切断して水素吸蔵合金電極を製作した。この際に、水素吸蔵合金の担持量を変えた同一面積の（すなわち、単位面積に担持される活物質の量を変えた）水素吸蔵合金電極Ａ１〜Ａ１１を作成した。これらの水素吸蔵合金電極Ａ１〜Ａ１１の合金充填量を表１に示す。
【００１９】
【表１】

図１は水素吸蔵合金電極の配置を示した模式図である。
図１において、上記の水素吸蔵合金電極が、両側の面において正極板と対向する負極板の部分（Ａ）である内側の２枚と、片側の面において正極板と対向する負極板の部分（Ｂ）である外側の２枚とに種々組合わせた計４枚とポリアミド系不織布のセパレータ２で封筒状に包み込まれた公知の発泡メタル式ニッケル正極板３を３枚（水酸化ニッケルを主体とする活物質の容量は合計９００ｍＡｈ）とを交互に積層して電極群を形成し、深絞りケース１にＫＯＨを主体とするアルカリ電解液とともに、上記の電極群を設置して、復帰式の安全弁を有する蓋板とケースとをケーザー溶接することによって、高さ６７ｍｍ、幅１６．４ｍｍ、厚さ６ｍｍのニッケル・金属水素化物電池を製作した。
【００２０】
水素吸蔵合金電極Ａ６を４枚用いた従来電池をａ１、水素吸蔵合金電極Ａ５を、両側の面において正極板と対向する負極板の部分である内側の２枚（Ａ）に、水素吸蔵合金電極Ａ７を、片側の面において正極板と対向する負極板の部分である外側の２枚（Ｂ）に用いた比較電池をｂ１、水素吸蔵合金電極Ａ４を、両側の面において正極板と対向する負極板の部分である内側の２枚（Ａ）に、水素吸蔵合金電極Ａ８を、片側の面において正極板と対向する負極板の部分である外側の２枚（Ｂ）に用いた本発明による実施例１の電池をｂ２、水素吸蔵合金電極Ａ３を、両側の面において正極板と対向する負極板の部分である内側の２枚（Ａ）に、水素吸蔵合金電極Ａ９を、片側の面において正極板と対向する負極板の部分である外側の２枚（Ｂ）に用いた本発明による実施例２の電池をｂ３、および水素吸蔵合金電極Ａ２を、両側の面において正極板と対向する負極板の部分である内側の２枚（Ａ）に、水素吸蔵合金電極Ａ１０を、片側の面において正極板と対向する負極板の部分である外側の２枚（Ｂ）に用いた本発明による実施例３の電池をｂ４、および水素吸蔵合金電極Ａ１を、両側の面において正極板と対向する負極板の部分である内側の２枚（Ａ）に、水素吸蔵合金電極Ａ１１を、片側の面において正極板と対向する負極板の部分である外側の２枚（Ｂ）に用いた実施例４の電池をｂ５と呼ぶ。表２に製作した電池の構成をしめす。
【００２１】
【表２】

以上の電池を、圧力センサを取り付けた電池内圧測定容器に設置し、室温にて１時間率の電流にて充電し、内圧の変化を測定した。結果を表３にしめす。
【００２２】
【表３】

すなわち、すべて同じ合金重量の負極を用いた従来電池ａ１よりも、両側とも正極に対向している負極の合金重量が、片側のみ正極に対向する負極の合金重量に対して、１０％以上多くなるように備えている本発明電池ｂ２、ｂ３、ｂ４、およびｂ５のほうが内圧の上昇が低く抑えられていることがわかる。
【００２３】
しかしながら、両側とも正極に対向している負極の合金重量が、片側のみ正極に対向する負極の合金重量に対して、１１０％以下である比較電池ｂ１の場合は、内圧の上昇を低く抑える効果はほとんど認められなかった。
【００２４】
つぎに、従来電池ａ１、比較電池ｂ１及び本発明電池ｂ２、ｂ３、ｂ４およびｂ５の充放電サイクル寿命試験をおこなった。このときの試験条件は、−ΔＶ制御方式（充電終止電圧差：５ｍＶ）で９００ｍＡ（１ＣｍＡ）の電流で充電し、９００ｍＡで電池電圧が１．０Ｖになるまで放電するものであり、容量確認試験［１８０ｍＡ（０．２ＣｍＡ）で終止電圧１．０Ｖまで放電］は５０サイクル毎におこなった。
【００２５】
このときの各電池が寿命（初期容量の８０％以下になるまで）に至るまでのサイクル数を表４に示す。すべて同じ合金重量の負極を用いた従来電池ａ１よりも、両側とも正極に対向している負極の合金重量が、片側のみ正極に対向する負極の合金重量に対して、１０％以上多く備えている本発明電池ｂ２、ｂ３、ｂ４、およびｂ５のほうが充放電サイクル寿命性能に優れていることがわかる。
【００２６】
しかしながら、両側とも正極に対向している負極の合金重量が、片側のみ正極に対向する負極の合金重量に対して、１１０％以下である比較電池ｂ１の場合、従来電池ａ１と同様の寿命であった。
【００２７】
【表４】

【００２８】
【発明の効果】
以上述べたように、本発明によれば、ニッケル・金属水素化物密閉形アルカリ蓄電池の充電時の内圧の上昇が効果的に抑制され、サイクル寿命が向上する。
【図面の簡単な説明】
【図１】本発明による角形電池の水素吸蔵合金電極の配置を示す模式図である。
【符号の説明】
１深絞ケース
２セパレータ
３正極板
Ａ両側の面において正極板と対向する水素吸蔵合金を主体とした負極板の部分
Ｂ片側の面において正極板と対向する水素吸蔵合金を主体とした負極板の部分 [0001]
BACKGROUND OF THE INVENTION
The present invention comprises a negative electrode plate having a negative electrode active material supported on both sides of a porous electrode substrate, a separator, a positive electrode plate having a positive electrode active material supported on the electrode substrate, an alkaline electrolyte, and a battery container. The present invention relates to a nickel-metal hydride sealed alkaline storage battery.
[0002]
[Prior art]
Sealed alkaline storage batteries, in particular, sealed nickel / hydride alkaline storage batteries comprising a negative electrode plate mainly composed of hydrogen storage alloy or cadmium and a positive electrode plate mainly composed of nickel hydroxide, have a high energy density. In recent years, it has been used as a power source for portable equipment and electric vehicles.
[0003]
These sealed alkaline storage batteries are called uncharged active materials at the end of charging (this is called “charge reserve”) so that oxygen gas is generated from the positive electrode before hydrogen gas is generated from the negative electrode during overcharging. Configure the battery so that.) Remains. The oxygen gas generated from the positive electrode is reduced and absorbed at the negative electrode to prevent gas accumulation in the battery and achieve sealing.
[0004]
[Problems to be solved by the invention]
In such a sealed alkaline storage battery, if it is attempted to increase the energy density of the battery and reduce the amount of charge reserve not involved in charge and discharge, hydrogen gas generation from the negative electrode tends to occur at the end of charge, and the battery safety valve Opened, gas and electrolyte solution in the battery was released, electrolyte solution drowned, and the battery life was shortened. This problem has been serious when a hydrogen storage alloy is used for the negative electrode because the hydrogen overvoltage is small and hydrogen is easily generated.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a negative electrode plate mainly composed of a hydrogen storage alloy in which a negative electrode active material is supported on both surfaces of a porous electrode substrate, which is a punching metal made of an alkali-resistant metal, and a separator A positive electrode plate carrying a positive electrode active material mainly composed of nickel hydroxide on an electrode substrate; a nickel-metal hydride sealed alkaline storage battery comprising an alkaline electrolyte and a battery container, wherein the positive electrode plate comprises: The portion (A) of the negative electrode plate facing the negative electrode plate through the separator and facing the positive electrode plate on both sides, and the portion (B) of the negative electrode plate facing the positive electrode plate on one side And the amount of the active material supported on the unit area of the part (A) of the negative electrode plate is 100% of the amount of the active material supported on the unit area of the part (B) of the negative electrode plate , more than 10% multi Providing nickel-metal hydride sealed alkaline storage battery.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the structure of the present invention, that is, in a nickel-metal hydride sealed alkaline storage battery, a negative electrode mainly composed of a hydrogen storage alloy in which a negative electrode active material is supported on both surfaces of a porous electrode substrate that is a punching metal made of an alkali-resistant metal A nickel-metal hydride sealed alkaline storage battery comprising a plate, a separator, a positive electrode plate carrying a positive electrode active material mainly composed of nickel hydroxide on an electrode substrate, an alkaline electrolyte and a battery container; The positive electrode plate is opposed to the negative electrode plate with the separator interposed therebetween, the negative electrode plate portion (A) facing the positive electrode plate on both sides, and the negative electrode plate facing the positive electrode on one side. Part (B), and the amount of the active material supported on the unit area of the part (A) of the negative electrode plate is the amount of the active material supported on the part (B) unit area of the negative electrode plate By more than the increase in the internal pressure during charging can be effectively suppressed, thereby improving the cycle life of the battery.
[0009]
Specifically, the cylindrical or oval cell constituted by winding a strip-shaped electrode, a negative electrode plate of the outermost and innermost portions, the negative electrode plate of the portion facing the positive electrode plate on one side of the plane ( In the prismatic battery corresponding to B) and configured by laminating flat electrodes, the outermost portion of the negative electrode plate corresponds to the portion (B) of the negative electrode plate facing the positive electrode plate on one side .
[0010]
In addition, since a large current can be charged without significantly increasing the internal pressure of the battery, rapid charging in a shorter time is possible.
[0011]
Although it is not clear about the mechanism by which the increase in the internal pressure of the battery is suppressed, the negative electrode plate facing the positive electrode plate on both sides is oxygen generated from the positive electrode at the end of charging when the charge / discharge reaction proceeds well. Gas can be absorbed smoothly.
[0012]
However, the negative electrode plate facing the positive electrode plate in the one surface, when the anode active material on the side not facing the positive electrode includes an electrode substrate of the country negative electrode plate of punching metal, a shadow of the imperforate portion of the punching metal Since the area of the portion to be large is large, it is estimated that most of the negative electrode active material hardly participates in the charging reaction.
[0014]
Therefore, the negative electrode plate portion (A) facing the positive electrode plate on both sides and the negative electrode plate portion (B) facing the positive electrode plate on one side, the negative electrode plate portion By making the amount of the active material supported on the unit area of (A) larger than the amount of the active material supported on the unit area of the portion (B) of the negative electrode plate, the portion (B) of the negative electrode plate In this case, the amount of the negative electrode active material that becomes a shadow of the electrode base of the negative electrode plate is reduced, and thus the effective reserve amount is large even if the volume of the negative electrode in the battery and the apparent reserve amount are the same. It is thought to be.
[0015]
Such an effect is that the amount of the active material supported on the unit area of the portion (A) of the negative electrode plate is 100% of the amount of the active material supported on the unit area of the portion (B) of the negative electrode plate. This is conspicuous when the content is more than 10%.
[0016]
【Example】
The invention is explained in detail by means of preferred embodiments.
[0017]
The negative electrode was manufactured by the following method.
Melt metal (raw material is bust necite), nickel, cobalt, manganese, and aluminum are melted in a high-frequency induction furnace in an argon atmosphere such that MmNi3.5 Co0.8 Mn0.3AAl0.4. The alloy lump was mechanically pulverized by a method of coarsely pulverizing with a jaw crusher and then finely pulverizing with a ball mill, and sieved to obtain a hydrogen storage alloy powder.
[0018]
Next, a paste-like mixture was prepared by kneading this hydrogen storage alloy powder mainly with a dispersion in which a binder was dispersed. This paste-like mixture was applied to both sides of a nickel-plated iron punching metal having a thickness of 0.05 μm and an aperture ratio of about 0.5, dried, pressed, cut into a predetermined size, and a hydrogen storage alloy electrode Was made. In this case, the same area with different responsible lifting amount of the hydrogen storage alloy (i.e., changing the amount of active material to be carried per unit area) created the hydrogen absorbing alloy electrodes A1-A11. The alloy filling amounts of these hydrogen storage alloy electrodes A1 to A11 are shown in Table 1.
[0019]
[Table 1]

FIG. 1 is a schematic view showing the arrangement of hydrogen storage alloy electrodes.
In Figure 1, the hydrogen absorbing alloy electrode, and two inner is a portion of the negative electrode plate facing the positive electrode plate in the plane of both sides (A), in terms of single-side positive electrode plate and facing the negative electrode plate Three pieces of known foam metal type nickel positive electrode plates 3 encapsulated in an envelope shape with a total of four pieces combined with the outer two pieces which are part (B) and a polyamide nonwoven fabric separator 2 (nickel hydroxide) The electrode group is formed by alternately laminating a main active material capacity of 900 mAh in total, and the electrode group is installed in the deep drawing case 1 together with an alkaline electrolyte mainly composed of KOH. A nickel-metal hydride battery having a height of 67 mm, a width of 16.4 mm, and a thickness of 6 mm was manufactured by Kaeser welding the lid plate having the safety valve and the case.
[0020]
The conventional battery using four hydrogen storage alloy electrodes A6 is a1, and the hydrogen storage alloy electrode A5 is formed on the two inner sheets (A), which are portions of the negative electrode plate facing the positive electrode plate on both sides. A comparative battery using A7 for the outer two sheets (B) which is the part of the negative electrode plate facing the positive electrode plate on one side, b1, the hydrogen storage alloy electrode A4 , the negative electrode facing the positive electrode plate on both sides Implementation according to the present invention in which the hydrogen storage alloy electrode A8 is used for the inner two sheets (A) which are the plate parts and the outer two sheets (B) which are the parts of the negative electrode plate facing the positive electrode plate on one side. The battery of Example 1 is b2, the hydrogen storage alloy electrode A3 is disposed on the inner two sheets (A) which are portions of the negative electrode plate facing the positive electrode plate on both sides, and the hydrogen storage alloy electrode A9 is disposed on the positive electrode on one side. two outer is a part of the negative electrode plate facing the plate (B) The battery of Example 2 according to the present invention using b3, and the hydrogen storage alloy electrode A2, the positive electrode plate and two inner is a portion opposing the negative electrode plate on both sides of the plane (A), the hydrogen storage alloy electrode A10 B4 and the hydrogen storage alloy electrode A1 on both sides of the battery of Example 3 according to the present invention, which is used for the outer two sheets (B) which are the parts of the negative electrode plate facing the positive electrode plate on one side surface The hydrogen storage alloy electrode A11 is placed on the inner two sheets (A) which are the parts of the negative electrode plate facing the positive electrode plate, and the outer two sheets (B) which are the parts of the negative electrode plate facing the positive electrode plate on one side. The battery of Example 4 used is called b5. Table 2 shows the configuration of the manufactured battery.
[0021]
[Table 2]

The above battery was placed in a battery internal pressure measurement vessel equipped with a pressure sensor, charged at room temperature with a current of 1 hour, and the change in internal pressure was measured. The results are shown in Table 3.
[0022]
[Table 3]

In other words, the alloy weight of the negative electrode facing the positive electrode on both sides is 10% or more higher than the conventional battery a1 using the negative electrode having the same alloy weight, relative to the alloy weight of the negative electrode facing the positive electrode on only one side. It can be seen that the batteries of the present invention b2, b3, b4, and b5 provided as described above have a lower increase in internal pressure.
[0023]
However, in the case of the comparative battery b1 in which the alloy weight of the negative electrode facing the positive electrode on both sides is 110% or less with respect to the alloy weight of the negative electrode facing the positive electrode on only one side, the effect of suppressing the increase in internal pressure is low. Almost not recognized.
[0024]
Next, a charge / discharge cycle life test was performed on the conventional battery a1, the comparative battery b1, and the inventive batteries b2, b3, b4, and b5. The test condition at this time is that the battery is charged with a current of 900 mA (1 CmA) with a -ΔV control method (end-of-charge voltage difference: 5 mV) and discharged until the battery voltage reaches 1.0 V at 900 mA, and a capacity confirmation test [Discharging to 180 V (0.2 CmA) to a final voltage of 1.0 V] was performed every 50 cycles.
[0025]
Table 4 shows the number of cycles until each battery reaches the end of its lifetime (until 80% or less of the initial capacity). Compared to the conventional battery a1 using negative electrodes having the same alloy weight, the weight of the negative electrode facing the positive electrode on both sides is 10% or more higher than that of the negative electrode facing the positive electrode on only one side. It turns out that this invention battery b2, b3, b4, and b5 are more excellent in charge / discharge cycle life performance.
[0026]
However, in the case of the comparison battery b1 in which the alloy weight of the negative electrode facing the positive electrode on both sides is 110% or less with respect to the alloy weight of the negative electrode facing the positive electrode on only one side, the life is the same as that of the conventional battery a1. It was.
[0027]
[Table 4]

[0028]
【The invention's effect】
As described above, according to the present invention, the increase in internal pressure during charging of the nickel-metal hydride sealed alkaline storage battery is effectively suppressed, and the cycle life is improved.
[Brief description of the drawings]
FIG. 1 is a schematic view showing the arrangement of hydrogen storage alloy electrodes of a prismatic battery according to the present invention.
[Explanation of symbols]
1 deep draw Case 2 separator 3 positive electrode plate A negative electrode mainly composed of a positive electrode plate facing the hydrogen absorbing alloy in the plane of the portion B piece side of the negative electrode plate mainly containing hydrogen absorbing alloy which faces the positive electrode plate at both sides of the surface Piece of board

Claims

A negative electrode plate mainly composed of a hydrogen storage alloy formed by supporting a negative electrode active material on both surfaces of a porous electrode substrate that is a punching metal made of an alkali-resistant metal, a separator, and a positive electrode active material mainly composed of nickel hydroxide. A nickel-metal hydride sealed alkaline storage battery comprising a positive electrode plate supported on an electrode substrate, an alkaline electrolyte, and a battery container, wherein the positive electrode plate faces the negative electrode plate with the separator interposed therebetween. A portion (A) of the negative electrode plate facing the positive electrode plate on the surface and a portion (B) of the negative electrode plate facing the positive electrode plate on one side, the portion (A) of the negative electrode plate The amount of the active material supported on the unit area of nickel / metal hydrogen is 10% or more when the amount of the active material supported on the unit area of the portion (B) of the negative electrode plate is 100%. monster Closed-form alkaline storage battery.