【発明の詳細な説明】[Detailed description of the invention]
［産業上の利用分野］
本発明は、電槽化成を行つて鉛蓄電池を製造す
る方法に関するものである。
［従来の技術］
陰極板と陽極板とをセパレータを介して積層し
て構成した極板群を電槽に収納して化成を行う電
槽化成法を行う場合には、陰極板及び陽極板とし
て、格子体にペーストを充填して乾燥した未化成
極板をそのまま用いている。
電槽化成を行う際には、電槽中に希硫酸を注入
して通電するが、この希硫酸としては、比較的比
重が高いものを用いる。その理由は、電解液量が
少ないために未化成活物質の硫酸鉛化が生じると
硫酸が消費されて電解液が水に近付き、電気伝導
度が下がるからである。経験的に比重1.210〜
1.260（20℃）の希硫酸が用いられている。
［発明が解決しようとする問題点］
電槽中に希硫酸を注入すると該希硫酸が未化成
活物質と反応して電池温度が上昇する。また比較
的大電流を用いることが多いため、通電後も高い
温度が維持される。電槽化成中極板が高温に維持
されると、極板の表面に硫酸鉛の強固な被膜が生
成され、この硫酸鉛が化成後も残留していわゆる
白残（硫酸鉛が残る現象）が生じ、化成不良の状
態になる。この傾向は特に陽極板に著しい。また
希硫酸として比重の高いものを用いると陽極活物
質の硫酸鉛化速度が速くなるため、白残が一層顕
著に生じる。
上記白残が生じるのを防ぐため、従来は電池を
水槽中で冷却しながら電槽化成を行つていた。こ
のように、従来は電槽化成を行うために水槽を必
要としたため、設備費が高くなるだけでなく、電
槽化成の際に電槽を水槽にセツトする手間が必要
なため、作業が面倒になるという問題があつた。
また希硫酸として比重が高いものを用いる必要が
あつたため、コストが高くなるという問題もあつ
た。
［問題点を解決するための手段］
本発明は、格子体にペーストを充填して乾燥し
た未化成極板を用いて極板群を構成し、該極板群
を電槽に収納して化成を行う鉛蓄電池の製造方法
において、温度上昇を抑制し、白残を生じさせる
ことなく電槽化成を行うことができるようにした
ものである。
そのため、本発明においては、極板群を構成す
る前に陰極板を予め希硫酸中に浸積して硫酸鉛化
処理を施す工程を行うようにした。
［発明の作用］
陰極板は化成の進行に伴つて金属鉛化するた
め、陰極板では陰極板で問題となる極板表面での
白残が発生することはない。従つて上記のように
陰極板を予め硫酸鉛化しておいても何等支障がな
い。
陰極板を予め硫酸鉛化しておくと、電槽化成の
際の発熱は主として陽極板から起こり、板からほ
とんど発熱しない。通常陽極及び陰極の未化成活
物質の重量比は１：１であるため、本発明の方法
のように陰極活物質を予め硫酸鉛化しておくと、
化成時における電池全体の50％程度減少させるこ
とができる。従つて冷却設備を省略するか、また
は水槽を用いない簡単な冷却設備（例えば送風フ
アン）で、白残を生じさせることなく電槽化成を
行うことができる。
また陰極活物質の硫酸鉛が金属鉛になると硫酸
分を放出するため、電解液として従来より比重の
小さい希硫酸を用いることができる。この場合、
陽極活物質が硫酸鉛化する速さが遅くなるため、
陽極板での白残の発生が一層抑制される。
［実施例］
以下通常の自動車用電池の未化成極板を用いて
行つた実施例について説明する。
実施例では熟成を終つた未化成陰極板を比重
1.260（20℃）の希硫酸中に浸漬し、液温を40℃と
して、１時間硫酸鉛化反応を行わせた。この処理
により、陰極板には約50〜60wt％の硫酸鉛が生
成した。この陰極板と未化成陽極板とを組合せて
極板群を構成し、12V，30Ahの電池を作成した。
電池の陽極未化成活物質は207g／４枚、陰極
活物質は386g／５枚であつた。陰極板には、約
50％の硫酸鉛が含まれているため、電槽化成に用
いる硫酸の比重は1.140（20℃）とした。これは、
化成後の硫酸の比重を通常用いられる電解液の比
重1.215（20℃）と同じにするためである。
化成は、電池の電槽中に上記の希硫酸を450
ml／セルずつ入れた大気中で通電することにより
行つた。
図面は、注液直後からの電池温度の変化を測定
した結果を従来法により電槽化成を行つた場合と
本発明の方法により電槽化成を行つた場合とにつ
いて示したもので、従来法では電池温度が注液直
後に70℃付近まで上昇し、１時間放置すると50℃
付近まで低下した。
これに対し、本実施例の方法による場合には注
液直後の電池温度の上昇が45℃にとどまり、その
後放置すると40℃まで低下した。また本実施例の
方法による場合、通電後の電池温度は従来方法に
よる場合に比べて約15℃低い温度を維持した。電
槽化成末期には、ガスの発生による発熱のため、
電池温度が再び上昇するが、この段階では化成は
ほぼ終了しているので問題は生じない。
化成終了後、電解後の比重を1.280（25℃）に調
整して、25℃の水槽中で6Aの放電を行い、この
放電終了後充電を行つて極板の表面を観察した。
その結果は次頁の表１の通りで、本実施例の方法
により製造した蓄電池の方が従来法により製造し
た電池より放電持続時間が約20分長かつた。この
場合放電は陽極により支配されていた。また電池
を解体して調べたところ、従来法による電池では
陽極板に白残が認められたが、本実施例の方法に
よる電池には白残が認められなかつた。
[Industrial Field of Application] The present invention relates to a method of manufacturing a lead-acid battery by carrying out battery cell formation. [Prior Art] When carrying out the battery cell formation method, in which a group of electrode plates, each consisting of a cathode plate and an anode plate laminated with a separator interposed therebetween, is housed in a battery case and chemically formed, the cathode plate and the anode plate are used as the cathode plate and the anode plate. , an unformed electrode plate whose lattice body is filled with paste and dried is used as it is. When chemically forming a container, dilute sulfuric acid is injected into the container and energized, and this dilute sulfuric acid has a relatively high specific gravity. The reason for this is that when the amount of electrolytic solution is small and the unformed active material becomes sulfated, the sulfuric acid is consumed and the electrolytic solution approaches water, resulting in a decrease in electrical conductivity. Empirically specific gravity 1.210~
1.260 (20℃) dilute sulfuric acid is used. [Problems to be Solved by the Invention] When dilute sulfuric acid is injected into the battery case, the dilute sulfuric acid reacts with the unformed active material and the battery temperature increases. Furthermore, since a relatively large current is often used, a high temperature is maintained even after the current is applied. When the electrode plate is kept at high temperature during the formation of the battery, a strong film of lead sulfate is formed on the surface of the electrode plate, and this lead sulfate remains even after formation, resulting in so-called white residue (a phenomenon in which lead sulfate remains). This results in poor chemical formation. This tendency is particularly remarkable for the anode plate. Furthermore, if dilute sulfuric acid with a high specific gravity is used, the rate of sulfate formation of the anode active material becomes faster, resulting in more noticeable white residue. In order to prevent the above-mentioned white residue from occurring, conventionally, battery cell formation was performed while cooling the battery in a water bath. In this way, in the past, a water tank was required to perform battery case formation, which not only increased equipment costs, but also made the work troublesome as it required time and effort to set the battery case in the water tank during battery case formation. There was a problem with becoming.
Furthermore, since it was necessary to use dilute sulfuric acid with a high specific gravity, there was also the problem of increased costs. [Means for Solving the Problems] The present invention constitutes a group of electrode plates using unformed electrode plates filled with paste in a lattice body and dried, and stores the group of electrode plates in a battery case to form a group of electrode plates. In the method for manufacturing lead-acid batteries, temperature rise is suppressed and battery cell formation can be performed without causing white residue. Therefore, in the present invention, before constructing the electrode plate group, a step of immersing the cathode plate in dilute sulfuric acid and subjecting it to sulfuric acid lead treatment is performed. [Operation of the Invention] Since the cathode plate becomes metallic lead as the chemical formation progresses, white residue on the surface of the cathode plate, which is a problem with cathode plates, does not occur in the cathode plate. Therefore, there is no problem even if the cathode plate is previously converted into lead sulfate as described above. If the cathode plate is converted into lead sulfate in advance, the heat generated during the formation of the battery case will mainly occur from the anode plate, and almost no heat will be generated from the plate. Normally, the weight ratio of the unformed active material of the anode and the cathode is 1:1, so if the cathode active material is previously converted to lead sulfate as in the method of the present invention,
The total weight of the battery during chemical formation can be reduced by about 50%. Therefore, by omitting cooling equipment or by using simple cooling equipment (for example, a blower fan) without using a water tank, battery cell formation can be performed without producing white residue. Further, when the lead sulfate of the cathode active material turns into metallic lead, it releases sulfuric acid, so dilute sulfuric acid, which has a lower specific gravity than conventional ones, can be used as the electrolyte. in this case,
Because the rate at which the anode active material turns into lead sulfate slows down,
The occurrence of white residue on the anode plate is further suppressed. [Example] Below, an example will be described in which an unformed electrode plate of a normal automobile battery was used. In the example, the specific gravity of the unformed cathode plate that has been aged is
It was immersed in dilute sulfuric acid at 1.260°C (20°C), and the sulfate lead reaction was carried out for 1 hour at a liquid temperature of 40°C. This treatment produced approximately 50-60 wt% lead sulfate in the cathode plate. This cathode plate and unformed anode plate were combined to form an electrode plate group, and a 12V, 30Ah battery was created. The unformed anode active material of the battery was 207 g/4 sheets, and the cathode active material was 386 g/5 sheets. The cathode plate has approx.
Since it contains 50% lead sulfate, the specific gravity of the sulfuric acid used for forming the container was set to 1.140 (at 20°C). this is,
This is to make the specific gravity of sulfuric acid after chemical formation the same as the specific gravity of the commonly used electrolytic solution, 1.215 (at 20°C). Kasei adds 450% of the above dilute sulfuric acid into the battery container.
This was carried out by applying electricity in the atmosphere containing ml/cell. The drawings show the results of measuring the change in battery temperature immediately after the injection of liquid in the cases where the battery case formation was performed using the conventional method and the case where the battery case formation was performed using the method of the present invention. The battery temperature rose to around 70℃ immediately after pouring the liquid, and after leaving it for 1 hour it rose to 50℃.
It has fallen to around 100%. On the other hand, in the case of the method of this example, the rise in battery temperature immediately after injection remained at 45°C, and then decreased to 40°C when left. Furthermore, when using the method of this example, the battery temperature after energization was maintained at about 15° C. lower than when using the conventional method. At the end of the tank formation process, due to heat generation due to gas generation,
Although the battery temperature rises again, no problem occurs because the chemical formation is almost completed at this stage. After completion of chemical formation, the specific gravity after electrolysis was adjusted to 1.280 (25°C), and a discharge of 6 A was performed in a water bath at 25°C. After completion of this discharge, charging was performed and the surface of the electrode plate was observed.
The results are shown in Table 1 on the next page, and the discharge duration of the storage battery manufactured by the method of this example was approximately 20 minutes longer than that of the battery manufactured by the conventional method. In this case the discharge was dominated by the anode. Further, when the battery was disassembled and examined, white residue was observed on the anode plate in the battery produced by the conventional method, but no white residue was observed in the battery produced by the method of this example.
【表】
［発明の効果］
以上のように、本発明の方法によれば、電槽化
成の際の温度上昇を抑制することができるため、
冷却設備を省略するか、または従来用いられてい
た冷却設備よりはるかに簡単な設備で、白残を生
じさせることなく電槽化成を行うことができる。
また電解液として従来より比重の小さい希硫酸を
用いることができるため、陽極活物質が硫酸鉛化
する速さを遅くして陽極板での白残の発生を一層
抑制することができ、化成不良が生じるのを防止
して、品質の良い電池を製造することができる。[Table] [Effects of the Invention] As described above, according to the method of the present invention, it is possible to suppress the temperature rise during the formation of the battery case.
By omitting cooling equipment or by using much simpler equipment than conventionally used cooling equipment, battery case formation can be performed without producing white residue.
In addition, since dilute sulfuric acid, which has a lower specific gravity than conventional ones, can be used as the electrolyte, it is possible to slow down the rate at which the anode active material turns into lead sulfate, further suppressing the occurrence of white residue on the anode plate, and resulting in poor chemical formation. It is possible to prevent this from occurring and produce high-quality batteries.
【図面の簡単な説明】[Brief explanation of the drawing]
図面は電解液の注入直後から電槽化成終了まで
の電池温度の変化を従来法による場合と本発明の
方法による場合とについて示した線図である。
The drawing is a diagram showing changes in battery temperature from immediately after injection of electrolytic solution until completion of battery cell formation in the case of the conventional method and the case of the method of the present invention.