【考案の詳細な説明】[Detailed explanation of the idea]
［産業上の利用分野］
本考案はクラツド式極板とゲル状電解液を用い
た密閉形鉛蓄電池の改良に関するものである。
［従来の技術・考案が解決しようとする問題点］
従来、陰極吸収式と言われる密閉形鉛蓄電池
は、ほとんどが小容量のものであつた。ところが
最近になつて、陰極吸収式技術の進歩につれて、
大容量の電池への期待が大きくなつてきている。
ここで言う陰極吸収式というのは過充電により陽
極から発生した酸素ガスを陰極で吸収することに
より、同時に陰極からの水素ガスの発生を防止す
ることにより、全体として密閉化を図ろうとする
ものである。このような陰極吸収式においては、
陽極で発生した酸素ガスを陰極へ拡散し易くする
と、電池の密閉反応効率を優れたものとすること
ができる。したがつて陽極板と陰極板を隔離する
隔離体にどのようなものを選択するかが重要な問
題であり、据置用電池や自動車用電池で一般に使
用されている隔離体では、十分な密閉反応効率を
上げられないという問題があつた。つまり、従来
の液式電池での隔離体の役目は名前のとおり、
陽・陰極板を分離することに主眼がおかれていた
ので、脱落した活物質による短絡を防止するため
に隔離体の孔径は小さい方が良いとされ、また隔
離体の親水性については常に希硫酸電解液に浸漬
されるので、初期の親水性があれば良いという考
え方であつたが、これでは酸素ガスの拡散が不充
分なために密閉反応効率が劣るという問題が発生
する。したがつて陰極吸収式密閉形鉛蓄電池の隔
離体にどのようなものを選定するかは重要な課題
であつた。
一方、前述したような大容量、例えば100〜
1000AHの密閉形鉛蓄電池は、主に停電などの非
常時に電池からエネルギーを供給する用途に用い
られるもので、高い信頼性を要求される。この場
合、陽極板にクラツド構造のものを使用すると、
特に信頼性に優れるということが従来の液式電池
において知られている。ところが密閉形鉛蓄電池
においてクラツド式陽極板を用いた時の隔離体の
構造については、どのような厚みで、どのような
材料を使用すれば良いかについてほどんど知られ
ていなかつた。例えば、従来のクラツド式陽極板
を用いた液式電池にゲル状電解液を注入して密閉
形鉛蓄電池を作製しても、その容量は液式電池の
場合に比べて約1/2まで低下し、密閉反応効率も
約1/2になるという問題があつた。即ち、容量か
ら見ると、ゲル状電解液を用いた電池と液状電解
液を用いた電池とでは、同じ極間隔であつても電
池として発揮し得る容量には大差を生じるという
問題であつた。この問題は種々検討した結果、次
のことに起因するものであつた。液式電池は通
常、陽・陰極板間の極間隔が1.0mmといつた比較
的小さいピツチで極板群が構成され、そして該極
板群は比較的大きい電槽の中央に配置され、極板
群の周囲には大量の希硫酸電解液が存在する構造
になつている。そのため液式電池においては、放
電により極板群内部の希硫酸電解液が消費されて
も、極板群の周囲の希硫酸電解液が極板群内部へ
拡散してくることにより十分な容量を発揮でき
る。しかし、ゲル状電解液を用いた電池の場合に
は、放電により極板群内部のゲル状電解液が消費
されても、極板群の周囲からゲル状電解液が極板
群内部へ拡散することが困難であるため、放電で
使われるほとんどのゲル状電解液は極板群内に存
在する電解液により賄われるためであつた。
本考案は上記した如き事柄に鑑み、クラツド式
陽極板を用いた液式電池に比べても容量に遜色の
ない、且つ密閉反応効率の優れたクラツド式密閉
形鉛蓄電池を提供するものである。
［問題点を解決するための手段］
即ち、本考案は陰極板の表面に親水性の材料か
らなる隔離体を当接し、且つ該隔離体とクラツド
式陽極板の間に枠体等で隙間を設けることによ
り、極板群内に十分な量のゲル状電解液を確保し
て十分な容量を発揮できるようにし、且つ適正な
密閉反応効率を確保するようにしたものである。
［実施例］
以下、図面を用いて本考案密閉形鉛蓄電池を具
体的に説明する。
図は本考案密閉形鉛蓄電池の極板群の構造の一
実施例を示すもので、１はクラツド式陽極板、２
はペースト式陰極板である。３はガラスセパレー
タ等の親水性材料からなる隔離体で、該隔離体３
は陰極板２の表面に当接されている。４は陽極板
１と隔離体３との間に隙間を形成するための枠体
で、陽極板１と隔離体３との間に挿入されてい
る。なお、枠体４に代えて他のものを用い、陽極
板１と隔離体３の間に隙間を設けるようにしても
良い。また枠体４の厚みは極板群内に保持したい
ゲル状電解液の量などを勘案して適宜定めればよ
い。
上記のように本考案実施例においては、陽極板
１と隔離体３と間に枠体４を挿入することにより
隙間を設けているので、この隙間に十分な量のゲ
ル状電解液を保持することができ、そのため十分
な容量を発揮できる。なお、実験した結果、液状
電池と比較しても遜色のない容量が得られること
を確認した。
次に上記した如き本考案実施例の密閉反応効率
および充放電サイクル寿命について試験した結果
を、種々の隔離体を用いたものの試験結果と一緒
に次表に示す。なお、表中の枠体は図に示すよう
なもの、微孔ゴムセパレータは通常液式電池で用
いられているもの、ポリエチレンセパレータはポ
リエチレン不織布に界面活性剤で親水処理を施し
たもの、またガラスセパレータは約３ミリミクロ
ンメータ径以下のガラス繊維不織布からなるもの
である。また密閉反応効率は密閉形電池のSBA
規格で定められているように電池の公称容量Ｃに
0.005を乗じた電流で過充電し、理論的に発生す
るガスのうち、どれだけの割合が電池内で吸収さ
れたかを示すものである。さらにサイクル寿命は
３時間率で1.7V／セルまで放電し、その後、
2.40V／セルでの定電圧充電を繰り返す方法で試
験した。
[Field of Industrial Application] The present invention relates to an improvement of a sealed lead-acid battery using a clad plate and a gel electrolyte. [Problems to be solved by conventional techniques and ideas] Conventionally, most sealed lead-acid batteries, which are called cathode absorption type, have a small capacity. However, recently, with the advancement of cathode absorption technology,
Expectations for high-capacity batteries are increasing.
The cathode absorption type referred to here is an attempt to achieve a hermetic seal as a whole by absorbing oxygen gas generated from the anode due to overcharging at the cathode, and at the same time preventing the generation of hydrogen gas from the cathode. be. In such a cathode absorption method,
By making it easier for oxygen gas generated at the anode to diffuse to the cathode, the efficiency of the sealed reaction of the battery can be improved. Therefore, it is important to decide what kind of separator to separate the anode plate and the cathode plate. The problem was that efficiency could not be improved. In other words, the role of the separator in conventional liquid batteries is as the name suggests.
Since the main focus was on separating the anode and cathode plates, it was thought that the pore size of the separator should be smaller to prevent short circuits caused by fallen active material, and the hydrophilicity of the separator was always considered to be rare. Since it is immersed in a sulfuric acid electrolyte, the idea was that it would be sufficient to have initial hydrophilicity, but this poses the problem of poor sealing reaction efficiency due to insufficient diffusion of oxygen gas. Therefore, what kind of separator to select for a cathode absorption type sealed lead-acid battery was an important issue. On the other hand, large capacity as mentioned above, for example 100~
1000AH sealed lead-acid batteries are primarily used to supply energy during emergencies such as power outages, and require high reliability. In this case, if you use a clad structure for the anode plate,
Conventional liquid type batteries are known to have particularly excellent reliability. However, when using a clad anode plate in a sealed lead-acid battery, little was known about the structure of the separator, such as the thickness and material that should be used. For example, even if a sealed lead-acid battery is made by injecting a gel electrolyte into a liquid battery that uses a conventional clad anode plate, the capacity will be reduced to about half that of a liquid battery. However, there was a problem that the sealing reaction efficiency was also reduced to about 1/2. That is, in terms of capacity, there was a problem in that a battery using a gel electrolyte and a battery using a liquid electrolyte had a large difference in the capacity they could exhibit even if the electrode spacing was the same. As a result of various studies, this problem was found to be caused by the following. In a liquid type battery, the electrode plate group is usually composed of relatively small pitches with an electrode spacing of 1.0 mm between the anode and cathode plates, and the electrode plate group is placed in the center of a relatively large battery case. The structure is such that a large amount of dilute sulfuric acid electrolyte exists around the plate group. Therefore, in a liquid type battery, even if the dilute sulfuric acid electrolyte inside the electrode plate group is consumed due to discharge, the dilute sulfuric acid electrolyte around the electrode plate group diffuses into the electrode group, so that sufficient capacity can be maintained. I can demonstrate it. However, in the case of a battery using a gel electrolyte, even if the gel electrolyte inside the electrode plate group is consumed due to discharge, the gel electrolyte will diffuse into the electrode group from around the electrode group. This is because most of the gel electrolyte used in discharge is supplied by the electrolyte present within the electrode plate group. In view of the above-mentioned problems, the present invention provides a closed-type sealed lead-acid battery with a capacity comparable to that of a liquid-type battery using a closed-type anode plate and excellent sealed reaction efficiency. [Means for Solving the Problems] That is, the present invention abuts a separator made of a hydrophilic material on the surface of the cathode plate, and provides a gap between the separator and the clad anode plate using a frame or the like. This ensures a sufficient amount of gel electrolyte within the electrode plate group to exhibit sufficient capacity, and also ensures appropriate sealing reaction efficiency. [Example] Hereinafter, the sealed lead-acid battery of the present invention will be specifically explained using the drawings. The figure shows an example of the structure of the electrode plate group of the sealed lead-acid battery of the present invention. 1 is a clad type anode plate, 2
is a paste type cathode plate. 3 is a separator made of a hydrophilic material such as a glass separator;
is in contact with the surface of the cathode plate 2. 4 is a frame for forming a gap between the anode plate 1 and the separator 3, and is inserted between the anode plate 1 and the separator 3. Note that another frame may be used instead of the frame 4, and a gap may be provided between the anode plate 1 and the separator 3. Further, the thickness of the frame 4 may be determined as appropriate by taking into account the amount of gel electrolyte that is desired to be held within the electrode plate group. As mentioned above, in the embodiment of the present invention, a gap is provided by inserting the frame 4 between the anode plate 1 and the separator 3, so that a sufficient amount of gel electrolyte can be held in this gap. Therefore, sufficient capacity can be exerted. In addition, as a result of experiments, it was confirmed that a capacity comparable to that of liquid batteries could be obtained. Next, the results of testing the sealed reaction efficiency and charge/discharge cycle life of the embodiments of the present invention as described above are shown in the following table, together with test results using various separators. The frame in the table is as shown in the figure, the microporous rubber separator is the one normally used in liquid batteries, the polyethylene separator is made of polyethylene nonwoven fabric treated with a surfactant to make it hydrophilic, and the glass The separator is made of glass fiber nonwoven fabric having a diameter of about 3 mm or less. In addition, the sealed reaction efficiency is the SBA of the sealed battery.
The nominal capacity of the battery C as specified in the standard
This shows how much of the gas theoretically generated by overcharging with a current multiplied by 0.005 is absorbed within the battery. Furthermore, the cycle life is discharged to 1.7V/cell at a 3 hour rate, then
The test was conducted by repeating constant voltage charging at 2.40V/cell.
【表】
該表より明らかなように，微孔ゴムセパレータ
のように非常に孔径が小さく、且つ厚いものを隔
離体として用いたNo.２の電池およびポリエチレン
セパレータのように本質的に親水性でない材質の
ものを隔離体として用いたNo.３の電池は、密閉反
応効率が劣り、充放電サイクル試験中に極板群内
の電解液は分解されて電池外に逸散し、該隔離体
が撥水性のために隔離体を界しての硫酸電解質の
移動が阻害されるために内部抵抗が大きくなるの
で比較的早期に寿命が尽きた。一方、枠体のみを
用いたNo.１の電池は、良好な密閉反応効率を示し
たが、サイクル寿命試験ではゲル状電解液に大き
な割れ目ができ、ここにゲル電解液から遊離して
溜つた離しよう液の放電利用率がゲル状電解液の
利用率よりも大きいため、放電の終期にはより低
比重となり陰極の鉛イオンの溶解度が上がる結
果、サイクル中に陰極からデンドライトが割れに
沿つて生長し、やがては陽極板へ短絡し、寿命と
なつた。これらに対し、陰極板表面に親水性に優
れたガラスセパレータを当接したNo.４の本考案に
よる電池とNo.５の電池は、該陰極板に当接した隔
離体のガス透過性が良好であるために良好な密閉
反応効率を示し、また陰極板表面が常に硫酸電解
質で均等に濡れているために該極板の表面は各部
分とも均一に放電され、部分的に低比重となるこ
とがないので良好なサイクル寿命性能を示した。
ただ、隔離体としてガラスセパレータのみを用
いたNo.５の電池は、極板間隔が狭く、十分な量の
ゲル状電解液を保持することができず、容量の点
で改善がみられなかつた。極板間隔を本願考案と
同程度になるようにガラスセパレータを複数枚重
ねるなど極端に厚くすれば、電池容量も改善され
るものと考えられるが、高価な微細ガラス繊維を
大量に用いることでコストが高くなる欠点があ
る。
上記のことによりクラツド式陽極板とゲル状電解
液を用いた密閉形鉛蓄電池において、陰極板の表
面に親水性材料からなる隔離体を当接し、且つ該
隔離体とクラツド式陽極板の間に枠体で隙間を設
けた構造にすれば、十分な容量を発揮することが
でき、且つ良好な密閉反応効率を得ることがで
き、さらにサイクル寿命を伸ばすことができるこ
とが明らかである。
［考案の効果］
以上述べたように本考案によれば、クラツド式
陽極板とゲル状電解液を用いた密閉形鉛蓄電池に
おいて、十分な容量を発揮することができ、且つ
良好な密閉反応効率を得ることができ、さらにサ
イクル寿命を伸ばすことができ、そのため大容量
密閉形鉛蓄電池を提供できるといつた優れた利点
を奏することができる。[Table] As is clear from the table, battery No. 2 uses a material with very small pore size and thick material as a separator, such as a microporous rubber separator, and a battery that is not essentially hydrophilic, such as a polyethylene separator. Battery No. 3, which used this material as a separator, had poor sealing reaction efficiency, and during the charge/discharge cycle test, the electrolyte in the electrode plate group was decomposed and escaped to the outside of the battery, causing the separator to dissipate. Due to its water repellency, the movement of the sulfuric acid electrolyte across the separator is inhibited, resulting in a high internal resistance and its lifespan ends relatively early. On the other hand, the No. 1 battery using only the frame showed good sealing reaction efficiency, but in the cycle life test, large cracks were formed in the gel electrolyte, where the gel electrolyte was separated and accumulated. Since the discharge utilization rate of the separating liquid is greater than that of the gel electrolyte, the specific gravity becomes lower at the end of discharge and the solubility of lead ions in the cathode increases, resulting in dendrites being removed from the cathode along the crack during the cycle. It grew and eventually shorted to the anode plate, reaching the end of its life. On the other hand, in the battery No. 4 according to the present invention and the battery No. 5 in which a glass separator with excellent hydrophilicity was brought into contact with the surface of the cathode plate, the gas permeability of the separator in contact with the cathode plate was good. Because of this, it shows good sealing reaction efficiency, and because the surface of the cathode plate is always evenly wetted with sulfuric acid electrolyte, the surface of the cathode plate is uniformly discharged in each part, and the specific gravity is low in some parts. It showed good cycle life performance because there was no However, battery No. 5, which used only a glass separator as a separator, had a narrow electrode spacing and was unable to hold a sufficient amount of gel electrolyte, so no improvement was seen in terms of capacity. . If the electrode plate spacing is made extremely thick, such as by stacking multiple glass separators, to the same extent as in the present invention, the battery capacity may be improved, but the use of large amounts of expensive fine glass fibers will increase the cost. It has the disadvantage of being high. As a result of the above, in a sealed lead-acid battery using a clad anode plate and a gel electrolyte, a separator made of a hydrophilic material is brought into contact with the surface of the cathode plate, and a frame is placed between the separator and the clad anode plate. It is clear that if the structure is provided with a gap, sufficient capacity can be exhibited, good sealing reaction efficiency can be obtained, and the cycle life can be extended. [Effects of the invention] As described above, according to the invention, a sealed lead-acid battery using a clad anode plate and a gel electrolyte can exhibit sufficient capacity and achieve good sealing reaction efficiency. It is possible to obtain excellent advantages such as being able to obtain a high capacity, further extending the cycle life, and therefore being able to provide a large-capacity sealed lead-acid battery.
【図面の簡単な説明】[Brief explanation of the drawing]
図は本考案密閉形鉛蓄電池の極板群の構造の一
実施例を示す一部切欠斜視図である。
１……クラツド式陽極板、２……ペースト式陰
極板、３……隔離体、４……枠体。
The figure is a partially cutaway perspective view showing an embodiment of the structure of the electrode plate group of the sealed lead-acid battery of the present invention. 1... Clad type anode plate, 2... Paste type cathode plate, 3... Separator, 4... Frame.