JP4812209B2

JP4812209B2 - Rib separator for lead acid battery

Info

Publication number: JP4812209B2
Application number: JP2001304648A
Authority: JP
Inventors: 忠正和田; 敬平島
Original assignee: Nippon Sheet Glass Co Ltd
Current assignee: Nippon Sheet Glass Co Ltd
Priority date: 2001-09-28
Filing date: 2001-09-28
Publication date: 2011-11-09
Anticipated expiration: 2021-09-28
Also published as: JP2003109573A

Description

【０００１】
【発明の属する技術分野】
本発明は、鉛蓄電池用セパレータに関し、更に詳しくは、肉薄シートのベース面に、電極板に当接させるように所定の間隔を存して多数条の主リブを設けた鉛蓄電池用リブ付きセパレータに関する。
【０００２】
【従来の技術】
従来の鉛蓄電池用リブ付きセパレータとしては、柔軟な合成樹脂製薄肉シートのベース面に、電極板に当接させるように所定の間隔を存して多数条の主リブを設けるようにしたものが使用されている。
【０００３】
【発明が解決しようとする課題】
上記、従来のリブ付きセパレータを極板群に組み込み、鉛蓄電池に構成した場合、その使用中において、充放電による陽極板の膨張、収縮などに伴う変形や、セパレータの特にリブのない平坦な肉薄ベース部の湾曲などにより、該セパレータの該肉薄シートのベース部は陽極面と接触し、その極板の活物質である酸化鉛により酸化されて、酸化劣化を起こし、ついには孔があき、その結果、極板間の短絡や電池寿命の短縮をもたらすという不都合を有していた。
これを防止するため、該リブの高さを著しく高くすることが考えられるが、極板面との間隔が大きくなり、電気抵抗の増大をもたらすという不都合を有するものである。
また、リブ付きセパレータとは別に、セパレータの酸化劣化を防止するため、平坦な肉薄セパレータ面にガラスマットを重合してなるガラスマット付きセパレータも提案されているが、該ガラスマットは、リブ付きセパレータに比べ製造コストの増大をもたらしてしまうものである。また、ガラス繊維にバインダを混在しているため、極板群に組み込んだ場合、電気抵抗の増大、電池の放電特性の劣化をもたらすという不都合もある。
そこで、このような従来の技術に鑑み、本出願人は、先に、平成３年実用新案登録願第７８６８０号において、肉薄シートベース面に間隔を存して多数条の主リブを設けたリブ付きセパレータの隣接する主リブ間に該主リブよりも高さの低いミニリブを少なくとも１条設けることにより、電池使用時に陽極板やセパレータの変形が生じても、該ミニリブに陽極板面が当接されることにより該セパレータのベース部が直接陽極板面と接触することを防止できるようにしたリブ付きセパレータを提案した。
しかしながら、このセパレータでは、ミニリブの断面形状が台形状となっており、上面が完全なフラットで、上面から側壁面へかけての面が角張った面に形成されている。このため、充放電による陽極板の膨張、収縮等に伴う変形や、セパレータの特にリブのない平坦な肉薄ベース部の湾曲等により、ミニリブに陽極板面が接触すると、該ミニリブの角張った面によって陽極板表面の活物質が掻き取られて脱落し易くなる問題がある。
【０００４】
【課題を解決するための手段】
本発明者等は、かかる要望に応えるべく、鋭意検討の結果、隣接する主リブ間に、前記リブよりも高さの低いミニリブを設けると共に、前記ミニリブ上面の少なくとも長辺に沿ってアールを設けることにより、電気抵抗の増大をもたらすことなく、放電特性の劣化なしに、肉薄シートのベース部の酸化劣化を防止し得る鉛蓄電池用リブ付きセパレータを構成できることを知見した。
本発明の鉛蓄電池用リブ付きセパレータは、かかる知見に基づきなされたもので、請求項１記載の通り、肉薄シートのベース面に、所定の間隔を存して多数条の主リブを設けた鉛蓄電池用リブ付きセパレータにおいて、隣接する主リブ間に、前記リブよりも高さの低いミニリブを設けると共に、前記ミニリブ上面の少なくとも長辺に沿ってアールを設けたことを特徴とする。
また、請求項２記載の鉛蓄電池用リブ付きセパレータは、請求項１記載の鉛蓄電池用リブ付きセパレータにおいて、前記ミニリブの短辺にもアールを設けたことを特徴とする。
また、請求項３記載の鉛蓄電池用リブ付きセパレータは、請求項１または２記載の鉛蓄電池用リブ付きセパレータにおいて、前記アールの曲率半径を０．０２〜０．２ｍｍの範囲に形成したことを特徴とする。
また、請求項４記載の鉛蓄電池用リブ付きセパレータは、請求項１乃至３の何れかに記載の鉛蓄電池用リブ付きセパレータにおいて、前記ミニリブの高さを主リブの１０〜５０％の高さに形成したことを特徴とする。
また、請求項５記載の鉛蓄電池用リブ付きセパレータは、請求項１乃至４の何れかに記載の鉛蓄電池用リブ付きセパレータにおいて、前記ミニリブを隣接する主リブ間の中央部近傍のみに設けたことを特徴とする。
また、請求項６記載の鉛蓄電池用リブ付きセパレータは、請求項１乃至５の何れかに記載の鉛蓄電池用リブ付きセパレータにおいて、前記主リブのピッチ間距離が５．０ｍｍ以上であることを特徴とする。
【０００５】
【発明の実施の形態】
図１は、本発明鉛蓄電池用リブ付きセパレータの一実施の形態の平面図、図２はその拡大断面図を示すもので、図中１０で示される本発明鉛蓄電池用リブ付きセパレータは、ポリエチレン樹脂シート等からなる肉薄シート１のベース面２に、電極板２０に当接させるように所定の間隔を存して多数条の主リブ３を設けると共に、これら隣接する主リブ３，３間に、前記リブ３よりも高さの低いミニリブ４を設けると共に、前記ミニリブ４の上面の長辺に沿ってアール４ａを設けるようにてある。図示のものでは、主リブ３，３間の中心線Ｌに沿って１本のミニリブ４のみを設けるようにしたものである。このミニリブ４の高さは主リブ３の高さの１／５に形成してある。
【０００６】
かくして、上記、ミニリブ付きセパレータを極板群に組み込み、鉛蓄電池に構成した場合、その使用中において、充放電による極板の膨張、収縮などに伴う変形や、セパレータの肉薄ベース部の湾曲が生じても、前記セパレータの主リブ間の中央近傍に設けられたミニリブによって、薄肉シートのベース部が極板面と接触するのが防止され、前記シートの酸化劣化は未然に防止され、その結果、内部短絡の防止、電池寿命の増大が図られる。特に、前記ミニリブの上面の長辺に沿ってアールを設けてあるため、極板がミニリブに当接した際に、極板の活物質がミニリブの上面のエッジによって脱落されるのを防止でき、電池寿命を長寿命化させることができる。
【０００７】
前記ミニリブ４は、図中Ｒで示した、隣接する主リブ３，３のピッチ間距離に対して中央から左右１０％の範囲内に設けることが好ましく、１本に限らず、２本など、複数本設けることもできる。
【０００８】
また、図示のミニリブ４は、主リブ３の高さの１／５の高さに形成したが、１／２以下の高さにすれば、電気抵抗の増大をもたらすことなく、前記薄肉シートのベース部が極板面と接触するのを防止することができる。また、このような薄肉シートのベース部の極板面との接触を防止するためには、最低でも１／１０程度の高さを有するように形成することが好ましく、従って、ミニリブの高さは、主リブの高さに対して１／２〜１／１０の範囲にするのが好ましい。
【０００９】
また、前記ミニリブは直線状に形成したが、図３に示すように、破断線状に形成してもよいし、或いは、図４に示すように、破断したものを、更に、傾斜配置するように形成してもよい。
これらの場合も、少なくともミニリブの上面の少なくとも長辺に沿ってアールを形成すればよい。勿論、短辺にもアールを設けることが、より好ましい。
【００１０】
【実施例】
次に、本発明鉛蓄電池用リブ付きセパレータの具体的実施例を、比較例と比較して説明する。
（実施例１）
本実施例の鉛蓄電池用リブ付きセパレータは、高密度ポリエチレン樹脂粉末と、無機粉体として平均粒径５μｍのシリカ粉末と、鉱物オイルとしてパラフィン系オイルとをヘンシェルミキサで混合し、得られた混合物を２軸押出機で押出し、成形ロールで加圧成形し、トリクロロエチレン中に浸漬して鉱物オイルを除去し、セパレータの鉱物オイル含有量が１３質量％となるようにした。そして、厚さ０．２５ｍｍのベース部上に、上辺０．４ｍｍ、底辺０．８ｍｍ、高さ１．００ｍｍ、断面積０．６０ｍｍ²の断面形状を有する主リブを１０ｍｍ間隔で連設するようにして形成した。また、前記主リブ間のほぼ中央に、上辺０．２ｍｍ、底辺０．４ｍｍ、高さ０．３０ｍｍ、断面積０．０９ｍｍ²（主リブの断面積比０．１５）の断面形状を有する直線状のミニリブを１本形成した。そして、このミニリブの上辺の長辺に沿って、曲率半径０．１ｍｍのアールを形成した。
【００１１】
（比較例１）従来品
主リブ間にミニリブを設けなかったこと以外は実施例１と同様にして、鉛蓄電池用リブ付きセパレータを作製した。
【００１２】
（比較例２）
ミニリブにアールを設けなかったこと以外は実施例１と同様にして、鉛蓄電池用リブ付きセパレータを作製した。
【００１３】
次に、得られた実施例並びに各比較例の鉛蓄電池用リブ付きセパレータにつき、下記に示す耐酸化時間試験を行い、セパレータの寿命評価を行うと共に、電池の始動性に影響する電気抵抗試験を行った。その結果を下記表１に示す。
［耐酸化時間］
試験容器に試料（セパレータ７０ｍｍ角）を１０ｋＰａの圧力がかかるようセットし、比重１．３００（２０℃）の電解液を１０００ｍｌ注入し、電界液温度を４５±２℃の状態で２．５Ａの調整をした。耐酸化時間は、端子電圧が２．６Ｖ以下または電圧差が０．２Ｖ以上となった時間で表示するようにした。
［電気抵抗］
ＪＩＳＣ２３１３に準拠した方法により測定した。
【００１４】
【表１】

【００１５】
表１に示すように、実施例の鉛蓄電池用リブ付きセパレータは、電気抵抗は従来品と同等で、耐酸化時間は２５％の向上が認められた。
また、比較例１（従来品）の鉛蓄電池用リブ付きセパレータは、実施例１の鉛蓄電池用リブ付きセパレータに比べ、電気抵抗は同等であったが、耐酸化時間では２５％も劣るものであった。
また、比較例２の鉛蓄電池用リブ付きセパレータは、実施例と同等に電気抵抗の上昇もなく、耐酸化時間の向上が認められたが、活物質の脱落が認められ、実施例に比べ、電池の長寿命化を達成することができなかった。
【００１６】
【発明の効果】
以上説明したように、本発明のリブ付きセパレータを鉛蓄電池に使用した場合、主リブ間に配置したミニリブにアールを設けることにより、極板とセパレータの薄肉シートベースとの接触を防止でき、また、電気抵抗を小さく維持できるばかりでなく、ミニリブと極板の当接時における活物質の脱落を防止でき、セパレータ寿命の長寿命化をもたらす効果を有する。
【図面の簡単な説明】
【図１】本発明鉛蓄電池用リブ付きセパレータの一実施の形態の平面図
【図２】同拡大断面図
【図３】本発明鉛蓄電池用リブ付きセパレータの実施の形態の一変形例を示す平面図
【図４】本発明鉛蓄電池用リブ付きセパレータの実施の形態の他変形例を示す平面図
【符号の説明】
１肉薄シート
２ベース面
３主リブ
４ミニリブ
４ａアール
１０鉛蓄電池用リブ付きセパレータ
２０極板
Ｈｓ主リブの高さ
Ｈｍミニリブの高さ
Ｌ中心線
Ｒ中央から左右１０％の範囲[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a lead-acid battery separator, and more specifically, a lead-acid battery rib-provided separator provided with a plurality of main ribs at predetermined intervals on a base surface of a thin sheet so as to contact an electrode plate. About.
[0002]
[Prior art]
As a conventional ribbed separator for lead-acid batteries, a plurality of main ribs are provided on a base surface of a flexible synthetic resin thin sheet with a predetermined interval so as to be in contact with an electrode plate. in use.
[0003]
[Problems to be solved by the invention]
When the above-described conventional ribbed separator is incorporated in the electrode plate group and configured as a lead-acid battery, during use, deformation due to expansion and contraction of the anode plate due to charge and discharge, and a flat thin wall with no ribs in particular. The base portion of the thin sheet of the separator comes into contact with the anode surface due to the curvature of the base portion, etc., and is oxidized by lead oxide which is the active material of the electrode plate, causing oxidative deterioration, and finally there is a hole. As a result, there is a disadvantage that a short circuit between electrode plates and shortening of battery life are brought about.
In order to prevent this, it is conceivable that the height of the ribs is remarkably increased. However, there is a disadvantage that the distance from the electrode plate surface is increased and the electrical resistance is increased.
In addition to the ribbed separator, a separator with a glass mat formed by polymerizing a glass mat on a flat thin separator surface has also been proposed in order to prevent oxidative deterioration of the separator. As a result, the manufacturing cost increases. In addition, since a binder is mixed in the glass fiber, when incorporated in the electrode plate group, there is an inconvenience that the electrical resistance is increased and the discharge characteristics of the battery are deteriorated.
Therefore, in view of such a conventional technique, the applicant of the present application previously described in 1991 Utility Model Registration Application No. 78680, a rib in which a plurality of main ribs are provided at intervals on the thin sheet base surface. By providing at least one mini-rib that is lower than the main rib between adjacent main ribs of the separator, the anode plate surface comes into contact with the mini-rib even if the anode plate or separator is deformed during battery use. Thus, a ribbed separator has been proposed in which the base portion of the separator can be prevented from coming into direct contact with the anode plate surface.
However, in this separator, the cross-sectional shape of the mini-rib is a trapezoidal shape, the upper surface is completely flat, and the surface from the upper surface to the side wall surface is formed into an angular surface. For this reason, when the anode plate comes into contact with the minirib due to deformation accompanying the expansion or contraction of the anode plate due to charging / discharging, or the curvature of the flat thin base portion without a rib in the separator, the angular surface of the minirib There is a problem that the active material on the surface of the anode plate is scraped off and easily falls off.
[0004]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have provided mini-ribs that are lower than the ribs between adjacent main ribs, and provided a radius along at least the long side of the upper surface of the mini-rib. As a result, it has been found that a separator with a rib for a lead storage battery that can prevent the deterioration of oxidation of the base portion of the thin sheet without deteriorating the discharge characteristics without increasing the electrical resistance.
The ribbed separator for a lead storage battery according to the present invention is based on such knowledge. As described in claim 1, lead having a plurality of main ribs provided on a base surface of a thin sheet at predetermined intervals. The separator with a rib for a storage battery is characterized in that a mini-rib having a height lower than that of the rib is provided between adjacent main ribs, and a radius is provided along at least the long side of the upper surface of the mini-rib.
The lead-acid battery rib-attached separator according to claim 2 is characterized in that, in the lead-acid battery rib-attached separator according to claim 1, a round is also provided on the short side of the mini-rib.
The lead-acid battery rib-attached separator according to claim 3 is the lead-acid battery rib-attached separator according to

claim

1 or 2, wherein the radius of curvature of the R is 0.02 to 0.2 mm. Features.
The lead-acid battery rib-attached separator according to claim 4 is the lead-acid battery rib-attached separator according to any one of claims 1 to 3, wherein the height of the mini-rib is 10-50% of the main rib. It is characterized by being formed.
Moreover, the lead-acid battery rib-attached separator according to claim 5 is the lead-acid battery rib-attached separator according to any one of claims 1 to 4, wherein the mini-rib is provided only in the vicinity of a central portion between adjacent main ribs. It is characterized by that.
The lead-acid battery rib-attached separator according to claim 6 is the lead-acid battery rib-attached separator according to any one of claims 1 to 5, wherein the pitch between the main ribs is 5.0 mm or more. Features.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a plan view of an embodiment of a separator with a rib for a lead storage battery of the present invention, FIG. 2 is an enlarged sectional view thereof, and the separator with a rib for a lead storage battery of the present invention indicated by 10 in the figure is polyethylene. A plurality of main ribs 3 are provided on the base surface 2 of the thin sheet 1 made of a resin sheet or the like at predetermined intervals so as to contact the electrode plate 20, and between the adjacent main ribs 3, 3. In addition to providing the mini-ribs 4 having a height lower than that of the ribs 3, the radius 4 a is provided along the long side of the upper surface of the mini-ribs 4. In the illustrated example, only one mini-rib 4 is provided along the center line L between the main ribs 3 and 3. The height of the mini-rib 4 is formed to be 1/5 of the height of the main rib 3.
[0006]
Thus, when the above-mentioned separator with mini-rib is incorporated in the electrode plate group and configured as a lead storage battery, deformation due to expansion / contraction of the electrode plate due to charge / discharge or bending of the thin base portion of the separator occurs during use. However, the mini-rib provided near the center between the main ribs of the separator prevents the base portion of the thin sheet from coming into contact with the electrode plate surface, and the oxidative deterioration of the sheet is prevented beforehand. Preventing internal short circuit and increasing battery life. In particular, since the round is provided along the long side of the upper surface of the mini-rib, when the electrode plate contacts the mini-rib, the active material of the electrode plate can be prevented from falling off by the edge of the upper surface of the mini-rib, Battery life can be extended.
[0007]
The mini-ribs 4 are preferably provided within a range of 10% on the left and right sides of the distance between the pitches of the adjacent main ribs 3 and 3 indicated by R in the figure. A plurality can be provided.
[0008]
In addition, the illustrated mini-rib 4 is formed to be 1/5 of the height of the main rib 3. However, if the height of the mini-rib 4 is 1/2 or less, the electrical resistance is not increased, and the thin-walled sheet is reduced. It is possible to prevent the base portion from coming into contact with the electrode plate surface. Further, in order to prevent contact with the electrode plate surface of the base portion of such a thin sheet, it is preferable to form it so as to have a height of at least about 1/10. It is preferable that the height is in the range of 1/2 to 1/10 with respect to the height of the main rib.
[0009]
Further, the miniribs are formed in a straight line, but as shown in FIG. 3, they may be formed in a broken line shape, or, as shown in FIG. You may form in.
In these cases as well, a radius may be formed at least along the long side of the upper surface of the minirib. Of course, it is more preferable to provide a radius on the short side.
[0010]
【Example】
Next, specific examples of the ribbed separator for the lead acid battery of the present invention will be described in comparison with comparative examples.
(Example 1)
The separator with ribs for a lead storage battery of this example is a mixture obtained by mixing a high-density polyethylene resin powder, silica powder having an average particle diameter of 5 μm as inorganic powder, and paraffinic oil as mineral oil with a Henschel mixer. Was extruded with a twin-screw extruder, pressure-formed with a forming roll, and immersed in trichlorethylene to remove mineral oil, so that the mineral oil content of the separator was 13% by mass. Then, main ribs having a cross-sectional shape having a top side of 0.4 mm, a base side of 0.8 mm, a height of 1.00 mm, and a cross-sectional area of 0.60 mm ² are continuously provided at intervals of 10 mm on a base portion having a thickness of 0.25 mm. Formed. In addition, a straight line having a cross-sectional shape having an upper side of 0.2 mm, a base side of 0.4 mm, a height of 0.30 mm, and a cross-sectional area of 0.09 mm ² (the cross-sectional area ratio of the main rib is 0.15) at the approximate center between the main ribs. A single mini-rib was formed. A round with a radius of curvature of 0.1 mm was formed along the long side of the upper side of the minirib.
[0011]
Comparative Example 1 A lead-acid battery ribbed separator was prepared in the same manner as in Example 1 except that no minirib was provided between the main ribs of the conventional product.
[0012]
(Comparative Example 2)
A separator with ribs for a lead storage battery was produced in the same manner as in Example 1 except that the rounds were not provided on the miniribs.
[0013]
Next, with respect to the separators with ribs for lead storage batteries of the obtained examples and comparative examples, the oxidation resistance time test shown below is performed, the life of the separator is evaluated, and the electrical resistance test that affects the startability of the battery is performed. went. The results are shown in Table 1 below.
[Oxidation resistance]
A sample (70 mm square separator) is set in a test container so that a pressure of 10 kPa is applied, 1000 ml of an electrolyte with a specific gravity of 1.300 (20 ° C.) is injected, and the electric field solution temperature is 45 ± 2 ° C. and 2.5 A. Adjusted. The oxidation resistance time is displayed as the time when the terminal voltage is 2.6 V or less or the voltage difference is 0.2 V or more.
[Electric resistance]
It measured by the method based on JISC2313.
[0014]
[Table 1]

[0015]
As shown in Table 1, the lead-acid battery ribbed separators of the examples were equivalent in electrical resistance to conventional products, and the oxidation resistance was improved by 25%.
In addition, the lead-acid battery rib-attached separator of Comparative Example 1 (conventional product) had the same electrical resistance as the lead-acid battery rib-attached separator of Example 1, but the oxidation resistance time was inferior by 25%. there were.
Moreover, the lead-acid battery rib-equipped separator of Comparative Example 2 showed no increase in electrical resistance as in the Example, and an improvement in oxidation resistance time was observed, but the active material was observed to fall off, compared to the Example. Long battery life could not be achieved.
[0016]
【The invention's effect】
As described above, when the ribbed separator of the present invention is used for a lead storage battery, contact between the electrode plate and the thin sheet base of the separator can be prevented by providing a round on the mini-rib disposed between the main ribs. In addition to being able to keep the electrical resistance small, it is possible to prevent the active material from falling off when the mini-rib and the electrode plate come into contact with each other, and the effect of prolonging the life of the separator is obtained.
[Brief description of the drawings]
FIG. 1 is a plan view of an embodiment of a separator with a rib for a lead storage battery of the present invention. FIG. 2 is an enlarged sectional view of the same. FIG. 3 shows a modification of the embodiment of the separator with a rib for a lead storage battery of the present invention. Plan view [FIG. 4] Plan view showing another modification of the embodiment of the ribbed separator for lead-acid battery of the present invention [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Thin sheet 2 Base surface 3 Main rib 4 Minirib 4a are 10 Separator with rib for lead acid battery 20 Electrode plate Hs Main rib height Hm Minirib height L Center line R 10% right and left from the center

Claims

In the lead-acid battery rib-attached separator in which a plurality of main ribs are provided at predetermined intervals on the base surface of the thin sheet, between adjacent main ribs, a mini-rib having a height lower than that of the ribs is provided. A ribbed separator for a lead storage battery, wherein a round is provided along at least the long side of the upper surface of the minirib.

2. A separator with ribs for a lead storage battery according to claim 1, wherein rounds are also provided on the short sides of the mini-ribs.

The lead-acid battery rib-attached separator according to claim 1 or 2, wherein the radius of curvature of the R is in a range of 0.02 to 0.2 mm.

The separator with a rib for a lead storage battery according to any one of claims 1 to 3, wherein the height of the mini-rib is 10 to 50% of the main rib.

The lead-acid battery ribbed separator according to any one of claims 1 to 4, wherein the mini-rib is provided only in the vicinity of a central portion between adjacent main ribs.

6. The lead-acid battery rib-attached separator according to claim 1, wherein a distance between pitches of the main ribs is 5.0 mm or more.