JP3721773B2

JP3721773B2 - Sealed lead acid battery

Info

Publication number: JP3721773B2
Application number: JP07708098A
Authority: JP
Inventors: 泰也阿部; 幸弘小野田; 宗良野田; 孝中嶋
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1998-03-25
Filing date: 1998-03-25
Publication date: 2005-11-30
Anticipated expiration: 2018-03-25
Also published as: JPH11273633A

Description

【０００１】
【発明の属する技術分野】
本発明は、密閉形鉛蓄電池に関するものであり、特にその電槽に関するものである。
【０００２】
【従来の技術】
密閉形鉛蓄電池は、充電時に正極から水の分解により発生した酸素ガスを、化１，化２に示すように負極と反応させることにより吸収除去し、密閉構造を可能にしている。
【０００３】
【化１】

【０００４】
【化２】

【０００５】
そこで負極の酸素ガス吸収反応を促進させるために、極板群の両端に負極を配置して、これと接する電槽内壁にリブを設けることにより、負極表面が気相と接触するような構造をとっている。また、この電槽内壁のリブは極板群の圧力がかかる電槽面を補強する役割も果たしている。電槽底部においては、活物質の脱落によるショートを防ぐ目的と、電池使用寿命末期に生じる正極板の高さ方向の伸びを収容するスペースを確保するために鞍を設けており、この鞍に極板底部に設けた突起部分を載せる構造をとっている。
【０００６】
ここで、電池の自己放電を抑制するためには、極板群に均等な圧力を加えて、マット状セパレータに含まれる電解液の分布を均一にしなければならない。また、電槽のリブと接している部分と接していない部分との圧力差による活物質利用率の違いを極力小さくしなければならない。さらに、負極の酸素ガス吸収反応を均一に行わせるために、気相部分を均等に配置しなければならない。このような理由から、電槽のリブは等間隔に配置する。
【０００７】
鞍に関しては、合成樹脂電槽の成形金型の単純化のために、電槽のリブと交わる位置に電槽のリブと同本数またはそれ以下の本数を配置する。
【０００８】
このとき、鞍と電槽のリブとが交わるエッジ部分には、エッジ部分を補強する構造、例えば内底隅に曲部を設ける。
【０００９】
図５は従来例の密閉形鉛蓄電池の電槽の断面図であり、図６は上部より見た平面図である。
【００１０】
図５，図６において、１は電槽、２はリブ、３は鞍、４は内底隅の曲部、５は負極板、６はセパレータ、７は正極板である。リブ２と鞍３は交わる位置に設けてあり、そのエッジ部分に内底隅の曲部４を設けている。
【００１１】
【発明が解決しようとする課題】
しかしながら、このような構造の場合、電槽１に極板群を挿入すると、両端の負極板５の底部の突起部分が内底隅の曲部４に邪魔され、均等に電槽１内に入らない。ひどい場合には、両端の負極板５が変形してしまう。このために極板群に均等な圧力がかからなくなり、電解液分布の不均一化や活物質利用率の差が生じ、充放電特性や寿命特性に悪影響を及ぼす。
【００１２】
そこで、本発明は内底隅の曲部が両端の負極板の電槽挿入の妨げにならないようにして、極板群を電槽に均等に挿入できるようにすることを目的としたものである。
【００１３】
【課題を解決するための手段】
上記の課題を解決するために本発明は、電槽の極板面と接する内壁に高さ方向に延びるリブと、電極底部に極板に対して垂直方向に延びる鞍とを交わらない位置に配設することを特徴とする。また、リブの高さが鞍と電槽内壁との交わるエッジ部分に設けた内底隅の曲部の半径よりも高いことを特徴とする。これにより、内底隅の曲部はリブによって隠れ、極板群両端の負極板に対する障害をなくすことができる。
【００１４】
【発明の実施の形態】
本発明は、電槽内壁に高さ方向に延びるリブと、電槽の底部に極板に対して垂直方向に延びる鞍とを互いに交わらない位置、すなわちねじれの位置に配設したものである。
【００１５】
さらに本発明は、リブの高さを内底隅の曲部の半径よりも高くしたものである。
【００１６】
このような構成とすることにより、内底隅の曲部はリブによって隠れ、極板群が挿入されるスペースには内底隅の曲部が存在しなくなる。よって、極板群は障害なく電槽に均等に挿入できる。また、両端の負極板が変形するようなことはなくなる。これにより、極板群に均等な圧力をかけることができ、電解液分布の不均一化や活物質利用率の差を抑えることができる。また、負極の酸素ガス吸収反応が均一に起こる。従って、密閉形鉛蓄電池の充放電特性および寿命特性を向上させることが可能となる。
【００１７】
（実施の形態１）
図１は本発明の実施の形態１における密閉形鉛蓄電池の電槽の断面図であり、図２は上部より見た平面図である。１は電槽、２はリブ、３は鞍、４は内底隅の曲部、５は負極板、６はセパレータ、７は正極板である。リブ２と鞍３は交わらない位置に設けてあり、電槽１の内壁と鞍３との交わるエッジ部分に内底隅の曲部４を設けている。内底隅の曲部４はリブ２の高さに隠れ、挿入される負極板５の障害は緩和される。
【００１８】
（実施の形態２）
図３は本発明の実施の形態２における電槽の内底隅の拡大断面図である。ｒは内底隅の曲部４の半径、ａはリブ２の高さの値を表す。高さａを半径ｒより大きくすることで内底隅の曲部４はリブ２によって完全に隠れ、挿入される負極板５の障害はなくなる。
【００１９】
【実施例】
以下、本発明の実施形態における具体的な実施例について、図を参照しながら説明する。
【００２０】
図１の本発明および図５の従来例の電槽において、リブ２の高さを１．０ｍｍ、内底隅の曲部４の半径ｒを０．７ｍｍとし、負極板５，セパレータ６，正極板７の厚みをそれぞれ２．３ｍｍ，２．４ｍｍ，４．３ｍｍとして２Ｖ２００Ａｈ（１０時間率）の電池を構成した。これらの電池について、６０℃雰囲気中で２．２３Ｖ／セルの定電圧トリクル充電を行ない確認した使用寿命について図４に示す。
【００２１】
図４に示すように、本発明の実施例における構成による電池の方が従来例における構成による電池よりも使用寿命のばらつきが小さいのは明らかである。また最小寿命については本発明の実施例における構成による電池が優れている。寿命に達した電池を分解調査したところ、従来例における構成による電池においては、負極板５の端板の底部突起部分が内底隅の曲部４に邪魔されて変形し、隣接する正極板７と短絡に至っているものがあった。本発明の実施例における構成による電池においては、負極板５の端板の変形による短絡が全くなく、早期に容量が低下するものがない。
【００２２】
なお、本発明の実施例においては鞍３と電槽１の内壁とが交わるエッジ部分に内底隅の曲部４を設けたが、例えばＣカット等を設けても本発明の効果を奏するものである。
【００２３】
【発明の効果】
以上のように、本発明により内底隅の曲部をリブによって隠すことができ、極板群を障害なく電槽に均等に挿入できる。これにより、極板群に均等な圧力をかけることができ、電解液分布の不均一や活物質利用率の差が抑えられ、酸素ガス吸収反応が均一に起こり、充放電特性および寿命特性に優れた密閉形鉛蓄電池の提供が可能となる。
【図面の簡単な説明】
【図１】本発明の実施の形態１における密閉形鉛蓄電池の電槽の断面図
【図２】同上部より見た平面図
【図３】本発明の実施の形態２における電槽の内底隅の曲部の拡大断面図
【図４】本発明の実施例における電池と従来例における電池の６０℃雰囲気中での寿命特性図
【図５】従来例の密閉形鉛蓄電池の電槽の断面図
【図６】同上部より見た平面図
【符号の説明】
１電槽
２リブ
３鞍
４内底隅の曲部
５負極板
６セパレータ
７正極板
ａ高さ
ｒ半径[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealed lead-acid battery, and more particularly to its battery case.
[0002]
[Prior art]
The sealed lead-acid battery absorbs and removes oxygen gas generated by decomposition of water from the positive electrode during charging by reacting with the negative electrode as shown in Chemical Formula 1 and Chemical Formula 2, thereby enabling a sealed structure.
[0003]
[Chemical 1]

[0004]
[Chemical formula 2]

[0005]
Therefore, in order to promote the oxygen gas absorption reaction of the negative electrode, a structure in which the negative electrode surface is in contact with the gas phase by disposing negative electrodes at both ends of the electrode plate group and providing ribs on the inner wall of the battery case in contact therewith. I am taking it. In addition, the rib on the inner wall of the battery case also serves to reinforce the battery case surface to which the pressure of the electrode plate group is applied. At the bottom of the battery case, a cage is provided for the purpose of preventing a short circuit due to falling off of the active material and to secure a space for accommodating the heightwise extension of the positive electrode plate that occurs at the end of the battery service life. It has a structure in which a protrusion provided on the bottom of the plate is placed.
[0006]
Here, in order to suppress the self-discharge of the battery, it is necessary to apply a uniform pressure to the electrode plate group to make the distribution of the electrolyte contained in the mat-like separator uniform. Moreover, the difference in the active material utilization rate due to the pressure difference between the portion in contact with the rib of the battery case and the portion not in contact with it must be minimized. Furthermore, in order to perform the oxygen gas absorption reaction of the negative electrode uniformly, the gas phase portion must be arranged uniformly. For this reason, the ribs of the battery case are arranged at equal intervals.
[0007]
With respect to the bag, in order to simplify the molding die of the synthetic resin battery case, the same number as or less than the number of ribs of the battery case is arranged at a position where it intersects with the ribs of the battery case.
[0008]
At this time, a structure that reinforces the edge portion, for example, a curved portion at the inner bottom corner, is provided at the edge portion where the basket and the rib of the battery case intersect.
[0009]
FIG. 5 is a sectional view of a battery case of a sealed lead-acid battery of a conventional example, and FIG. 6 is a plan view seen from above.
[0010]
5 and 6, 1 is a battery case, 2 is a rib, 3 is a trough, 4 is a curved portion of an inner bottom corner, 5 is a negative electrode plate, 6 is a separator, and 7 is a positive electrode plate. The rib 2 and the flange 3 are provided at the intersecting positions, and a curved portion 4 at the inner bottom corner is provided at the edge portion.
[0011]
[Problems to be solved by the invention]
However, in the case of such a structure, when the electrode plate group is inserted into the battery case 1, the protruding portions at the bottoms of the negative electrode plates 5 at both ends are obstructed by the bent portions 4 at the inner bottom corners, and the battery case 1 enters the battery case 1 evenly. Absent. In severe cases, the negative electrode plates 5 at both ends are deformed. For this reason, an equal pressure is not applied to the electrode plate group, the electrolyte distribution becomes non-uniform, and the difference in the active material utilization rate occurs, which adversely affects charge / discharge characteristics and life characteristics.
[0012]
Therefore, the present invention aims to make it possible to evenly insert the electrode plate group into the battery case so that the curved portion of the inner bottom corner does not interfere with the insertion of the battery case of the negative electrode plates at both ends. .
[0013]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is arranged at a position where a rib extending in the height direction on the inner wall contacting the electrode plate surface of the battery case and a flange extending in a direction perpendicular to the electrode plate do not intersect with each other. It is characterized by providing. Moreover, the height of a rib is higher than the radius of the curved part of the inner bottom corner provided in the edge part where a ridge and a battery case inner wall cross. As a result, the curved portion at the inner bottom corner is hidden by the rib, and the obstruction to the negative electrode plates at both ends of the electrode plate group can be eliminated.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the rib extending in the height direction on the inner wall of the battery case and the ridge extending in the direction perpendicular to the electrode plate are arranged at a position where they do not cross each other, that is, a twisted position.
[0015]
Further, according to the present invention, the height of the rib is higher than the radius of the curved portion at the inner bottom corner.
[0016]
With this configuration, the bent portion at the inner bottom corner is hidden by the rib, and the bent portion at the inner bottom corner does not exist in the space where the electrode plate group is inserted. Therefore, the electrode plate group can be evenly inserted into the battery case without obstruction. Further, the negative electrode plates at both ends are not deformed. Thereby, an equal pressure can be applied to the electrode plate group, and the uneven distribution of the electrolyte and the difference in the active material utilization rate can be suppressed. Further, the oxygen gas absorption reaction of the negative electrode occurs uniformly. Therefore, it is possible to improve the charge / discharge characteristics and life characteristics of the sealed lead-acid battery.
[0017]
(Embodiment 1)
1 is a cross-sectional view of a battery case of a sealed lead-acid battery according to Embodiment 1 of the present invention, and FIG. 2 is a plan view seen from above. 1 is a battery case, 2 is a rib, 3 is a trough, 4 is a curved portion at the inner bottom corner, 5 is a negative electrode plate, 6 is a separator, and 7 is a positive electrode plate. The rib 2 and the flange 3 are provided at positions where they do not intersect, and a curved portion 4 at the inner bottom corner is provided at an edge portion where the inner wall of the battery case 1 and the flange 3 intersect. The curved portion 4 at the inner bottom corner is hidden by the height of the rib 2, and the obstacle of the inserted negative electrode plate 5 is alleviated.
[0018]
(Embodiment 2)
FIG. 3 is an enlarged cross-sectional view of the inner bottom corner of the battery case according to Embodiment 2 of the present invention. r represents the radius of the curved portion 4 at the inner bottom corner, and a represents the height value of the rib 2. By making the height a larger than the radius r, the curved portion 4 at the inner bottom corner is completely hidden by the rib 2 and the obstruction of the inserted negative electrode plate 5 is eliminated.
[0019]
【Example】
Hereinafter, specific examples in the embodiments of the present invention will be described with reference to the drawings.
[0020]
In the battery case of the present invention of FIG. 1 and the conventional example of FIG. 5, the height of the rib 2 is 1.0 mm, the radius r of the curved portion 4 at the inner bottom corner is 0.7 mm, the negative electrode plate 5, the separator 6, the positive electrode A battery of 2V200 Ah (10 hour rate) was constructed with the thickness of the plate 7 being 2.3 mm, 2.4 mm, and 4.3 mm, respectively. FIG. 4 shows the service life of these batteries confirmed by performing a constant voltage trickle charge of 2.23 V / cell in a 60 ° C. atmosphere.
[0021]
As shown in FIG. 4, it is clear that the battery according to the configuration of the embodiment of the present invention has a smaller variation in the service life than the battery according to the configuration of the conventional example. Moreover, the battery by the structure in the Example of this invention is excellent about the minimum lifetime. As a result of disassembling and investigating a battery that has reached the end of its service life, in the battery having the configuration of the conventional example, the bottom protrusion portion of the end plate of the negative electrode plate 5 is obstructed by the curved portion 4 at the inner bottom corner and deforms, and the adjacent positive electrode plate 7 There was something that led to a short circuit. In the battery according to the configuration of the embodiment of the present invention, there is no short circuit due to the deformation of the end plate of the negative electrode plate 5, and there is no battery whose capacity is rapidly reduced.
[0022]
In addition, in the Example of this invention, although the curved part 4 of the inner bottom corner was provided in the edge part where the basket 3 and the inner wall of the battery case 1 intersect, even if it provides C cut etc., there exists an effect of this invention It is.
[0023]
【The invention's effect】
As described above, according to the present invention, the curved portion at the inner bottom corner can be hidden by the rib, and the electrode plate group can be evenly inserted into the battery case without obstruction. As a result, uniform pressure can be applied to the electrode plate group, non-uniformity in the electrolyte distribution and difference in the active material utilization rate are suppressed, oxygen gas absorption reaction occurs uniformly, and the charge / discharge characteristics and life characteristics are excellent. It is possible to provide a sealed lead-acid battery.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a battery case of a sealed lead-acid battery in Embodiment 1 of the present invention. FIG. 2 is a plan view seen from above. FIG. 3 is an inner bottom of the battery case in Embodiment 2 of the invention. Enlarged cross-sectional view of the curved portion of the corner [FIG. 4] Life characteristics in a 60 ° C. atmosphere of the battery in the embodiment of the present invention and the battery in the conventional example [FIG. [Fig. 6] Plan view from above. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery case 2 Rib 3 鞍 4 Curved part of inner bottom corner 5 Negative electrode plate 6 Separator 7 Positive electrode plate a Height r Radius

Claims

A sealed lead-acid battery in which a positive electrode plate, a negative electrode plate, and an electrode plate group consisting of a mat type separator that also serves as an electrolyte solution holding body are housed in a battery case made of a synthetic resin, on an inner wall in contact with the electrode plate surface of the battery case A plurality of ribs extending in the height direction are provided, and a ridge extending in a direction perpendicular to the electrode plate is arranged at a position where the rib does not intersect the rib at the bottom of the battery case , and the height of the rib is determined between the rib and the battery case. A sealed lead-acid battery characterized in that it is higher than the radius of the curved portion of the inner bottom corner provided at the edge portion where the inner wall intersects .