JP4531189B2

JP4531189B2 - Lead plate for lead acid battery

Info

Publication number: JP4531189B2
Application number: JP2000092567A
Authority: JP
Inventors: 徹郎高間; 能弘江口
Original assignee: GS Yuasa International Ltd
Current assignee: GS Yuasa International Ltd
Priority date: 2000-03-30
Filing date: 2000-03-30
Publication date: 2010-08-25
Anticipated expiration: 2020-03-30
Also published as: JP2001283838A

Description

【０００１】
【発明の属する技術分野】
本発明は、鉛蓄電池の改良、殊に鉛蓄電池用極板の改良に関する。
【０００２】
【従来の技術】
従来、鉛蓄電池に多く用いられている極板は、通常上部に耳部と称する突起および格子状のます目を有する鋳造またはエキスパンド格子体に活物質ペーストを塗布して作製されている。このようなペースト式極板を用いた鉛蓄電池は、前記極板間にリブを有する板状のセパレータあるいは繊維状のガラスマットセパレータがはさまれた極群を有し、前記極群に緊圧をかけた状態で電槽内に収納された構造となっている。
【０００３】
鉛蓄電池を充放電し続けると、正極活物質粒子は粗大化すると共に互いの結合力が徐々に低下する。ペースト式極板は隣接するセパレータの緊圧のみで活物質を保持しているので、外部から振動を受けるなどして極板から活物質が徐々に脱落する。この結果、電池容量が低下し、サイクル寿命性能が低下するなどの問題点を有していた。
【０００４】
上記問題を解決するためにクラッド式極板が使用されている。クラッド式極板は、ガラス繊維スリーブにフェノール樹脂等の樹脂溶液を含浸させて硬化させた複数個からなる多孔質チューブに、鉛又は鉛合金からなる芯金を挿入し、活物質を充填した後、開口部を樹脂で密閉して作製されている。
【０００５】
この極板は、活物質が前記チューブに包囲かつ固定されているため、ペースト式極板の欠点である活物質の脱落が抑制され、サイクル寿命特性が優れるという特徴がある。しかしながらクラッド式極板は、各チューブが芯金の上部のみで集電され、極板の薄型化が難しいため、高率放電性能がペースト式極板に劣るという欠点があった。
【０００６】
【発明が解決しようとする課題】
一般に、鉛蓄電池の高率放電性能を向上させるために、極板および極間を薄くし、極板枚数を増やす方法がある。ペースト式極板は、極板厚さを１ミリ程度まで薄くできるため、高率放電性能に優れた鉛蓄電池を提供できる。しかしながら、近年、さらなる高出力化および長寿命化の要望があり、従来の極板ではこれら要望を十分満足させるには限界があった。
【０００７】
一方、鉛または鉛合金箔をパンチング加工した集電体の両面に活物質を塗布した極板が考えられている。この極板は、その厚みを容易に薄くでき近年の高出力の要望に答えることができる。しかしながらこの極板は、集電体が完全な平板であり、従来のペースト極板の集電体の如く三次元構造を持つものより、活物質の保持力が弱い。このため、高率放電性能が優れる反面、サイクル寿命性能が従来のペースト式極板より劣るという問題点を有していた。
【０００８】
本発明は、上記問題点に鑑みてなされたものであって、薄型化が可能で、活物質の脱落を防止した高率放電性能かつサイクル寿命性能の優れた鉛蓄電池用極板を提供しようとするものである。
【０００９】
【課題を解決するための手段】
本発明は、以上の課題を解決する為、鉛または鉛合金箔をエンボス加工した集電体の両面に、耐酸性で多孔質の板が接着され、前記集電体と板の間に形成された空間に、活物質が充填されていること特徴とする。
【００１０】
本発明に係る鉛蓄電池用極板は、エンボス加工した鉛または鉛合金箔の集電体を用いるので、１ミリ以下の薄型化が容易に製作可能となり、高率放電性能が向上する。また、集電体の両面に、耐酸性で多孔質の板が接着されているので、活物質が包囲かつ固定され、長期にわたり活物質の脱落を防止でき、以ってサイクル寿命性能が向上する。
【００１１】
【発明の実施の形態】
以下、本発明の実施形態について図面を参照して説明する。
【００１２】
図1は、本発明の一実施形態を示す一部切欠き斜視図、図２は、図１の線Ａ―Ａに沿う断面図、図３は、図１の線Ｂ―Ｂに沿う断面図、図４は、本発明の他の実施形態を示す一部切欠き斜視図、図５は、図４の線Ｃ−Ｃに沿う断面図、図６は、図４の線Ｄ−Ｄに沿う断面図、図７は、本発明の実施例と比較例と従来例の各々のサイクル寿命特性を示すグラフ、図８は、図７と同様の放電特性を示すグラフである。
【００１３】
図において、１は鉛−カルシウム−錫合金からなる集電体、２は耐酸性で多孔質の板、３は耐酸性の接着剤、４は活物質、５は集電体１をエンボス加工して形成した凹凸、６は本発明の極板である。
【００１４】
図1〜３に示す実施形態１では、集電体１は、側辺１aと平行な線に沿って側面三角形の凹凸５が形成され、凹凸が形成された線と線の間に平板部１bを有する。そして、全ての凹凸５の先端面５a（以下、エッジと称する）が同一面となり、この面に接着剤３が塗布され板２と接着している。すなわち、図では凸部のエッジ５aに上側の板２が、凹部のエッジ５aに下側の板２が接着している。そして、凹凸５と板２の空間７、および平板部１bと板２の空間７に活物質４が充填されている。
【００１５】
図４〜６に示す実施形態２は、集電体１に平板部１bを有しない以外は実施形態１と同じである。本実施形態２は実施形態１に比べ平板部１bがないだけ活物質４が多く充填でき、体積容量効率に優れるが、集電効率が実施形態１より劣り、側部からの応力に弱く、作業性も劣る。
【００１６】
【実施例】
次に、本発明の製造方法について説明する。
【００１７】
まず、鉛―カルシウム−スズ合金からなる厚さ２００μの鉛合金のシートを、最大厚さが５００μになるように凹凸形状の金型で上下からプレスすることによりエンボス加工し、集電体１を作製する。次に、前記集電体両面に活物質ペーストを塗着して、熟成、乾燥する。乾燥後、エッジ５aが露出するように表面を研磨する。さらに、耐酸性で多孔質の板２として、多孔度８０％、厚さ１００μｍの鉛ガラス板２を用意する。エッジ５aに耐酸性の無機接着剤３を塗布し、鉛ガラス板２と前記集電体１の両面のエッジ５aを貼りつけ厚さ０．７ミリの極板６を完成する。
【００１８】
ここで、集電体１、板２および極板６の厚さ、サイズ、多孔度、形状は本実施例に限定されるものではなく、極板の設計仕様により自由に変更することができる。例えば実施形態1や実施形態２のように、目標性能にあわせて構造を変更してもよい。
【００１９】
また、本発明極板に使用する接着剤３として、無機接着剤を用いたが、たとえばエポキシ樹脂やポリイミド樹脂などの耐酸性の接着剤であればよく、本実施例に限定されるものではない。ただ、耐酸性の接着剤の中でも、ＳｉＯ₂、Ａｌ₂Ｏ₃、ＺrＯ₂を構成要素に含む無機接着剤は、長期にわたり集電体１と鉛ガラス板２の接着を確保する上で好ましい。
【００２０】
鉛蓄電池の正極板は、充放電を繰り返すうちに、活物質粒子が粗大化すると共に互いの結合力が徐々に低下する。その際、本発明極板６は、集電体の両面に貼り付けた板２が空間７に充填された活物質４を包囲、固定し、極板６からの脱落を防止する。本発明の実施例では、活物質４の脱落防止に多孔性の鉛ガラス板２を用いたが、耐酸性で多孔性の板であれば活物質４の脱落を防止することができる。また、板２の材質に導電性のものを用いても、集電効率か向上するので、高率放電性能を向上させる上で好ましい。
【００２１】
次に、本発明を用いた電池と従来の極板を用いた電池の寿命試験について説明する。
【００２２】
前記構成からなる正負極板６と、材質がＰＥでリブを有し多孔質構造の板状セパレータを用いて、公知の組立て方法により単セルからなる本発明に係る電池Ａ（発明電池Ａと称する）を作製した。また、従来のペースト式極板およびクラッド式極板を用いた以外は本発明による電池と同構成で、１０時間率放電容量（定格容量）が同じである比較電池ＢおよびＣを作製した。これら電池に電解液を注入して電槽化成を行った後、充放電サイクル寿命試験を４００サイクル行った。その結果を図７に示す。なお、試験条件は、放電がＣ／４（Ｃは定格容量の値を示す数値）の定電流で２時間放電し、充電は、０．１Ｃの定電流で充電量が放電容量の１１５％とし、放電容量が初期容量の８０％になった時点で寿命とした。
【００２３】
図７に示すように、比較電池Ｂは２００サイクルで寿命になったのに対して、発明電池Ａおよび比較電池Ｃは、比較電池Ｂに比べ寿命性能に優れていた。
一方、寿命試験前および比較電池Ｂが寿命を迎えた時点（２００サイクル）で、各電池の高率放電試験を行った。試験条件は、３Ｃの定電流放電で、放電終止電圧を１．２Ｖ／セルとし、定格容量（１０時間率放電容量）を１００％としたときの放電容量％を測定した。その結果を図８に示す。比較電池Ｂは、寿命時の放電容量の低下が大きく、初期容量の６０％になった。比較電池Ｃは、放電容量の低下は少ないものの、初期時点から放電容量が他の電池より低かった。電池Ａは、初期時点から放電容量が他の電池より高く、放電容量の低下もほとんどなかった。寿命試験後、各電池を解体調査したところ、電池Ｂの正極活物質の脱落が進行していることが確認された。一方、電池Ａの極板６は、電池Ｂのような脱落の兆候は見られなかった。
【００２４】
以上の結果、本発明の極板６は、極板の薄型化と活物質４の脱落の防止を行うことができるので、高率放電性能かつサイクル寿命性能の両性能に優れた鉛蓄電池用極板を提供できる。
【００２５】
以上実施例に述べた効果は、実験に用いた液式鉛蓄電池以外に、ゲル式またはその他の電解液保持方式等の鉛蓄電池等、形式の如何にかかわらず同様であった。
【００２６】
【発明の効果】
以上説明した通り、本発明によれば、エンボス加工した鉛または鉛合金箔の集電体を用いるので、１ミリ以下の薄型化が容易に製作可能となり、高率放電性能が向上する。また、集電体の両面に、耐酸性で多孔質の板が接着されているので、活物質が包囲かつ固定され、長期にわたり活物質の脱落を防止でき、以ってサイクル寿命性能が向上する。
【図面の簡単な説明】
【図１】本発明の一実施形態を示す一部切欠き斜視図である。
【図２】図１の線Ａ−Ａに沿う断面図である。
【図３】図１の線Ｂ―Ｂに沿う断面図である。
【図４】本発明の他の一実施形態を示す一部切欠き斜視図である。
【図５】図４の線Ｃ−Ｃに沿う断面図である。
【図６】図４の線Ｄ―Ｄに沿う断面図である。
【図７】本発明に係る電池Ａと比較電池Ｂのサイクル寿命特性を示すグラフである。
【図８】本発明に係る電池Ａと比較電池Ｂの高率放電試験の結果を示すグラフである。
【符号の説明】
１集電体
２板
４活物質
６極板
７空間[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a lead storage battery, and particularly to an improvement of a lead storage battery electrode plate.
[0002]
[Prior art]
Conventionally, an electrode plate often used for a lead-acid battery is usually produced by applying an active material paste to a cast or expanded lattice body having protrusions called lattices and lattice-shaped cells on the upper portion. A lead-acid battery using such a paste-type electrode plate has an electrode group in which a plate-like separator having a rib or a fiber-like glass mat separator is sandwiched between the electrode plates, and the electrode group is tightly pressed. It has a structure that is housed in the battery case in a state of being applied.
[0003]
When the lead-acid battery is continuously charged and discharged, the positive electrode active material particles become coarse and the mutual binding force gradually decreases. Since the paste type electrode plate holds the active material only by the pressure of the adjacent separator, the active material is gradually dropped from the electrode plate due to vibration from the outside. As a result, there are problems such as a decrease in battery capacity and a decrease in cycle life performance.
[0004]
In order to solve the above problem, a clad plate is used. The clad electrode plate is filled with an active material by inserting a cored bar made of lead or lead alloy into a porous tube made of a plurality of impregnated glass fiber sleeves and impregnated with a resin solution such as phenol resin. The opening is sealed with resin.
[0005]
This electrode plate is characterized in that since the active material is surrounded and fixed in the tube, dropping of the active material, which is a drawback of the paste type electrode plate, is suppressed, and the cycle life characteristics are excellent. However, the clad electrode plate has a drawback that the high-rate discharge performance is inferior to that of the paste electrode plate because each tube collects current only at the upper part of the core metal and it is difficult to make the electrode plate thin.
[0006]
[Problems to be solved by the invention]
In general, in order to improve the high-rate discharge performance of a lead storage battery, there is a method of increasing the number of electrode plates by thinning the electrode plates and the distance between the electrodes. Since the paste type electrode plate can reduce the electrode plate thickness to about 1 mm, it is possible to provide a lead storage battery excellent in high rate discharge performance. However, in recent years, there has been a demand for higher output and longer life, and the conventional electrode plate has a limit to satisfy these demands sufficiently.
[0007]
On the other hand, an electrode plate in which an active material is applied on both sides of a current collector obtained by punching lead or a lead alloy foil is considered. This electrode plate can be easily reduced in thickness and can meet the recent demand for high output. However, in this electrode plate, the current collector is a perfect flat plate, and the holding power of the active material is weaker than that of a conventional paste electrode plate current collector having a three-dimensional structure. For this reason, the high rate discharge performance is excellent, but the cycle life performance is inferior to that of the conventional paste type electrode plate.
[0008]
The present invention has been made in view of the above-described problems, and is intended to provide an electrode plate for a lead-acid battery that can be reduced in thickness and has excellent high-rate discharge performance and cycle life performance that prevents the active material from falling off. To do.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an acid-resistant porous plate bonded to both surfaces of a current collector embossed with lead or a lead alloy foil, and a space formed between the current collector and the plate. Further, it is characterized by being filled with an active material.
[0010]
Since the electrode plate for a lead storage battery according to the present invention uses an embossed lead or lead alloy foil current collector, it can be easily manufactured to be 1 mm or less in thickness, and the high rate discharge performance is improved. In addition, an acid-resistant porous plate is bonded to both sides of the current collector, so that the active material is surrounded and fixed, and the active material can be prevented from falling off over a long period of time, thereby improving the cycle life performance. .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
1 is a partially cutaway perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG. 4 is a partially cutaway perspective view showing another embodiment of the present invention, FIG. 5 is a sectional view taken along line CC in FIG. 4, and FIG. 6 is taken along line DD in FIG. FIG. 7 is a cross-sectional view, FIG. 7 is a graph showing the cycle life characteristics of Examples, Comparative Examples, and Conventional Examples of the present invention, and FIG. 8 is a graph showing the same discharge characteristics as FIG.
[0013]
In the figure, 1 is a current collector made of a lead-calcium-tin alloy, 2 is an acid-resistant porous plate, 3 is an acid-resistant adhesive, 4 is an active material, 5 is an embossed current collector 1 Concavities and convexities 6 formed in this way are electrode plates of the present invention.
[0014]
In the first embodiment shown in FIGS. 1 to 3, the current collector 1 has a triangular triangular surface 5 formed along a line parallel to the side 1a, and a flat plate portion 1b between the lines where the unevenness is formed. Have And the front end surface 5a (henceforth an edge) of all the unevenness | corrugations 5 turns into the same surface, The adhesive agent 3 is apply | coated to this surface and it adhere | attaches on the board 2. FIG. That is, in the drawing, the upper plate 2 is bonded to the convex edge 5a, and the lower plate 2 is bonded to the concave edge 5a. Then, the active material 4 is filled in the space 7 between the unevenness 5 and the plate 2 and the space 7 between the flat plate portion 1 b and the plate 2.
[0015]
The second embodiment shown in FIGS. 4 to 6 is the same as the first embodiment except that the current collector 1 does not have the flat plate portion 1b. Compared with Embodiment 1, this Embodiment 2 can be filled with more active material 4 as long as there is no flat plate portion 1b, and is excellent in volumetric capacity efficiency. However, the current collection efficiency is inferior to that in Embodiment 1, and is weak against stress from the side. Also inferior.
[0016]
【Example】
Next, the manufacturing method of this invention is demonstrated.
[0017]
First, a lead alloy sheet made of lead-calcium-tin alloy having a thickness of 200 μm was embossed by pressing it from above and below with a concave and convex mold so that the maximum thickness was 500 μm. Make it. Next, an active material paste is applied to both sides of the current collector, aged and dried. After drying, the surface is polished so that the edge 5a is exposed. Further, a lead glass plate 2 having a porosity of 80% and a thickness of 100 μm is prepared as the acid-resistant and porous plate 2. An acid-resistant inorganic adhesive 3 is applied to the edge 5a, and the lead glass plate 2 and the edges 5a on both sides of the current collector 1 are attached to complete an electrode plate 6 having a thickness of 0.7 mm.
[0018]
Here, the thickness, size, porosity, and shape of the current collector 1, the plate 2, and the electrode plate 6 are not limited to the present embodiment, and can be freely changed according to the design specifications of the electrode plate. For example, as in the first and second embodiments, the structure may be changed according to the target performance.
[0019]
Moreover, although the inorganic adhesive agent was used as the adhesive agent 3 used for this invention electrode plate, it should just be acid-resistant adhesive agents, such as an epoxy resin and a polyimide resin, for example, and is not limited to a present Example. . However, among acid-resistant adhesives, an inorganic adhesive containing SiO ₂ , Al ₂ O ₃ , and ZrO ₂ as a constituent element is preferable for securing the adhesion between the current collector 1 and the lead glass plate 2 over a long period of time.
[0020]
As the positive electrode plate of the lead-acid battery repeats charging and discharging, the active material particles become coarse and the mutual binding force gradually decreases. At this time, the electrode plate 6 of the present invention surrounds and fixes the active material 4 filled in the space 7 with the plates 2 attached to both surfaces of the current collector, and prevents the electrode plate 6 from falling off. In the embodiment of the present invention, the porous lead glass plate 2 is used to prevent the active material 4 from falling off, but the active material 4 can be prevented from falling off if it is an acid-resistant and porous plate. In addition, even if a conductive material is used for the plate 2, the current collection efficiency is improved, which is preferable for improving the high rate discharge performance.
[0021]
Next, a life test of a battery using the present invention and a battery using a conventional electrode plate will be described.
[0022]
Using the positive and negative electrode plates 6 having the above-described structure and a plate-like separator made of PE and having a porous structure, the battery A according to the present invention comprising a single cell by a known assembly method (referred to as the invention battery A). ) Was produced. Also, comparative batteries B and C having the same configuration as the battery according to the present invention except for using the conventional paste type electrode plate and the clad type electrode plate and having the same 10 hour rate discharge capacity (rated capacity) were produced. After injecting the electrolyte into these batteries to form a battery case, a charge / discharge cycle life test was conducted 400 cycles. The result is shown in FIG. The test conditions were as follows: discharging was performed at a constant current of C / 4 (C is a numerical value indicating the rated capacity) for 2 hours, and charging was performed at a constant current of 0.1 C and the charge amount was 115% of the discharge capacity. The life was determined when the discharge capacity reached 80% of the initial capacity.
[0023]
As shown in FIG. 7, the comparative battery B reached the end of its life in 200 cycles, whereas the inventive battery A and the comparative battery C were superior in the life performance compared to the comparative battery B.
On the other hand, the high rate discharge test of each battery was performed before the life test and when the comparative battery B reached the end of life (200 cycles). The test conditions were 3C constant current discharge, discharge end voltage was 1.2 V / cell, and discharge capacity% was measured when rated capacity (10 hour rate discharge capacity) was 100%. The result is shown in FIG. In comparison battery B, the discharge capacity at the end of its life decreased greatly, and became 60% of the initial capacity. The comparative battery C had a lower discharge capacity than the other batteries from the initial point, although the discharge capacity did not decrease much. Battery A had a higher discharge capacity than the other batteries from the initial point, and there was almost no decrease in the discharge capacity. When each battery was disassembled after the life test, it was confirmed that the positive electrode active material of battery B was being removed. On the other hand, the electrode 6 of the battery A did not show any signs of dropping as in the battery B.
[0024]
As a result, since the electrode plate 6 of the present invention can reduce the thickness of the electrode plate and prevent the active material 4 from falling off, the electrode for a lead storage battery excellent in both high rate discharge performance and cycle life performance. Can provide a board.
[0025]
The effects described in the above examples were the same regardless of the type of the lead type storage battery such as a gel type or other electrolytic solution holding system in addition to the liquid type lead storage battery used in the experiment.
[0026]
【The invention's effect】
As described above, according to the present invention, since an embossed lead or lead alloy foil current collector is used, a thickness of 1 mm or less can be easily manufactured, and high-rate discharge performance is improved. In addition, an acid-resistant porous plate is bonded to both sides of the current collector, so that the active material is surrounded and fixed, and the active material can be prevented from falling off over a long period of time, thereby improving the cycle life performance. .
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a cross-sectional view taken along line BB in FIG.
FIG. 4 is a partially cutaway perspective view showing another embodiment of the present invention.
FIG. 5 is a cross-sectional view taken along line CC in FIG.
6 is a cross-sectional view taken along line DD in FIG.
7 is a graph showing cycle life characteristics of a battery A and a comparative battery B according to the present invention. FIG.
FIG. 8 is a graph showing the results of a high rate discharge test of the battery A and the comparative battery B according to the present invention.
[Explanation of symbols]
1 current collector 2 plate 4 active material 6 electrode plate 7 space

Claims

An acid-resistant porous plate is bonded to both sides of a current collector embossed with lead or a lead alloy foil, and a space formed between the current collector and the plate is filled with an active material; Lead plate for lead storage battery.