JP4904632B2

JP4904632B2 - Lead acid battery

Info

Publication number: JP4904632B2
Application number: JP2001112333A
Authority: JP
Inventors: 浩岡本; 和吉米津
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2001-04-11
Filing date: 2001-04-11
Publication date: 2012-03-28
Anticipated expiration: 2021-04-11
Also published as: JP2002313349A

Description

【０００１】
【発明の属する技術分野】
本発明は自動車等に用いられる鉛蓄電池に関するものである。
【０００２】
【従来の技術】
近年、鉛蓄電池の格子体は、生産性を向上する目的として鋳造による生産から鉛−カルシウム合金からなる鉛合金シートにエキスパンド加工を施すことにより連続的に生産できるエキスパンド工法によるものが多く、特にエキスパンド工法には主としてレシプロ方式が多く用いられている。
【０００３】
このレシプロ方式によるエキスパンド工法は、一般的に間欠的に鉛合金シートを金型に送り込みプレス機で金型を上下方向に動作させることで鉛合金シートにスリットを形成すると同時にスリットで挟まれた格子骨となる部分をシートの幅方向へ展開伸張して網目を形成するものである。このため、鉛合金シートには一定の強度が必要であり、この強度を確保するために鉛合金シート中にはカルシウムを０．０５質量％以上、錫を２．０質量％以下添加していた。
【０００４】
カルシウム含有量が０．０５質量％未満もしくはカルシウムが実質上含有されない鉛合金シートをレシプロ方式によりエキスパンド加工した場合は、網目展開幅のばらつきが生じたり、エキスパンド加工中に鉛合金シートが金型に対して蛇行するといった現象が生じる。したがって、このような現象を抑制するために鉛合金中のカルシウム含有量は０．０５質量％以上にすることが必要であった。
【０００５】
しかしながら鉛合金中にカルシウムを添加した場合、腐食されやすいＰｂ₃Ｃａといった金属間化合物が結晶粒界中に析出することにより鉛合金は腐食しやすくなるという欠点があった。
【０００６】
このようなカルシウム含有量が０．０５質量％とした鉛合金を用いた圧延体から形成したレシプロ方式によるエキスパンド格子体を正極に用いた場合には格子骨の表面から均一に腐食する。この時、格子骨は体積膨張することで格子体には伸びが発生する。
【０００７】
特に、展開伸張方向に枠骨が存在しないエキスパンド格子体の場合には格子骨が体積膨張する結果、エキスパンド格子体が展開伸張方向に伸びることになる。このようなエキスパンド格子体は展開伸張方向を格子体の上下方向として一端に格子耳部、他の一端に格子底部を形成しており、格子体が正極板の上下方向に伸びることによって正極板が負極板のストラップ部と短絡して急速に蓄電池容量が低下することがあった。
【０００８】
このような現象は、負極板の枚数が正極板の枚数と同枚数か正極板の枚数より１枚少ない構成を有する蓄電池において顕著である。このような極板群構成の場合、極板群の端に位置する２枚の極板のうち、一方もしくは両方が正極板となる。
【０００９】
このような極板群の端（以下端板と略称する）が正極板の場合であって、正極板端板が直接電槽内壁に接する構成、すなわち、特に負極板が袋状セパレータに収納されるか、もしくは袋状セパレータではなく、リーフ状のセパレータを用いた構成の場合、この端板となる正極板は腐食により上下方向に著しく伸び、負極ストラップ等の負極部材と接触することで短絡を発生させる確率が、他の端板でない正極板に比べて大きいことが解ってきた。
【００１０】
負極板に挟まれている正極板の場合、正極板の活物質と負極活物質の膨張によって正極板の両面は比較的均一に正極板の厚み方向の応力によって上下方向の伸びが抑制されるが、端板の場合は両面が充分に保持されていないため上下方向の伸びが大きくなるものと推測される。
【００１１】
【発明が解決しようとする課題】
本発明はこのような正極格子体の腐食変形によって正極板上部で負極ストラップ等の負極部材と接触することによる短絡と、これによる電池の急速な容量低下を抑制した長寿命の鉛蓄電池を提供することを目的とする。
【００１２】
【課題を解決するための手段】
この目的を達成するために本発明の請求項１に記載の発明は、鉛合金の圧延シートに断続したスリットを平行に複数条形成するとともに、スリット形成と同時にスリット間に形成された線条部を前記圧延シート面に対して上下方向に交互に突出させ、前記圧延シートを前記スリットと直交する方向に展開伸張して形成したロータリーエキスパンド格子体を少なくとも正極に備えた鉛蓄電池において、前記鉛合金の圧延シートはカルシウムが０．０２質量％未満の鉛−錫合金としたことを特徴とする鉛蓄電池を示すものである。
【００１４】
本発明の請求項２に記載の発明は、請求項１に記載の構成を備えた鉛蓄電池において鉛合金の圧延シートの錫含有量を１．０質量％以上とすることを示すものである。
【００１５】
本発明の請求項３に記載の発明は、圧延シートに断続したスリットを平行に複数条形成するとともに、スリット形成と同時にスリット間に形成された線条部を前記圧延シート面に対して上下方向に交互に突出させ、前記圧延シートを前記スリットと直交する方向に展開伸張して形成したロータリーエキスパンド格子体を少なくとも正極に備えた鉛蓄電池において、前記圧延シートは錫が１．０ないし３．０質量％、カルシウムが０．０２質量％未満、残部を鉛としたことを示すものである。
【００１６】
本発明の請求項４に記載の発明は、請求項１ないし３のいずれかに記載の構成を備えた鉛蓄電池において、負極板の枚数は前記正極板の枚数以下としたことを示すものである。
【００１７】
さらに本発明の請求項５に記載の発明は、請求項４に記載の構成を備えた鉛蓄電池において、電槽内壁に直接接触する正極板を備えた構成を示すものである。
【００１８】
【発明の実施の形態】
本発明の実施の形態について説明する。
【００１９】
カルシウムを０．０２質量％未満とする鉛−錫合金の圧延シート１を図１で示したようにロータリー方式のエキスパンド工法により正極格子を形成する。ロータリー方式のエキスパンド加工では凸状加工刃２を形成した円盤状カッター３を間隔を設けて積層したカッターロール４を噛み合わせ、このカッターロール４の対の間に圧延シート１を通過させる。
【００２０】
この凸状加工刃２間には平坦部５が設けられており、断続スリット（図示せず）が円盤状カッター３の積層数に応じた条数分だけ平行に形成されると同時に、平行に隣接するスリットに囲われた線条部６は凸状加工刃２の先端形状に対応して、圧延シート１面から上下方向に突出するように塑性変形する。
【００２１】
その後、圧延シート１の幅方向の両側部をチャック等の挟持手段で挟持して両側部を幅方向に展開伸張して格子網目部を形成する。この格子網目部に常法による鉛蓄電池用ペーストを充填後、熟成乾燥して本発明の鉛蓄電池用の正極板が形成される。
【００２２】
ロータリー方式のエキスパンド加工は正極格子体の格子骨は互いに直交する２方向、すなわち、圧延シートの上下方向と幅方向に順次展開伸張して形成される。圧延シート側部をチャック等で挟持して、チャック間隔を広げることにより幅方向への展開が寸法精度よく行われるので、特に鉛合金中のカルシウムを０．０５質量％以上としなくても展開寸法を正確にすることができる。
【００２３】
また、圧延シートは上下方向からカッターロールの対に挟み込まれて加工されるので、加工中に圧延シートとカッターロールの対の位置関係を容易に一定に保持することができる。
【００２４】
さらに、本発明の効果は極板群を構成する負極板の枚数が正極板の枚数と同数かもしくは１枚少ない構成とした鉛蓄電池とすることにより顕著になる。
【００２５】
本発明の効果は広い範囲の合金系の組み合わせにおいて認められるが、特に錫添加量については１．０質量％から３．０質量％の領域において顕著な効果を示す。合金中のカルシウム含有量を０．０２質量％未満、特にカルシウムを含有させず、錫濃度が１．０質量％を超えると結晶粒が緻密化して腐食を遅延させることができる。このため、腐食は徐々に進行するため電池の容量も徐々に低下し、従来の錫−カルシウム系合金格子を用いた鉛蓄電池のように急激に容量低下することがない。
【００２６】
本発明の構成は極板群を構成する負極板の枚数が正極板枚数と同枚数かもしくは１枚少ない鉛蓄電池に適用することが好ましい。このような枚数の構成の鉛蓄電池は端板の一方もしくは両方が正極板となり、端板としての正極板はその両面を負極板によって加圧されていないため、腐食による上下方向の伸びが端板でない正極板に比較して著しく大きくなり、この正極端板と負極ストラップ等の負極部材と短絡して容量低下する可能性が高いため、腐食の進行が遅い本発明を正極板に適用するのが好ましい。
【００２７】
さらに負極板を袋状セパレータに収納することによって、正極板が袋状セパレータに収納されない構成の場合には正極端板が電槽内壁に接触する構成となる。特に電槽内壁は平滑であるので、この正極端板は他の正極板に比較して上下方向の伸びがさらに大きくなる。したがって、特に電槽内壁に対向する正極端板が袋状セパレータに収納されないこのような構成の鉛蓄電池に適用して本発明はより顕著な効果を奏することができる。
【００２８】
また、本発明において正極格子表面に鉛−錫合金層、鉛−錫合金層および鉛−アンチモン−錫合金層等の過放電回復性を向上させる合金層を形成することももちろん可能である。
【００２９】
【実施例】
次に、本発明の一実施例について説明する。
【００３０】
表１に示すような構成で鉛合金圧延シートを作製し、エキスパンド加工を施したのちに常法による鉛蓄電池ペーストを充填し、熟成乾燥することにより鉛蓄電池用の正極板とした。また、鉛合金圧延シートは厚さ１０ｍｍの鋳造スラブを冷間圧延して最終厚みを１．０ｍｍとした。
【００３１】
【表１】

【００３２】
表１に示す正極板の中でレシプロエキスパンド工法により、格子合金中のカルシウムが０．０４質量％以下のもの（Ｂ１，Ｂ２およびＢ３）は鉛合金圧延シートをエキスパンド加工する段階で蛇行が生じたり、網目展開部の幅寸法のばらつきが非常に大きく、以降の試験は行わなかった。
【００３３】
表１のＢ１，Ｂ２およびＢ３を除く正極板と微孔製のポリエチレンからなる袋状セパレータに収納された常法による負極板とを用いて極板群を構成し、表２に示した構成で公称電圧１２Ｖ，５時間率定格容量４８Ａｈの鉛蓄電池を作製した。
【００３４】
【表２】

【００３５】
表２に示した電池の軽負荷寿命試験（ＪＩＳＤ５３０１）を７５℃気相雰囲気下で放電時間を２分として行った。この寿命試験結果を図２に示す。
【００３６】
図２から明らかなように従来の電池Ｆ，Ｇでは寿命試験中に急激に容量低下が見られた。これらの電池について分解調査を行ったところ、電槽内壁に直接接する正極板の格子が腐食伸張することにより正極板と負極板が短絡していた。
【００３７】
一方、本発明の電池Ａ，Ｈは良好な寿命特性を備えていることがわかる。ところが、正極格子中のカルシウム含有量が０．０２質量％以上のもの（電池Ｂ，Ｃ，Ｄ，Ｅ，Ｉ，Ｊ，Ｋ，Ｌ，ＭおよびＮ）は、寿命が段階的に低下してしまう。これらのことから本発明においては正極格子合金中のカルシウム含有量を０．０２質量％未満とすることが好ましい。
【００３８】
電池Ａおよび電池Ｈは、良好な寿命が得られる。これらの本発明の電池について正極格子骨のねじれた部分で腐食が優先的に進行するため、従来例の均一に腐食した正極格子よりもその伸び量は低下していた。
【００３９】
また、極板群構成について考察するならば正極板と負極板が同枚数であり、特に正極板が電槽内壁に直接接している電池Ｆ，Ｇにおいては正極端板が他の正極板よりも腐食伸張して急激な容量低下を伴った短寿命という問題がある。ところが、このような構成においてもロータリーエキスパンド加工に特定する本発明によれば極めて優れた寿命特性が得られるとともに、正極−負極間の短絡による急激な寿命低下を抑制するという効果が得られる。
【００４０】
さらに、このような問題は負極板枚数が正極板枚数よりも１枚少ない構成においても同様に発生する問題（両方の正極端板が電槽内壁に直接接する）であるので、このような極板群構成においても本発明の構成を用いると顕著な効果を得ることができる。
【００４１】
【発明の効果】
以上の説明から明らかなように、本発明の構成によれば鉛蓄電池の正極の伸張による極板群上部での短絡を防止し電池の急激な容量低下を抑制するとともに、長寿命の鉛蓄電池を得ることができる。
【図面の簡単な説明】
【図１】ロータリー方式によるエキスパンド加工工程の一部を示す説明図
【図２】本発明の実施例，比較例および従来例による電池の寿命特性図
【符号の説明】
１圧延シート
２凸状加工刃
３円盤状カッター
４カッターロール
５平坦部
６線条部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lead storage battery used in automobiles and the like.
[0002]
[Prior art]
In recent years, the grids of lead-acid batteries are often produced by the expansion method, which can be continuously produced by producing a lead alloy sheet made of a lead-calcium alloy from the production by casting for the purpose of improving productivity. The reciprocating method is mainly used as the construction method.
[0003]
In general, the reciprocating expansion method is a method in which a lead alloy sheet is intermittently fed into a mold and the mold is moved up and down by a press machine to form slits in the lead alloy sheet and at the same time sandwiched between the slits. A portion that becomes a bone is developed and stretched in the width direction of the sheet to form a mesh. For this reason, the lead alloy sheet needs a certain strength, and in order to ensure this strength, 0.05 mass% or more of calcium and 2.0 mass% or less of tin were added to the lead alloy sheet. .
[0004]
When a lead alloy sheet having a calcium content of less than 0.05% by mass or containing substantially no calcium is expanded by a reciprocating method, variation in the mesh development width may occur, or the lead alloy sheet may become a mold during the expansion process. A phenomenon such as meandering occurs. Therefore, in order to suppress such a phenomenon, the calcium content in the lead alloy has to be 0.05% by mass or more.
[0005]
However, when calcium is added to the lead alloy, there is a drawback that the lead alloy is easily corroded by the precipitation of intermetallic compounds such as Pb ₃ Ca which are easily corroded in the crystal grain boundaries.
[0006]
When the reciprocating expanded lattice formed from a rolled body using a lead alloy having a calcium content of 0.05% by mass is used for the positive electrode, it corrodes uniformly from the surface of the lattice bone. At this time, the lattice bone expands in volume, so that the lattice body is stretched.
[0007]
In particular, in the case of an expanded lattice body in which no frame bone exists in the expansion / extension direction, the expanded lattice body extends in the expansion / extension direction as a result of volume expansion of the lattice bone. Such an expanded lattice body has a lattice extension portion at one end and a lattice bottom portion at the other end with the expansion and extension direction as the vertical direction of the lattice body, and the positive electrode plate is formed by extending the lattice body in the vertical direction of the positive electrode plate. The storage battery capacity sometimes dropped rapidly due to a short circuit with the strap portion of the negative electrode plate.
[0008]
Such a phenomenon is remarkable in a storage battery having a configuration in which the number of negative electrode plates is the same as the number of positive electrode plates or one less than the number of positive electrode plates. In the case of such an electrode plate group configuration, one or both of the two electrode plates positioned at the end of the electrode plate group are positive electrode plates.
[0009]
The end of such an electrode plate group (hereinafter abbreviated as end plate) is a positive electrode plate, and the positive electrode end plate is in direct contact with the inner wall of the battery case, that is, the negative electrode plate is housed in a bag-like separator. In the case of using a leaf-shaped separator instead of a bag-shaped separator, the positive electrode plate serving as the end plate extends significantly in the vertical direction due to corrosion, and a short circuit is caused by contact with a negative electrode member such as a negative electrode strap. It has been found that the probability of generation is higher than that of other positive electrode plates.
[0010]
In the case of the positive electrode plate sandwiched between the negative electrode plates, the expansion of the active material of the positive electrode plate and the negative electrode active material are relatively uniform on both surfaces of the positive electrode plate, but the vertical elongation is suppressed by the stress in the thickness direction of the positive electrode plate. In the case of the end plate, it is presumed that since the both surfaces are not sufficiently held, the elongation in the vertical direction is increased.
[0011]
[Problems to be solved by the invention]
The present invention provides a long-life lead-acid battery that suppresses a short circuit caused by contact with a negative electrode member such as a negative electrode strap at the upper part of the positive electrode plate due to such corrosion deformation of the positive electrode grid, and a rapid decrease in the capacity of the battery due to this. For the purpose.
[0012]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 of the present invention forms a plurality of slits in parallel in the lead alloy rolled sheet in parallel, and at the same time the slits are formed, the filaments formed between the slits. In a lead storage battery having at least a positive electrode with a rotary expanded grid formed by alternately projecting the rolled sheet in the vertical direction with respect to the rolled sheet surface and expanding and extending the rolled sheet in a direction perpendicular to the slit. The rolled sheet shows a lead storage battery characterized in that it is a lead-tin alloy having a calcium content of less than 0.02 mass% .
[0014]
Invention of Claim 2 of this invention shows that the tin content of the rolling sheet | seat of a lead alloy shall be 1.0 mass% or more in the lead storage battery provided with the structure of Claim 1.
[0015]
In the invention according to claim 3 of the present invention, a plurality of slits that are intermittently formed in the rolled sheet are formed in parallel, and at the same time the slits are formed, the linear portions formed between the slits are formed in the vertical direction with respect to the rolled sheet surface. In a lead storage battery having at least a positive electrode with a rotary expanded grid formed by expanding and extending the rolled sheet in a direction perpendicular to the slit, the rolled sheet is made of 1.0 to 3.0 tin. This indicates that the mass%, calcium is less than 0.02 mass% , and the balance is lead.
[0016]
The invention according to claim 4 of the present invention shows that in the lead-acid battery having the structure according to any one of claims 1 to 3 , the number of the negative electrode plates is equal to or less than the number of the positive electrode plates. .
[0017]
Furthermore, the invention described in claim 5 of the present invention is a lead storage battery having the configuration described in claim 4 , and shows a configuration including a positive electrode plate that is in direct contact with the inner wall of the battery case.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described.
[0019]
It leads to a calcium to less than 0.02 wt% - by expanding method of a rotary type as shown rolled sheet 1 of tin alloy in FIG. 1 to form the positive grid. The expanding process of the low Tali over scheme intermeshing cutter roll 4 with a disk-shaped cutter 3 forming the convex processing blade 2 are laminated at an interval, to pass the rolled sheet 1 between a pair of the cutter roller 4.
[0020]
A flat portion 5 is provided between the convex processing blades 2, and intermittent slits (not shown) are formed in parallel by the number of strips corresponding to the number of stacked disc-like cutters 3, and at the same time in parallel. Corresponding to the tip shape of the convex processing blade 2, the linear portion 6 surrounded by the adjacent slit is plastically deformed so as to protrude in the vertical direction from the surface of the rolled sheet 1.
[0021]
Thereafter, both sides in the width direction of the rolled sheet 1 are sandwiched by a clamping means such as a chuck, and both sides are expanded and expanded in the width direction to form a lattice network. After filling the lattice mesh portion with a paste for a lead storage battery according to a conventional method, it is aged and dried to form the positive electrode plate for the lead storage battery of the present invention.
[0022]
In the rotary type expanding process, the lattice bone of the positive electrode lattice body is formed by expanding and extending sequentially in two directions orthogonal to each other, that is, in the vertical direction and the width direction of the rolled sheet. Since the side of the rolled sheet is sandwiched between chucks and the chuck spacing is widened, expansion in the width direction is performed with high dimensional accuracy. Therefore, the expansion dimension can be achieved even if the calcium content in the lead alloy is not more than 0.05% by mass. Can be accurate.
[0023]
In addition, since the rolled sheet is processed by being sandwiched between the pair of cutter rolls from above and below, the positional relationship between the pair of rolled sheet and cutter roll can be easily maintained constant during processing.
[0024]
Furthermore, the effect of the present invention becomes remarkable when the lead storage battery is configured such that the number of negative electrode plates constituting the electrode plate group is the same as or less than the number of positive electrode plates.
[0025]
The effect of the present invention is recognized in a wide range of alloy system combinations, but particularly with respect to the amount of tin added, a remarkable effect is exhibited in the region of 1.0% by mass to 3.0% by mass. The calcium content in the alloy 0.0 less than 2% by weight, in particular not containing calcium, tin concentration exceeds 1.0 wt% and the crystal grains can delay corrosion densified. For this reason, since corrosion progresses gradually, the capacity | capacitance of a battery also falls gradually, and a capacity | capacitance fall does not suddenly like the lead acid battery using the conventional tin-calcium type alloy lattice.
[0026]
The configuration of the present invention is preferably applied to a lead storage battery in which the number of negative electrode plates constituting the electrode plate group is the same as or less than the number of positive electrode plates. In the lead-acid battery having such a number of configurations, one or both of the end plates are positive plates, and the positive plate as the end plate is not pressurized by the negative plates on both sides. The present invention is applied to the positive electrode plate having a slow progress of corrosion because the positive electrode end plate and the negative electrode member such as the negative electrode strap are likely to be short-circuited to reduce the capacity. preferable.
[0027]
Further, by storing the negative electrode plate in the bag-shaped separator, the positive electrode end plate comes into contact with the inner wall of the battery case when the positive electrode plate is not stored in the bag-shaped separator. In particular, since the inner wall of the battery case is smooth, the positive electrode end plate is further elongated in the vertical direction as compared with other positive electrode plates. Therefore, the present invention can be more effective when applied to the lead storage battery having such a configuration in which the positive electrode end plate facing the inner wall of the battery case is not housed in the bag-shaped separator.
[0028]
In the present invention, it is of course possible to form an alloy layer for improving the overdischarge recovery properties such as a lead-tin alloy layer, a lead-tin alloy layer, and a lead-antimony-tin alloy layer on the surface of the positive electrode lattice.
[0029]
【Example】
Next, an embodiment of the present invention will be described.
[0030]
A lead alloy rolled sheet having a structure as shown in Table 1 was prepared, expanded, filled with a lead storage battery paste by a conventional method, and aged and dried to obtain a positive electrode plate for a lead storage battery. The lead alloy rolled sheet was cold-rolled from a cast slab having a thickness of 10 mm to a final thickness of 1.0 mm.
[0031]
[Table 1]

[0032]
In the positive electrode plate shown in Table 1, when the calcium in the lattice alloy is 0.04% by mass or less (B1, B2, and B3) by the reciprocating expansion method, meandering may occur at the stage of expanding the lead alloy rolled sheet. The variation in the width dimension of the mesh developed part was very large, and the subsequent test was not performed.
[0033]
The electrode plate group was constituted by using the positive electrode plate excluding B1, B2 and B3 in Table 1 and the negative electrode plate stored in a bag-shaped separator made of microporous polyethylene, and the structure shown in Table 2 was used. A lead-acid battery having a nominal voltage of 12 V and a 5-hour rate rated capacity of 48 Ah was produced.
[0034]
[Table 2]

[0035]
The light load life test (JIS D5301) of the battery shown in Table 2 was performed in a gas phase atmosphere at 75 ° C. with a discharge time of 2 minutes. This life test result is shown in FIG.
[0036]
As is clear from FIG. 2, in the conventional batteries F and G, the capacity was rapidly reduced during the life test. When these batteries were disassembled and investigated, the positive electrode plate and the negative electrode plate were short-circuited due to the corrosion and expansion of the grid of the positive electrode plate in direct contact with the inner wall of the battery case.
[0037]
On the other hand, it can be seen that the batteries A and H of the present invention have good life characteristics. However, the calcium content of the positive electrode lattice is 0.0 2% by weight or more of (battery B, C, D, E, I, J, K, L, M and N), the lifetimes decrease stepwise End up. In the present invention these reasons, it is preferable that the calcium content of the positive grid alloy 0.0 less than 2 wt%.
[0038]
Batteries A and the battery H are good good lifetime can be obtained. In these batteries of the present invention, corrosion preferentially proceeds at the twisted portion of the positive electrode lattice, and therefore the amount of elongation was lower than that of the positively corroded positive electrode lattice of the conventional example.
[0039]
Further, when considering the configuration of the electrode plate group, the number of the positive electrode plates and the number of the negative electrode plates is the same, and in particular in the batteries F and G in which the positive electrode plates are in direct contact with the inner wall of the battery case, the positive electrode end plates are more than the other positive electrode plates. There is a problem of short life with a sudden capacity drop due to corrosion extension. However, even in such a configuration, according to the present invention specified for the rotary expanding process, an extremely excellent life characteristic can be obtained, and an effect of suppressing a rapid life reduction due to a short circuit between the positive electrode and the negative electrode can be obtained.
[0040]
Further, since such a problem is also a problem that occurs in a configuration in which the number of negative electrode plates is one less than the number of positive electrode plates (both positive electrode end plates are in direct contact with the inner wall of the battery case), such an electrode plate Even in the group configuration, a remarkable effect can be obtained by using the configuration of the present invention.
[0041]
【Effect of the invention】
As is apparent from the above description, according to the configuration of the present invention, a short circuit in the upper part of the electrode plate group due to the extension of the positive electrode of the lead storage battery is prevented, and a rapid capacity decrease of the battery is suppressed. Obtainable.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a part of an expanding process using a rotary method. FIG. 2 is a battery life characteristic diagram according to examples, comparative examples, and conventional examples of the present invention.
DESCRIPTION OF SYMBOLS 1 Rolled sheet 2 Convex processing blade 3 Disc shaped cutter 4 Cutter roll 5 Flat part 6 Line part

Claims

A plurality of slits intermittently formed in the lead alloy rolled sheet are formed in parallel, and at the same time when the slits are formed, the linear portions formed between the slits are alternately projected in the vertical direction with respect to the rolled sheet surface, and the rolled sheet In the lead storage battery provided with at least the positive electrode of the rotary expanded lattice formed by expanding and expanding in the direction perpendicular to the slit, the rolled sheet of the lead alloy is a lead-tin alloy having a calcium content of less than 0.02% by mass . Lead acid battery characterized by that.

The lead acid battery according to claim 1, wherein the content of tin in the rolled sheet of the lead alloy is 1.0 mass% or more.

A plurality of slits intermittently formed on the rolled sheet are formed in parallel, and at the same time as the slits are formed, the linear portions formed between the slits are alternately projected in the vertical direction with respect to the rolled sheet surface, and the rolled sheet is formed into the slits. In a lead storage battery having at least a positive electrode with a rotary expanded lattice formed by expanding and stretching in a direction orthogonal to the rolling sheet, the rolled sheet has 1.0 to 3.0 mass% tin and less than 0.02 mass% calcium, A lead storage battery characterized in that the remainder is lead.

The lead acid battery according to any one of claims 1 to 3 , wherein the number of the negative electrode plates is equal to or less than the number of the positive electrode plates.

The lead acid battery of Claim 4 provided with the positive electrode plate which contacts a battery case inner wall directly.