【０００１】
【発明の属する技術分野】
本発明は、連続鋳造格子体を用いた鉛蓄電池に関するものである。
【０００２】
【従来の技術】
従来、鉛蓄電池用集電体である連続鋳造格子体の内骨形状は、湯流れ性を考慮しなくてよいために、それは自由であった。
【０００３】
しかし、鋳物と鋳型の型離れの問題から、連続鋳造格子体の複数の内骨部が交差して囲まれた空間部の形状は図４に示すように正三角形であった（例えば、特許文献１参照。）
次に、これら複数の内骨部が交差して囲まれた空間部の形状が正三角形の従来の連続鋳造格子体１の構造について説明する。この連続鋳造格子体１は、枠骨２と内骨３からなっている。枠骨２は水平方向に平行に対向する横枠骨部２ａと、垂直方向に平行に対向する縦枠骨部２ｂとで構成されている。内骨３は、枠骨２の水平方向の横枠骨部２ａと垂直方向の縦枠骨部２ｂとに平行関係にない複数本の互いに交差する斜め内骨部３ａ，３ｂと、縦枠骨部２ｂに平行関係をなす複数本の縦内骨部３ｃとを備え、これら縦内骨部３ｃは互いに交差する各斜め内骨部３ａ，３ｂの各交差部４の縦向きに並ぶ群の交差部４間のみを結んで一体に形成されている。これら斜め内骨部３ａ，３ｂと縦内骨部３ｃとで囲まれて形成される空間部５の形状は正三角形であり、各正三角形の空間面積は等しくなっていた。
【０００４】
上側の横枠骨部２ａには１つの耳部６が突設され、下側の横枠骨部２ａには複数の足部７が突設されていた。
【０００５】
【発明が解決しようとする課題】
しかしながら、このように斜め内骨部３ａ，３ｂと縦内骨部３ｃとで囲まれて形成される空間部５の形状が正三角形となっている連続鋳造格子体１に活物質を充填した極板は、活物質の膨張収縮及び格子腐食による応力が３方向に均一にかかるため、その形状である正三角形が相似形で大きくなって、正三角形内の空間部の面積も大きくなり、次に収縮が起って活物質が収縮すると、内骨部３ａ，３ｂ，３ｃと活物質との接触が小さくなり、またはなくなり、その結果、蓄電物質である活物質と集電体である内骨部との電気的パスが小さくなり、またはなくなり、鉛蓄電池の容量が小さくなるという問題点があった。
【０００６】
本発明の目的は、活物質の膨張収縮及び格子腐食による応力が作用しても、活物質と内骨部との電気的パスが小さくなるのを抑制して、容量低下を防止できる鉛蓄電池を提供することにある。
【０００７】
【課題を解決するための手段】
本発明は、連続鋳造格子体に活物質が充填された極板が用いられている鉛蓄電池を対象とする。
【０００８】
本発明に係る鉛蓄電池では、連続鋳造格子体の複数の内骨部が交差して囲まれた空間部の形状が二等辺三角形であり、この二等辺三角形の頂角が６０°未満であることを特徴とする。
【０００９】
このように連続鋳造格子体の複数の内骨部が交差して囲まれた空間部の形状を二等辺三角形にし、この二等辺三角形の頂角を６０°未満にすると、この二等辺三角形は長い２辺とそれより短い１辺とで構成されるゆえ、活物質の膨張収縮及び格子腐食による応力がこの二等辺三角形の各辺に不均一にかかることになり、活物質と内骨部との電気的パスの減少を防止でき、鉛蓄電池の容量低下を抑え、長寿命化させることができる。
【００１０】
この場合、二等辺三角形内の空間部の面積をＡ、この二等辺三角形の周長をＬとしたとき、Ａ／Ｌの比率が１．３９以下であることが好ましい。このように頂角を小さくし、Ａ／Ｌが小さいものほど鉛蓄電池を長寿命にすることができる。
【００１１】
また、Ａ／Ｌが小さいものほど、活物質の脱落量を少なくすることができる。
【００１２】
【発明の実施の形態】
図１は本発明に係る鉛蓄電池で用いる連続鋳造格子体の実施の形態の一例を示す正面図である。なお、前述した図４と対応する部分には、同一符号を付けてしめしている。
【００１３】
本例の連続鋳造格子体１では、斜め内骨部３ａ，３ｂと縦内骨部３ｃとで囲まれて形成される空間部５の形状が二等辺三角形であり、且つこの二等辺三角形の頂角が６０°未満となっている。また、二等辺三角形内の空間部５の面積をＡ、この二等辺三角形の周長をＬとしたとき、Ａ／Ｌの比率が１．３９以下である。
【００１４】
このように連続鋳造格子体１の複数の内骨部３ａ，３ｂ，３ｃが交差して囲まれた空間部５の形状を二等辺三角形にし、該二等辺三角形の頂角を６０°未満にすると、この二等辺三角形は長い２辺とそれより短い１辺とで構成されるゆえ、活物質の膨張収縮及び格子腐食による応力がこの二等辺三角形の各辺に不均一にかかることになり、活物質と内骨部との電気的パスの減少を防止でき、鉛蓄電池の容量低下を抑え、長寿命化させることができる。
【００１５】
また、二等辺三角形内の空間部５の面積をＡ、この二等辺三角形の周長をＬとしたとき、Ａ／Ｌの比率を１．３９以下とすると、頂角を小さく、Ａ／Ｌが小さいものほど鉛蓄電池を長寿命にすることができる。また、Ａ／Ｌが小さいものほど、活物質の脱落量を少なくすることができる。
【００１６】
【実施例】
以下、本発明の鉛蓄電池の実施例を、従来例と対比して説明する。
【００１７】
（従来例）
従来例の連続鋳造格子体１は、前述した図４に示すように斜め内骨部３ａ，３ｂと縦内骨部３ｃとで囲まれて形成される空間部５の形状が正三角形であり、Ｐｂ−Ｓｂ１．５質量％の組成とし、表１の記号ａの仕様とした。
【００１８】
【表１】
この連続鋳造格子体１を用いて正極板を、次のようにして作成した。まず、鉛粉に対して１３質量％の希硫酸（比重１．２６：２０℃）と、鉛粉に対して１２質量％の水とを混練して正極活物質ペーストを作った。次に、この正極活物質ペースト８５ｇを表１の記号ａに示す内骨部形状の連続鋳造格子体１に充填してから、温度５０℃、湿度９５％中に１８時間放置して熟成した後に温度１１０℃中に２時間放置し、乾燥して未化成正極板を作った。次に、負極活物質ペースト７３ｇを格子体からなる集電体に充填してから、温度５０℃、湿度９５％中に１８時間放置して熟成した後に温度１１０℃中に２時間放置し、乾燥して未化成負極板を作った。
【００１９】
次に、未化成正極板７枚と未化成負極板８枚とを、各負極板には袋状セパレータを被せて積層して各極板群を作った。そして、各極板群を電槽内に配置してから、電槽内に比重１．２６（２０℃）の希硫酸である電解液を注液し、９Ａで４２時間通電して鉛蓄電池Ａを作成した。
【００２０】
（実施例）
本実施例の連続鋳造格子体１は、前述した図１に示すように斜め内骨部３ａ，３ｂと縦内骨部３ｃとで囲まれて形成される空間部５の形状が二等辺三角形であり、Ｐｂ−Ｓｂ１．５質量％の組成とし、表１の記号ｂ，ｃ，ｄの仕様とした。
【００２１】
この連続鋳造格子体１を用いて、従来例と同様の手順で鉛蓄電池Ｂ，Ｃ，Ｄを作成した。
【００２２】
完成した従来例の電池Ａ及び実施例の電池Ｂ，Ｃ，Ｄを、各仕様毎に５個ずつ、７５℃の周囲温度でＪＩＳ軽負荷寿命試験を行った。試験サイクルの３０秒目電圧（各仕様の平均値）の推移を図２に示す。その結果、頂角を最も小さく且つＡ／Ｌが小さいものほど長寿命になることが判る。
【００２３】
また、従来例の電池Ａ及び実施例の電池Ｂ，Ｃ，Ｄを、各仕様毎に２個ずつ、ＪＩＳ軽負荷寿命試験２８８０サイクル終了後、これら電池を解体し、かくセルから正極板を１枚取り出し、その重量を測定し、初期重量から減算して活物質の脱落量を測定した。その結果を図３に示す。その結果、電池Ｂ，Ｃ，Ｄを比較して、Ａ／Ｌが小さいものほど、活物質の脱落量が少ないことが判った。
【００２４】
【発明の効果】
本発明に係る鉛蓄電池では、連続鋳造格子体の複数の内骨部が交差して囲まれた空間部の形状が二等辺三角形であり、該二等辺三角形の頂角が６０°未満であるので、この二等辺三角形は長い２辺とそれより短い１辺とで構成されるゆえ、活物質の膨張収縮及び格子腐食による応力がこの二等辺三角形の各辺に不均一にかかることになり、活物質と内骨部との電気的パスの減少を防止でき、鉛蓄電池の容量低下を抑え、長寿命化させることができる。
【００２５】
この場合、二等辺三角形内の空間部の面積をＡ、二等辺三角形の周長をＬとしたとき、Ａ／Ｌの比率が１．３９以下で、小さいものほど鉛蓄電池を長寿命にすることができる。また、Ａ／Ｌが小さいものほど、活物質の脱落量を少なくすることができる。
【図面の簡単な説明】
【図１】本発明に係る鉛蓄電池で用いる連続鋳造格子体の実施の形態の一例を示す正面図である。
【図２】従来例の電池Ａと実施例の電池Ｂ，Ｃ，Ｄとを、７５℃でＪＩＳ軽負荷寿命試験を行った際のサイクル回数と３０秒目電圧の推移を示す図である。
【図３】従来例の電池Ａと実施例の電池Ｂ，Ｃ，Ｄとを、７５℃でＪＩＳ軽負荷寿命試験を行った際の２８８０サイクル時の正極活物質脱落量を示す比較図である。
【図４】従来の鉛蓄電池で用いている連続鋳造格子体の正面図である。
【符号の説明】
１ 連続鋳造格子体
２ 枠骨
２ａ 横枠骨部
２ｂ 縦枠骨部
３ 内骨
３ａ，３ｂ 斜め内骨部
３ｃ 縦内骨部
４ 交差部
５ 空間部
６ 耳部
７ 足部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lead storage battery using a continuous cast lattice.
[0002]
[Prior art]
Conventionally, the shape of the inner bone of the continuous cast lattice, which is a current collector for a lead storage battery, has been free since it is not necessary to consider the flowability of the molten metal.
[0003]
However, due to the problem of mold separation from the casting and the mold, the shape of the space surrounded by the plurality of inner bones of the continuous casting lattice body is an equilateral triangle as shown in FIG. 1)
Next, the structure of the conventional continuous casting lattice 1 in which the shape of the space surrounded by the plurality of inner bones crossing each other is an equilateral triangle will be described. This continuous casting lattice body 1 includes a frame bone 2 and an inner bone 3. The frame 2 includes a horizontal frame 2a facing in parallel in the horizontal direction and a vertical frame 2b facing in parallel in the vertical. The inner bone 3 includes a plurality of crossed oblique inner bones 3a and 3b which are not parallel to the horizontal horizontal frame bone 2a and the vertical vertical frame bone 2b of the frame bone 2, and a vertical frame bone. A plurality of vertical inner bone portions 3c in parallel with the portion 2b, and the vertical inner bone portions 3c intersect a group of vertically intersecting portions 4 of the oblique inner bone portions 3a and 3b intersecting each other. It is formed integrally by connecting only the portions 4. The shape of the space portion 5 formed by being surrounded by the oblique inner bone portions 3a and 3b and the vertical inner bone portion 3c is an equilateral triangle, and the equilateral triangles have the same spatial area.
[0004]
One ear 6 protrudes from the upper horizontal frame 2a, and a plurality of feet 7 protrude from the lower horizontal frame 2a.
[0005]
[Problems to be solved by the invention]
However, a pole in which the active material is filled in the continuous cast lattice body 1 in which the shape of the space portion 5 formed by being surrounded by the oblique inner bone portions 3a and 3b and the vertical inner bone portion 3c is an equilateral triangle. In the plate, the stress due to the expansion and contraction of the active material and the lattice corrosion is uniformly applied in three directions, so that the shape of the equilateral triangle becomes similar and larger, and the area of the space in the equilateral triangle also becomes larger, When the active material shrinks due to contraction, the contact between the inner bones 3a, 3b, 3c and the active material decreases or disappears, and as a result, the active material as a power storage material and the inner bone as a current collector are reduced. However, there is a problem that the electrical path to the lead storage battery is reduced or eliminated, and the capacity of the lead storage battery is reduced.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a lead-acid battery that can suppress a decrease in an electrical path between an active material and an inner bone portion even when stress due to expansion and contraction of an active material and lattice corrosion acts, thereby preventing a reduction in capacity. To provide.
[0007]
[Means for Solving the Problems]
The present invention is directed to a lead-acid battery using an electrode plate in which a continuous cast lattice is filled with an active material.
[0008]
In the lead-acid battery according to the present invention, the shape of the space surrounded by the plurality of inner bones of the continuous cast lattice body is an isosceles triangle, and the apex angle of the isosceles triangle is less than 60 °. It is characterized by.
[0009]
If the shape of the space surrounded by the plurality of inner bones of the continuous cast lattice intersects in this manner is an isosceles triangle and the apex angle of the isosceles triangle is less than 60 °, the isosceles triangle is long. Since it is composed of two sides and one shorter side, the stress due to the expansion and contraction of the active material and the lattice corrosion is unevenly applied to each side of the isosceles triangle, so that the active material and the inner bone part are not connected to each other. A decrease in the number of electric paths can be prevented, a decrease in the capacity of the lead storage battery can be suppressed, and the life can be extended.
[0010]
In this case, when the area of the space in the isosceles triangle is A and the circumference of the isosceles triangle is L, the ratio of A / L is preferably 1.39 or less. In this way, the vertical angle can be reduced, and the smaller the A / L, the longer the life of the lead storage battery.
[0011]
Further, the smaller the A / L, the smaller the amount of the active material dropped off.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a front view showing an example of an embodiment of a continuous cast lattice used in a lead storage battery according to the present invention. Parts corresponding to those in FIG. 4 described above are denoted by the same reference numerals.
[0013]
In the continuous cast lattice body 1 of this example, the shape of the space portion 5 formed by being surrounded by the oblique inner bone portions 3a and 3b and the vertical inner bone portion 3c is an isosceles triangle, and the top of the isosceles triangle. The angle is less than 60 °. When the area of the space 5 in the isosceles triangle is A and the circumference of the isosceles triangle is L, the ratio of A / L is 1.39 or less.
[0014]
When the space 5 surrounded by the plurality of internal bones 3a, 3b, 3c of the continuous cast lattice 1 intersects in this manner is an isosceles triangle, and the apex angle of the isosceles triangle is less than 60 °. Since this isosceles triangle is composed of two long sides and one shorter side, stress due to expansion and contraction of the active material and lattice corrosion is applied unevenly to each side of the isosceles triangle. It is possible to prevent a decrease in the electrical path between the substance and the inner bone part, suppress a decrease in the capacity of the lead storage battery, and prolong the life.
[0015]
When the area of the space portion 5 in the isosceles triangle is A and the circumference of the isosceles triangle is L, if the ratio of A / L is 1.39 or less, the apex angle is small and A / L is small. The smaller the battery, the longer the life of the lead storage battery. Further, the smaller the A / L, the smaller the amount of the active material dropped off.
[0016]
【Example】
Hereinafter, an embodiment of the lead storage battery of the present invention will be described in comparison with a conventional example.
[0017]
(Conventional example)
In the conventional continuous cast lattice body 1, as shown in FIG. 4 described above, the shape of the space portion 5 formed by being surrounded by the oblique inner bone portions 3a and 3b and the vertical inner bone portion 3c is an equilateral triangle. The composition was Pb-Sb 1.5% by mass, and the specification of symbol a in Table 1 was used.
[0018]
[Table 1]
A positive electrode plate was prepared using the continuous cast lattice 1 as follows. First, a positive electrode active material paste was prepared by kneading 13% by mass of dilute sulfuric acid (specific gravity: 1.26: 20 ° C.) with respect to lead powder and 12% by mass of water with respect to lead powder. Next, 85 g of this positive electrode active material paste was filled into the continuous cast lattice 1 having an inner bone shape shown by the symbol a in Table 1, and then left for 18 hours at a temperature of 50 ° C. and a humidity of 95% for aging. It was left at a temperature of 110 ° C. for 2 hours and dried to form an unformed positive electrode plate. Next, 73 g of the negative electrode active material paste is filled into a current collector made of a lattice, left to stand at a temperature of 50 ° C. and a humidity of 95% for 18 hours, aged at 110 ° C. for 2 hours, and dried. As a result, an unformed negative electrode plate was produced.
[0019]
Next, seven unformed positive electrode plates and eight unformed negative electrode plates were laminated on each negative electrode plate with a bag-shaped separator placed over them to form each electrode plate group. Then, after disposing each electrode plate group in the battery case, an electrolytic solution which is a diluted sulfuric acid having a specific gravity of 1.26 (20 ° C.) is injected into the battery case, and electricity is supplied at 9 A for 42 hours to lead-acid battery A. It was created.
[0020]
(Example)
In the continuous cast lattice body 1 of this embodiment, as shown in FIG. 1 described above, the shape of the space portion 5 formed by being surrounded by the oblique inner bone portions 3a and 3b and the vertical inner bone portion 3c is an isosceles triangle. Yes, the composition was Pb-Sb 1.5% by mass, and the specifications of symbols b, c, and d in Table 1 were used.
[0021]
Using the continuous casting grid body 1, lead storage batteries B, C and D were prepared in the same procedure as in the conventional example.
[0022]
The JIS light load life test was performed on the completed conventional battery A and the batteries B, C, and D of the embodiment at an ambient temperature of 75 ° C. for each specification. FIG. 2 shows the transition of the voltage at the 30th second of the test cycle (average value of each specification). As a result, it can be seen that the one with the smallest apex angle and the smaller A / L has a longer life.
[0023]
After 2880 cycles of the JIS light load life test were completed for each of the battery A of the conventional example and the batteries B, C, and D of the embodiment, the batteries were disassembled, and the positive electrode plate was removed from the cell. The sheet was taken out, its weight was measured, and the amount of the active material dropped was measured by subtracting it from the initial weight. The result is shown in FIG. As a result, comparing the batteries B, C, and D, it was found that the smaller the A / L, the smaller the amount of the active material dropped off.
[0024]
【The invention's effect】
In the lead-acid battery according to the present invention, the shape of the space surrounded by the plurality of inner bones of the continuous cast lattice is an isosceles triangle, and the apex angle of the isosceles triangle is less than 60 °. Since this isosceles triangle is composed of two long sides and one shorter side, stress due to expansion and contraction of the active material and lattice corrosion is applied unevenly to each side of the isosceles triangle. It is possible to prevent a decrease in the electrical path between the substance and the inner bone part, suppress a decrease in the capacity of the lead storage battery, and prolong the life.
[0025]
In this case, when the area of the space in the isosceles triangle is A and the circumference of the isosceles triangle is L, the ratio of A / L is 1.39 or less, and the smaller the ratio, the longer the life of the lead storage battery. Can be. Further, the smaller the A / L, the smaller the amount of the active material dropped off.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of an embodiment of a continuous cast grid used in a lead storage battery according to the present invention.
FIG. 2 is a diagram showing the transition of the number of cycles and the voltage at the 30th second when a JIS light load life test was performed at 75 ° C. for the battery A of the conventional example and the batteries B, C, and D of the example.
FIG. 3 is a comparison diagram showing the amount of positive electrode active material falling off at 2880 cycles when a conventional battery A and batteries B, C, and D of the example were subjected to a JIS light load life test at 75 ° C. .
FIG. 4 is a front view of a continuous cast lattice used in a conventional lead storage battery.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Continuous cast lattice body 2 Frame bone 2a Horizontal frame bone 2b Vertical frame bone 3 Inner bone 3a, 3b Diagonal inner bone 3c Vertical inner bone 4 Intersection 5 Space 6 Ear 7 Foot
