JP2002260671A - Lead storage battery - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the adhesiveness of the interface between an expanded lattice body and an active material in a positive electrode plate, and to prevent the discharge capacity from being reduced early regardless of heavy load or light load, and to achieve extremely long life performance. To obtain an excellent lead storage battery. SOLUTION: A coating layer 3 made of a lead-tin alloy as a first layer and a lead-antimony alloy as a second layer is provided on the surface of a positive electrode grid 2 made of an expanded grid of a lead-calcium-tin alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a lead storage battery having at least a positive electrode plate, a negative electrode plate, and a separator holding an electrolytic solution between these electrode plates.

[0002]

2. Description of the Related Art A battery using a Pb-Ca alloy lattice for a negative electrode and a Pb-Sb alloy lattice for a positive electrode (hereinafter abbreviated as an HB battery), a Pb-Ca-Sn alloy lattice for a negative electrode and a positive electrode. Batteries (hereinafter abbreviated as Ca batteries) and batteries using a Pb-Sb alloy lattice for the negative and positive electrodes (hereinafter abbreviated as CB batteries).

[0003] Since the Pb-Sb alloy lattice is used for the positive lattice in the HB battery and the CB battery, the HB battery and the CB battery have extremely high corrosion resistance at high temperatures due to the effect of antimony.
Since the CB battery uses a Pb-Ca alloy lattice for the positive electrode plate, it undergoes high intergranular corrosion at high temperatures, and therefore has problems such as rupture or short-circuit of the lattice due to elongation of the lattice, and is extremely poor in high-temperature durability. It is a weak battery. However, since the decrease in the hydrogen overvoltage of the negative electrode due to the precipitation of Sb as in the HB battery does not occur, the generation of gas and the decrease in the electrolyte are small,
This battery is essential for maintenance-free operation.

In recent years, lead-acid batteries have been replaced with HB batteries or antimony in which the amount of antimony added to the alloy of the positive electrode grid has been reduced, in order to suppress accidental discharge during standing and to reduce water replenishment due to decomposition of the electrolyte during use. The use of Ca batteries that do not contain has increased.

[0005] As the antimony content or antimony content content has been reduced as described above, problems have arisen in elongation, corrosion, and the like of the lattice when the Pb-Ca alloy is used at a high temperature. As a countermeasure to solve this problem, a positive electrode grid body having excellent corrosion resistance has been studied.

Therefore, the oxidative corrosion of the positive grid alloy structure, which is highly resistant to corrosion at high temperatures, or the cast grid in the positive electrode,
Focusing mainly on intergranular corrosion of the cast lattice, an expanded lattice body has been proposed, in which a slit is formed in a lead alloy sheet produced by rolling and then expanded to form a lattice shape. The expanded lattice body has a lamellar rolled structure, and has excellent corrosion resistance as compared with the cast lattice body because the crystal grain boundaries that cause corrosion are dispersed.

[0007]

A conventional lead-acid battery using a high-temperature corrosion-resistant positive electrode grid alloy as a positive electrode grid and a lead-acid battery using an expanded lattice as a positive electrode grid have a problem in that the positive electrode grid elongates due to oxidative corrosion because of high-temperature corrosion resistance. Although it is smaller than conventional lead-acid batteries that do not use a positive electrode grid alloy, it has the advantage that it is unlikely to have a short life due to deformation and breakage of the battery case due to elongation of the grid body, short circuit due to contact with the negative electrode plate, etc. In addition, due to the reduction of oxidative corrosion, the adhesion at the interface between the lattice and the active material is reduced, and the capacity is suddenly reduced during use of the battery due to the peeling or falling off of the active material, which leads to a problem that the life is extended. .

It is an object of the present invention to improve the adhesiveness of the interface between the expanded grid and the active material in the positive electrode plate, and to prevent the discharge capacity from being rapidly lowered regardless of heavy load or light load. An object of the present invention is to provide an excellent lead storage battery.

Another object of the present invention is to improve the adhesion at the interface between the coating layer and the expanded lattice in the positive electrode plate and to suppress the passivation of the active material at the interface between the expanded lattice and the active material. It is another object of the present invention to provide a lead-acid battery capable of preventing sulfuric acid from entering the interface and preventing corrosion of the expanded lattice.

[0010]

According to the present invention, there is provided a positive electrode plate, a negative electrode plate, and a separator holding an electrolytic solution between these electrode plates, and a positive electrode lattice body holding an active material of the positive electrode plate is made of a lead-calcium alloy. The aim is to improve lead-acid batteries composed of expanded grids.

In the lead storage battery according to the present invention, a coating layer made of a lead-tin alloy as a first layer and a lead-antimony alloy as a second layer is provided on the surface of a positive electrode grid made of an expanded grid of a lead-calcium alloy. Is provided.

Further, the lead storage battery according to the present invention has a lead-tin alloy as a first layer and a second layer as a second layer on at least the inside or outside surface of the eyes of a positive electrode grid made of an expanded grid of a lead-calcium alloy. A coating layer made of a lead-antimony alloy is provided.

As described above, a coating layer made of a lead-tin alloy as the first layer and a lead-antimony alloy made as the second layer is provided on the surface of the positive electrode grid made of the expanded grid of the lead-calcium alloy, or Providing a coating layer made of a lead-tin alloy as the first layer and a lead-antimony alloy as the second layer on at least the inner or outer surface of the positive electrode grid made of the calcium alloy, Lead with excellent life performance, with improved adhesion at the interface with the active material, suppression of the passivation of the active material at the interface, and no early decline in discharge capacity regardless of heavy or light load. A storage battery can be obtained.

Further, in the lead storage battery according to the present invention, when the groove extending from the coating layer side to the surface of the grid is formed, the adhesion between the coating layer and the expanded grid is improved, and the coating layer and the positive grid are formed. It is possible to obtain a lead-acid battery that can suppress the passivation of the active material at the interface with the body, prevent sulfuric acid from entering the interface, and prevent corrosion of the expanded lattice.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to a plurality of examples and comparative examples.

Comparative Example 1 The lead storage battery of Comparative Example 1 was manufactured as follows. First, a negative electrode plate was made. That is, lead powder and 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 with respect to the lead powder)
C.) and 12% by mass of water with respect to the lead powder to prepare a negative electrode active material paste. The density of this paste is
3.5 g / cm ³ . Next, 73 g of the obtained negative electrode active material paste was filled in a current collector composed of a lattice of a lead-calcium-tin alloy of 0.05 mass% Pb-Ca-0.6 mass% of Sn, After aging for 18 hours in a humidity of 95%, it was left for 2 hours at a temperature of 110 ° C. and dried to form an unformed negative electrode plate.

Next, a positive electrode plate was made. That is, a positive electrode active material paste was prepared by kneading lead powder, 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 ° C.) with respect to the lead powder, and 12% by mass of water with respect to the lead powder. . The density of this paste was 3.5 g / c.
m is ^3. Next, the obtained positive electrode active material paste 103
g of Pb-Ca 0.05% by mass-Sn0.8% by mass into a current collector composed of a lattice of lead-calcium-tin alloy, and then left at a temperature of 50 ° C and a humidity of 95% for 18 hours. After aging, it was left at 110 ° C. for 2 hours and dried to produce an unformed positive electrode plate.

Next, eight unformed negative electrode plates and seven unformed positive electrode plates
The plates were alternately laminated with a glass fiber separator interposed therebetween to make each electrode plate group. After placing these electrode plates in a battery case, an electrolytic solution was injected into the battery case to produce each unformed lead storage battery. The electrolyte is dilute sulfuric acid having a specific gravity of 1.225 (20 ° C.).

Next, this unformed lead-acid storage battery was formed at 9 A for 42 hours to obtain a lead-acid battery 80D26 (JISD5301) for a vehicle of Comparative Example 1.
Described) was completed.

Comparative Example 2 The lead storage battery of Comparative Example 2 was manufactured as follows. First, a negative electrode plate was made. That is, lead powder and 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 with respect to the lead powder)
C.) and 12% by mass of water with respect to the lead powder to prepare a negative electrode active material paste. The density of this paste is
3.5 g / cm ³ . Next, 73 g of the obtained negative electrode active material paste was filled in a current collector composed of a lattice of a lead-calcium-tin alloy of 0.05 mass% Pb-Ca-0.6 mass% of Sn, After aging for 18 hours in a humidity of 95%, it was left for 2 hours at a temperature of 110 ° C. and dried to form an unformed negative electrode plate.

Next, a positive electrode plate was made. That is, a positive electrode active material paste was prepared by kneading lead powder, 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 ° C.) with respect to the lead powder, and 12% by mass of water with respect to the lead powder. . The density of this paste was 3.5 g / c.
m is ^3. Next, the obtained positive electrode active material paste 103
g of Pb-Ca 0.08% by mass-Sn1.3% by mass into a current collector composed of a lattice of lead-calcium-tin alloy, and then left at a temperature of 50 ° C and a humidity of 95% for 18 hours. After aging, it was left at 110 ° C. for 2 hours and dried to produce an unformed positive electrode plate.

Next, eight unformed anode plates and seven unformed cathode plates 7 were formed.
The plates were alternately laminated with a glass fiber separator interposed therebetween to make each electrode plate group. After placing these electrode plates in a battery case, an electrolytic solution was injected into the battery case to produce each unformed lead storage battery. The electrolyte is dilute sulfuric acid having a specific gravity of 1.225 (20 ° C.).

Next, this unformed lead-acid battery was converted to a lead-acid battery 80D26 (JISD5301) for automobiles of Comparative Example 2 by forming it at 9A for 42 hours.
Described) was completed.

Comparative Example 3 The lead storage battery of Comparative Example 3 was manufactured as follows. First, a negative electrode plate was made. That is, lead powder and 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 with respect to the lead powder)
C.) and 12% by mass of water with respect to the lead powder to prepare a negative electrode active material paste. The density of this paste is
3.5 g / cm ³ . Next, 73 g of the obtained negative electrode active material paste was filled in a current collector composed of a lattice of a lead-calcium-tin alloy of 0.05 mass% Pb-Ca-0.6 mass% of Sn, After aging for 18 hours in a humidity of 95%, it was left for 2 hours at a temperature of 110 ° C. and dried to form an unformed negative electrode plate.

Next, a positive electrode plate was made. That is, a positive electrode active material paste was prepared by kneading lead powder, 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 ° C.) with respect to the lead powder, and 12% by mass of water with respect to the lead powder. . The density of this paste was 3.5 g / c.
m is ^3. Pb-Ca 0.05 mass% -Sn1.4 mass%
Using a lead-calcium-tin alloy.
This lead-calcium-tin alloy plate was rolled to a thickness of 1/10, slit, and developed to produce an expanded lattice. Next, 103 g of the positive electrode active material paste was filled in the current collector made of the expanded lattice, and then heated at a temperature of 50%.
After aging for 18 hours at 95 ° C, 95% humidity,
It was left at 0 ° C. for 2 hours and dried to form an unformed positive electrode plate.

Next, eight unformed negative electrode plates and seven unformed positive electrode plates
The plates were alternately laminated with a glass fiber separator interposed therebetween to make each electrode plate group. After placing these electrode plates in a battery case, an electrolytic solution was injected into the battery case to produce each unformed lead storage battery. The electrolyte is dilute sulfuric acid having a specific gravity of 1.225 (20 ° C.).

Next, this unformed lead storage battery was formed at 9A for 42 hours to obtain a lead storage battery 80D26 (JISD5301) for a vehicle of Comparative Example 3.
Described) was completed.

(Example 1) The lead storage battery of Example 1 was manufactured as follows. First, a negative electrode plate was made. That is, lead powder and 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 with respect to the lead powder)
C.) and 12% by mass of water with respect to the lead powder to prepare a negative electrode active material paste. The density of this paste is
3.5 g / cm ³ . Next, 73 g of the obtained negative electrode active material paste was filled in a current collector composed of a lattice of a lead-calcium-tin alloy of 0.05 mass% Pb-Ca-0.6 mass% of Sn, After aging for 18 hours in a humidity of 95%, it was left for 2 hours at a temperature of 110 ° C. and dried to form an unformed negative electrode plate.

Next, a positive electrode plate was prepared. That is, a positive electrode active material paste was prepared by kneading lead powder, 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 ° C.) with respect to the lead powder, and 12% by mass of water with respect to the lead powder. . The density of this paste was 3.5 g / c.
m is ^3. Next, Pb-Ca 0.05 mass% -Sn1.4
It is cast into a plate using a mass% lead-calcium-tin alloy. This lead-calcium-tin alloy sheet is rolled to a thickness of 1/10. At this time, 100 µm of Pb-Sn3.0 mass%
Is rolled as a first layer, and a 100 μm Pb-Sb 2.0 mass% lead-antimony alloy foil is rolled on both sides as a second layer on the outside of the first layer to form an expanded sheet. did. The expanded sheet was slit and developed to produce an expanded lattice 1 as shown in FIG. The expanded lattice 1 has a lead-calcium-tin alloy expanded positive electrode lattice 2 on at least the inner or outer surface of the eyes as a first layer.
The structure has a coating layer 3 made of a tin alloy and a lead-antimony alloy as a second layer. Next, 103 g of the positive electrode active material paste was filled in the current collector made of the expanded lattice body 1, and after being aged for 18 hours at a temperature of 50 ° C. and a humidity of 95%, the mixture was heated at 110 ° C. for 2 hours. Leave for a while,
After drying, an unformed positive electrode plate was prepared.

Next, eight unformed negative electrode plates and seven unformed positive electrode plates
The plates were alternately laminated with a glass fiber separator interposed therebetween to make each electrode plate group. After placing these electrode plates in a battery case, an electrolytic solution was injected into the battery case to produce each unformed lead storage battery. The electrolyte is dilute sulfuric acid having a specific gravity of 1.225 (20 ° C.).

Next, this unformed lead-acid storage battery was formed at 9 A for 42 hours, and the lead-acid storage battery 80D26 (JISD5301) for automobiles of the first embodiment was used.
Described) was completed.

(Example 2) The lead storage battery of Example 2 was manufactured as follows. First, a negative electrode plate was made. That is, lead powder and 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 with respect to the lead powder)
C.) and 12% by mass of water with respect to the lead powder to prepare a negative electrode active material paste. The density of this paste is
3.5 g / cm ³ . Next, 73 g of the obtained negative electrode active material paste was filled in a current collector composed of a lattice of a lead-calcium-tin alloy of 0.05 mass% Pb-Ca-0.6 mass% of Sn, After aging for 18 hours in a humidity of 95%, it was left for 2 hours at a temperature of 110 ° C. and dried to form an unformed negative electrode plate.

Next, a positive electrode plate was made. That is, a positive electrode active material paste was prepared by kneading lead powder, 13% by mass of dilute sulfuric acid (specific gravity 1.26: 20 ° C.) with respect to the lead powder, and 12% by mass of water with respect to the lead powder. . The density of this paste was 3.5 g / c.
m is ^3. Pb-Ca 0.05 mass% -Sn1.4 mass%
Using a lead-calcium-tin alloy.
This lead-calcium-tin alloy sheet is rolled to a thickness of 1/10. At this time, 100 µm of Pb-Sn3.0 mass% lead-
A tin alloy foil was rolled as a first layer, and a 100 μm Pb—Sb 2.0 mass% lead-antimony alloy foil as a second layer was superimposed on both sides and rolled to form an expanded sheet. The expanded sheet is rolled over the above two kinds of alloy foils and a metal roller is used to apply a width of 2 m.
m grooves were created. A slit was made in the grooved expanded sea and developed, thereby producing an expanded lattice. As shown in FIG. 2, this expanded lattice 1 has a lead-tin alloy foil 3 a as a first layer and a second layer on at least the inner or outer surface of the eyes of an expanded positive electrode lattice 2 of a lead-calcium-tin alloy. A coating layer 3 made of a lead-antimony alloy foil 3b is provided, and a plurality of grooves 4 are provided on the surface of the coating layer 3 from the coating layer 3 side to the surface of the positive electrode grid body 2. I have. Next, 103 g of the positive electrode active material paste was filled into the current collector made of the expanded lattice body 1 and left to stand at 50 ° C. and 95% humidity for 18 hours to ripen. Leave for a while,
After drying, an unformed positive electrode plate was prepared.

Next, eight unformed negative electrode plates and seven unformed positive electrode plates
The plates were alternately laminated with a glass fiber separator interposed therebetween to make each electrode plate group. After placing these electrode plates in a battery case, an electrolytic solution was injected into the battery case to produce each unformed lead storage battery. The electrolyte is dilute sulfuric acid having a specific gravity of 1.225 (20 ° C.).

Next, this unformed lead storage battery was formed at 9 A for 42 hours to obtain a lead storage battery 80D26 (JISD5301) for a vehicle according to the first embodiment.
Described) was completed.

After completion of the 5-hour rate capacity test, these lead storage batteries were left in a thermostat at -15 ° C. for 18 hours to discharge 300 A. The voltage at the 5th second at that time is shown in FIG. When the adhesion between the lattice and the active material is reduced, the IR drop is increased, and the voltage at the 5th second when discharging at -15 ° C. and 300 A is greatly reduced. From FIG. 3, it can be seen that the lead storage battery of Comparative Example 2 using the highly corrosion-resistant grid alloy and the lead storage battery of Comparative Example 3 using the untreated expanded grid body have a greatly reduced voltage at the 5th second. This is because of the high corrosion resistance,
It can be said that the adhesion at the active material interface is greatly reduced. In the lead storage batteries of Examples 1 and 2, the voltage at the 5th second is high because the surface of the expanded lattice is subjected to the treatment for improving the adhesion between the lattice and the active material. In the lead storage batteries of Examples 1 and 2, the Sb foil rolled simultaneously with the sheet rolling at the lattice-active material interface has a function of improving the adhesion at the interface. Further, the lead storage battery of Example 2 has a function of improving the adhesion between the Sb foil and the Sn foil and the grid by providing grooves on the surface of the grid.
As a result, the voltage at the fifth second of the lead storage battery of the second embodiment is increased.

Next, a heavy load life test was performed on these lead storage batteries. The test conditions were as follows: charge and discharge at 20 A for 1 hour after discharging at 20 A for 1 hour at an ambient temperature of 40 ° C, repeat charge and discharge as one cycle, and repeat every 25 cycles until the terminal voltage becomes 10.2 V at 20 A at 25 cycles Discharge was performed and the discharge duration was measured. The number of lifespan is half the capacity of the 5-hour rate capacity,
That is, the number of times was 22.5 Ah. FIG. 4 shows the transition of the duration of the 20 A discharge during the life test.

In the case of a calcium battery, when deep discharge is continuously performed as in a heavy load life test, the active material at the lattice interface is passivated, and the capacity is reduced at an early stage. Further, even when the adhesion between the lattice and the active material interface is poor, sulfuric acid easily enters the interface, which causes passivation of the active material. From FIG. 4, it can be seen that the lead storage battery of Comparative Example 3 uses an untreated expanded lattice body, and thus has a short life due to poor adhesion at the interface. Since the lead storage batteries of Comparative Examples 1 and 2 use the cast lattice, the life cycle is longer than that of the lead storage battery of Comparative Example 3 using the expanded lattice. Since the lead-acid battery of Comparative Example 1 uses a grid alloy having lower corrosion resistance than the lead-acid battery of Comparative Example 2, the lattice-active material has good adhesion and the life cycle is slightly longer. In the lead storage batteries of Examples 1 and 2, the passivation of the active material at the lattice-active material interface is suppressed by the effect of Sb because the Sb foil layer exists at the lattice-active material interface. are doing. As a result, Comparative Examples 1, 2, and
The life cycle is greatly extended as compared with the lead storage battery of No. 3. This is because, in the lead storage battery of Example 2, the grooves were formed on the surface of the grid, thereby improving the adhesion between the grid and the foil (coating layer).

FIG. 5 shows Comparative Examples 1, 2 and 3 and Examples 1 and 2.
3 shows the results of an overcharge life test of each lead storage battery. The test conditions for the overcharge life test were as follows: a battery was charged at 4.5 A under an ambient temperature of 75 ° C for 110 hours, then left for 58 hours,
Discharge at 150 A for 30 seconds and measure the voltage. This one
As a cycle, repeat the same cycle,
The point at which the voltage at the 30th second became 7.2 V or less was defined as the life cycle. FIG. 5 shows the transition of the voltage for 30 seconds during the discharge of 150 A. The overcharge life test largely affects mainly the durability of the lattice. The lead storage battery of Comparative Example 1 has a short life because a lattice alloy having low corrosion resistance is used. As the corrosion resistance of the grid body improves, the cycle life of each lead storage battery of Comparative Example 2 and Comparative Example 3 increases in order. In the lead storage batteries of Example 1 and Example 2, corrosion of the lattice body is suppressed by the effect of the Sn foil on the first layer on the surface of the lattice body. In addition, since the Sb foil is present in the second layer on the surface of the lattice, the second layer of Sb foil having low corrosion resistance is selectively corroded, which has the effect of delaying the corrosion of the lattice. In the lead storage battery of Example 2, since the adhesiveness of the foil to the grid is improved, direct contact of sulfuric acid with the grid is prevented. This extends the life cycle of the lead-acid battery of the second embodiment.

[0040]

According to the lead-acid battery of the present invention, the surface of the positive electrode grid composed of the expanded lattice of the lead-calcium alloy is coated with a lead-tin alloy as the first layer and a lead-antimony alloy as the second layer. A layer is provided, or a lead-tin alloy, a second layer,
Since a coating layer made of a lead-antimony alloy is provided as a layer, the adhesion at the interface between the coating layer and the positive electrode grid is improved, the passivation of the active material at the interface is suppressed, and heavy loads and light loads are reduced. It is possible to obtain a lead storage battery with extremely excellent life performance, in which the discharge capacity does not decrease early regardless of the load.

Further, in the lead-acid battery according to the present invention, since the groove extending from the coating layer side to the surface of the grid is formed, the adhesion between the coating layer and the expanded grid is improved, and the coating layer and the positive grid are formed. Suppresses the passivation of the active material at the interface with the body,
A lead-acid battery that can prevent sulfuric acid from entering the interface and prevent corrosion of the expanded lattice can be obtained.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part of an expanded positive electrode grid used in a first example of an embodiment of a lead storage battery according to the present invention.

FIG. 2 is an enlarged sectional view of a coating layer of an expanded positive electrode grid used in a second example of the embodiment of the lead storage battery according to the present invention.

FIG. 3 shows a comparison between a lead storage battery of a comparative example and an embodiment of the present invention.
FIG. 9 is a comparison diagram of the voltage at the 5th second when discharging 300 A at 15 ° C.

FIG. 4 is a diagram showing a relationship between a battery capacity and a life cycle in a heavy load life test in a lead storage battery of a comparative example and an example of the present invention.

FIG. 5 is a diagram showing the relationship between the voltage at the 30th second and the number of cycles at 150 A discharge in the overcharge life test in the lead storage batteries of the comparative example and the example of the present invention.

[Explanation of Signs] 1 Expanded grid 2 Expanded positive grid 3 Coating layer 3a Lead-tin alloy foil 3b as first layer 3b Lead-antimony alloy foil as second layer 4 Groove

Continuation of the front page (72) Inventor Satoshi Minoura 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo Inside Shin-Kobe Electric Co., Ltd. (72) Inventor Kazuya Sasaki 2-87-7 Nihonbashi Honcho, Chuo-ku, Tokyo Shin-Kobe Electric Co., Ltd. In-house (72) Inventor Takafumi Kondo 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo F-term in Shin-Kobe Electric Co., Ltd. 5H017 AA01 AS10 BB02 BB07 BB14 CC05 DD01 DD05 EE00 EE01 EE02 EE03

Claims (3)

[Claims] 1. A positive electrode plate, a negative electrode plate, and a separator holding an electrolytic solution between the electrode plates, and a positive electrode lattice member holding an active material of the positive electrode plate is formed of an expanded lattice member of a lead-calcium alloy. In a lead-acid battery, a coating layer made of a lead-tin alloy as a first layer and a lead-antimony alloy as a second layer is provided on a surface of a positive electrode grid made of an expanded grid of the lead-calcium alloy. A lead-acid battery characterized by the above-mentioned. 2. A positive electrode plate, a negative electrode plate, and a separator holding an electrolytic solution between these electrode plates, and a positive electrode lattice member holding an active material of the positive electrode plate is formed of an expanded lattice member of a lead-calcium alloy. In the lead-acid battery, at least on the inner or outer surface of the eye of the positive electrode grid composed of the expanded lattice of the lead-calcium alloy,
A lead-acid battery provided with a coating layer made of a lead-tin alloy as a first layer and a lead-antimony alloy as a second layer. 3. The lead-acid battery according to claim 1, wherein a groove extending from the coating layer side to the surface of the positive electrode grid is formed in the positive electrode grid.