JPH04109558A - Positive electrode plate for lead storage battery and manufacture thereof - Google Patents

Abstract

PURPOSE:To make the capacity efficiency excellent and extend the life during float and cyclic use by using as a current collector glass fiber nonwoven fabric on which a highly conductive SnO2 film is formed and whose contact portion is fixed, and impregnating the current collector with a paste of positive electrode active material. CONSTITUTION:A conductive SnO2 film doped with a third material is attached to the surface of glass fiber nonwoven fabric of fiber diameter 0.1 to 20mum and porosity 80 to 98% and thereby electron conductivity is provided to the surface and the mutual contact portion of the fibers of the glass fiber nonwoven fabric. This glass fiber nonwoven fabric is used as a current collector and is impregnated with positive electrode active material so as to form a positive electrode plate for a lead storage battery. The glass fiber nonwoven fabric should preferably have a fiber diameter of 0.1 to 5mum and a porosity of 80 to 98%. The glass fibers may be silica glass fibers not containing alkali or such ones whose core is borosilicate glass containing alkali and which are coated on their surface with a silica layer. The third material is fluorine or antimony. The apparent density of the positive electrode active material is desirably 2.0 to 3.2g/cm<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to lead-acid batteries used as floats such as hack-up power supplies for computers, communication equipment, etc.
The present invention relates to a positive electrode plate for a lead-acid battery used in lead-acid batteries that are used for alternate charging and discharging such as those for cycle service, particularly lead-acid batteries that require a long life, and a method for manufacturing the same.

Prior Art and its Problems The life of the positive electrode plate is controlled by the softening of the active material, the corrosion of the lattice, the accompanying elongation of the lattice, that is, the short circuit between the positive and negative electrode plates at the strump f due to growth. Conventionally, in order to improve this life mode, (1) by increasing the thickness of the positive electrode plate itself,
Control the amount of growth.

(2) In order to improve the corrosion resistance of the lattice and increase its mechanical strength, the content of Sn is increased.

(3) Insert a short-circuit prevention plate made of insulating resin under the electrode group strap of the negative electrode plate.

(4) The size of the positive electrode plate is made sufficiently smaller than the internal dimensions of the battery case so that it can be grown.

The following methods have been adopted. However, in (1), the positive electrode plate becomes thicker, making the battery larger and heavier.
Method (2) increases the battery price and has problems with the castability of the lattice, while method (3) is expected to be effective in delaying the timing of short-circuiting, but the growing lattice deforms the battery case. (4) has the disadvantage that the battery capacity decreases because the size of the electrode plate becomes smaller.

Paste-type electrode plates used in lead-acid batteries are usually manufactured by coating, aging, drying, and chemically forming a paste-like active material onto a cast or expanded lead alloy lattice. Due to manufacturing constraints of this lattice, the bones that make up the lattice cannot be made too thin, so the ratio of the lattice to the electrode plate cannot be reduced. This means that the ratio of active material per unit volume of the electrode plate cannot be increased, so the capacity obtained as a battery will be small.
Furthermore, since the distance between the active material and the current collector becomes long, it has the disadvantage that the efficiency of charging and discharging becomes low.

In addition, since a cast or expanded lattice has a small contact area with the active material, especially in the case of antimony-free alloys, the lattice corrosion layer is preferentially discharged over the active material, resulting in the lead sulfate insulating layer, It has the disadvantage of forming a so-called "F barrier layer" and shortening its lifespan.

When a cast or expanded grid is repeatedly charged and discharged, it tends to elongate (growth) due to changes in the volume of the active material, and if the growth in the height direction becomes significant, it will quickly short-circuit with the negative electrode plate strap, resulting in a very long service life. This results in a short battery life.

JP-A-60-1.758 discloses that the active material and the current collector have the same level of conductivity as the active material, and are resistant to oxidation and reduction at the normal charging and discharging voltage of lead batteries. On the other hand, it has been proposed to improve the conductivity of the positive electrode active material by incorporating a thermodynamically stable substance into the paste.

In this method, a conductive material is simply dispersed in an active material, and the dispersed materials are not necessarily in contact with each other, so the effect of improving conductivity is small and it is not possible to dramatically improve conductivity. It's Nakka.

Further, Japanese Patent Application Laid-Open No. 62-276765 describes that an element useful for lead batteries is constructed by combining tin oxide and E-glass with increased acid resistance. The glasses recommended herein contain by weight approximately 60% silica, less than about 35% alumina, and oxides of alkali and alkaline earth metals. The present inventors used a glass fiber sheet of E-glass, immersed it in a tin compound, and then fired it to attach a conductive SnO□ film. It precipitated on the film, significantly deteriorating the adhesion with glass and conductivity, and increasing the internal resistance of the battery, making it difficult to improve the battery characteristics.

JP-A No. 60-175376 discloses that glass fibers are coated with tin oxide and kneaded with resin for use in lead batteries; A lead-acid battery is made of a second layer made of a material and a first layer made of a resin base material adjacent thereto, and glass fiber coated with tin oxide is mixed as a conductive additive from the first layer to the second layer. It has been proposed to make an electrode plate for each. The inventors tried to fabricate a battery using this method, but the utilization rate was significantly improved, probably due to the small amount of contact between the positive electrode active material and the glass fiber to which the conductive SnO□ film, which is the current collector, was attached. It became disconnected.

OBJECTS OF THE INVENTION The present invention overcomes these drawbacks, and aims to provide a positive electrode plate for lead-acid batteries that has particularly excellent volumetric efficiency and has a long life in float and cycle use, and an inexpensive manufacturing method thereof. It is something to do.

Furthermore, the present invention particularly aims at giving priority to the lattice corrosion layer in the case of antimony-free alloys in which the lattice bones are made extremely thin and the ratio of the lattice to the electrode plate is reduced to improve charging and discharging efficiency. It is an object of the present invention to provide a positive electrode plate for a lead-acid battery that does not have the disadvantage of forming a so-called "barrier layer" and reaching the end of its life early due to discharging, and also does not corrode and therefore does not undergo growth.

Structure of the Invention The positive electrode plate for a lead-acid battery according to the present invention is produced by immersing a glass fiber nonwoven fabric in a mixed solution of a tin compound and an antimony or fluorine compound and baking it, thereby continuously doping antimony or fluorine on the surface of the glass fiber. A highly conductive SnO□ film was attached to the surface of the single glass fiber and the contact area between the glass fibers, and a glass fiber nonwoven fabric with the contact area fixed was used as a current collector. , which can be obtained at low cost by impregnating it with a positive electrode active material paste, and if the glass fiber is a silica glass fiber that does not contain an alkali content, or if the glass fiber contains an alkali content,
It is characterized by the use of glass fibers whose surfaces are coated with a silica layer to prevent the elution of alkaline components.

In addition, the apparent density of the cathode active material paste to be impregnated is 2.0.
It is characterized in that it is preferably as small as ~3.2 g/cd.

Example Examples of the present invention will be described below.

(Example 1) Fabric weight 528 using quartz glass fiber with a diameter of 0.5 μm
A nonwoven fabric of g/rrf was produced.

A mixed solution of tin bisacetylacetonate (20 wt%) and antimony triisopropoxide (14.7 wt%) was prepared. The solvent was isopropyl alcohol.

The quartz glass fiber nonwoven fabric was immersed in this mixed solution, and 4
It was pulled at a speed of 0 cm/win, dried at 100°C for 30 minutes, and then fired at 500°C for 60 minutes to form an antimony-doped SnO□ film with a thickness of about 0.2 μm on the surface of the glass fiber. Continuous nonwoven fabric sheet 1
was created. This nonwoven fabric sheet 1 consists of the surface of single glass fibers and the highly conductive Sn
A glass fiber nonwoven fabric was used to form an O□ film and the contact portion was fixed, and the thickness was 3.8 m, the porosity was 92%, and the maximum pore diameter was 18 μm.

Separately, Pb 0.06wt%CaO, 5wt%
A lead plate 2 made of Sn alloy was prepared. This lead plate 2 has a thickness of 1.5 mm and a width of 50 mm, and as shown in FIG. be done.

Using this lead plate 2, the upper part of the nonwoven fabric sheet 1 was sandwiched between the two lead plates 2 so as to enable contact current collection from the nonwoven fabric, thereby obtaining a current collecting member.

Next, this was impregnated with a paste, aged and hardened to obtain an unformed positive electrode plate X according to the present invention. Connect the glass fiber to S
The dimensions of the electrode plate, in which a nonwoven fabric fixed with a n0g film and made highly conductive was used as a current collector, were 38 mm in width, 68 mm in length, and 3.3 mm in thickness. In the unformed positive electrode plate X, the active material and the nonwoven fabric sheet are in contact to enable electron conduction, and can be charged and discharged through the tabs 3 made of lead alloy.

A conventional unformed positive electrode plate A having the same dimensions was obtained by casting using a conventional method without using a conductive nonwoven fabric.

Two types of positive electrode plates obtained in this way, a negative electrode plate prepared by the conventional method, and 90% glass fiber with a diameter of 1 μm or less,
Combine with a paper-made separator made of 10% glass fiber with a diameter of 19 μm to form a pole group, insert it into a battery case, glue the lid, and inject electrolyte to obtain two types of unformed sealed lead-acid batteries. Next, this battery was chemically formed in a container to obtain a sealed lead-acid battery X according to the present invention and a conventional sealed lead-acid battery A.

When the capacity of the obtained battery was examined, the results shown in Table 1 were obtained. Note that the capacity test was based on the capacity of the conventional sealed lead acid battery A of 4AH/20HR, and the sealed lead acid battery X according to the present invention was also tested under the same conditions.

Table 1 is shown in the margin below. When these two types of sealed lead-acid batteries were subjected to a float life test, the results shown in FIG. 2 were obtained. In the float life test, the cells were continuously overcharged at a constant voltage of 2.30 V per cell, and the capacity was checked at a 3-hour rate every 3 weeks. The ambient temperature was 40° C. for acceleration. Next, when these two types of batteries were subjected to a cycle life test, the results shown in FIG. 3 were obtained.

Cycle life test: 0.25CA discharge for 2 hours, 0,
Charging and discharging were performed under 6-hour charging conditions using ICA, and the test was conducted at a rate of 3 hours every 50 cycles.

(Example 2) A borosilicate glass fiber nonwoven fabric containing an alkali content was mixed with ethyl silicate 40 (25 wt%) and ethanol (72 wt%).
), water (2wt%) and IN hydrochloric acid (1wt%), pulled up at a speed of 20cm/w+in, and fired at 500"C for 15 minutes. As a result, the surface of the glass fiber was 0.05μm. It is coated with silica to a thickness of 100 mL to prevent alkaline components from leaching out.

Total of the quartz glass fiber nonwoven fabric sheet used in Example 1, the glass fiber nonwoven fabric sheet thus preventing alkaline content elution, and the glass fiber nonwoven fabric sheet not subjected to alkali content elution prevention. Three types of nonwoven fabric sheets were prepared.

These nonwoven fabric sheets were mixed with tin octylate (204%) and silver fluoride (atomic ratio S) using n-butanol as a solvent.
40cio
/win, dried at 100°C for 30 minutes, and then fired at 500°C for 60 minutes to form SnO2 doped with fluorine to a thickness of about 0.2 μm on the surface of the glass fiber.
A film was formed. In this way, nonwoven fabric sheet 2 (quartz glass fiber ■), nonwoven fabric sheet 3 (borosilicate glass fiber treated to prevent alkali elution), and nonwoven fabric sheet 4 (
Borosilicate glass fiber without alkali elution prevention treatment■
)It was created.

A lead plate for current collection was attached to these sheets by the same method as in Example 1, and the apparent density of the positive electrode active material was 2.6 g.
/cwt, is impregnated with an active material, aged and hardened, and unformed positive electrode plate Y (quartz glass fiber ■) according to the present invention,
Z (borosilicate glass fiber (■) treated to prevent alkali elution) and U (borosilicate glass fiber (■) treated to prevent alkali elution) were obtained, and sealed lead-acid batteries Y and Z according to the present invention using these and the comparative example A sealed lead acid battery U was obtained. The dimensions of this electrode plate are medium 4311Iff+, length 75mm, and thickness 3.
．． It was 3 mm.

The inner dimension of the battery case used, facing the positive electrode plate grid, is 4 in the width direction.
Since it is 5 axes, the margin in the width direction of the electrode plate is 2ao for sealed lead acid batteries Y, Z and U, and 7ao for the conventional example.
Met. Further, the distance between the lower surface of the negative electrode plate electrode group strap and the upper part of the positive electrode plate rib was 5 mm in the case of the present invention, and 12 circles in the case of the conventional example. Furthermore, the sealed lead acid battery Y of the present invention,
Although the short-circuit prevention plate was not used in Z and the comparative sealed lead-acid battery U, it was used in the case of a conventional sealed lead-acid battery.

When the capacity of the obtained battery was examined, the results shown in Table 2 were obtained. The capacity test was based on the capacity 4AH/2011R of the conventional sealed lead-acid battery A, and the sealed lead-acid battery Y22 according to the present invention and the sealed lead-acid battery U of the comparative example were also tested under the same conditions.

Furthermore, when these sealed lead-acid batteries Y and Z were subjected to a float life test and a cycle life test, the results shown in Figures 2 and 3 were as follows.
The results shown in the figure were obtained. The float life test and cycle life test were the same as in Example 1. Note that, as shown in Table 2, the sealed lead-acid battery U of the comparative example did not show an increase in capacity as the product of the present invention, so it was used in the life test.

Table 2 (Example 3) Using the glass fiber nonwoven fabric 1 used in Example 1, an unchemically formed positive electrode plate X and an apparent density of 1.8 g/cd and 3.5
/cd comparative example unformed positive electrode plate ■.

Each W was manufactured. The dimensions of these plates are 38m wide.
m, length 68 mm, and thickness 3.3 mm.

Three types of positive electrode plates obtained in this way, a negative electrode plate made by the conventional method, and 90% glass fiber with a diameter of ram or less,
Combined with a paper-made separator made of 10% glass fiber with a diameter of 19 μm to form a pole group, insert it into a battery case, glue the lid, and inject electrolyte to obtain three types of unformed sealed lead-acid batteries. Next, this battery was chemically converted into a sealed lead-acid battery according to the present invention (apparent density: 2.6 g/d), and a sealed lead-acid battery (apparent density: 1.8 g/cffl) of the comparative example. )
and sealed lead-acid battery W (apparent density 3.5/cell)
I got it.

At this time, the force with which the separator pressed the electrode plate, ie, the tension, was 20 kg/dmZ for each battery.

The capacity test was conducted based on the capacity 4^H/20HR of the conventional sealed lead-acid battery A in Example 1, and the same for the sealed lead-acid battery X according to the present invention and the sealed lead-acid batteries ■ and W of the comparative example. Tested under the following conditions.

When the capacity of the obtained battery was examined, the results shown in Table 3 were obtained. Further, when the sealed lead acid batteries V, X, and W were subjected to a cycle life test, the results shown in FIG. 3 were obtained. The conditions for the cycle life test were the same as in Example 1.

Table 3: The positive electrode plate for lead-acid batteries of the present invention has an antimony- or fluorine-doped SnO□ conductive film attached to the surface of glass fibers to impart electronic conductivity, and the interlacing points of the glass fibers are bonded together. It consists of an electronically conductive nonwoven fabric and an active material impregnated into the current collecting member.

An electronically conductive nonwoven fabric can be obtained by coating the surface of a nonconductive glass fiber with stannic oxide doped with antimony or fluorine, as in the above embodiment.

The coating thus obtained does not take part in the charging/discharging reactions of the battery, is stable over a long period of time, does not corrode, and has high conductivity.

The positive electrode plate for a lead-acid battery obtained by the present invention is a 5nOz cathode plate doped with antimony or fluorine on the surface of glass fiber.
In addition to the electron conductivity provided by the conductive coating, the intertwined points of the glass fibers are also connected to enable electron conduction, so that the conventional method, for example, as described in JP-A-60-1758, By dispersing in the paste a substance having the same level of conductivity as the active material between the substance and the current collector, the conductivity can be dramatically improved compared to a case where the substances are not necessarily in contact with each other.

In order to obtain an electronically conductive nonwoven fabric, it is not impossible to use a method of plating the surface of glass fibers with lead or use of lead fibers themselves. However, the lead in the fibers is corroded by battery charging and discharging, and eventually loses its function as a current collector, and non-woven fabrics made from lead fibers become denser and filled with active materials. The capacity is not large compared to the grid obtained by conventional casting or expanding methods, and the capacity cannot be increased. Moreover, it is undesirable because it has low strength and poor handling.

Therefore, preferred non-conductive fibers are ones that have high mechanical strength and can provide high porosity when rubbed into a non-woven fabric, and the fine glass fibers used in the present invention are optimal ones that satisfy the above conditions. . The diameter of the fibers used is preferably thin in order to increase the contact density with the active material. The recommended diameter is 0.1 μm to 20 μm, more preferably 0.111 m to 5 μm, and the length is 0.1 to 5 mm.
It is made into a sheet using a wet process from single fibers. This is because if the fiber diameter is smaller than 0.1 μm, the contact density with the active material will be high, but the mechanical strength will be very weak and it will be difficult to handle. On the other hand, if the fiber diameter is larger than 20 μm, the mechanical strength is excellent, but the contact density with the active material is low and the effect of the present invention is reduced. Furthermore, if the length of the fibers is shorter than 0.1 mm or longer than 5 mm, it is difficult to make a nonwoven fabric.

In this case, you may use Ingu as necessary to improve handling, but it should be kept to a minimum in order to select a material that does not impair the conductivity of the coating and to avoid adverse effects on the battery. It is.

In addition, considering the adhesion between the 5nOt and glass fiber, the glass fiber nonwoven fabric should be heat cleaned and the Na'' from the glass should be removed.

Considering the elution of alkaline substances such as Ca'', when using quartz glass or borosilicate glass that does not contain these substances, the glass fiber must be coated with a silica layer to prevent the elution of alkaline substances. .

This is because the glass fibers must be kept at a high temperature when firing the SnO□ film.

That is, when a borosilicate glass fiber containing an alkali content is used as the core material, when the SnO□ film is fired, the alkali metal ions in the glass are thermally diffused and transferred to the Sn0g film. As a result, the conductivity of the SnO film is greatly reduced, and its effectiveness as a current collector is extremely reduced. This can be seen in Example 2
This is clear from the comparative example.

In order to prevent this, it is effective to coat the surface of the glass fiber with a silica layer in advance. This is because, if coated, the alkali metal ions thermally diffused from the glass cannot pass through the thin silica layer, so the conductivity of the 5n02 film will not be reduced.

However, it goes without saying that such pretreatment is not necessary for borosilicate glass in which alkali metal ions are not eluted.

In addition, the apparent density of the positive electrode active material impregnated into the grid for lead-acid batteries according to the present invention can be 2.0 to 3.8 g/d, but in order to improve high rate characteristics, Since it is advantageous to include as much sulfuric acid as possible, the apparent density of the positive electrode active material is preferably in the range of 2.0 to 3.2 g/cd. This is because, as is clear from Example 3, the apparent density is 3.2 g/aI! If it is larger than
This is because the sulfuric acid necessary for high-rate discharge cannot be secured in the electrode plate, so the high-rate characteristics cannot be improved much. On the other hand, if it is smaller than 2.0 g/aA, the binding of the active material becomes poor and at the same time the utilization rate of the active material becomes extremely high, resulting in a short life.

Generally, when the apparent density of the active material is low, the number of contact points with the lattice body is reduced, and the supply of sulfuric acid is also increased, which causes an early decrease in capacity. However, the lattice body of the present invention differs from ordinary ones in that the surface area of the current collector 6 is extremely large, so that the contact area between the current collector and the active material is an order of magnitude larger.

Therefore, the apparent area of the active material can be reduced without causing the early capacity reduction as described above, and the high-rate discharge characteristics essential for a backup power source can be dramatically improved. In addition, it is possible to increase the utilization rate of the active material.

The lead-acid battery using the lead-acid battery lattice according to the present invention has a volumetric efficiency that is superior to conventional products by approximately 12% according to Example 1 and approximately 24 to 25% according to Example 2. . This is because according to the present invention, the pore volume of the lattice is increased by nearly 10% compared to the conventional one, and there is no need to take into account life restrictions due to growth of the positive electrode lattice during float and cycle use. This is because it is possible to insert a larger size electrode plate into a battery case of the same size than before. This is because, while in the case of conventional cast grids, the filling volume ratio of active material was approximately 80%, in the case of the grid body for lead-acid batteries of the present invention, this ratio was increased to nearly 90%. This is because the nonwoven fabric is electronically conductive, so the number of contacts between the active material and the current collector is an order of magnitude greater.Moreover, even if the lattice ratio is reduced in this way,
This is because less current is used for corrosion and more current is used for charging the active material, ultimately improving charging efficiency, and the corrosion resistance itself is also significantly superior. With this configuration, the number of contacts between the active material and the current collector increases by an order of magnitude, so the efficiency of charging and discharging is improved, and the lattice corrosion layer of the antimony-free alloy is preferentially used for discharging. This overcomes the disadvantage of premature end-of-life due to the formation of a so-called "barrier layer".

In fact, a sealed lead-acid battery X using this lattice body.

The causes of short lifespans for Y and Z were softening of the active material of the positive electrode plate, corrosion of the lead plate for current collection, and depletion of the electrolyte. Sealed lead 1M batteries Y and Z did not use short-circuit prevention plates. Although there was no short circuit at the bottom of the negative electrode slap, no short circuit occurred.

This is because the porosity of the nonwoven fabric sheet made of glass fiber coated with tin oxide is high, and the coating does not participate in the charge/discharge reactions of the battery, making it stable and free from corrosion, improving charge/discharge efficiency. It is presumed that the most important effect is that the corrosion resistance itself is extremely excellent. Note that the porosity of the nonwoven fabric is preferably 80 to 98%. This is because if it is 98% or more, it becomes difficult to manufacture a nonwoven fabric, and if it is 80% or less, the volumetric efficiency becomes poor.

The sealed lead-acid battery using the positive electrode plate for a lead-acid battery according to the present invention does not require increasing the amount of Sn in the grid as in the conventional case.
Further, a short-circuit prevention plate is not required, and the cost is extremely low.

Regarding the positive electrode plate for lead-acid batteries according to the present invention, an example has been described so far in which it is used in a sealed lead-acid battery, but the present invention is not limited to this. It goes without saying that similar effects can be expected when applied to any other lead-acid batteries.

Effects of the Invention As detailed above, according to the present invention, it is possible to provide an inexpensive positive electrode plate for lead-acid batteries that has particularly excellent volumetric efficiency and has a long life in float and cycle use. In particular, by making the lattice bones extremely thin and reducing their proportion of the lattice plate, the charging and discharging efficiency was improved.
It is possible to provide an inexpensive positive electrode plate for lead-acid batteries that does not have the disadvantage that the lattice corrosion layer in the case of antimony-free alloys preferentially discharges and causes so-called F-harry layer yo, leading to premature end of life. The value is great.

[Brief explanation of drawings]

Figure 1 is a perspective view of the positive electrode plate for a lead-acid battery according to the present invention before the lead plate is crimped, Figures 2 and 3 are diagrams showing the float and cycle life characteristics of a sealed lead-acid battery, and Figure 4 is a lead plate. FIG. 3 is a side sectional view of the positive electrode plate for a lead-acid battery according to the present invention after being crimped. Batteries X, Y, Z: Sealed lead-acid battery battery V invented by Wood;
W: Sealed lead-acid battery of comparative example Battery A: Conventional sealed lead-acid battery 1: Non-woven fabric sheet 2: Lead plate 3: Center part (ear)

Claims (1)

[Claims] 1) A conductive SnO_2 film doped with a third substance is attached to the surface of a glass fiber nonwoven fabric with a fiber diameter of 0.1 to 20 μm and a porosity of 80 to 98%, and the fiber surface and fibers are in contact with each other. 1. A positive electrode plate for a lead-acid battery, characterized in that a nonwoven glass fiber fabric having electron conductivity is used as a current collector, and the current collector is impregnated with a positive electrode active material. 2) Conductive S doped with a third substance on the surface of a glass fiber nonwoven fabric with a fiber diameter of 0.1 to 5 μm and a porosity of 80 to 98%
A positive electrode plate for a lead-acid battery, characterized in that a glass fiber nonwoven fabric to which an nO_2 film is attached and which imparts electronic conductivity to the fiber surface and the contact portion between the fibers is used as a current collector, and is impregnated with a positive electrode active material. 3) The positive electrode plate for a lead-acid battery according to claim 1 or 2, wherein the glass fiber is a silica glass fiber containing no alkali. 4) The positive electrode for a lead-acid battery according to claim 1 or 2, wherein the glass fiber has a core material of borosilicate glass containing an alkali content, and a silica layer is coated on the surface. Board. 5) A positive electrode plate for a lead-acid battery according to claim 1, 2, 3, or 4, wherein the third substance is fluorine. 6) A positive electrode plate for a lead-acid battery according to claim 1, 2, 3, or 4, wherein the third substance is antimony. 7) The apparent density of the positive electrode active material is 2.0 to 3.2 g/cm
A positive electrode plate for a lead-acid battery according to claim 1, 2, 3, 4, 5, or 6, characterized in that the positive electrode plate is ^2. 8) By immersing and firing a continuous nonwoven fabric of glass fibers in a mixed solution of a tin compound and an antimony or fluorine compound, continuous highly conductive SnO_2 is formed on the surface of the single glass fibers and in the contact areas between the glass fibers. A method for producing a positive electrode plate for a lead-acid battery, in which a film is attached and a current collector having a fixed contact portion is impregnated with a positive electrode active material paste. 9) The method for manufacturing a positive electrode plate for a lead-acid battery according to claim 8, wherein the glass fiber has a diameter of 0.1 to 5 μm. 10) The method for manufacturing a positive electrode plate for a lead-acid battery according to claim 8 or 9, characterized in that silica glass fiber containing no alkali is used as the glass fiber. 11) A patent claim characterized in that the glass fiber is made of borosilicate glass containing an alkali content as a core material and whose surface is coated with a silica layer to prevent elution of the alkali content. Range 8 or 9
A method for producing a positive electrode plate for a lead-acid battery as described in .