WO2012105190A1

WO2012105190A1 - Lead storage battery

Info

Publication number: WO2012105190A1
Application number: PCT/JP2012/000473
Authority: WO
Inventors: 健治泉; 久間　義文
Original assignee: パナソニック株式会社
Priority date: 2011-02-01
Filing date: 2012-01-25
Publication date: 2012-08-09
Also published as: DE112012000639T5; JPWO2012105190A1; CN103262299A

Abstract

Provided is a lead storage battery that has favorable overall properties and withstands long-term use, cell characteristics gradually decreasing with use, by adopting a mat shaped separator having increased durability. The lead storage battery is provided with: a battery case; a partition wall that partitions the battery case, forming a plurality of cell chambers; a plurality of electrode plate groups that are housed in each cell chamber and that laminate a positive electrode plate and a negative electrode plate with a separator therebetween; an electrolyte liquid housed in the cell chambers; and a lid that is provided with a control valve and that closes the aperture of each cell chamber. The separator comprises a nonwoven fabric containing glass fibers, polyester fibers, acrylic fibers, and an inorganic powder. In the separator, with the mass ratio of the glass fibers being A, the mass ratio of the polyester fibers being B, the mass ratio of the acrylic fibers being C, the mass ratio of the inorganic powder being D, and A+B+C+D being 100: 0.2 ≤ D/(A+B+C+D) ≤ 0.4, B < C, and 1.2 ≤ (B+C)/A ≤ 1.67.

Description

Lead storage battery

The present invention relates to a lead-acid battery.

Lead-acid batteries used for starting vehicles have come to be used for auxiliary machines (engines) of hybrid vehicles, etc., with the recent spread of environmentally friendly vehicles. Especially for accessories, there are various mounting points on vehicles, and they are often mounted in places other than under the bonnet where maintenance and inspection are difficult. When mounted at a place where such maintenance and inspection are difficult, it is suitable to use a sealed lead-acid battery which does not require water replenishment. Therefore, sealed lead storage batteries are widely used as “lead storage batteries for auxiliary equipment”.

This lead-acid battery for auxiliary equipment forms an electrode plate group by alternately combining positive electrodes and negative electrodes formed by filling a lead alloy with an active material mainly containing lead in a grid made of lead alloy via a mat-like separator, The electrode plate group is inserted into a battery case having cell chambers, and the electrode plate groups of adjacent cell chambers are connected in series, and the upper portion of the battery case is sealed with a lid. It is configured by doing. By adopting this configuration, the storage battery for the auxiliary device can be reduced by reacting oxygen generated during charging with the negative electrode and sulfuric acid which is an electrolyte solution, so that the reduction of the electrolyte solution can be suppressed as much as possible, and the battery can be sealed. it can. The mat-like separator is made of non-woven fabric or the like, and is a separator whose thickness decreases when pressure is applied in the thickness direction.

In Patent Document 1, with regard to a general sealed lead-acid battery, a finely divided positive electrode active material penetrates a separator to reach a counter electrode (negative electrode) while improving discharge performance (duration in high-rate discharge) at low temperature There is disclosed a separator for preventing an internal short circuit generated thereby and prolonging the life. The separator of Patent Document 1 comprises about 40% of polyester resin fibers having a fiber diameter of 2 to 8 μm, about 40% of glass fibers having a fiber diameter of 2 to 8 μm, and about 5% of acrylic fibers for binding these fibers. This is a mat-like separator having a maximum pore diameter of 30 to 60 μm by adding together approximately 15% of silicon oxide powder having a particle diameter of 1 μm or less and diatomaceous earth having a particle diameter of 3 to 5 μm.

Japanese Patent Application Laid-Open No. 62-066566

However, when the separator of Patent Document 1 is adopted for an auxiliary lead storage battery, although the above-described effects can be obtained, when the separator is used for a long time, a new deterioration mode (an expanded positive grid passes through the separator It has been found that the short circuit suddenly makes it unusable. Furthermore, it has also been found that if the separator is made into a bag shape in order to prolong the life, the processability for forming a bag is inferior.

The present invention solves the above-mentioned problems, and by adopting a mat-like separator with improved durability, battery performance gradually decreases with use, and can withstand long-term use, and An object of the present invention is to provide a lead storage battery having high overall characteristics.

In order to solve the above-described problems, the lead storage battery of the present invention includes a battery case, partition walls which divide the battery case to form a plurality of cell chambers, and is stored in each of the cell chambers, and a positive electrode through a separator. A lead-acid battery comprising: a plurality of electrode plate groups in which a plate and a negative electrode plate are stacked; an electrolytic solution stored in the cell chamber; and a lid provided with a control valve and closing an opening of each cell chamber The separator is made of non-woven fabric containing glass fibers, polyester fibers, acrylic fibers and inorganic powder, and in the separator, the mass ratio of the glass fibers is A, and the mass ratio of the polyester fibers is B When the mass ratio of the acrylic fiber is C, and the mass ratio of the inorganic powder is D, A + B + C + D = 100, 0.2 ≦ D / (A + B + C + D) ≦ 0.4, and B <C and 1 It has a configuration which is 2 ≦ (B + C) /A≦1.67.

When the lead storage battery is installed such that the lid is located at the top, the liquid surface of the electrolyte may be located above the upper end of the electrode plate group.

The inorganic powder preferably contains silica.

It is preferable that red lead (red lead) be contained in an amount of 5% by mass or more and less than 10% by mass in the active material of the positive electrode plate.

As described above, since the separator configuration is optimized, it is possible to provide a lead-acid battery having high overall characteristics while enduring long-term use, centering on the lead-acid battery for auxiliary equipment.

FIG. 1 is a perspective view showing a lead storage battery of the present invention. FIG. 2 is an enlarged schematic view showing the configuration of the separator.

Before describing the embodiments of the present invention, the background of the present invention will be described below.

In the case of a general starting lead storage battery for automobiles, the phenomenon that the active material falls off due to the softening of the positive electrode from the positive electrode and the reaction material decreases, and the phenomenon that the positive electrode grid corrodes are the main causes of battery life reduction. The lead-acid battery for start-up is mounted on a place where it is easy to replace, and when either phenomenon progresses, the start-up performance gradually decreases and finally the battery life is reached. Therefore, since the customer can easily replace the lead storage battery by detecting the timing of replacement of the lead storage battery due to the deterioration of the starting performance and being installed in a place that is easy to replace, battery deterioration due to these two phenomena is a major problem It does not become.

However, unlike the lead-acid batteries for start-up mentioned above, since lead-acid batteries for auxiliary equipment are mounted in places where maintenance is difficult, they can withstand long-term use other than unnecessary water replenishment (in view of replacement at automobile inspection Life of more than 3 years) is required. Therefore, a configuration suitable for prolonging the life is taken, such as reducing the amount of lead used as the active material of the positive electrode than that of a general starting lead storage battery.

In the present invention, when the lead storage battery for auxiliary equipment is used for a long time (about 3 years) without maintenance as described above, the phenomenon that the lead storage battery suddenly becomes unusable regardless of the deterioration of the starting performance of the battery occurs. They found it. When the lead storage battery was disassembled and the cause was examined, it was found that the positive electrode grid itself was expanded to cause a short circuit through the separator. And even if it used the separator described in patent document 1, although the former phenomenon (influence of the refined active material) could be suppressed, it turned out that the latter phenomenon (influence of the expanded positive electrode lattice) can not be suppressed.

The phenomenon that a miniaturized positive electrode active material shorts through a separator is already known, and this phenomenon can be suppressed by using the separator disclosed in Patent Document 1. However, it has been found that the separator disclosed in Patent Document 1 can not prevent the phenomenon that the positive electrode grid itself found newly breaks through the separator.

As a result of the inventors of the present invention earnestly studying the above-mentioned facts, the technique of Patent Document 1 alone is insufficient for optimizing the configuration of the mat-like separator (due to the influence of the expanded positive grid) It has been found that the internal short circuit can be overcome. The mat-like separator is a separator made of non-woven fabric or the like whose volume decreases when compressed. The main points of overcoming the problem are the following four.

First, the mat-like separator is composed of glass fibers, polyester fibers, acrylic fibers, and inorganic powders. This is a configuration common to Patent Document 1. Acrylic fibers play the role of a binder for fusing glass fibers and polyester fibers.

Second, assuming that the mass ratio of glass fibers in the separator is A, the mass ratio of polyester fibers is B, the mass ratio of acrylic fibers is C, and the mass ratio of inorganic powder is D, 0.2 ≦ D / ( It is made to satisfy A + B + C + D) ≦ 0.4. By increasing the compounding ratio of the inorganic powder to various fibers as compared with Patent Document 1, it is possible to prevent the expanded positive electrode grid from easily penetrating the separator.

Third, satisfy B <C. In order to extend the life, the mat-like separator is formed into a bag shape (for example, thermocompression bonding), but at that time, the processability is inferior because the mechanical strength is small with glass fiber alone. For this purpose, organic fibers such as polyester fibers are mixed. However, if the organic fiber is substantially only polyester fiber as in Patent Document 1, the separator is deteriorated and physically collapsed due to long-term use, and the inorganic powder held inside is dropped, and It was found that the bonding strength between the fibers was reduced, and as a result, the mechanical strength was extremely reduced and the positive electrode grid penetrated the separator to cause an internal short circuit. Therefore, in the present invention, the acrylic fiber, which was added in a small amount only for the purpose of expressing the binding function in Patent Document 1, was significantly increased in the present invention, and the retention of the inorganic powder was significantly improved. As a result, it is possible to improve both the electrolytic solution wettability of the separator by increasing the separator pore size and to strengthen the bonding strength between the fibers for a long time, and the expanded positive grid makes the separator easy. It is possible not to go through.

Fourth, 1.2 ≦ (B + C) /A≦1.67 is satisfied. The inventors do not use glass fibers and organic fibers in equal amounts as in Patent Document 1, but increase the ratio of organic fibers to improve the retention of inorganic powder by the synergistic effect of three types of fibers. We found that it was possible to optimize the pore structure and utilized this.

By using a mat-like separator formed so as to satisfy the above four points and be A + B + C + D = 100, it can withstand long-term use while maintaining the overall characteristics of the battery (it becomes suddenly unusable) It will be possible to provide lead-acid batteries for auxiliary equipment that do not cause discomfort to customers.

The above-mentioned separator has a configuration in which the liquid level of the electrolyte is higher than the upper end of the electrode plate group (there are more electrolytes than general sealed lead-acid batteries), and the amount of red lead to be included as the active material of the positive electrode is 5 Its performance is effective when it is used for a sealed lead-acid battery having a configuration that enables use over a long period of time, such as a configuration of 10% by mass (the extension of the positive electrode grid increases with the extension of the service life). It is preferable to be able to work.

If the inorganic powder is silica, it has the function of enhancing the water retentivity inside the separator by the water absorbency of the silica, which is preferable. Since diatomaceous earth also has the same function as silica, diatomaceous earth may be used as the inorganic powder.

(Embodiment 1)
Embodiments will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a lead storage battery of the present embodiment, and FIG. 2 is a schematic view in which a part of a separator is enlarged.

The positive electrode 1a and the negative electrode 1b are made to face each other through the mat-like separator 1c to constitute the electrode plate group 1. The electrode plate group 1 is housed together with an electrolytic solution (not shown) in each cell chamber 2b of the battery case 2 divided into a plurality of cell chambers 2b by the partition walls 2a, and the lid 3 provided with the control valve 3a By closing the opening of the tank 2, a lead storage battery is configured. The positive electrode 1a is configured by filling a positive electrode active material into a positive electrode grid, and the negative electrode 1b is configured by filling a negative electrode active material into a negative electrode grid.

The separator 1c is composed of glass fibers 4a, polyester fibers 4b, acrylic fibers 4c, and inorganic powder 4d. When the mass ratio of glass fiber 4a is A, the mass ratio of polyester fiber 4b is B, the mass ratio of acrylic fiber 4c is C, and the mass ratio of inorganic powder 4d is D, A + B + C + D = 100, 0.2 It is ≦ D / (A + B + C + D) ≦ 0.4 and B <C and 1.0 ≦ (B + C) /A≦1.67. Polyester fibers and acrylic fibers are made of a material that is immersed in sulfuric acid and does not deteriorate even if current flows. Specifically, polyester fibers can be exemplified by polyethylene terephthalate (PET) fibers, and acrylic fibers Can be exemplified by polyacrylonitrile fiber.

The present embodiment has the following three features in addition to the fact that the separator 1c is formed of the glass fiber 4a, the polyester fiber 4b, the acrylic fiber 4c, and the inorganic powder 4d.

First, assuming that the mass ratio of glass fiber 4a is A, the mass ratio of polyester fiber 4b is B, the mass ratio of acrylic fiber 4c is C, and the mass ratio of inorganic powder 4d is D, 0.2 ≦ D / ( A + B + C + D) ≦ 0.4 is satisfied.

By using the lead storage battery for a long time, the positive grid is expanded. Therefore, the inventors found that even if the configuration of the separator 1c is as robust as in Patent Document 1, the expanded positive grid easily penetrates the separator 1c. Then, when the compounding ratio of the inorganic powder 4d with respect to various fibers was made large compared with patent document 1, it discovered that this could be prevented. Here, when D / (A + B + C + D) is less than 0.2, the expanded positive electrode grid comes to penetrate the separator 1c by using the lead storage battery for a long time. Conversely, when D / (A + B + C + D) exceeds 0.4, the inorganic powder 4d is excessive, and the mechanical strength of the separator 1c is extremely reduced.

Next, the mass ratio C of the acrylic fiber 4c is made larger than the mass ratio B of the polyester fiber 4b (B <C). In order to cope with the long life, the mat-like separator is formed into a bag (for example, thermocompression bonding) so that the active material dropped from the electrode plate is received in the bag. When processing into a bag shape, only glass fiber 4a has small mechanical strength and is inferior in processability, so organic fibers such as polyester fiber 4b are mixed. However, organic fibers mixed with polyester fiber 4b as in Patent Document 1 In the majority of cases, two problems occur with long-term use. First, the polyester fiber 4b itself is denatured, and the inorganic powder 4d held inside is dropped with it. As a result, the pore diameter of the separator 1c is increased to cause physical collapse. Second, the bonding strength between the glass fiber 4a and the organic fiber (polyester fiber 4b) is reduced. As a result, the expanded positive electrode grid penetrates the separator 1c whose mechanical strength is extremely reduced, causing an internal short circuit.

In the present embodiment, the amount of the fusion binder is significantly increased by significantly increasing the amount of the acrylic fiber 4c, which is added only in a small amount in Patent Document 1, so that the retention of the inorganic powder 4d is significantly improved. It has become possible. Therefore, the pore diameter of the separator 1c can be maintained large to improve the wettability of the electrolytic solution, and it is possible to achieve both of strengthening the bonding strength between the fibers for a long time. As a result, the expanded positive electrode grid can be prevented from easily penetrating the separator 1c. Further, by greatly increasing the proportion of acrylic fibers, when the separator 1c is processed into a bag shape by thermocompression bonding or the like, the seal location is melted smoothly, and the processability is improved.

Furthermore, compared with patent document 1, the ratio of the organic fiber (polyester fiber 4b and acrylic fiber 4c) with respect to the glass fiber 4a is increased (1.2 <= (B + C) / A <= 1.67). By setting this ratio, a synergetic effect of the three types of fibers is generated, although details are under investigation, and the retention of the inorganic powder 4d and the pore structure can be optimized. Specifically, in the case of constituting a non-woven fabric with one kind of fibers, the fibers entangle each other and the size and distribution of pores which are gaps between the fibers become uneven, but different kinds of fibers are mixed. When the nonwoven fabric is formed, the size and distribution of the pores become uniform, so the mechanical strength of the separator is improved and the retention of the inorganic powder is also enhanced. Here, even if (B + C) / A is less than 1.2, conversely, even if (B + C) / A exceeds 1.67, the synergetic effect of the separator 1c described above is reduced, so the short circuit resistance and the battery The characteristics are degraded.

By satisfying the above three points as A + B + C + D = 100, as shown in FIG. 2, the acrylic fiber 4c is dispersed so that the binding property of the basic constitution consisting of the glass fiber 4a and the polyester fiber 4b is enhanced. It is possible to form the separator 1c having a structure in which the inorganic powder 4d fills the large pores generated in the basic configuration. Use of such a separator 1c provides the lead-acid battery of the present embodiment that can endure long-term use (without causing sudden discomfort to customers due to sudden incapability) while maintaining the overall characteristics of the battery. become able to.

In addition, the liquid level of the electrolyte is higher than the upper end of the electrode plate group 1 (there are more electrolytes than general sealed lead-acid batteries), and the amount of lead red to be included as the active material of the positive electrode 1a is 5 The separator according to the present embodiment is a lead-acid battery in which the positive electrode grid is more easily expanded because the use period is extended by incorporating a (long-life) technology that can be used over a long period of time, such as a configuration of 10% by mass. It is preferable to use Red lead has the effect of improving the initial charging efficiency.

Further, it is more preferable to use silica as the inorganic powder 4d, since the electrolytic solution is easily held inside the separator 1c by the water absorption of the silica, and the overall characteristics of the battery are improved.

The positive electrode 1a is formed by casting or expanding a lead alloy made of a Pb-Ca alloy or the like, and applying a paste obtained by kneading a positive electrode active material made of lead powder and red lead and the like with sulfuric acid. Formed by The negative electrode 1 b is formed by applying a paste obtained by kneading a negative electrode active material made of lead powder and the like with sulfuric acid to a negative electrode grid formed by casting or expanding a lead alloy made of a Pb—Ca alloy. Polypropylene can be used as the material of the battery case 2 and the lid 3. A well-known thing can be used for the control valve 3a.

Hereinafter, the effects of the present embodiment will be described in more detail by way of examples.

The positive electrode active material consisting of 92% by mass of lead powder and 8% by mass of red lead was kneaded with sulfuric acid to form a paste. This paste was applied to a positive electrode grid formed by expanding a lead alloy made of a Pb—Ca alloy to fabricate a positive electrode 1a. Then, this positive electrode 1a was sandwiched between various mat-like separators 1c shown in (Table 1), and the separator was contained in a bag shape by a thermocompression bonding method.

On the other hand, appropriate amounts of barium sulfate, carbon and lignin compound were added to a negative electrode active material consisting of lead powder, and the mixture was kneaded with sulfuric acid to form a paste. This paste was applied to a negative electrode grid formed by expanding a lead alloy made of a Pb—Ca alloy to prepare a negative electrode 1 b.

The electrode plate group 1 was formed by facing both surfaces of the positive electrode 1a included in the bag-like separator 1c to the negative electrode 1b. Then, the electrode plate group 1 is inserted into each cell chamber 2b of the battery case 2 divided into six cell chambers 2b by the partition walls 2a, and the ear portion corresponding to the upper end of the positive electrode 1a is joined to the positive electrode inside the cell chamber 2b. While being bonded to the member, the ear portion corresponding to the upper end of the negative electrode 1 b was bonded to the negative electrode bonding member. The positive electrode bonding member and the negative electrode bonding member of the adjacent cell chamber 2b are bonded via the inter-plate bonding member, and the positive electrode bonding member is a positive electrode terminal that is not bonded to the inter-plate bonding member in the cells at both ends. A negative electrode bonding member not bonded to the inter-plate bonding member was bonded to the negative electrode terminal.

An electrolytic solution is injected into all of the cell chambers 2b so that the liquid level is higher than the upper end of the electrode plate group 1, and the opening 3 of the battery case 2 is closed by the lid 3 provided with the control valve 3a. A lead-acid battery denoted as 55D23 in JIS D5301 (commonly referred to as S55D23) was produced. The lead storage battery has a height of 202 mm, a width of 173 mm, a length of 232 mm, and a nominal capacity of 43 Ah, excluding the terminals. These are called batteries 1 to 10.

On the other hand, lead storage batteries fabricated in the same manner as batteries 3 and 5 except that the height of electrode plate group 1 and the liquid surface height of the electrolyte are the same for batteries 3 and 5 are batteries 11 and 12, respectively. . In addition, lead storage batteries fabricated in the same manner as the battery 3 except that the amount of lead red powder to be included as a positive electrode active material is changed with respect to the battery 3 are referred to as batteries 13, 15, 17 and 19. Further, lead storage batteries produced in the same manner as the battery 5 except that the amount of lead red powder to be included as a positive electrode active material is changed with respect to the battery 5 are referred to as batteries 14, 16, 18 and 20. Further, a lead storage battery produced by changing the mass ratio of polyester fiber to acrylic fiber of the battery 6 to 19: 21 is referred to as a battery 21.

The above batteries 1 to 21 are subjected to a constant voltage charge of 14.0 V (maximum current 25 A) at 75 ° C. for 120 hours, left for 2 days, and then discharged for 5 seconds at 300 A Did. When the terminal voltage after 5 seconds became 3 V or less, it was judged that each battery had reached the life. The number of cycles that reached the end of the life and the causes of the end of the life clarified by the subsequent decomposition are also described in (Table 1), respectively.

In the present embodiment, under the high temperature of 75 ° C., the ideal lead-acid battery (high durability of the separator 1c) reaches its life due to a gradual voltage drop due to liquid dead or capacity decrease, and has the conventional problem ( The lead storage battery with low durability of the separator 1c has reached its life due to a rapid voltage drop due to a short circuit. The

batteries

2, 3, 4, 8, 9, 11, 13, 15, 17, 19, 21 are the batteries of the embodiment, and the batteries 1, 5, 6, 7, 10, 12, 14, 16, 16 , 20 are batteries of the comparative example. The battery of the example has reached the end of life by 17 to 20 cycles due to liquid depletion and a gradual voltage drop due to capacity reduction, and the cell of the comparative example has reached the life of 12 to 15 cycles due to the short circuit. The above-mentioned endurance test is conducted at 75 ° C., which is an accelerated test about 10 times the use in a high temperature area (use at about 40 ° C.). Therefore, while the 17 cycles in the example are the number of cycles usable in a high temperature area for 3 years or more, the 15 cycles in the comparative example are the number of cycles that will have a life of less than 3 years. In view of the fact that the maintenance company carries out replacement of the lead storage battery, it can be said that the 15 cycles are not practical and the 17 cycles have characteristics sufficient for practical use.

As a result, as shown in (Table 1), among the batteries 1 to 10 using the separator 1c of various configurations, the mass ratio of the glass fiber 4a is A, the mass ratio of the polyester fiber 4b is B, and the acrylic fiber 4c Assuming that the mass ratio is C, the mass ratio of silica is D as the inorganic powder 4d, and A + B + C + D = 100, 0.2 ≦ D / (A + B + C + D) ≦ 0.4 and B <C and 1.0 ≦ (B + C) The batteries 2 to 4, 8 and 9 satisfying /A≦1.67 resulted in a large number of life cycles. In addition, these batteries have reached the end of their life gradually, and the reason for reaching the end of life is liquid wither and capacity loss (reduction of reaction substances due to softening and dropping of the active material, or increase of reaction resistance due to corrosion of the positive grid). Not only is it a long service life, but it enables customers and maintenance companies to detect the necessity of replacement by car inspection etc. without hesitation.

On the other hand, the battery 1 in which D / (A + B + C + D) is less than 0.2 rapidly reached the life due to the short circuit. As a result of investigating the cause, it was found that a dropout of the positive electrode active material penetrates into the separator 1c while the expanded positive electrode grid penetrates the separator 1c. This is because the inorganic powder 4d (silica) is too small, so the separator 1c loses the repulsive force against expansion of the positive electrode grid, and the portion with the large pore diameter inside the separator 1c (inorganic powder 4d is missing) It can be inferred that the positive electrode active material permeated into the part).

Conversely, the battery 5 with D / (A + B + C + D) exceeding 0.4 also rapidly reached the life due to the short circuit. As a result of investigating the cause, the positive electrode grid broke the separator 1 c and caused a short circuit. It can be inferred that this is because the mechanical strength of the separator 1 c is extremely reduced because the inorganic powder 4 d (silica) is excessive.

The battery 6 with B = C also rapidly reached the life due to the short circuit. As a result of investigating the cause, it was found that the original form of the separator 1c is broken. This is because the polyester fiber 4b is altered and the inorganic powder 4d (silica) falls off from the separator 1c, and the bonding strength between the glass fiber 4a and the polyester fiber 4b is reduced due to the shortage of the acrylic fiber 4c. It can be inferred that it did not melt smoothly (it was difficult to maintain the bag shape from the initial state). On the other hand, battery 21 with B: C 19: 21 has 17 cycles and has a long life, and battery performance gradually declines due to liquid shortage and capacity reduction, and battery life is reaching its end. It is easy to make a judgment that it is necessary for a long time.

In addition, both the battery 7 in which (B + C) / A is less than 1.2 and the battery 10 in which (B + C) / A exceeds 1.67 rapidly reach the life due to the short circuit. As a result of investigating the cause, it was found that the original form of the separator 1c is broken. This is because when the balance (B + C) / A between the glass fiber 4a and the organic fiber (polyester fiber 4b and acrylic fiber 4c) deviates from the proper range, the separator 1c can not maintain the ideal structure as shown in FIG. It can be inferred that the synergetic effect is reduced and not only the short circuit resistance but also the battery characteristics are deteriorated.

By the way, in the battery 3 which is a preferred example of the present embodiment, the liquid level of the electrolytic solution is made higher than the upper end of the electrode plate group 1 in order to enable long-term use, and a general sealed type The amount of electrolytic solution is larger than that of the lead storage battery, and the amount of red lead to be included as the active material of the positive electrode 1a is 8% by mass. For this reason, as compared with the battery 5 in which D / (A + B + C + D) exceeds 0.4, the life characteristics are dramatically improved. The same applies to the comparison between the batteries 15 and 17 (D / (A + B + C + D) within the appropriate range) and the batteries 16 and 18 (D / (A + B + C + D) deviates from the appropriate range).

However, the battery 11 (D / (A + B + C + D) is in the appropriate range) and the battery 12 (D / (A + B + C + D) deviates from the appropriate range) whose electrolyte level is the same as the upper end of the electrode group 1 In this case, the degree of improvement of the life characteristics is not as remarkable as the combination described above. This means that the batteries 13 and 19 (D / (A + B + C + D) are in the appropriate range) and the batteries 14 and 20 are such that the amount of the red lead to be included as the active material of the positive electrode 1a deviates from the preferable range for prolonging the life. The same applies to comparison with (D / (A + B + C + D) deviates from the appropriate range). In addition, in the osmotic short circuit of the active material, which is the cause of reaching the life of the battery 20, the fiber can not hold the inorganic powder because the amount of the inorganic powder 4d is too large. This is a result of penetration of the positive electrode active material into the part where 4d is missing, and the battery suddenly becomes unusable as in the case of a short circuit due to the separator being broken, and the useful life for the user is reached.

That is, since the short circuit resistance is significantly improved by using the separator 1c of the present embodiment, the liquid level of the electrolytic solution is made larger than the height of the electrode plate group 1 on the premise of long-term use. It is understood that it is preferable from the viewpoint of prolonging the battery life that it is preferable to weave the configuration or the configuration in which the amount of the lead red powder to be included as the active material of the positive electrode 1a is 5 to 10% by mass.

(Other embodiments)
The above embodiments and examples are illustrative of the present invention, and the present invention is not limited to these examples. When the mass ratio A of glass fiber, the mass ratio B of polyester fiber, the mass ratio C of acrylic fiber, and the mass ratio D of inorganic powder are A + B + C + D = 100, 0.2 ≦ D / (A + B + C + D) ≦ 0. 4 and B <C, and 1.2 ≦ (B + C) /A≦1.67 may be used, and the composition ratio is not limited to the examples. The structure and shape of the lead storage battery, the number of cell chambers, etc. are not particularly limited.

By utilizing the present invention, the characteristics and quality of the lead-acid battery for the auxiliary device of the hybrid vehicle are greatly improved. Since hybrid vehicles are products that suppress global exhaustion due to energy exhaustion and carbon dioxide, they can greatly contribute to the industry by spreading the present invention.

1 electrode group 1a positive electrode 1b negative electrode 1c separator 2 battery 2a partition 2b cell chamber 3 lid

3a control valve

4a glass fiber

4b polyester fiber 4c acrylic fiber 4d inorganic powder

Claims

Battery case,
A partition that partitions the battery case to form a plurality of cell chambers;
A plurality of electrode plate groups accommodated in each of the cell chambers and having a positive electrode plate and a negative electrode plate laminated via a separator;
An electrolytic solution stored in the cell chamber;
A lead storage battery comprising a control valve and a lid closing the opening of each of the cell chambers,
The separator is made of non-woven fabric containing glass fiber, polyester fiber, acrylic fiber and inorganic powder,
In the separator, when the mass ratio of the glass fiber is A, the mass ratio of the polyester fiber is B, the mass ratio of the acrylic fiber is C, and the mass ratio of the inorganic powder is D, A + B + C + D = 100, 0 2. Lead acid battery which is 2 ≦ D / (A + B + C + D) ≦ 0.4, and B <C and 1.2 ≦ (B + C) /A≦1.67.
When the lead storage battery is installed so that the lid is positioned at the top, the liquid level of the electrolyte is positioned above the upper end of the electrode plate group. Lead-acid battery.
The lead acid battery according to claim 1, wherein the inorganic powder contains silica.
The lead storage battery according to claim 1, wherein the active material of the positive electrode plate contains 5% by mass or more and less than 10% by mass of lead.