DE112012000639T5 - lead-acid battery - Google Patents

Abstract

It is an object of the present disclosure to provide a lead-acid battery in which a mat-shaped separator having improved durability is used, so that long-term use of the lead acid battery can be realized even with a gradual reduction in battery performance associated with the use of a lead acid battery, and that good overall properties can be realized. The lead-acid battery of the present disclosure comprises a container; a partition partitioning the container into a plurality of cell chambers; a plurality of electrode groups each disposed in a corresponding one of the cell chambers and comprising positive and negative electrode plates stacked with a separator interposed therebetween; an electrolyte injected into the cell chambers and a lid including a control valve and configured to close an opening of each cell chamber. The separator is made of a nonwoven fabric containing glass fibers, polyester fibers, acrylic fibers and inorganic powder. When A + B + C + D = 100, wherein A represents a mass fraction of the glass fibers, B represents a mass fraction of the polyester fibers, C represents a mass fraction of the acrylic fibers and D represents a mass fraction of the inorganic powder, the separator satisfies 0.2 ≦ D / (A + B + C + D) ≦ 0.4, B <C and 1.2 ≦ (B + C) / A ≦ 1.67.

Description

Technical area

The present invention relates to a lead-acid battery.

State of the art

Due to the recent popularization of environmentally friendly motor vehicles, also lead acid batteries, which were used for starting motor vehicles, for. B. used for accessories (engines) of hybrid batteries. In particular, a lead-acid battery for an accessory is mounted in various areas of a vehicle. It is often the case that a lead acid battery is mounted in a different area of a vehicle than in an area under the hood, and that it is difficult to perform the maintenance and inspection. When the lead-acid battery is mounted in an area of a vehicle in which maintenance and inspection are difficult to perform, it is convenient to use a sealed lead-acid battery in which water replenishment is not necessary. Therefore, the sealed lead-acid batteries have been widely used as "lead-acid batteries for accessories".

The lead-acid battery for accessories is structured as follows. Lattices made of a lead alloy are each filled with an active material containing lead, thereby forming positive and negative electrodes. The positive and negative electrodes are sequentially alternately stacked with a mat-shaped separator disposed between adjacent positive and negative electrodes, thereby forming an electrode group. The electrode groups are accommodated in a container containing a plurality of cell chambers. After the container, d. H. whose upper portion is closed by a lid in a state in which the electrode groups in the adjacent cell chambers are connected in series with each other, the mat-shaped separators are soaked with the electrolyte introduced into the container. The foregoing construction of the lead-acid battery for accessories allows oxygen generated during charging to react with the negative electrode or with sulfuric acid serving as the electrolyte, thereby reducing oxygen. Therefore, the reduction of the electrolyte can be suppressed as much as possible. As a result, the sealed lead-acid battery can be realized. The mat-shaped separator is a separator, which z. B. is formed of a nonwoven fabric and having a thickness which is reduced when pressure is applied in a thickness direction of the separator.

Patent Document 1, in the context of a typical sealed lead-acid battery, discloses a separator which improves discharge performance (ie, high current discharge duration) at a low temperature and which internal short circuit due to penetrating a separator with a fine active positive electrode material and guiding it to a counter electrode (negative electrode), reduced or prevented, to extend the life of the lead-acid battery. The separator disclosed in Patent Document 1 is a mat-shaped separator formed to have a maximum pore size of 30-60 μm in such a manner that a powder of a silica having a particle size of 1 μm or less and diatomaceous earth having a particle size of 3-5 microns, a total of about 15%, added to a mixture of about 40% polyester resin fibers each having a diameter of 2-8 microns, about 40% glass fibers each having a diameter of 2-8 microns and about 5% acrylic fibers be used to connect the polyester resin fibers and the glass fibers together.

List of citations

Patent document

• Patent Document 1: Japanese Patent Publication No. S62-066566

Summary of the invention

Technical problem

In the case where the lead acid battery separator disclosed in Patent Document 1 was used, the following was found. Although the aforementioned advantages could be realized, the lead-acid battery is suddenly unusable during a long-term use of the separator, due to another state of destruction (ie short circuit caused by the penetration of an extended positive electrode grid through the separator). Further, when the separator is formed into a bag-like shape to increase the life of the battery, the workability is lowered due to the bag shape of the separator.

The present disclosure has been made to overcome the foregoing drawbacks, and it is an object of the present disclosure to provide a lead-acid battery in which a mat-shaped separator having improved durability is used, so that the long-term use of the lead-acid battery can be realized even with a gradual one Reduction of battery performance, which accompanies the use of the lead acid battery, and that good overall performance can be achieved.

the solution of the problem

In order to solve the above problem, a lead-acid battery of the present disclosure comprises a container; a partition partitioning the container into a plurality of cell chambers; a plurality of electrode groups each disposed in a corresponding one of the cell chambers and comprising positive and negative electrode plates stacked with a separator interposed therebetween; an electrolyte injected into the cell chambers and a lid comprising a control valve and configured to close an opening of each cell chamber. The separator is made of a nonwoven fabric containing glass fibers, polyester fibers, acrylic fibers and inorganic powder. When A + B + C + D = 100, wherein A represents a mass fraction of the glass fibers, B represents a mass fraction of the polyester fibers, C represents a mass fraction of the acrylic fibers and D represents a mass fraction of the inorganic powder, the separator satisfies 0.2 ≦ D / (A + B + C + D) ≦ 0.4, B <C and 1.25 ≦ (B + C) / A ≦ 1.67.

When the lead-acid battery is constructed so that the lid is located at the outermost side, a liquid surface may be located higher than an upper end of each electrode group.

The inorganic powder preferably contains silica.

An active material of the positive electrode plate preferably contains red lead of 5 mass% or more and less than 10 mass%.

Advantages of the invention

Since the structure of the separator is optimized as described above, lead-acid batteries, mainly lead-acid batteries for accessories, which are usable for long periods and have good overall properties, can be realized.

Brief description of the drawings

1 FIG. 12 is a perspective view illustrating a lead-acid battery of the present disclosure. FIG.

2 shows an enlarged schematic view illustrating a structure of the separator.

Description of the embodiments

Before describing an embodiment of the present disclosure, details relating to the present disclosure will be described below.

For a typical lead-acid battery for starting automobiles, the following phenomena are the major factors that shorten a life of the battery: a phenomenon in which an active material expands and falls from a positive electrode, thereby reducing a reactant; and a phenomenon in which a positive electrode grid corrodes. The lead acid battery for starting the motor vehicle is mounted in an area of the vehicle in which the replacement of the lead acid battery can be easily performed. Further, cranking performance is gradually reduced as the aforementioned phenomenon continues, resulting in battery depletion. Therefore, a user can predict a timing of the replacement of the lead-acid battery from a reduction in the cranking performance, and can easily replace the lead-acid battery because of the advantage that the battery is located in a place by simply performing the replacement of the lead-acid battery. Therefore, the deterioration or destruction of the lead-acid battery due to the foregoing two problems is not considered a major problem.

Since a lead-acid battery for an accessory, unlike the lead-acid battery for starting, is fixed in an area of the vehicle in which maintenance is difficult, it is a long-term use (ie, a life of three or more years before replacement at a safety inspection). the lead acid battery necessary, in addition to the fact that no water needs to be refilled. For this reason, an embodiment for extending the battery life is employed, such as a configuration in which the amount of red lead used as the positive active electrode material is reduced as compared with a typical lead-acid battery for starting a motor vehicle.

The present inventors have found that when the lead-acid battery for accessories is used for a long period of time (eg, three years) without maintenance as described above, a phenomenon occurs that results in a state in which the lead-acid battery suddenly becomes is unusable, regardless of the deterioration of a performance of lead acid battery. As a result of investigation of the decomposed lead-acid battery based on the above-mentioned phenomenon, it has been found that the positive electrode grid itself expands and penetrates a separator and hence shorts occur. Furthermore, it has been found that the separator disclosed in Patent Document 1 can be used to reduce the former phenomenon (an influence of the fine active material), but can not be used for the latter phenomenon (an influence of the extended positive electrode grid ) to reduce.

The phenomenon in which the fine active electrode material penetrates the separator to cause short circuits has already been known, and the separator disclosed in Patent Document 1 can be used to reduce such a phenomenon. However, the newly-discovered phenomenon in which the positive electrode grid itself penetrates the separator can not be reduced or prevented by the separator disclosed in Patent Document 1.

The present inventors have found, as a result of intensive researches of the above facts, that optimizing an embodiment of a mat-shaped separator overcomes the problem (ie, short circuit caused by the influence of the extended positive electrode grid) which is not completely overcome by the method disclosed in Patent Document 1 becomes. It should be noted that the mat-shaped separator is a separator formed e.g. B. from a nonwoven fabric with a volume which reduces when pressure. The four points to overcome the problem are as follows.

A first point is that the mat-shaped separator contains glass fiber, polyester fibers, acrylic fibers and inorganic powder. Such a configuration is the same as disclosed in Patent Document 1. The acrylic fibers serve as a binder to bond the glass fibers and the polyester fibers together.

A second point is that the separator satisfies 0.2 ≤ D / (A + B + C + D) ≤ 0.4, where "A" represents the mass fraction of the glass fibers, "B" represents the mass fraction of the polyester fibers, "C "Represents the mass fraction of the acrylic fibers and" D "represents the mass fraction of the inorganic powder. In such a manner that the mixing ratio of the inorganic powder to each kind of the fibers is larger than disclosed in the Patent Document 1, the extended positive electrode grid can be prevented from easily penetrating the separator.

A third point is that the separator satisfies B <C. The mat-shaped separator is worked into a bag form (by, for example, thermocompression bonding) to extend the life of the battery. Since the separator containing only the glass fibers has low mechanical strength, the processability thereof is low. Therefore, organic fibers such as the polyester fibers are blended. However, the following has been found in the case that substantially only the polyester fibers are contained as the organic fibers as in Patent Document 1. The separator is deteriorated due to a long-term use, resulting in a physical breakdown. Then, the inorganic powder held inside the fibers is dropped and the bonding force among the fibers is reduced. As a result, the mechanical strength is significantly reduced and the positive electrode plate penetrates the separator. This leads to an internal short circuit. Although a small amount of acrylic fibers are added in Patent Document 1 only for the purpose of a fiber bonding function, for such a reason, the amount of acrylic fibers in the present disclosure is remarkably increased to remarkably increase the force for holding the inorganic powder. Therefore, the electrolyte wettability in can be improved in such a way that the pore size of the separator is increased and the bonding force among the fibers can be increased over a long period of time. Therefore, the extended positive electrode grid can be prevented from easily penetrating the separator.

A fourth point is that the separator satisfies 1.2 ≤ (B + C) / A ≤ 1.67. The present inventors found the following and used such a finding favorably. The glass fibers and the organic fibers are not used in equal proportions as in Patent Document 1, but the proportion of the organic fibers is larger than that of the glass fibers. Therefore, due to a synergistic effect of the three types of fibers, the power to hold the inorganic powder can be improved, and a pore structure can be optimized.

The use of a mat-shaped separator configured to satisfy the above four points and A + B + C + D = 100 realizes a lead-acid battery for an accessory which is durable over a long period while retaining all the characteristics of the battery ( ie a user is not disadvantaged by being suddenly unusable).

The aforesaid separator is preferably used for a sealed lead-acid battery having the configuration permitting long-term use (ie, the configuration in which the amount of expansion of a positive electrode grid is increased by the extension of the period of use), such as the configuration in which a liquid surface of an electrolyte is disposed higher than an upper end of an electrode group (ie, more electrolyte is used in comparison with a typical sealed lead-acid battery) or the configuration in which the amount of the red lead serving as a positive electrode active material is a range of 5-10 mass% falls. In such a case, the performance of the lead acid battery is not blocked.

Silica is preferably used as the inorganic powder because the water absorbency of the separator is increased by the water absorption ability of the silica. Since the diatomaceous earth has a function similar to the silica, diatomaceous earth can be used as the inorganic powder.

First Embodiment

An embodiment will be described with reference to the drawings.

1 FIG. 10 is a perspective view showing a lead-acid battery of the present embodiment. FIG. 2 shows an enlarged schematic view of a part of the separator.

Positive electrodes 1a and negative electrodes 1b lie opposite each other, wherein a mat-shaped separator 1c between adjacent ones of the positive electrodes 1a and the negative electrodes 1b is arranged, whereby an electrode group 1 is formed. The electrode group 1 is combined with an electrolyte (not shown in the figure) in each of a plurality of cell chambers 2 B a container received by dividing the container by partitions 2a be formed. Subsequently, an opening of the container 2 from a lid 3 containing a control valve 3a closed. In the aforementioned manner, a lead-acid battery is formed. It should be noted that the positive electrode 1a is formed by filling a positive electrode grid with a positive electrode active material and the negative electrode 1b is formed by a negative electrode grid is filled with a negative electrode active material.

The separator 1c contains as components glass fibers 4a , Polyester fibers 4b , Acrylic fibers 4c and inorganic powder 4d , When A + B + C + D = 100, where "A" is the mass fraction of the glass fibers 4a represents, "B" the mass fraction of the polyester fibers 4b represents, "C" the mass fraction of acrylic fibers 4c and "D" represents the mass fraction of the inorganic powder 4d is satisfied, the following is satisfied: 0.2 ≦ D / (A + B + C + D) ≦ 0.4, B <C and 1.0 ≦ (B + C) / A ≦ 1.67. The polyester fibers and the acrylic fibers are made of materials whose quality is not changed even when power is applied when the fibers are impregnated with sulfuric acid. In particular, examples of the polyester fibers include polyethylene terephthalate (PET) fibers, and examples of the acrylic fibers include polyacrylonitrile fibers.

In addition to the feature that the glass fibers 4a , the polyester fibers 4b , the acrylic fibers 4c and the inorganic powder 4c the separator 1c The following three features will be described in the present embodiment.

First, the following satisfies 0.2 ≦ D / (A + B + C + D) ≦ 0.4, where "A" is the mass fraction of the glass fibers 4a represents, "B" the mass fraction of the polyester fibers 4b represents, "C" the mass fraction of acrylic fibers 4c and "D" represents the mass fraction of the inorganic powder 4d represents.

The positive electrode grid is extended due to long-term use of the lead-acid battery. The present inventors have found that, even if the separator 1c is designed to be stable as in Patent Document 1, the extended positive electrode grid is simply the separator 1c penetrates. The present inventors also found that the mixing ratio of the inorganic powder 4d is increased to each type of fiber, in comparison with the description of Patent Document 1, whereby the penetration of the positive electrode grid is prevented or reduced. When D / (A + B + C + D) is less than 0.2, the positive electrode grid penetrates the separator 1c due to the long-term use of the lead-acid battery. On the contrary, when D / (A + B + C + D) exceeds 0.4, the mechanical strength of the separator becomes 1c due to the excess of the inorganic powder 4d significantly reduced.

Next is the mass fraction C of the acrylic fibers 4c greater than the mass fraction B of the polyester fibers 4b (B <C). To increase the life of the battery, the mat-shaped separator is formed in a bag shape (by, for example, thermocompression bonding) to receive the active material fallen from the electrode plate. As the separator, which only the gas fibers 4a contains, has low mechanical strength and low processability, the glass fibers 4a with organic fibers, such as polyester fibers 4b mixed when the separator is worked into a bag shape. If the polyester fibers 4b As in Patent Document 1, the majority of organic fibers which are mixed are mixed, there are two disadvantages due to long-term use. The first downside is that the quality of the polyester fiber 4b itself is changed and the inorganic powder 4d which is inside the polyester fiber 4b held, will fall out in connection with this change. Then the pore size of the separator 1c increases, resulting in a physical breakdown. The second drawback is that the binding force under the glass fibers 4a and the organic fibers (polyester fibers 4b ) is reduced. As a result, the extended positive electrode grid penetrates the separator 1c which has an extremely low mechanical strength, thereby causing an internal short circuit.

Although only a small amount of acrylic fibers are added in Patent Document 1, the amount of the acrylic fibers becomes 4c significantly increased in the present embodiment, and thereby the amount of fusion bonding agent is significantly increased. Therefore, the force becomes the inorganic powder 4d to keep up, significantly increased. Consequently, the wettability of the electrolyte may be due to the larger pore size of the separator 1c can be improved and a binding force among the fibers can be strengthened over a long period of time. As a result, the electrode grid penetrates the separator 1c not easy. Furthermore, since the proportion of acrylic fibers is significantly increased, the separator 1c at a sealing part of which melted in a smooth manner when the separator 1c is worked by thermocompression bonding in a bag form, whereby the processability is improved.

Furthermore, the proportion of the organic fibers (ie, the polyester fibers 4b and the acrylic fibers 4c ) to the gas fibers 4a in comparison with that described in Patent Document 1, increases (1.0 ≦ (B + C) / A ≦ 1.67). As such a ratio is employed, a synergistic effect of the three types of fibers is produced, although a detailed explanation is still made, and the power to the inorganic powder 4d to keep it, and a pore structure are optimized. in particular, in the case where a nonwoven fabric is formed of a single fiber type, the size and distribution of the pores, each defined by a space between adjacent ones of the fibers, is uneven due to entanglement of the fibers. However, when a nonwoven fabric is formed from a mixture of different types of fibers, the size and distribution of the pores are uniform. Therefore, the mechanical strength of a separator is improved and the force to hold the inorganic powder is increased. Even if (B + C) / A is less than 1.2 or exceeds 1.67, the synergistic effect of the separator becomes 1c reduces, and therefore the short-circuit resistance and the battery properties are reduced.

If A + B + C + D = 100 and the aforementioned three points are met, the separator can 1c be formed with the following structure: the acrylic fibers 4c are dispersed so that the bond in a basic configuration formed by the glass fibers 4a and the polyester fibers 4b is increased and large pores formed in the basic configuration are with the inorganic powder 4d filled. A use of the separator 1c realizes the lead-acid battery of the present embodiment, which is stable over a long period of time while retaining all the characteristics of the battery (ie, a user does not suffer from being suddenly unusable).

The separator of the present embodiment is preferably used for a lead-acid battery comprising a positive electrode grid which tends to expand as a result of a period of use being prolonged by employing a method allowing long-term use (ie, a method for extending the battery life), such as the method in which a liquid surface of an electrolyte is arranged higher than an upper end of an electrode group (ie, more electrolyte is used in comparison with a typical sealed lead-acid battery) or the method in which the amount of red Lead, which acts as an active material for a positive electrode 1a serves, falling within a range of 5-10 mass%. Red lead has an effect of improving initial charge efficiency.

Silica is more preferable than the inorganic powder 4d used. This is because the electrolyte becomes easier in the separator due to the water absorption ability of the silica 1c can be kept and therefore the overall properties of the battery can be improved.

The positive electrode 1a is formed in such a manner that a paste formed by mixing sulfuric acid with the positive electrode active material made of e.g. B. lead suboxide powder and red lead is applied to the positive electrode grid, made of a lead alloy, such as Pb-Ca alloy, and formed by casting or expansion. The negative electrode 1b is formed in such a manner that a paste formed by mixing sulfuric acid with the negative electrode active material made of e.g. B. lead suboxide powder is applied to the negative electrode grid, made of a lead alloy, such as Pb-Ca alloy, and formed by casting or expansion. Polypropylene can be used as materials for the container 2 and the lid 3 be used. A well-known control valve can be used as the control valve 3a be used.

Advantages of the present embodiment will be described below in detail with reference to an example.

example

A paste was formed by mixing sulfuric acid with an active positive electrode material prepared from 92% by weight of lead suboxide powder and 8% by weight of red lead. The paste was applied to a positive electrode grid made of a lead alloy such as Pb-Ca alloy, and formed by expansion. In the above manner became a positive electrode 1a educated. Subsequently, in the state in which the positive electrode 1a of any type of mat-shaped separator 1c as shown in (Table 1), the separator was formed into a bag shape by thermocompression bonding, thus forming the positive electrode 1a to surround.

In the meantime, barium sulfate, carbon and a lignin compound in an appropriate amount were added to an active negative electrode material made of lead suboxide powder, and a paste was formed by mixing the result with sulfuric acid. The paste was applied to a negative electrode grid made of a lead alloy such as Pb-Ca alloy and molded by stretching. In the above manner, a negative electrode became 1b educated.

An electrode group was formed in which both surfaces of the positive electrode 1a that of the bag-shaped separator 1c surrounded, the negative electrodes 1b are opposite. Subsequently, the electrode group became 1 into each of the six cell chambers 2 B a container introduced by dividing the container 2 by means of partitions 2a be formed. In the cell chamber 2 B were ear parts of the positive electrodes 1a at the upper ends thereof are connected to a connecting element of the positive electrodes, and ear portions of the negative electrodes at the upper ends thereof are connected to a connecting element of the negative electrodes. Subsequently, the positive electrode connecting member of one of the cell chambers became 2 B and the negative electrode connecting part of an adjacent one of the cell chambers 2 B connected via an intermediate electrode connection element. The positive electrode connecting member, which was not connected to the interelectrode connecting member in one of the outermost cells, was connected to a positive electrode terminal, and the negative electrode connecting member, which was not connected to the interelectrode connecting member in the other outermost cell, was connected to a negative electrode terminal connected.

An electrolyte was added to all of the cell chamber 2 B injected so that a liquid surface higher than the upper ends of the electrode groups 1 was arranged and an opening of the container 2 was included with a 3 a control valve 3a locked. As a result, a lead acid battery was specified as "55D23" (typically "S55D23") according to JIS D5301 educated. The lead-acid battery had, without the connection, an outer height of 202 mm, an external width of 173 mm and an external length of 232 mm. Furthermore, the lead-acid battery had a nominal capacity of 43 Ah. Such a lead-acid battery was used as each of the first to tenth batteries.

The eleventh and twelfth lead-acid batteries were formed from the third and fifth batteries in a manner similar to the third and fifth batteries, except that the height of the electrode group 1 and the height of the liquid surface were changed to the same level. Further, the thirteenth, fifteenth, seventeenth, and nineteenth lead acid batteries were formed from the third battery in a manner similar to the third battery, except that the amount of the red lead serving as the positive electrode active material was changed. Further, the fourteenth, sixteenth, eighteenth and twentieth lead acid batteries were formed from the fifth battery in a manner similar to the fifth battery except that the amount of the red lead serving as the positive electrode active material was changed. In addition, the twenty-first lead-acid battery was formed from the sixth battery, so that the mass ratio between the polyester fibers and the acrylic fibers was changed to 19: 2.

An endurance test was conducted by repeating the cycle wherein, after a constant-voltage charge was conducted at 14.0V (maximum current of 25A) at a temperature of 75 ° C for 120 hours, the first to twenty-first batteries was allowed to stand for two days and then discharged at 300 A for 5 seconds. When the terminal voltage reached 3 V or less after the five seconds of discharge, the battery was judged exhausted. The number of cycles until each battery was exhausted and the reason for the exhaustion of each battery identified by disassembling the battery are both shown in (Table 1).

In the present example, an ideal lead-acid battery (including a high-resistance separator 1c ) at a high temperature of 75 ° C, due to a voltage drop caused by the drying out of the liquid or a power loss, whereas a lead-acid battery (containing a less stable separator 1c ) with a conventional problem due to a large voltage loss caused by a short circuit exhausted. It should be noted that the second, third, fourth, eighth, ninth, eleventh, thirteenth, fifteenth, seventeenth, nineteenth and twenty-first battery were batteries of the example, and the first, fifth, sixth, seventh, tenth, twelfth, fourteenth , sixteenth, eighteenth and twentieth battery, batteries of a comparative example. The batteries of the example exhausted in the seventeenth to twentieth cycle due to a slow voltage drop caused by the drying out of the liquid or a power loss, whereas the batteries of the comparative example exhausted in the twelfth to fifteenth cycle due to short circuit. It should be noted that the durability test was conducted at 75 ° C, and was an approximately 10-fold acceleration test for use in a high-temperature environment (ie, use at about 40 ° C). Therefore, seventeen cycles in the example showed that the battery can be used for 3 years or more in the high-temperature environment and fifteen cycles in the comparative example showed that the battery was exhausted in less than three years. Considering the replacement of a lead-acid battery by a mechanic in a safety inspection which is necessary every three years, a battery usable for fifteen cycles is not practical, and the battery usable for seventeen cycles is suitable for practical use.

As is clear from (Table 1), the results show the following. From the first to the tenth battery, where separators 1c with different configurations, the second to fourth, eighth and ninth batteries satisfied 0.2 ≦ D / (A + B + C + D) ≦ 0.4, B <C and 1.2 ≦ (B + C) / A ≤ 1.67 when A + B + C + D = 100, where "A" is a mass fraction of the glass fibers 4a represents, "B" a mass fraction of the polyester fibers 4b represents, "C" a mass fraction of the acrylic fibers 4c and "D" represents a mass fraction of the silica which is an inorganic powder 4d serves. Furthermore, the second to fourth, eighth and ninth batteries each had a larger number of cycles until the battery was exhausted. In addition, since the second to fourth, eighth and ninth batteries each gradually came to the end of battery life due to dehydration or degradation (ie, decrease in reactant, softening and precipitation of the active material, or increase in reaction resistance due to corrosion the positive electrode grid), the batteries not only have a long life, but a user or a mechanic can easily determine whether it is necessary for the battery z. As in the safety inspection to replace.

On the other hand, the first battery, where D / (A + B + C + D) was less than 0.2, quickly came to an end of battery life due to a short circuit. As a result of checking the reasons, it was found that the extended positive electrode grid is the separator 1c had penetrated and the precipitated active positive electrode material penetrated the separator 1c , This is due to the following assumption. As the amount of inorganic powder 4d (Silica) was too low, so the repulsive force of the separator 1c was lost to the expansion of the positive electrode grid, and the active positive electrode material penetrated a large pore area (the area in which no inorganic powder 4d located) of the separator 1c ,

The fifth battery, at which D / (A + B + C + D) exceeded 0.4, also quickly came to the end of battery life due to short circuit. As a result of the investigation of the reasons, it turns out that the positive electrode grid is the separator 1c penetrated, causing a short circuit. This is due to the following assumption. As the amount of inorganic powder 4d (Silica) was too large, the mechanical strength of the separator became 1c extremely reduced.

The sixth battery, at which B = C, also quickly came to the end of battery life due to a short circuit. As a result of investigation of the reasons, the original form of the separator went 1c lost. This is due to the following assumption. The quality of polyester fibers 4b was changed and therefore the inorganic powder fell 4d (Silica) from the separator 1c , Furthermore, the binding force between the glass fibers 4a and the polyester fibers 4b due to the lack of acrylic fibers 4c was reduced, and a mechanical seal was not melted in a seal part of it in a smooth manner (ie, it was difficult to maintain the bag shape in the initial state). On the other hand, the twenty-first battery in which B: C was 10:21 indicated seventeen cycles, indicating a long battery life, and was exhausted due to a gradual decrease in battery performance caused by the drying out of the liquid or a drop in performance. Therefore, the determination of the need to replace the battery is simplified over a long period of time.

The seventh battery, where (B + C) / A is less than 1.2, and the tenth battery, at which (B + C) / A exceeded 1.67, also quickly came to the end of battery life due to a short circuit. As a result of investigation of the reasons, the original form of the separator went 1c lost. This is due to the following assumption. If (B + C) / A, the balance between the glass fibers 4a and the organic fibers (ie, the polyester fibers 4b and the acrylic fibers 4c ), falls within an appropriate range, the ideal structure of the separator 1c , as in 2 shown, not retained. In this way, a synergistic effect was reduced and therefore not only the resistance to short circuit but also the battery characteristics were reduced.

For a long-term use, the third battery, which is a preferable example of the present embodiment, has been designed such that the liquid surface of the electrolyte is higher than the upper end of the electrode group 1 and that the amount of electrolyte was larger than that of a typical sealed lead-acid battery. Furthermore, the third battery was designed so that the amount of the positive electrode active material 1a serving red lead was 8 mass%. Therefore, the life characteristics were dramatically improved as compared with the fifth battery in which D / (A + B + C + D) exceeded 0.4. The same applies to the comparison between the fifteenth and seventeenth battery (D / (A + B + C + D) falls within an appropriate range) and the sixteenth and eighteenth battery (D / (A + B + C + D) does not fall in the appropriate area).

When comparing the eleventh battery (D / (A + B + C + D) falls within the appropriate range) and the twelfth battery (D / (A + B + C + D) does not fall within the appropriate range) where the Liquid surface of the electrolyte of the height of the upper end of the electrode group 1 However, the improvement in fatigue life was not as conspicuous as compared with the previous combinations. The same applies to the comparison between the thirteenth and nineteenth battery (D / (A + B + C + D) falls within the appropriate range) and the fourteenth and twentieth battery (D / (A + B + C + D) does not fall in the appropriate range) in which the amount of red lead serving as a positive electrode active material is out of the range suitable for extending battery life. Short circuit due to the penetration of the active material, ie the cause of the exhaustion of the twentieth battery, resulted from the fact that the fibers could not hold the inorganic powder due to an excess of the inorganic powder 4d and that the active positive electrode material is the large pore region (the region where no inorganic powder 4d is present) of the separator 1c penetrates. The battery was suddenly unusable, as in the case where short circuit due to the crack of the separator occurred, and the exhaustion of the battery is disadvantageous to a user.

That is, the separator 1c The present embodiment is used to remarkably improve short-circuit resistance. Therefore, provided that the battery is used for a long time, e.g. Example, the configuration in which the liquid surface of the electrolyte is disposed higher than the electrode group, or the configuration in which the amount of serving as the active material of the positive electrode red lead is 5-10 mass%, preferably taking into account the life of Battery inserted.

Other Embodiment

The present embodiment and examples have been cited as examples of the present disclosure, and the present invention is not limited to these examples. Any mixing ratio may be used as long as 0.2 ≦ D / (A + B + C + D) ≦ 0.4, B <C and 1.2 ≦ (B + C) / A ≦ 1.67 are satisfied. 0.2 ≦ D / (A + B + C + D) ≦ 0.4, B <C and 1.2 ≦ (B + C) / A ≦ 1.67 are satisfied when A + B + C + D = 100, where "A" represents the mass fraction of the glass fibers, "B" represents the mass fraction of the polyester fibers, "C" represents the mass fraction of the acrylic fibers, and "D" represents the mass fraction of the inorganic powder. The mixing ratio is not limited to those described in the examples. The structure and shape of the lead-acid battery, the number of cells, etc. are not limited to the foregoing.

Industrial applicability

The present disclosure is used to significantly improve the properties and quality of lead acid batteries for hybrid vehicle accessories. Because hybrid vehicles serve to global warming due to energy consumption or carbon dioxide, the widespread use of the present disclosure to industry can significantly contribute.

LIST OF REFERENCE NUMBERS

1

electrode group

1a

Positive electrode

1b

Negative group

1c

separator

2

container

2a

partition wall

2 B

cell wall

3

cover

3a

control valve

4a

glass fiber

4b

polyester fiber

4c

acrylic fiber

4d

Inorganic powder

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• JP 62-066566 [0005]

Cited non-patent literature

• JIS D5301 [0046]

Claims (4)

Lead acid battery, comprising a container; a partition partitioning the container into a plurality of cell chambers; a plurality of electrode groups each disposed in a corresponding one of the cell chambers and comprising positive and negative electrode plates stacked with a separator interposed therebetween; an electrolyte which is injected into the cell chambers and a lid comprising a control valve and adapted to close an opening of each cell chamber, wherein the separator is formed of a nonwoven fabric containing glass fibers, polyester fibers, acrylic fibers and inorganic powder, and when A + B + C + D = 100, wherein A represents a mass fraction of the glass fibers, B represents a mass fraction of the polyester fibers, C represents a mass fraction of the acrylic fibers and D represents a mass fraction of the inorganic powder, the separator is 0.2 ≦ D / ( A + B + C + D) ≤ 0.4, B <C and 1.2 ≤ (B + C) / A ≤ 1.67. The lead-acid battery according to claim 1, wherein when the lead-acid battery is constructed so that the lid is disposed on an outermost side, a liquid surface is disposed higher than an upper end of each electrode group. The lead-acid battery according to claim 1, wherein the inorganic powder contains silica The lead-acid battery according to claim 1, wherein an active material of the positive electrode plate preferably contains red lead of 5 mass% or more and less than 10 mass%.

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