JP7185981B2 - Grids and lead-acid batteries - Google Patents

Description

The present invention relates to grids and lead-acid batteries.

Lead-acid batteries are widely used for industrial and consumer purposes because of their reliability and low price, and demand for lead-acid batteries for automobiles (so-called batteries) is particularly high.

Patent Literature 1 describes a lead-acid battery having a positive plate and a negative plate. In this lead-acid battery, each of the positive electrode plate and the negative electrode plate is configured by filling an active material in a lead alloy grid. Then, the positive electrode plate and the negative electrode plate are alternately laminated with a separator interposed therebetween, the current collecting portions of the positive electrode plate and the negative electrode plate are collectively welded to the strap for each polarity, and the inter-cell connection portion or the electrode column is connected to the strap. , an electrode plate group.

JP 2012-230838 A

By the way, recent automobiles have an increasing number of electrical components, so the load on the battery is increasing. As a result, the discharge amount of the battery is increasing. As an index of the amount of discharge of a battery, there is a depth of discharge (DOD). The depth of discharge DOD indicates that the greater the value, the greater the amount of discharge. When the battery is charged and discharged in a state where the DOD is large, a muddy state (softening phenomenon) in which the bonds between the active materials on the positive electrode plate become weak progresses, and the active material gradually falls off from the lattice. Moreover, since lead-acid batteries mounted on automobiles are exposed to large vibrations for a long period of time, the dropout of the active material from the grid becomes significant. When the active material falls off from the lattice, there arises a problem that the life of the electrode plate (especially the positive electrode plate) is shortened.

Accordingly, an object of one aspect of the present invention is to provide a grid body and a lead-acid battery that can suppress dropout of an active material.

A grid according to one aspect of the present invention is a grid that is used in an electrode plate of a lead-acid battery and contains lead. and at least one of the plurality of through holes has an opening area on the first surface that is different from an opening area on the second surface.

When this grid is used for the electrode plate of a lead-acid battery, the active material is retained on the first surface, the second surface, and the plurality of through holes, and the first surface and the second surface are parallel to each other. Therefore, the active material tends to fall off from the first surface and the second surface. However, in at least one of the plurality of through-holes penetrating the first surface and the second surface, the opening area on the first surface and the opening area on the second surface are different, so the active material is less likely to fall out of the through-holes. . This can prevent the active material from falling off.

In all of the plurality of through-holes, the opening area on the first surface and the opening area on the second surface may be different. In this lattice body, since the opening areas on the first surface and the opening areas on the second surface are different in all of the plurality of through holes, it is possible to further suppress the falling off of the active material.

In all of the plurality of through holes, the opening area on the first surface may be larger than the opening area on the second surface. In this grid body, since the opening area on the first surface is larger than the opening area on the second surface in all of the plurality of through holes, the grid body can be easily formed, and the active material can be dispensed from the first surface side. By filling with , the filling property of the active material in the grid is improved.

A total opening area of the plurality of through holes on the first surface may be larger than a total opening area of the plurality of through holes on the second surface. In this lattice body, since the total opening area of the plurality of through holes on the first surface is larger than the total opening area of the plurality of through holes on the second surface, the active material as a whole is less likely to drop out of the through holes.

A recess may be formed in at least one inner wall surface of the plurality of through holes. In this grid, since the recesses are formed in the inner wall surface of at least one of the plurality of through holes, the active material enters the recesses. Thereby, it is possible to further prevent the active material from falling off.

Recesses may be formed in all the inner wall surfaces of the plurality of through holes. In this grid, since the recesses are formed in all the inner wall surfaces of the plurality of through-holes, the active material enters the recesses. Thereby, it is possible to further prevent the active material from falling off.

At least one of the plurality of through-holes may have a first tapered portion that expands to reach the first surface and a second tapered portion that expands to reach the second surface. In this lattice, each of the plurality of through-holes has a first tapered portion and a second tapered portion, so that the active material filled in the through-holes spreads on both sides of the first surface and the second surface. That is, the active material has a shape that sandwiches the lattice from both sides of the first surface and the second surface. Therefore, it is possible to further prevent the active material from coming off.

Each of the plurality of through-holes may have a first tapered portion that expands to reach the first surface and a second tapered portion that expands to reach the second surface. In this lattice, each of the plurality of through-holes has a first tapered portion and a second tapered portion, so that the active material filled in the through-holes spreads on both sides of the first surface and the second surface. That is, the active material has a shape that sandwiches the lattice from both sides of the first surface and the second surface. Therefore, it is possible to further prevent the active material from coming off.

In a lead-acid battery according to one aspect of the present invention, any one of the grids described above is used as a grid of at least one of the positive electrode plate and the negative electrode plate. In this lead-acid battery, any one of the grid bodies described above is used as the grid body of at least one of the positive electrode plate and the negative electrode plate, so that it is possible to prevent the active material from coming off.

By the way, in the positive electrode lattice, as the charge and discharge are repeated, the bonds between the active materials become weaker (softening phenomenon) progresses. Therefore, the grid may be a positive grid used for the positive plate. As a result, it is possible to efficiently prevent the active material from coming off.

According to the present invention, falling off of the active material can be suppressed.

1 is a perspective view showing the overall structure and internal structure of a lead-acid battery according to one embodiment; FIG. FIG. 2 is a perspective view showing an electrode group of the lead-acid battery shown in FIG. 1; It is a front view which shows a positive electrode plate (negative electrode plate). 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. It is a front view which shows the grid|lattice which concerns on one Embodiment. FIG. 6 is a schematic cross-sectional view showing a part of the lattice body shown in FIG. 5; It is a schematic cross section which shows a part of lattice of a modification. It is a schematic cross section which shows a part of lattice of a modification. It is a schematic cross section which shows a part of lattice of a modification.

Hereinafter, preferred embodiments of a lead-acid battery according to one aspect of the present invention will be described in detail with reference to the drawings. In addition, suppose that the same code|symbol is attached|subjected to the same or corresponding part in all the figures. Further, a numerical range indicated using "-" indicates a range including the numerical values described before and after "-" as the minimum and maximum values, respectively. Moreover, "A or B" may include either one of A and B, or may include both.

<Lead storage battery>
FIG. 1 is a perspective view showing the overall configuration and internal structure of a lead-acid battery 1 according to one embodiment. As shown in FIG. 1 , a lead-acid battery 1 includes a container 2 with an open top and a lid 3 that closes the opening of the container 2 . The container 2 and the lid 3 are made of polypropylene, for example. The lid 3 is provided with a positive electrode terminal 4 , a negative electrode terminal 5 , and a liquid port plug 6 for closing the liquid injection port provided in the lid 3 .

Inside the container 2, there are an electrode group 7, a positive electrode column 8 connecting the electrode group 7 to the positive electrode terminal 4, a negative electrode column (not shown) connecting the electrode group 7 to the negative electrode terminal 5, dilute sulfuric acid and the like. of electrolyte are contained.

FIG. 2 is a perspective view showing the electrode group 7. FIG. As shown in FIG. 2 , the electrode group 7 includes a positive electrode plate 9 , a negative electrode plate 10 , and a separator 11 arranged between the positive electrode plate 9 and the negative electrode plate 10 .

3 is a front view showing the positive electrode plate 9 (negative electrode plate 10), and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. As shown in FIGS. 3 and 4 , the positive electrode plate 9 has a positive grid (positive electrode current collector) 12 and a positive electrode active material (positive electrode material) 13 . The positive electrode grid body 12 is a grid body of the positive electrode plate 9, and has a grid portion 12a and an ear portion 12b integrally formed with the grid portion 12a and projecting from one end of the grid portion 12a. The positive electrode active material 13 is the active material of the positive electrode plate 9 and held by the positive electrode grid 12 . The negative plate 10 has a negative grid (negative collector) 14 and a negative active material (negative material) 15 . The negative electrode grid 14 is a grid of the negative electrode plate 10, and has a grid portion 14a and an ear portion 14b integrally formed with the grid portion 14a and projecting from one end of the grid portion 14a. The negative electrode active material 15 is the active material of the negative electrode plate 10 and held by the negative electrode lattice 14 . The positive electrode grid 12 and the negative electrode grid 14 are made of a lead alloy. The lead alloy may be an alloy containing tin, calcium, antimony, selenium, silver, bismuth, etc. in addition to lead. Specifically, for example, an alloy containing lead, tin and calcium (Pb—Sn -Ca-based alloy).

The electrode group 7 has a structure in which a plurality of positive electrode plates 9 and negative electrode plates 10 are alternately laminated in a direction substantially parallel to the opening surface of the container 2 with separators 11 interposed therebetween. That is, the positive electrode plate 9 and the negative electrode plate 10 are arranged so that their main surfaces extend in the direction perpendicular to the opening surface of the container 2 . In the electrode group 7 , the tabs 12 b of the positive grids 12 of the plurality of positive plates 9 are collectively welded with a positive strap 16 . Similarly, the ears 14 b of the negative grids 14 of the plurality of negative plates 10 are collectively welded together with a negative strap 17 . The positive strap 16 and the negative strap 17 are connected to the positive terminal 4 and the negative terminal 5 via the positive pole 8 and the negative pole, respectively.

Next, a method for manufacturing the lead-acid battery 1 will be described. The manufacturing method of the lead-acid battery 1 includes an electrode plate manufacturing process for obtaining electrode plates (the positive electrode plate 9 and the negative electrode plate 10) and an assembly process for obtaining the lead-acid battery 1 by assembling constituent members including the electrode plates.

In the electrode plate manufacturing process, for example, for each of the positive electrode plate 9 and the negative electrode plate 10, the electrode material paste (negative electrode material paste and positive electrode material paste) is held in grids (positive grid 12 and negative grid 14) ( filling), followed by aging and drying to obtain an unformed electrode plate.

The positive electrode material paste is obtained, for example, by adding additives (short fibers for reinforcement, etc.) and water to the raw materials of the positive electrode active material (lead powder, red lead (Pb3O4), etc.), and then adding dilute sulfuric acid and kneading. be done. After holding (filling) this positive electrode material paste in the positive electrode grid 12, for example, it is aged for 15 to 60 hours in an atmosphere with a temperature of 35 to 85° C. and a humidity of 50 to 98 RH%, and is aged for 15 to 60 hours at a temperature of 45 to 80°C. By drying for 30 hours, an unformed positive electrode plate is obtained.

The negative electrode material paste is prepared, for example, by adding an additive (carbon material, barium sulfate, reinforcing short fiber, resin having a sulfone group and/or a sulfonate group, etc.) to the raw material of the negative electrode active material (lead powder, etc.) and performing a dry process. After obtaining a mixture by mixing, dilute sulfuric acid and water are added and kneaded. After holding (filling) this negative electrode material paste in a current collector, for example, it is aged for 15 to 30 hours in an atmosphere with a temperature of 45 to 65 ° C. and a humidity of 70 to 98 RH%. By drying for a certain period of time, an unformed negative electrode plate is obtained.

In the assembly process, for example, an unformed negative electrode plate and an unformed positive electrode plate are alternately laminated with the separator 11 interposed therebetween, and the ears 12b of the positive electrode lattice 12 are connected (welded, etc.) to each other with the positive electrode strap 16. At the same time, the ears 14b of the negative grid 14 are connected (welded, etc.) with the negative strap 17 to obtain the electrode group 7 . This electrode group 7 is arranged in the container 2 to produce an unformed battery. Next, after injecting an electrolytic solution (dilute sulfuric acid, etc.) into the unformed battery, a DC current is applied to form the battery case. The lead-acid battery 1 is obtained by adjusting the specific gravity of the electrolytic solution after chemical conversion to an appropriate specific gravity.

The chemical conversion conditions and the specific gravity of sulfuric acid can be adjusted according to the properties of the electrode active material. Instead of performing the chemical conversion treatment after the assembly process, a large number of electrode plates after aging and drying in the electrode plate manufacturing process may be collectively immersed in a chemical conversion tank (tank chemical conversion).

<Lattice body>
Subsequently, the positive electrode grid 12 and the negative electrode grid 14 used for the positive electrode plate 9 and the negative electrode plate 10 of the lead-acid battery 1 described above will be described in more detail. In the present embodiment, since the positive grid 12 and the negative grid 14 are basically the same shape, the positive grid 12 and the negative grid 14 are collectively described below as the grid 21 .

FIG. 5 is a front view showing a grid according to one embodiment. FIG. 6 is a schematic cross-sectional view showing part of the grid shown in FIG. As shown in FIGS. 3 to 6, the grid body 21 (the positive grid body 12 and the negative grid body 14) is integrally formed with the grid portion 22 (the grid portion 12a and the grid portion 14a) and the grid portion 22. Ear portion 23 (ear portion 12b and ear portion 14b) projecting from one end of portion 22 is provided. The grid 21 corresponds to the positive grid 12 and the negative grid 14, the grid 22 corresponds to the grid 12a and the grid 14a, and the ears 23 correspond to the ears 12b and 14a. corresponding to each of the portions 14b.

The lattice portion 22 is formed in a substantially rectangular thin plate shape, and includes a first surface 22a and a second surface 22b parallel to each other, and a plurality of through holes 22c passing through the first surface 22a and the second surface 22b. I have it. Therefore, when the grid portion 22 is used as the electrode plate (the positive electrode plate 9 and the negative electrode plate 10) of the lead-acid battery 1, the active material (the positive electrode active material 13 and the negative electrode active material 15) is placed on the first surface of the grid portion 22. 22a, second surface 22b, and a plurality of through holes 22c. In addition, the active material is not held on the upper part of the lattice part 22 (the upper part of the first surface 22a and the second surface 22b). There is no distinction between the first surface 22a and the second surface 22b, and either surface of the lattice portion 22 may be the first surface 22a or the second surface 22b. The number, shape, size, etc. of the through-holes 22c formed in the lattice portion 22 are not particularly limited, and are appropriately set within a range in which the active material can be appropriately retained.

In the grid portion 22, at least one of the plurality of through holes 22c has a different opening area on the first surface 22a and an opening area on the second surface 22b. In this case, the lattice portion 22 may be formed with through holes 22c in which the opening area on the first surface 22a and the opening area on the second surface 22b are the same. Moreover, either the opening area on the first surface 22a or the opening area on the second surface 22b may be larger or smaller.

Here, the opening area on the first surface 22a and the opening area on the second surface 22b are defined as follows. Let the surface of the first surface 22a be a first reference surface, and let the surface of the second surface 22b be a second reference surface. Since the first surface 22a and the second surface 22b are parallel to each other, the first reference plane and the second reference plane are also parallel to each other. If the first surface 22a and the second surface 22b are slightly uneven due to manufacturing errors or the like, the surfaces excluding the unevenness are defined as the first reference surface and the second reference surface. Then, the opening of the through hole 22c on the first reference plane and the second reference plane is the opening of the through hole 22c on the first surface 22a and the second surface 22b, and the opening area is the first surface 22a and the second surface 22b. The opening area in

As described above, in the lattice body 21 according to the present embodiment, when it is used as the electrode plate of the lead-acid battery 1, the active material is held on the first surface 22a, the second surface 22b, and the plurality of through holes 22c. However, since the first surface 22a and the second surface 22b are parallel to each other, the active material easily falls off from the first surface 22a and the second surface 22b. However, in at least one of the plurality of through-holes 22c passing through the first surface 22a and the second surface 22b, the opening area on the first surface 22a and the opening area on the second surface 22b are different. It becomes difficult to fall off from 22c. This can prevent the active material from falling off.

Moreover, in the lead-acid battery 1 according to the present embodiment, since the grid 21 is used as the positive grid 12 and the negative grid 14, it is possible to prevent the positive electrode active material 13 and the negative electrode active material 15 from coming off.

The present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the gist of the present invention.

For example, in all of the plurality of through holes 22c, the opening area on the first surface 22a and the opening area on the second surface 22b may be different. In this case, the grid portion 22 does not have the through holes 22c in which the opening area on the first surface 22a and the opening area on the second surface 22b are the same. Moreover, like the lattice part 22B of the lattice body 21A of the modified example shown in FIG. and the through holes 22c having an opening area smaller than that of the second surface 22b. In this way, in all of the plurality of through-holes 22c, the opening area on the first surface 22a and the opening area on the second surface 22b are different, thereby further suppressing the fallout of the active material.

Also, in all of the plurality of through holes 22c, the opening area on the first surface 22a may be larger than the opening area on the second surface 22b. In this case, the grid portion 22 does not have through holes 22c whose opening area on the first surface 22a is smaller than the opening area on the second surface 22b. In this way, in all of the plurality of through-holes 22c, the opening area on the first surface 22a is larger than the opening area on the second surface 22b, so that the lattice body 21 can be easily formed, By filling the active material from the first surface 22a side, the filling property of the active material into the grid 21 is improved.

Also, the total opening area of the plurality of through holes 22c on the first surface 22a may be larger than the total opening area of the plurality of through holes 22c on the second surface 22b. The total opening area of the plurality of through-holes 22c on the first surface 22a is the sum of the opening areas of the through-holes 22c on the first surface 22a, and the total opening area of the plurality of through-holes 22c on the second surface 22b is , is the sum of the opening areas of the through-holes 22c on the second surface 22b. In this case, like the lattice portion 22A of the lattice body 21A shown in FIG. The through holes 22c having an area smaller than the opening area of the second surface 22b may be mixed. Thus, by making the total opening area of the plurality of through-holes 22c on the first surface 22a larger than the total opening area of the plurality of through-holes 22c on the second surface 22b, the active material as a whole difficult to fall off from.

In addition, in the cross section in the direction orthogonal to the first surface 22a and the second surface 22b, the inner wall surfaces of the plurality of through holes 22c may be formed linearly, but the lattice of the modified example shown in FIG. Like the grid portion 22B of the body 21B, at least one inner wall surface of the plurality of through holes 22c may be formed with a recess 22d into which the active material enters. In this case, recesses 22d may be formed in all the inner wall surfaces of the plurality of through holes 22c. In addition, not only the concave portion 22d but also the convex portion may be formed, so that the entire surface may be uneven. The number, shape, size, and the like of the recesses 22d are not particularly limited, and can be appropriately set as long as the active material can enter. By forming the recess 22d on the inner wall surface of at least one of the plurality of through holes 22c in this manner, the recess 22d is formed on all the inner wall surfaces of the plurality of through holes 22c. As a result, the active material enters into the recess 22d. Thereby, it is possible to further prevent the active material from falling off.

Moreover, in the cross section in the direction perpendicular to the first surface 22a and the second surface 22b, the inner wall surface of each of the plurality of through holes 22c may be formed linearly. Like the grid portion 22C of the body 21C, at least one of the plurality of through holes 22c includes a first tapered portion 22e that spreads to reach the first surface 22a and a second tapered portion 22f that spreads to reach the second surface 22b. , may be used. The opening area of the first surface 22a and the opening area of the second surface 22b change as the inclination angle θ1 of the first tapered portion 22e and the inclination angle θ2 of the second tapered portion 22f increase, or And, the larger the second taper portion 22f, the larger it becomes.

In this case, each of the plurality of through holes 22c, that is, all of the plurality of through holes 22c may have the first tapered portion 22e and the second tapered portion 22f. In the first tapered portion 22e, the through-hole 22c extends to the first surface 22a while being inclined in a widening direction with respect to the first surface 22a in a cross section perpendicular to the first surface 22a. Similarly, in the second tapered portion 22f, the through-hole 22c extends to the second surface 22b while being inclined in a widening direction with respect to the second surface 22b in a cross section orthogonal to the second surface 22b. In addition, in the cross section in the direction perpendicular to the first surface 22a and the second surface 22b, the first tapered portion 22e and the second tapered portion 22f do not necessarily have to be linear as long as they have a tapered shape as a whole. , may be curved or uneven. Thus, at least one of the plurality of through-holes 22c has the first tapered portion 22e and the second tapered portion 22f, so that the active material filled in the through-holes 22c spreads over the first surface 22a and the second tapered portion 22f. It becomes the shape which spreads out on both sides of the surface 22b. That is, the active material has a shape that sandwiches the lattice portion 22C of the lattice body 21C from both sides of the first surface 22a and the second surface 22b. Therefore, it is possible to further prevent the active material from coming off.

By the way, in the positive electrode lattice, as the charge and discharge are repeated, the bonds between the active materials become weaker (softening phenomenon). does not occur. Therefore, the lattice 21 may be used only as the positive electrode lattice 12 . As a result, it is possible to efficiently prevent the active material from coming off.

DESCRIPTION OF SYMBOLS 1... Lead-acid battery, 2... Battery case, 3... Lid, 4... Positive electrode terminal, 5... Negative electrode terminal, 6... Liquid port plug, 7... Electrode group, 8... Positive electrode column, 9... Positive electrode plate, 10... Negative electrode plate, DESCRIPTION OF SYMBOLS 11... Separator 12... Positive electrode grid 12a... Grid part 12b... Ear part 13... Positive electrode active material 14... Negative electrode grid part 14a... Grid part 14b... Ear part 15... Negative electrode active material 16... Positive electrode side strap 17 Negative electrode side strap 21, 21A, 21B, 21C Grid body 22, 22A, 22B, 22C Grid portion 22a First surface 22b Second surface 22c Through hole 22d .

Claims (4)

A lattice body that is used for the electrode plate of a lead-acid battery and contains lead and has the same overall thickness ,
a first surface and a second surface parallel to each other;
a plurality of through holes penetrating the first surface and the second surface,
In at least two of the plurality of through-holes, the opening area on the first surface and the opening area on the second surface are different,
At least two of the plurality of through-holes have a first tapered portion that extends to the first surface and a second tapered portion that extends to the second surface,
grid. A grid containing lead used for the electrode plate of a lead-acid battery,
a first surface and a second surface parallel to each other;
a plurality of through holes penetrating the first surface and the second surface,
In at least one of the plurality of through-holes, the opening area on the first surface and the opening area on the second surface are different,
The plurality of through-holes include a through-hole having an opening area on the first surface larger than the opening area on the second surface and a through-hole having an opening area on the first surface smaller than the opening area on the second surface. a through-hole comprising
grid. At least one of the plurality of through-holes has a first tapered portion that extends to the first surface and a second tapered portion that extends to the second surface,
3. The grid according to claim 2 . The grid according to any one of claims 1 to 3 is used as the grid for at least one of the positive electrode plate and the negative electrode plate,
lead-acid battery.

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