JP2011048911A - Grid substrate for lead-acid battery and lead-acid battery using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grid substrate for a lead-acid battery which has a good filling property of a paste-type active material on the opposite side of a filling surface without exposing an inside frame, as well as the lead-acid battery using the same. <P>SOLUTION: The grid substrate for the lead-acid battery is provided with a frame bone 1, a vertical bone and a horizontal bone which form the grid, and are arranged inside the frame bone. The thickness of the vertical bone and/or the horizontal bone is made thinner than the thickness of the frame bone 1, and all of the vertical bone and the horizontal bone are made within a thickness range of the frame bone 1, and are separated from one of the faces formed by the frame bone 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a grid substrate for a lead storage battery and a lead storage battery using the grid substrate.

Batteries are roughly classified into primary batteries represented by manganese, mercury, alkali and the like, and rechargeable secondary batteries represented by lead, nickel-cadmium, lithium ion, nickel-hydrogen and the like.
At present, since it is frequently used in mobile phones and the like, development of small and high-performance batteries such as lithium ion batteries and nickel metal hydride batteries as next-generation secondary batteries is progressing.
On the other hand, the lithium ion battery and the nickel-hydrogen battery are disadvantageous in terms of price, and in particular, the former requires sufficient consideration in terms of safety. Lead-acid batteries are mainly used in industrial batteries for instantaneous voltage drop countermeasures, automobile batteries, and the like.

There are two types of electrode plates for lead-acid batteries: Tudor type, Cladding type, Paste type, etc. Among them, the paste type electrode plate is often used because of its high productivity and low cost.
This paste-type electrode plate (hereinafter referred to as “electrode plate”) has an active material using a paste-like lead compound or the like attached to a lattice substrate formed of lead or a lead alloy, and is further aged and dried. Is produced.

  As described above, the lattice substrate has a structure as shown in FIG. 1 for the purpose of holding the paste-like active material. The lattice substrate 5 is formed by disposing the longitudinal bones 2 and the lateral bones 3 in a lattice shape inside the frame bone 1 and providing the ears 4 thereon. Then, the lattice substrate 5 is filled with an active material and held.

  Usually, the filling of the active material is performed by applying the pressure to the paste-like active material from the filling surface of the lattice substrate 5 by passing the lattice substrate 5 through a paste filling machine, and applying a roller to the filling surface. The active material applied from the filling surface of the lattice substrate 5 is also caused to wrap around the back side of the lattice substrate 5.

However, in the filling of the active material, the paste-like active material wraps around the back side of the lattice substrate 5 due to the properties of the paste, and the bones inside the frame bone (vertical bone 2 and horizontal bone 3) may be exposed. . The exposure of the inner bone not only lowers the adhesion between the lattice substrate and the active material, but also promotes lead sulphate conversion of the inner bone, resulting in a concern that the battery life may be shortened.
Therefore, in order to prevent the exposure of the inner bone, a method of preliminarily arranging the inner bone in the direction of the filling surface and pushing the inner bone in the direction opposite to the filling surface by filling with the active material to prevent the bone from being exposed. Has been performed (see Patent Document 1).

JP 02-114451 A

  However, although the structure of the lattice substrate described in Patent Document 1 can be applied to a thin lattice substrate or a thin lattice substrate with a thin inner bone, the inner bone is easily deformed by filling of the active material, but the thick lattice substrate or the inner In the lattice substrate having a thick bone, the inner bone is not pushed out by the pressure at the time of filling, and remains in an eccentric arrangement before filling. In such a state, the bone on the filling surface side is likely to be exposed, and the paste-like active material wraps around on the side opposite to the filling surface, so that the bone is easily corroded, and the bone and the active material are not corroded. In addition, there is a problem that the conductivity is lost because lead sulfate is easily generated.

  Also, when filling a high-density paste-like active material to extend the cycle life, because the paste is hard, the biased inner bone is deformed to the center in the grid substrate thickness direction after filling. However, the wraparound of the paste-like active material on the opposite side is not improved.

  The present invention provides a lead-acid battery grid substrate and a lead-acid battery using this grid substrate, which have good filling properties of the pasty active material on the opposite side of the filling surface without exposing the inner bone. The purpose is to do.

The present invention relates to the following.
(1) A frame bone, and a vertical bone and a horizontal bone which are arranged inside the frame bone and form a lattice are provided. The longitudinal bone and / or the lateral bone is thinner than the frame bone. A lead-acid battery grid substrate in which all of the vertical bones and horizontal bones are within the range of the thickness of the frame bones and are spaced apart from one surface formed by the frame bones.
(2) The grid substrate for a lead storage battery according to item (1), wherein the vertical bone and / or the horizontal bone are a mixture of a thick bone and a thin bone having different bone diameters.
(3) A lead storage battery using the lead substrate for a lead storage battery according to (1) or (2).

In the lattice substrate for lead storage battery of the present invention, the thickness of the longitudinal bone and / or the lateral bone disposed inside the frame bone is thinner than the thickness of the frame bone, and the longitudinal bone and the lateral bone are frame bones. One surface to be formed is spaced apart. Therefore, the paste-like active material pushed out from the filling surface can easily pass through the separated portion, and the active material is exposed without exposing the longitudinal bone and the lateral bone on the surface (one surface) opposite to the filling surface. Can be covered.
Further, even when the longitudinal bone and the lateral bone have a thickness close to that of the frame skeleton, the longitudinal bone and the lateral bone do not move to the central portion after the filling of the active material. Filling with a substance is also possible.
When the vertical and / or horizontal bones are mixed with thick and thin bones with different bone diameters, the active material is prevented from falling off the electrode plate, and the corrosion resistance and ease of wrapping of the active material are excellent. .
Furthermore, the lead-acid battery of the present invention does not shorten the battery life without exposing the vertical and horizontal bones.

It is a top view of the conventional lattice board | substrate. It is sectional drawing of a lattice board | substrate. It is sectional drawing of the lattice board | substrate which concerns on this invention. 2 is a cross-sectional view of a lattice substrate A. FIG. 3 is a cross-sectional view of a lattice substrate B. FIG. 2 is a cross-sectional view of a lattice substrate C. FIG. 2 is a cross-sectional view of a lattice substrate D. FIG. It is the schematic of the filling apparatus used for the present Example. It is a 60 degreeC trickle life test result.

(Frame bone)
The frame bone described in the present invention forms the outer frame (outer shape) of the lattice substrate, and the shape is not limited, but the inner shape of the outer case of the lead storage battery to be used finally. More specifically, a material that is square or rectangular in plan view can be used.
The cross-sectional shape of the frame bone is not particularly limited, but a rhombus or hexagon having a large contact area with the active material is desirable in order to improve the adhesion with the active material.
The thickness of the frame bone is equal to the thickness of the lattice substrate (the substrate before being filled with the active material), and does not necessarily mean the maximum thickness of the frame bone. The thickness of the frame bone is not particularly limited, but preferably about 1 to 6 mm. This is because when the thickness is less than 1 mm, the physical strength is insufficient, the handling at the time of manufacture is deteriorated, and it is difficult to produce by the gravity casting method. Conversely, in the case of a grid substrate thicker than 6 mm, it becomes difficult to uniformly fill the paste-like active material up to the back surface without exposing the bone.
The material of the frame bone is lead as a main raw material, and tin, calcium, antimony, etc. can be used as the alloy material for this, and it is preferable to use both tin and calcium. This is because when calcium is added, the rate of self-discharge can be reduced, and the addition of tin suppresses the susceptibility to bone corrosion, which is a problem when calcium is added. It is because it can do.

(Longitudinal and transverse bones)
The longitudinal bone and the lateral bone described in the present invention are arranged so as to form a lattice inside the frame bone described above (inside the region divided by the frame bone). Bone arranged in parallel to the long dimension direction is called a longitudinal bone, and a bone arranged in a perpendicular direction is called a horizontal bone.
The vertical and horizontal bones maintain the outer shape of the frame bone and carry the active material described later, and the number of arrangement is within a range in which the outer shape of the frame bone is not deformed and the active material is not dropped off. Can be set arbitrarily.

It is not necessary to use the same thickness for the longitudinal bone or the transverse bone, and it is possible to use a thick bone and a fine bone that is thinner than this thick bone. It is preferable to arrange one or a plurality of thin bones between the thick bones and the thick bones so that they are not continuously arranged. This is because the thin bones 7 and 7 are arranged between the thick bones 6 and 6, as shown in FIG. 2B, rather than the thick bones 6 being continuously arranged as shown in FIG. 2A. This is because the active material is more likely to wrap around the back surface of the lattice substrate.
The thickness of the thin bone does not necessarily need to be one type, and a plurality of types can be used that are thinner than the thickness of the thick bone.
In addition, the longitudinal bone and the lateral bone can be arranged with either the thick bone or the thin bone only in one of them, and the other can have the same thickness. Both of them preferably have thick bones and thin bones.
The thickness described here indicates a diameter when the cross-sectional shape of the bone is circular, and is defined as an average value of the maximum length and the minimum length when the cross-section of the bone is non-circular.

All of the longitudinal and lateral bones are arranged within the thickness of the frame bone. That is, the vertical bone and the horizontal bone are arranged in a region formed by two surfaces in the thickness direction formed by the frame bone, and do not protrude outward from the region. Therefore, when the active material is filled, the frame bone portion supports the force from the roller, so that no local stress is applied to the longitudinal bone and the lateral bone, and there is no portion protruding from the active material.
Further, the longitudinal bone and the lateral bone are all arranged so as to be separated from one surface formed by the frame bone.
One surface described here is one of the two surfaces in the thickness direction formed by the frame bone described above. More specifically, as shown in FIG. It is any one surface of the upper surface or lower surface formed by the upper end and lower end which are. And this one surface turns into the surface facing the filling surface 8 at the time of filling with an active material, and the active material with which it filled from the filling surface goes around easily by providing separation.
The vertical bone and the horizontal bone are spaced apart from one of the surfaces described above, but are not necessarily spaced from the other surface (filling surface 8) and are flush with the filling surface. It can also be arranged. When arranged in this way, when filling the active material, the pressure from the roller can be distributed not only to the frame bone but also to the vertical bone and / or the horizontal bone, making it easier to prevent deformation of the lattice substrate. .

  The cross-sectional shapes of the longitudinal bone and the lateral bone are not particularly limited as in the case of the frame bone, but a rhombus or hexagon having a large contact area with the active material is desirable in order to improve the adhesion with the active material. Further, the cross-sectional shapes of the longitudinal bone and the lateral bone are not necessarily the same.

  The material of the vertical bone and the horizontal bone may be the same as or different from the frame bone described above, but the frame bone, the vertical bone and the horizontal bone can be easily formed integrally. It is preferable to use the same one.

(Lattice substrate manufacturing method)
The lattice substrate can be manufactured by various methods, and a gravity casting method (GDC: Gravity Die Casting), a continuous casting method, an expanding method, a punching method, or the like can be used, but it is preferable to use a gravity casting method. . This is because there is no theoretical limit to the thickness of the grid that can be cast, and it is easy to manufacture a grid substrate having both thick and thin bones, and it has excellent current collecting characteristics and corrosion resistance. .
The gravity casting method will be described in more detail. The raw material metal (alloy) of the lattice substrate is melted, and the molten metal (alloy) is poured by gravity into a mold that can withstand the molten metal (alloy) and cast. The lattice substrate can be formed at high speed.

(Active material)
The above-described lattice substrate is loaded with an active material to form an electrode plate. The active material is not particularly limited, but kneaded lead powder containing lead monoxide, water, sulfuric acid, etc. (cut fiber, carbon powder, lignin, barium sulfate, lead tan etc. according to the characteristics of the positive electrode and negative electrode) The additive may be added in some cases.

(Filling of active material)
The filling of the active material can be performed by various methods. The paste-like active material applied with pressure to the lattice substrate is pushed out of the filling machine, and this active material is pushed by a roller. Thus, the exposure can be performed without exposing the longitudinal bone and the lateral bone.

Embodiments of the present invention will be described below with reference to the drawings.
(Production of lattice substrate)
Lead alloy with 1.6% by mass of tin and 0.08% by mass of calcium added to lead to melt the entire mixture to 100% by mass is used for the positive electrode by gravity casting using four different molds. The lattice substrate A, the lattice substrate B, the lattice substrate C, and the lattice substrate D were prepared.

<Example 1: Lattice substrate A>
The size of the lattice substrate A was prepared with a length of 385 mm, a width of 140 mm, and a thickness of 5.8 mm. In addition, the vertical and horizontal bones formed inside the frame bone have thick and thin bones, and the cross-sectional shape is a hexagon that is long in the vertical direction, as shown in FIG. , Height: 5.6 mm, width: 4.3 mm, and thin bone 7 have a height: 3.6 mm and a width: 3.4 mm.
It should be noted that the height of the frame bone 1 and the thick bone 6 is flush with the upper surface in the thickness direction, that is, the filling surface 8, and the difference in height between the frame bone 1 and the thick bone 6 on the opposite surface of the filling surface is 0.2 mm.

<Example 2: Lattice substrate B>
The size of the lattice substrate B was prepared such that length: 385 mm, width: 140 mm, and thickness: 5.8 mm. Further, the vertical and horizontal bones formed inside the frame bone have thick and thin bones, and the cross-sectional shape is a hexagon that is long in the vertical direction, as shown in FIG. , Height: 5.4 mm, width: 4.3 mm, and fine bone 7 have a height: 3.6 mm and a width: 3.4 mm.
It should be noted that the height of the frame bone 1 and the thick bone 6 is flush with the upper surface in the thickness direction, that is, the filling surface 8, and the difference in height between the frame bone 1 and the thick bone 6 on the opposite surface of the filling surface is 0.4 mm.

<Comparative Example 1: Lattice substrate C>
The size of the lattice substrate C was prepared such that length: 385 mm, width: 140 mm, and thickness: 5.8 mm. Further, as shown in FIG. 6, the cross-sectional shapes of the longitudinal bone and the lateral bone formed inside the frame bone are hexagons that are long in the vertical direction, and all the longitudinal and lateral bones have a height of 3 .2 mm, width: 2.4 mm.
Note that the longitudinal bone and the lateral bone are not flush with the upper surface and the lower surface formed by the frame bone 1 and are lower than both surfaces.

<Comparative Example 2: Lattice substrate D>
The size of the lattice substrate D was prepared with a length of 385 mm, a width of 140 mm, and a thickness of 5.8 mm. Further, in the vertical bone and the horizontal bone formed inside the frame bone, there are a thick bone and a thin bone, and the cross-sectional shape is a hexagon that is long in the vertical direction, as shown in FIG. The height: 5.8 mm, the width: 4.3 mm, and the fine bone 7 are the height: 3.6 mm and the width: 3.4 mm.

(Confirmation of fillability of active material)
An active material filling experiment was performed on the above-described lattice substrates A, B, C, and D using a filling machine having a structure shown in FIG. 8 and then aging and drying were performed. A chemical positive plate was prepared.
The active material used was prepared by the following steps.
The mass of the lead powder containing lead monoxide as a main component is 100% by mass, 0.1% by mass of polyester fiber is added and mixed, and then 12% by mass of water and 16% by mass of dilute sulfuric acid are added and kneaded again. Thus, a paste-like active material for the positive electrode was produced.

(Filling result)
Table 1 shows the results obtained by filling the above-described pasty active material into 100 lattice substrates A, B, C, and D, respectively, and visually recognizing the backside of the active material.
Note that “unsuitable reverse” means that the paste-like active material is not reversed and a part of the longitudinal bone or the lateral bone is exposed.
The filling of the active material is performed when the lattice substrate 5 is set on the filling belt 10 that is moved by the rotating roller 9 and reaches the position immediately below the hopper 12 that houses the paste-like active material 11. The work roll 14 is rotated to push the pasty active material 11 against the lattice substrate 5.
Then, the lattice substrate 5 is pressed down on the portion of the paste-like active material 11 by a roller (not shown) so that the paste-like active material is turned around.

As shown in Table 1 above, in Examples 1 and 2, the back is good and the active material was supported on 100 lattice substrates. It was not exposed and could be covered with the active material.
In Comparative Example 1, the thickness of the bone was thinner than in Examples 1 and 2 and therefore there was no unsuitable reverse side. However, in Comparative Example 2 in which the bone was thick, the reverse side unsuitable was 27%. It has occurred.
That is, it can be understood that in the case of a lattice substrate having a thick bone, the inappropriateness of the back side can be greatly reduced by the present invention.

(Production of control valve type lead acid battery)
A method for producing two types of control valve type lead-acid batteries using the above-described lattice substrate A and lattice substrate C will be described below.
In the positive electrode plate, the active material produced by the above-described method was filled in the electrode plate lattices A and C, and aged and dried.
Moreover, what was produced with the method shown below was used for the negative electrode plate.
The negative electrode plate was prepared by melting a lead alloy prepared by adding tin: 0.2% by mass and calcium: 0.1% by mass to make the whole mixture 100% by mass, and longitudinally: 385 mm, laterally: 140 mm, by a gravity casting method. A lattice substrate having a thickness of 3.0 mm (cross-sectional shape: a hexagon having a height of 2.6 mm and a width of 1.8 mm in which all bones of a longitudinal bone and a transverse bone are formed) was prepared. On this lattice substrate, lignin: 0.2% by mass, barium sulfate: 0.1% by mass with respect to the mass of lead powder mainly composed of lead monoxide, carbon powder such as ordinary commercially available graphite: 0.2% by mass, polyester fiber: 0.1% by mass is added and mixed. Next, after adding 12% by mass of water and kneading, the paste-like active material kneaded again by adding 13% by mass of dilute sulfuric acid was filled. After the filling, it was aged and dried to obtain a negative electrode plate.
The above-described positive electrode plate and negative electrode plate are alternately laminated one by one with a separator in between, and the same electrode plates are connected with a strap to produce an electrode plate group consisting of 24 positive electrode plates / 25 negative electrode plates. did. This electrode plate group was put in a battery case, diluted sulfuric acid was injected, and chemical conversion was performed to produce a 2V-1500 Ah control valve type lead storage battery.
Each battery used what was mentioned above in common about the negative electrode plate, and produced the batteries A and C which used the positive electrode plate with the lattice board | substrate A and the lattice board | substrate C, respectively.

(Control valve type lead-acid battery life test)
A trickle life acceleration test (constant voltage charging voltage: 2.23 V) in accordance with JIS-C 8704-2-1 was conducted in a constant temperature bath of 60 ° C. using each of the batteries prepared above (lead storage battery has an air temperature of 60 1 month in ℃ is equivalent to one year at 25 ℃) Moreover, the battery measured the 0.25CA discharge capacity in a 25 degreeC environment every month, and confirmed the transition of discharge capacity.

(Life test result)
FIG. 9 shows the results of a 60 ° C. trickle life test. The battery C produced in Comparative Example 1 passed the life in about 11.5 months, whereas the battery A produced in the electrode plate of Example 1 was about 18.5 months and about 1.6 times longer in life. Met. When the battery C which had reached the end of its life was disassembled, the positive electrode plate was severely stretched by corrosion, and it was found that this was the cause of the life. That is, in the lattice substrate C, it can be understood that the battery life is short although the reverse is good.
From the above results, it can be seen that the lattice substrate of Example 1 can provide a long-life lead-acid battery that is excellent in fillability of the active material paste.

DESCRIPTION OF SYMBOLS 1 ... Frame bone, 2 ... Vertical bone, 3 ... Horizontal bone, 4 ... Ear part, 5 ... Lattice substrate, 6 ... Thick bone, 7 ... Fine bone, 8 ... Filling surface, 9 ... Rotating roller, 10 ... Filling belt, DESCRIPTION OF SYMBOLS 11 ... Paste-like active material, 12 ... Hopper, 13 ... Rotary blade, 14 ... Paste supply roll

Claims (3)

A frame bone, and a longitudinal bone and a horizontal bone arranged inside the frame bone and forming a lattice,
The vertical bone and / or horizontal bone is thinner than the frame bone,
A lead-acid battery grid substrate in which all the vertical bones and horizontal bones are within the thickness range of the frame bones and are spaced apart from one surface formed by the frame bones.   The lead-acid battery grid substrate according to claim 1, wherein the vertical bone and / or the horizontal bone are a mixture of a thick bone and a thin bone having different bone diameters.   The lead acid battery using the grid | lattice board | substrate for lead acid batteries of Claim 1 or 2.

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