JPS5819868A - Manufacture of grid for lead storage battery - Google Patents

Abstract

PURPOSE:To increase the adhesiveness between a grid and an active material by introducing a lead alloy sheet between rollers, which have irregular surfaces formed by making particles with a given hardness to adhere to the surface of a base roll, before the said lead alloy sheet is subjected to expanding work. CONSTITUTION:Before a lead alloy sheet 2 is introduced into a grid-formation expanding device 5, the sheet 2 is introduced between a pair of irregularity-formation rollers 3 so as to form irregularities over the surfaces of the sheet 2. Here, the roller 3 is made by subjecting the surface of an iron-steel roll to sandblasting to make a base, and coating the roll with alumina particles by fusing pulverized alumina powder to the base by plasma-arc welding so as to form irregularities over the surface. By the means mentioned above, highly dense irregularities can be easily provided over the sheet 2. Consequently, the cycle life of a battery can be increased by highly improving the adhesiveness between a grid and an active material by subjecting thus treated sheet 2 to expanding work to make the grid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to surface treatment of a lattice body in a method for manufacturing a lattice body for a lead-acid battery in which the lattice body is manufactured by mechanically processing a lead alloy sheet.

Conventionally, a book mold type casting method has been used to manufacture grid bodies for lead-acid batteries, but in response to recent demands for maintenance-free, smaller and lighter batteries, especially automobile batteries, the casting method has been adopted. Highly productive methods of continuously machining sheets of lead alloys, such as expand processing and punching methods, are being adopted.

However, in the above machining method, since a roll-finished lead alloy sheet with a fairly smooth surface is used as the material, the surfaces of the four sides of the bones of the manufactured lattice body are quite smooth, and the lattice body and active material are This has the disadvantage of poor physical interlocking and spring attachment, resulting in short battery life.

The purpose of the present invention is to remove the defects of the lattice body formed by the above-mentioned machining method, especially the expanded process, and to eliminate the unevenness of the expanded lattice body surface during the continuous and penetrating manufacturing process. By increasing the physical interlocking between the lattice and the active material and improving the adhesion, it ensures the exchange of electrons at the lattice-active material interface for a long period of time during battery charging and discharging. As a result, it is an object of the present invention to provide a grid body that can improve battery life performance.

The present invention is a method of creating a highly uneven surface on the surface of an expanded lattice body. Before the expanded process, a lead alloy sheet is used to adhere particles having appropriate hardness and shape almost uniformly. and place the particles on a roller having unevenness formed by the particles on the surface,
The purpose is to continuously compress the surface to the required degree of unevenness.

In the present invention, in a continuous process, the surface of the die that is used for IIK, which is expanded to form a lattice body, and the opposite surface are both rolled by the roller (K). The above two surfaces of the lead alloy sheet are the four sides of the bone of the band-like lattice body after being expanded.
This corresponds to the two sides that form the inner surface of the mass of the lattice body, and these two sides form a shape ζ that surrounds the active material, thus holding the active material best. In addition, in the present invention, the method utilizes the unevenness formed by the bond between particles attached to the roller and the degree of stacking, rather than adding unevenness to the roller itself, but the generally used steel roller itself In order to form unevenness on a roller, there are methods such as applying a heavy load with a highly hard material, partially melting it with a high-temperature heat source, or making the roller itself by forming unevenness on a mold and casting. In either case, it is difficult to create dense irregularities that match the inventive idea. On the other hand, the degree of unevenness of the grid that effectively improves battery life performance varies depending on the required battery performance ζ, but in the depth direction of the unevenness,
The width of the opening is approximately 1ζ-αO35wm to 0.08 mm. Furthermore, the compression by the rollers should be carried out within a range that does not exceed the dimensions of the above-mentioned irregularities, and desirably, the compression should be carried out so that a space can be secured in which the lead alloy compressed by the convex parts of the rollers can escape through plastic deformation. be. Blackboard ζ
If the sheet is compressed beyond the above range, the length and width dimensions of the sheet will change, making it impossible to obtain the designed lattice body in subsequent expansion processing.

An embodiment of the present invention will be described.

FIG. 1 shows an outline of the method of the present invention for forming irregularities on the surface of a lead alloy sheet. Rolled stock lead alloy sheet (alloy composition: 0.8 wt% Ca, 0.5
Lead alloy sheet 2 (weight 158n, balance Pb) supplied (width 1ows).

Expanding processing device S for forming a grid (thickness LO)
Before entering lζ, expand sheet 2! While moving IIC, the upper number ζ of the pair of unevenness forming rollers 3 is moved to form unevenness on the surface of the sheet 2. The sheet 4 on which the irregularities have been formed is then subjected to an expansion process by an expansion device SK, and becomes a strip-like grid body 6.

Next, the unevenness forming roller 3 is formed by the following method. The roller itself is made of ordinary steel and processed to the extent that it can be used as a finishing roll, but after sandblasting the surface to prepare a base, fine powder of alumina (purity S East 99-) is applied to that part. (average particle size 10 μm) is thermally sprayed by plasma spraying to coat the surface of the roller with alumina particles. At this time, unevenness is formed depending on the degree of bonding and stacking of alumina particles, but the degree of unevenness was adjusted by changing the distance between the thermal spray nozzle and the sprayed surface so that the degree of unevenness was O, OS- on average. . Further, thermal spraying was carried out while sequentially measuring the thickness so that the thickness of the coating layer became uniform - ζ, and the final thickness of the coating layer was about 3 m.

The sheet 2 was compressed using the pair of unevenness forming rollers 3 thus created, and the distance between the rollers 3 at that time was 0.95 m from convex surface to convex surface.

The compression rate for sheet 2 was set at 5tlIpc. The second diagram shows the relationship between the sheet 2 and the unevenness forming roller 3.
FIG. 2 is a sectional view taken along the line am' in FIG. 1.

The set compression interval means that the unevenness of the roller 3 will cause the sheet 2 to fall from both sides.
The rollers 3 and 3 are designed to bite into each other by α025cm, and an escape space 7 is secured when the sheet 2 is compressed and the lead alloy is pushed away by the convex portions of the rollers 3.

In this way, the sheet 4 on which unevenness and convexity are formed is expanded to become a band-like lattice body 6.
Figure 3 shows an enlarged view of the main parts.

The uneven surface of the sheet 4 becomes two sides 8 of the four sides of the ribs of the strip-shaped lattice body 6, which form the inner surface of the mass. The upper band-like grid body 6 is then cut to the size of the battery grid body, and the portion 6 that is not expanded as shown in FIG.
Cut so that the ears become the lattice body.

The battery cycle life of the expanded lattice body that was continuously manufactured using the method described above was compared with that of a conventional lattice body that was simply expanded. The electrode plates were made using a conventional method.1 The above lattice was filled with paste, aged, and chemically formed to have dimensions W145-XH111.The test battery consisted of 5 anode plates and 6 cathode plates of these plates. are arranged alternately through separators, and the open circuit voltage t
This is an OV battery. Charge/discharge cycle conditions are discharge 10A,
1 & 5 minutes, charging is ZSV constant voltage charging (limited current 2s)
After 11 minutes, the capacity was checked during the cycle by completely discharging the IOA. FIG. 4 shows the change in discharge capacity of the battery during the above charge/discharge cycle. As can be seen from Figure 4,
A battery using an expanded lattice body in which irregularities are continuously and efficiently formed on the lattice body by the method of the present invention is different from a conventional battery B using a p-lattice body that has been simply expanded.
It has a much longer lifespan. Therefore, it can be seen that the surface treatment method according to the present invention is extremely effective in improving battery life performance.

As described above, according to the present invention, the adhesion between the active material and the lattice body is improved, the battery life is greatly improved, and the lattice body can be produced in a continuous process, which has industrial value. It's large.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the manufacturing process in a method for manufacturing a lead-acid battery lattice body showing an embodiment of the present invention, and FIG. 2 is a diagram of a of FIG.
3 is an enlarged perspective view of the main part of the strip-shaped lattice body, and FIG. 4 is a graph showing the relationship between charge/discharge cycles and battery discharge capacity of the product of the present invention and the conventional product. 2 is a lead alloy sheet, 3 is a pair of unevenness forming rollers, and S is an extension processing device patent applicant Shin-Kobe Electric Machinery Co., Ltd.

Claims (1)

[Claims] In a method of manufacturing a lattice body for a lead-acid battery by expanding a lead alloy sheet, the surface of the lead alloy sheet is coated with particles having a certain hardness almost uniformly to form irregularities before being expanded. on a roller that has a
A method for manufacturing a grid for lead-acid batteries, comprising a step of continuously compressing to a certain degree of unevenness.