JPS6151379B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a battery active material filling device that continuously fills a moving foamed metal with a paste-like active material. A sponge-like porous metal body with a three-dimensional structure that has a series of voids.

An object of the present invention is to provide an apparatus for filling a moving foamed metal with a paste-like active material using a sliding jig, in which the flexibility (hardness) of a plurality of rubbing plates attached to at least one sliding jig is The purpose is to improve the filling efficiency of the active material by changing the

Conventionally, in lead-acid batteries, the main methods used to fill battery active materials into a substrate are to fill a porous substrate or grid with the active material in powder form, or to apply it in a paste form. has been done. On the other hand, alkaline batteries have also adopted a filling method similar to the above, or a method in which a sintered body is impregnated with a salt solution of an active material, and this is converted into an active material by electrolysis, thermal decomposition, chemical treatment, etc.

In such a method, in the case of a sintered body, it is necessary to repeat impregnation and conversion with the active material salt solution several times to 10 or more times, making the process complicated. On the other hand, a method in which a lattice, that is, a conductive porous body is used as a substrate, and a paste-like active material is applied to it,
Manufacture is simpler than the sintering method, and continuous manufacturing is possible by using a screen, expanded metal, perforated plate, etc. as the conductive porous body. However, in the paste type, the active material is bonded to the conductor using a binder, etc., so the electrical bond is weak.
Voltage and life characteristics, especially high rate discharge characteristics, etc. are slightly inferior to sintered bodies. For this reason, it has been considered to fill the sintered body with a paste-like active material, but in conventional sintered bodies, the pores are small and it is difficult to fill the active material and is not practical.

However, recently, sponge-like porous metal materials, ie, the foamed metals, have been attracting attention. In the case of this foamed metal, the porosity can be increased to over 90%, and the pore size can be changed freely.
The active material, conductive powder, binder, etc. are mixed to form a paste, which can be directly filled in a single operation. Therefore, the manufacturing process of impregnating and converting the active material with a salt solution, as in the case of a sintered body, is simplified. In addition, improvements in high rate discharge characteristics, life characteristics, etc. can be expected compared to conventional paste types.

However, filling this foamed metal with a paste-like mixture mainly consisting of active material powder is not the same as when applying it to the surface of a general two-dimensional screen, perforated plate, expanded metal, etc. In contrast, in order to fill the inside of a three-dimensional porous body, simply applying a paste mixture to the surface of a foam metal or passing it through a paste active material will not fill the foam surface. Even though it looks like it is, there is hardly any filling inside.

Therefore, in order to continuously fill a long strip of foamed metal with an active material, it is necessary to perform an operation in which gas or liquid in the voids of the foamed metal is replaced with the active material by mechanical means. It turned out that it does. Therefore, a method has been proposed in which a paste-like active material or powder is forcibly filled while reciprocating a rubber-like rubbing plate close to or in contact with the surface of the foamed metal.

However, in this method, if a rubber-like rubbing plate with relatively high flexibility is used, if the paste-like active material is soft, it will be filled well at the beginning of filling, but as it approaches the end of filling, it will be forcibly pushed. Furthermore, it is difficult to fill the active material in the form of a hard paste. In addition, using a hard rubbing plate with low flexibility is good for hard paste-like active materials and late-stage filling, but in the early stage, the parts that are not filled with active material will be rubbed strongly with the rubbing plate, so foamed metal It was found that the surface of the material was closed, making it difficult for the active material to be filled.

In view of the above, the filling device of the present invention improves the filling efficiency of the active material by using a sliding jig in which a plurality of rubbing plates are arranged and fixed so that the degree of flexibility is gradually reduced in the direction of movement of the foam metal. It is something to do.

The present invention will be explained below with reference to Examples.

FIG. 1 shows an active material filling device according to the present invention, in which 1 is a long strip of foamed metal that is continuously or intermittently filled in the direction of the arrow in the figure along guide rollers 2, 3, 4, and 5. Moving. 6 is a paste tank containing a paste-like active material 7; 8 is a porous support plate integrally provided in the upper opening; 9 is a stirrer provided in the tank 6; 10 is a driving motor for the stirrer; 9 is driven, the active material 7 in the tank 9 is stirred and the active material is supplied onto the foamed metal 1 moving on the porous support plate 8. Reference numeral 11 denotes a sliding jig main body, on the lower surface of which a plurality of rubbing plates 12 are arranged and attached, and the rubbing plates 12 are slid back and forth on the foamed metal 1 in its longitudinal direction by a crank jig 13. A plurality of these sliding jigs may be used.

FIG. 2 shows details of the sliding jig, and the rubbing plates 12 are arranged so that the degree of flexibility decreases in the direction of movement of the foamed metal 1. In this example, three rubbing plates each having the same degree of flexibility are used as a set.
The degree of flexibility is made to decrease in the order of 12a, 12b, and 12c. The degree of flexibility of each rubbing plate may be changed individually, but as in the above example, a plurality of rubbing plates having approximately the same degree of flexibility may be made into a set, and the degree of flexibility of each set may be made different.

Suitable materials for the rubbing plate include rubbers such as butyl rubber, neoprene rubber, and silicone rubber, and synthetic resins such as soft polyvinyl chloride and polyethylene. In order to vary the flexibility of the rubbing plates,
This can be done by changing the material or the thickness of the rubbing plate.

Next, a specific example will be explained.

As foam metal, porosity approximately 96%, length 5m,
Using foamed nickel with a width of 150 mm and a thickness of 3.0 mm, the active material paste is made by adding approximately 10% by weight of nickel powder as a conductive material to nickel hydroxide powder, and then adding water or an aqueous solution of carboxymethyl cellulose and stirring thoroughly. The internal volume of the paste tank is approximately 50. On the other hand, for the rubbing plates of the sliding jig, three sets of four butyl rubber plates with a width of 160 mm and the same thickness are used, and the thickness of each set of rubbing plates is 3.
The thicknesses were arranged in order of increasing thickness in the direction of movement of the foam metal: mm, 4 mm, and 5 mm. The amplitude of the sliding jig equipped with this rubbing plate is approximately 80 mm, and the moving speed is approximately 1
cycles/second, and the moving speed of the foam metal is 0.5
mm/sec.

After filling the paste under the above conditions, the paste was compressed to a thickness of 2.4 mm using a pair of rollers at a pressure of 500 kg/cm ² , and the average filling amount per 24 c.c. volume of the substrate was 25 g.

On the other hand, as a comparative example, the thickness of the rubbing plate was the same as 3 mm, and the other conditions were the same as above.
The average filling amount per 24 c.c. was 22 g. Therefore, the packing density of the example of the present invention is about 1.2 times that of the comparative example.

As described above, according to the present invention, the packing density of the active material is improved, which is advantageous for increasing the capacity of the battery, and the effect is particularly significant as the substrate becomes larger.

Although the example uses a nickel electrode,
The present invention can be applied to filling active materials such as cadmium, lead, and iron that can be in the form of a paste.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of a paste filling device used in an embodiment of the present invention, and FIG. 2 is a side view of its sliding jig. 1... Porous body, 7... Paste active material, 11
...Sliding jig, 12...Scrubbing plate.

Claims (1)

[Scope of Claims] 1. A sponge-like porous metal body having a three-dimensional structure having continuous voids is moved, and the upper surface of the porous metal body is moved together with a paste-like active material using at least one sliding jig. an apparatus for filling a porous metal body with the paste-like active material by rubbing the porous metal body, the apparatus comprising a plurality of rubbing plates whose hardness or thickness is changed in the direction of movement of the porous metal body and whose degree of flexibility is successively decreased; 1. A filling device for battery active material, characterized in that a sliding jig is used in which a sliding jig is arranged and fixed. 2. The battery active material filling device according to claim 1, wherein a paste-like active material filling container is provided below the sponge-like metal porous body through a porous support plate. 3. The battery active material filling device according to claim 1 or 2, wherein the rubbing plate is made of soft synthetic resin or rubber.