JPS6054742B2 - Manufacturing method of electrode plates for lead-acid batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to synthetic fibers added to the active material of electrode plates for lead-acid batteries.

Conventionally, the active material of the electrode plates for lead-acid batteries has a thickness of 2 to 5 denier and a length of 2 to 5 denier to prevent the active material from falling off during the electrode plate manufacturing process, the lead-acid battery assembly process, or the use of the lead-acid battery. For example, synthetic fibers made of a copolymer of acrylic and vinyl chloride, which have an acid resistance of about 0.5 to 3 mm, are mixed.

However, since the synthetic fibers described above have smooth surfaces, they have poor adhesion to the active material, and cannot be said to be sufficiently effective in preventing the active material from falling off.

Although the effect of adding synthetic fibers to prevent the active material from falling off can be expected to some extent by increasing the amount of synthetic fibers added or increasing the length,
On the other hand, there are limits to increasing the amount added or increasing the length because there is a risk of deterioration of the filler in the paste to the grid substrate, which may cause problems in the manufacturing process of the equipolar plate. be. Recently, attempts have been made to change the cross-sectional shape of synthetic fibers or process the fibers into waves, but these efforts have little effect and are often impractical. In view of the above points, the present invention aims to improve adhesion with the active material by retaining powder of a lead compound used as a raw material for the active material in the synthetic fibers added, thereby reducing the dropout of the active material. ,
The aim is to reduce the occurrence of defects in the electrode plate manufacturing process and lead-acid battery assembly process, thereby extending battery life.

The present invention will be described in detail as follows.

A raw material consisting of a polyolefin synthetic resin, a fine powder of a seasick lead compound, and a plasticizer is heated and kneaded, and then processed and molded into fibers having a predetermined thickness. Thereafter, the plasticizer is eluted or extracted. Lead compounds that can be applied to the present invention include lead powder (consisting of approximately 65 to 80% lead oxide and 35 to 20% metallic lead), lead sulfate, red lead, which are currently commonly used as raw materials for active materials. Examples include lead dioxide and mixtures thereof. The synthetic fiber thus obtained uniformly retains the lead compound inside. Furthermore, the lead compound has micropores formed by the extracted plasticizer, allowing easy penetration of the electrolyte. Therefore, most of the lead compounds in the synthetic fibers will be chemically converted by performing normal chemical conversion after filling the lattice substrate with paste, and will become integrated with the surrounding active material layer, thereby improving the adhesion between the lattice substrate and the active material. is significantly improved. The adhesion of fibers to strong winds and active materials changes depending on the blending ratio of resin, lead compound, and plasticizer.

Generally, if the amount of resin is increased in an attempt to increase the strength of the fiber, the adhesion with the active material will decrease, and if the amount of lead compound is increased in an attempt to improve the adhesion with the active material, the strength of the fiber will become brittle. Therefore, overall, the optimal blending ratio range of the three components is resin/lead compound/plasticizer = 15-30/8-1.
7/58 to 75 (all percentages by weight). Example 1 Pellet-shaped low-density polyethylene (25% by weight) and lead powder [a mixture of lead oxide (75%) and metallic lead (25%)]
[wt%]] and petroleum oil (6 rut weight) in a mixer, the raw materials were heated and kneaded at 200±10°C, and then extruded to obtain long fibers of about 3 denier.

Thereafter, the plasticizer in the fibers was extracted by ultrasonication in a trichlorethylene solution. The synthetic fiber thus obtained was cut into a length of about 1 mm.

This was added at a ratio of 0.0% by mass to the lead powder, and the paste was kneaded in the same predetermined manner as in the prior art, and then filled into a grid base to obtain an electrode plate. Example 2 Pellet-shaped low-density polyethylene (25% by weight), red lead (15% by weight) and petroleum oil (6% by weight)
The raw materials mixed in a mixer are heated and kneaded at 200±10'C.

Thereafter, porous fibers were obtained in the same manner as in Example 1, and the paste was added to lead powder, kneaded, and then filled into a grid base to obtain an electrode plate. Next, the anode plate after chemical conversion obtained by the present invention was heated to 50C! The amount of active material falling off when dropped from the height R onto the iron plate alternately on the front and back sides is as shown in the drawing. As is clear from the drawings, it can be seen that in the electrode plate to which the fiber holding lead powder according to the present invention was added, the active material was less likely to fall off, and the strength of the active material was improved. Similar results were also obtained for electrode plates that were not chemically formed.

The length, thickness, and amount of the synthetic fibers added to the electrode plate according to the present invention shown in the drawings to retain lead powder were the same as those of the conventional electrode plate.

In the drawings, A represents a conventional electrode plate, and B represents an electrode plate according to the present invention. As described above, according to the present invention, defects caused by falling off of active material from electrode plates during the manufacturing process of storage batteries are significantly reduced, and there is no occurrence of short circuits at the bottom of the electrode group due to fallen active material, which improves the life performance of storage batteries. The industrial value is enormous as it improves the

[Brief explanation of drawings]

The drawing shows the electrode plate obtained by the present invention and the conventional electrode plate.
FIG. 2 is a comparison diagram showing the amount of active material falling off when dropped from a height of 0d. A is a conventional electrode plate, and B is an electrode plate according to the present invention.

Claims (1)

[Claims] 1 Raw materials consisting of polyolefin synthetic resin, lead compound powder, and plasticizer are heated and kneaded, then formed into a fiber having a predetermined thickness, and the plasticizer is eluted or extruded to maintain porosity. A method for producing electrode plates for lead-acid batteries, characterized by cutting fibers into predetermined lengths and adding them to a paste.