JPH0346762A - Electrode plate for lead storage battery - Google Patents

Abstract

PURPOSE:To obtain a battery of a stable service life by making the amount of Sb to an active substance given to the mesh body near the lug of a grid larger than the amount of Sb to an active substance given to the mesh body separated from the lug. CONSTITUTION:A thin layer including Sb is formed on the surface of a lead alloy sheet, it is expanding-processed to use as a grid, and the amount of Sb to an active substance given to the mesh body near the lug of the grid in the height direction of the mesh body is made larger than the amount of Sb to an active substance given to the mesh body separated from the lug, so as to improve the cycle life in a deep discharge. By presenting the Sb in the surface of the grid, not only the combination force of the grid whose surface is reformed and the active substance is improved, but also a part of the Sb is dissolved into the active substance to reform the active substance. And by presenting the amount of the Sb to the active substance given to the mesh body near the lug larger than that to the active substance given to the mesh body farther from the lug, the positions used frequently are reformed preponderantly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improvements in electrode plates for lead-acid batteries.
In particular, the present invention provides a battery that is both maintenance-free and has cycle life characteristics in deep discharge.

Conventional technology In recent years, lead-acid batteries have been developed with the aim of achieving both maintenance-free properties and deep discharge cycle life characteristics.

A technique has been proposed to add antimony to a lattice surface that does not contain antimony. A typical method of this technology is a method in which a slab and a thin layer containing antimony are stacked and rolled to integrate them, and this method is extremely effective industrially.

Problems to be Solved by the Invention However, when testing a number of battery configurations, it has become clear that there is some variation in the number of cycles of deep discharge. Further detailed analysis revealed that the position in the height direction of the electrode plate where a large amount of antimony is present influences the number of lifetimes.

The present invention aims to minimize the deterioration of maintenance-free performance and improve the cycle life in deep discharge in a configuration using the technique of applying a thin layer containing antimony as described above.

Means for Solving the Problems The present invention has a configuration in which a thin layer containing antimony is formed on the surface of a lead alloy sheet, and this is expanded to be used as a lattice. The cycle life in deep discharge is improved by making the amount of antimony relative to the amount of active material applied to the near net-like body larger than the amount of antimony relative to the amount of active material applied to the net-like body distant from the ears. It is something.

The presence of antimony on the lattice surface not only modifies the lattice surface and improves the bonding strength between the lattice and the active material, but also has the effect of dissolving some antimony within the active material and modifying the active material. There is. Here, in the present invention, by making the amount of antimony with respect to the amount of active material applied to the net-like body near the ear part larger than the amount of antimony with respect to the amount of active material applied to the net-like body farther away, the cycle life in deep discharge can be improved. The reason for this improvement is that the utilization rate of the active material located near the ear is higher than that of the active material located further away. Therefore, it is extremely effective to focus on modifying frequently used parts.

In FIG. 1, in the height direction of the electrode plate, the net-like bodies closest to the ears are 1, 2, and so on. ......n, and the amount of antimony added to each network is AlA2,...
...Ao, the active material in each network is Bl,
B2 ,...B, the present invention provides Ai
/Bi≧AJ/BJ (however, 1≦i×j≦n).

By the way, regarding how to specifically implement the present invention, it is generally considered that the sizes of the nets are the same, and that Bi = BJ, that is, the amount of active material in the nets is the same. In this case, the above inequality becomes A1≧AJ. In other words, it is sufficient to increase the amount of antimony applied to the net-like body near the ears. For example, as shown in Figs. 4 and 5, the thickness of the thin layer applied to the portion near the ears at the stage of obtaining the lead sheet can be increased. This can be solved by increasing the thickness of the coating or increasing the antimony content, but this is not a good method in terms of productivity. Industrially, it is effective to apply only one type of thin layer containing antimony and to increase the width of the mesh bones near the ears during the expansion process, which also improves the voltage characteristics. But it's effective.

Example The present invention will be explained below using examples.

First, an expanded lattice with 18 net-like bodies in the height direction was prepared. As an example of the technique of the present invention, the i closest to the ear =
The width of the bone of the reticular body from 1 to i=6 is 1.1 mm, i=
The width of the reticular bone from 7 to 1=12 is 1.0 + ms,
The width of the cancellous bone from 1=13 to 1=18 is 0.9+
Battery A uses a lattice of n+w as the positive electrode, and as a conventional technology, the width of the bone of the reticular body from i=1 to i=6 is 0.9.
mm, from i=7 to 1=12, the width of the cancellous bone is 1.0
+m+, 1=A battery B using a lattice with a mesh width of 1.1 m from 13 to 1-18 as the positive electrode was made with a 5-hour rate capacity of 48 Ah, and a deep discharge cycle life test was conducted. I did it. The amount of antimony applied to the positive electrode grids of Batteries A and B was 0.1 wt % based on the weight of the grids, under the same conditions. In addition, the cycle life test with deep discharge is 20A.
One cycle is defined as discharging for 1 hour at 14.8V (maximum current 20A) and charging for 5 hours at
The battery was discharged with OA, and the number of cycles until the mouth pressure reached 7.2V for 30 seconds and the amount of liquid loss during the life test were investigated.

The results are shown in FIGS. 2 and 3.

As is clear from FIG. 2, battery A using the technology of the present invention had a lifespan approximately 30% longer than battery B.

When we disassembled a battery that had reached the end of its life and observed the condition of the positive electrode active material, we found that the active material in Battery A had softened uniformly, whereas the active material in Battery B had softened only in the upper part, with only the ear parts softening. Not much softening was observed at the base of the seeds, which was far away from the soil.

In addition, as can be seen from FIG. 3, the liquid reduction characteristics of battery A and battery B were equivalent.

Effects of the Invention As described above, the present invention significantly improves the cycle life in deep discharge without substantially reducing the maintenance-free property, and is effective in providing a battery having a stable life.

[Brief explanation of drawings]

Figure 1 shows an example of a lattice obtained by expanded expansion, Figure 2 shows an example of cycle life test results in a deep discharge, and Figure 3 shows an example of a cycle life test result in a deep discharge. The liquid reduction characteristic diagrams, FIGS. 4 and 5, are cross-sectional views of a lead alloy sheet having a thin layer containing antimony applied to the surface thereof. Battery A...Battery of the present invention, Battery B...
Conventional battery, C...The part that is expanded. D...The part that is not expanded and becomes the ear part when the electrode plate is processed.

Claims (2)

[Claims] (1) Apply a thin layer containing antimony to the surface of a lead alloy sheet, expand this sheet, use it as a grid, and apply it to the mesh near the grid ears in the height direction of the mesh of the grid. 1. An electrode plate for a lead-acid battery, characterized in that the amount of antimony relative to the amount of active material applied is greater than the amount of antimony relative to the amount of active material applied to the net-like body distant from the ears. (2) In the process of developing the sheet into a mesh, the bone width of the mesh near the ears is made thicker than the bone width of the mesh farther away. Plate for lead-acid battery as described.