JPS59157969A - Manufacture of lead storage battery - Google Patents

Abstract

PURPOSE:To improve the recovery of the capacity of a battery that use a Sb free lead alloy grid after it stands alone by leaving the battery itself alone in pressure reduction state after the formation of a container. CONSTITUTION:When a battery to which 40hr continuous formation is made by assembling the non-formation assembled element for the positive and negative electrodes of an N50Z type battery, inserting it in a container, mounting a container cover, injecting an electrolyte, and applying current is left alone for 24hr under the pressure reduction of 150mm.Hg, the foams adsorbed in an active material porous hole are degassed and the low class lead oxide layer on the active material surface is made to contact by the diffusion of a formation liquid and then lead sulfate pbso4 is chemically produced while standing alone. Though the pbso4 is poor in reaction, i.e. resistant to irreversibility, the pbso4 is fully changed into pbo2 by performing supplementary charge at 10hr rate current for 30min subsequently, thereby removing the low class oxide. Once the pbo2 has been formed, the irreversible pbso4 is produced subsequently and returns to the original pbso4 and at the same time self discharge is reduced.

Description

[Detailed description of the invention] The present invention is lead-based 71! It concerns the method of manufacturing ponds.

There are various types of lead-acid batteries, and they can be categorized by use into automobiles, industrial batteries, etc., categorized by shape into sealed batteries, etc., and further divided into lattice alloy compositions by p b - ``Sb-free lead alloy (this is called ``Sb'')
There are maintenance-free batteries that use ``b-free lead alloy''. The method for manufacturing lead-acid batteries of the present invention is effective for all of these batteries.

Generally, the anode and cathode grids made of lead-acid batteries or the above alloys are filled with an active material paste prepared by kneading lead oxide with a dilute sulfuric acid mixture, and then energized. Unformed electrode plates replace lead oxide with lead dioxide (pbo2
), the cathode chemically formed plate is made of lead oxide with spongy lead (Pb
), each becomes an anode plate and a town.

The present invention basically improves the chemical formation process of the electrode plates in a lead-acid battery 1 manufactured through such a manufacturing process. The chemical formation efficiency of the cathode plate is extremely high, and there are no problems with quality.The anode plate undergoes electrolytic oxidation when a predetermined constant current is passed through it, and the lead acid of the active material paste is removed. compound or lead dioxide (p b 0
2) becomes. In the next step, electrolytic oxidation is carried out from around the lattice bones through the unformed active material layer to the surface of the unformed electrode plate in contact with the chemical solution in a dendritic manner through points of low resistance within the unformed active material layer. Then, electrolytic oxidation appears in spots on the surface of the unformed electrode plate, and it spreads over the entire surface of the unformed electrode plate. At that time, the area between the lattice bones and the surface within the active material is electrolytically oxidized in a dendritic manner, and many unformed active material layers are present. The chemical formation continues in this part, and the chemical formation ends when all of the unformed active material layer becomes lead dioxide. At the final stage of chemical formation, since chemical formation has been completed around the lattice bones, dendritic parts, and the surface of the unformed electrode plate, water decomposition naturally occurs and oxygen (02) gas is released from the areas where chemical formation has been completed. Occur. In the unformed active material layer between the lattice ribs and the surface of the unformed electrode plate, 02 gas bubbles are generated from the surface of the lattice bone, and conversely, the chemical liquid from the surface of the unformed electrode plate permeates and diffuses into this unformed active material layer. I have to do it. In other words, the formation (electrolytic oxidation) of this unformed active material layer must be achieved under extremely inefficient conditions, and the generated gas is adsorbed into the complex-shaped pores in the unformed active material layer. As a result, the diffusion of the chemical solution between the surface of the gas bubbles and the porous surface of the unformed active material becomes extremely poor, and even if electrolytic oxidation is performed, the efficiency of any part is extremely poor, and in the end, the paste Lead oxide is lead dioxide (P
bO2) and PbO,l (n<2) and Pb5
It is possible that the chemical formation is completed with a lower lead oxide such as O-PbOn (n<2). The first problem with such electrode plates is that (1) it is difficult to develop capacity, especially in the early stages. (2) If left as is, these lower lead oxides will chemically turn into lead sulfate (PBSO4).
It becomes a highly irreversible nonconductor, and even if you perform recovery charging such as supplementary charging, it is difficult to restore the capacity to its original capacity (it is difficult to use for one battery for applications that require quick charging. (1) and (
The tendency of 2) appears more often in maintenance-free batteries using grids made of Sb-free lead alloys than in batteries using grids made of conventional pb-Sb alloys. Naturally, batteries in the future will tend to require less maintenance.
Improvements in the chemical conversion process that eliminate the above-mentioned defects would be extremely significant.

The present invention eliminates the above-mentioned drawbacks, and the chemical formation is completed while the generated gas remains trapped in the porous surface of the unformed active material layer, and the harmful substances between the scum surface and the surface of the active material multi-holes are removed. This method eliminates the possibility that lower lead oxides remain without being sufficiently converted into PbO2.

Examples of the present invention will be described. After assembling the negative and anode unformed electrode plates of the N50Z type battery, inserting them into the electric fence and attaching the battery case lid, the electrolyte solution (chemical solution) is injected and the electricity is turned on for 40 hours continuously. A battery with a chemical composition of 91 was left as it was under a reduced pressure of, for example, 150 mmHg for 24 hours, and then supplementary charging was performed. When we investigated the performance of the N50Z type battery, the results shown in Table 1 were different. A typical example of the Sb-free lead alloy is a pb-Ca alloy.

[Comparing the product 1.2 of the present invention and the conventional product 1.2] The ratio of the product 1.2 of the present invention was 20, which was an increase of 20 compared to the conventional product 1.2. Also, after being left at 40℃ for 90 days, it was heated to 300℃ at -15℃.
Regarding the high rate discharge capacity of A, if conventional product 1 is 100, conventional product 2 is 300, inventive product 1 is 2000, and inventive product 2 is 600, and both inventive products 1 and 2 are 100% higher than conventional product 1.
．． It increased compared to 2. Furthermore, after the second high rate discharge, 148
■The number of cycles it takes to reach the initial 5 HR capacity (100 coefficient) with constant voltage recovery charging under the conditions of 25℃ and 8 hours is 2 cycles and 3 cycles for conventional products 1.2 and 3 cycles, respectively. On the other hand, inventions 1 and 2 are excellent in that both recover in one cycle. This is due to the fact that when left under reduced pressure after completion of chemical formation according to the present invention, the air bubbles trapped in the pores of the active material are degassed, and the low lead oxide layer on the surface of the active material comes into contact with the diffusion of the chemical liquid. During storage, lead sulfate (Pb) is chemically released.
SO4). This p b s o 4 has a property that is desired for reactivity, that is, it is strongly irreversible. After that, if we conduct it for 30 minutes at a current rate of 10 hours, this type of Pb s o 4 will completely become PbO □, and the lower oxides will disappear, and once Once PbO2 is formed in this way, it becomes reversible PbSO4, and it returns to its original state with a simple recovery method, and at the same time, self-discharge itself is reduced (for some reason, this tendency f Sb-free lead alloys It tends to be noticeable in cases of

In this example, the depressurization was left for 24 hours before supplementary charging, but the same effect could be obtained even if the depressurization was done for, for example, the first 05 hours out of the 24 hours, and then for 235 hours under constant pressure. was gotten.

As shown above, the present invention can increase the capacity by simply leaving the battery itself in a reduced pressure state after forming the battery case, and in particular, the capacity of a battery using a 3b lead alloy grid after being left is increased. By significantly improving the shortcoming of poor recovery performance, this technology has tremendous value, as it will lead to expanded applications for maintenance-free batteries in the future.

patent applicant

Claims (1)

[Claims] The grid is filled with active material paste, and the battery's electrode plates are assembled using unformed electrode plates that are dried and aged. After the battery is housed and electrolyte is poured, chemical formation is performed, and after the formation is complete, A method for producing a lead-acid battery, which comprises: leaving the battery under reduced pressure and then recharging it; or, after completion of chemical formation, leaving it under reduced pressure, leaving it at normal pressure, and then recharging it.