JPS59157957A - Manufacture of lead-acid battery - Google Patents

Abstract

PURPOSE:To suppress the breakdown of active material particles, increase life of a lead-acid battery, and increase utilization of an active material by bringing a plate before formation into contact with a metal complex forming solution, then charging it in a dilute sulfuric acid solution. CONSTITUTION:A plate before formation is brought into contact with a metal complex forming solution, then charged in a dilute sulfuric acid solution. For example, a paste type plate before formation prepared by coating a lead alloy grid with a paste by a conventional method, drying, and aging is accommodated into a container with a separator. 10g/l disodium ethylenediaminetetraacetate solution as a complex forming agent is poured in the container until the plates sink, then they are allowed to stand for one hour, or after pouring, a battery is charged at a current of 5hr rate for one hour. The solution poured in the container is removed, then a dilute sulfuric acid is poured, or with a part of solution is left in the container, a dilute sulfuric acid solution is poured. After that, a battery is charged for formation at a current of 5hr rate for 30hr.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in the electrode plates of lead-acid batteries.

Conventional configurations and their problems In lead-acid batteries, improvements in active material utilization and life span are
This remains an important issue. The main causes of life deterioration are the miniaturization of the positive electrode active material and the resulting softening and falling off of the active material layer. Capacity and voltage characteristics deteriorate further due to the weakening of the bonding force between particles, and it is said that it is fundamentally difficult to achieve both high capacity and long life.

The weakening of the electrode plate as described above is not limited to the positive electrode plate, but also occurs in the negative electrode when the group pressure is low. Whether it is to improve the kneading life or to increase the capacity, the basic Q factor is to suppress miniaturization and prevent deterioration of the bonding strength of the active material particles.

. In the past, attempts have been made to utilize the binding strength of thermoplastic resins as a means of increasing the binding strength of particles such as those mentioned above, and although some improvement in properties has been observed, the particles that are not affected by the binding strength of the resin tend to collapse. I am helpless and am relieved to explore additives from a completely new perspective.

The purpose of the present invention is to suppress the disintegration of the particles themselves. 1i
The purpose is to simultaneously measure the utilization rate of lead-acid batteries and the utilization rate of active materials.

Structure of Invention 1 In the first aspect of the present invention, the unformed plate is brought into contact with an aqueous solution of a metal complexing agent without being shredded, and then subjected to IL treatment in dilute sulfuric acid to form blue mold.

DESCRIPTION OF EMBODIMENTS The features and effects of the present invention will be described below with reference to Examples. The effect of the present invention on improving the strength of the active material is common to all types of batteries, so an example will be given using a paste type lead-acid battery, which is the most versatile.

First, in order to bring the unformed board into contact with the aqueous solution of the complexing agent, which is the first step of the present invention, in addition to simply immersing it in the aqueous solution, in the immersed state, an electrical device such as applying an electrolytic current is used. It is also possible to do this.

As an example, a paste-type unformed plate manufactured by applying lead paste on a lead alloy grid using a conventional method, drying, and aging is stored in a battery container via a separator.
As a complexing agent, a 10.9/l aqueous solution of ethylenic acid (1) thorium was poured into the plate until the electrode plate was submerged in water, and the plate was left immersed for 1:1 hour. This was designated as iA, and the one in which current was applied for 1 hour at a rate of 6 hours after injection of the liquid was designated as B.

The complexing agent used is ethylenediaminetetraacetic acid (EDT).
~, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid, N-oxyethylethylenediaminetriacetic acid, ethylene glycol bisβ-aminoethyl ethertetraacetic acid, or salts of these with elements Ia) and b of the periodic table are effective. However, as in the example, the power of salt is more effective than the acid veneer mentioned above, and the medium-C is also EDTA ninato l)
Lamb salt ('EDTA Nina' because it has excellent properties)
l) Rum salt was also applied for the following examples. Dimensions,
As for the concentration of the complexing agent, there is some effect even below 0.1% by weight (although there is some effect in the relatively high concentration region, it is effective in a wide range beyond the saturated region, and can be selected arbitrarily).゜Sorry, it is also effective to use a surfactant in the process of bringing the above aqueous solution into contact with the untreated board.As an example, after storing the untreated board in a container, A non-ionic surfactant polyoxyethylene alkyl needle was added to an aqueous solution, which was press-fitted until the electrode plate was submerged in water, then the plate was shaken and left immersed for 1 hour. A product D was produced by applying current at a certain rate for 1 hour.

Next, after going through the first step described in Section 2, at the stage of proceeding to chemical charging in dilute sulfuric acid, there are cases where dilute sulfuric acid is injected after removing the remaining amount of the previously injected liquid, and at least the remaining amount is removed. A method of additionally injecting dilute sulfuric acid while leaving a portion of the sulfuric acid remaining can be applied. This means that the first step of the present invention is performed by separately placing the electrode plates in an electrolytic container, rather than necessarily incorporating the electrode plates in the battery container and performing the so-called battery cell formation as in the examples. and then incorporate it into a battery case and perform the main chemical formation.
This suggests the possibility of technological developments such as performing the second process in a separate electrolytic tank.

Regarding the treatment method for these liquids, after applying each of the above ABCD formulations, a method was performed in which the residual liquid was removed, and a method in which dilute sulfuric acid was injected without removing the residual liquid. The former was A1. B1゜C1, Dl, A2 for the latter
, B2 , , C2, , D2. Note that the concentration of sulfuric acid can be selected at any desired value, but the specific gravity is 1.15 to 1.2.
5, and chemical formation charging was performed for 30 hours at a rate of 5 hours. In addition, in the conventional, classical chemical conversion method that does not use any complexing agent as in the present invention, an unformed board is initially placed in dilute sulfuric acid,
A sample E was produced using a method in which chemical charging was performed for 30 hours at a current rate of 5 hours. Furthermore, as a comparison sample, instead of contacting the complexing agent aqueous solution in advance, a sulfuric acid aqueous solution was injected into the cell container from the beginning, and EDTA (EDTA) was poured into the container from the beginning.
l) Sample F was prepared by adding ram and carrying out normal chemical formation for 30 hours at a current rate of 6 hours.

On the other hand, compared to the case where a salt such as the disodium salt of EDTA is used as a complexing agent, it is better to use an aqueous solution of EDT, which is a saturated solution of acid crystals dissolved in water, according to A1. A sample is prepared and designated as G1. .

A charge/discharge cycle test was conducted using a battery prototyped as described in the notes. In the charge/discharge cycle test, the battery was repeatedly charged for 11 hours at a current rate of 3 hours with a discharge depth of 80 inches and a current rate of 10 hours.

The results are shown in Figure 1.

As can be seen in Figure 1, the comparison product E, to which no complexing agent was applied, showed the earliest deterioration under the above severe conditions.

Even if a complexing agent is used, the first step of the present invention is followed.As in F, the unformed board is immersed in dilute sulfuric acid from the beginning and the complexing agent is added there. Also, the desired effect (-j: not obtained.Furthermore, G1 applied in the form of ED and TA diluted acid also seems to have some effect, or has remarkable effects such as A, B, C, and D. is not allowed.However, the soaking time is 2.
If you take a long time like 0 to 50 hours, there is a tendency for some improvement. On the other hand, the feature of the present invention, that is, the effect of bringing the unformed board into contact with the aqueous solution of the complexing agent in advance is as follows.
In contrast, in the case of the present invention, the active material of the electrode plate and the exposed part of the lattice turn dark purple when brought into contact with a complexing agent in dilute sulfuric acid. We believe that this is closely related to the fact that a stable complex is formed and does not disappear even when it comes into contact with dilute sulfuric acid. Ru. Is it a broken complexing agent?
The tendency for a substance to be in a salt state is closely related to its solubility, and is thought to be related to the fact that the solubility is low unless it is in a salt state.

Furthermore, B1. B2 is A1 which is not energized after liquid injection. A2
They tend to have a slightly better lifespan compared to

Does this mean that the IC that is energized speeds up the movement of metal ions? 1
It is thought that the formation of a stable complex occurs with a relatively high probability due to monomerization. 1, one in which the solution was changed to an aqueous sulfuric acid solution, and one in which an aqueous sulfuric acid solution was added/ζ, that is, A1 and A2. Comparing B1 and B2, there is almost no difference in lifespan between those with liquid changes and those with additional addition.C1, C2 with added surfactant
, DI, D2i are Al with addition 1 to no addition, A2. B1
It can be seen that the life characteristics are even more excellent than that of B2.

Figure 2 does not show a comparison of the utilization rates of active materials determined from the initial capacity. A1. A2. B1, B2. CI, C2゜Dl,
It can be seen that B2 is superior to E, F, and G1 by about 20% or more.

As described above, according to the present invention, the active material utilization rate can be further increased compared to conventional products, and the life span can be significantly extended. Therefore, the present invention is also useful for expanding the use of lead-acid batteries to applications that require a long life, such as small power machines, electric vehicles, and photo-drifts, which will be developed in the future.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the cycle life of lead-acid batteries produced by various manufacturing methods, and FIG. 2 is a diagram showing the active material utilization rate.

Claims (1)

[Claims] (1) A method for manufacturing a lead-acid battery, characterized in that an unformed plate is brought into contact with an aqueous solution of a metal complexing agent in step 6, and then chemically charged in sulfuric acid. (odor) The method for producing a lead-acid battery according to claim 1, wherein the metal complexing agent is a salt of ethylenediaminetetraacetic acid and an element of group 1a of the periodic table. A method for producing a lead-acid battery as described in item 1 of the scope of requirements for feature 'A'``1!l-'', which is characterized in that in the step of bringing the aqueous solution into contact, the electrode plates are polarized by first applying electricity. In the step of bringing the aqueous solution of the complexing agent into contact, a surfactant is added to the solution. After the chemically formed electrode plate group is stored in the final battery case, it is brought into contact with an aqueous solution of a metal complexing agent, and then at least a portion of the aqueous solution remains, and dilute sulfuric acid is poured into this for chemically charging. A method for manufacturing a lead-acid battery according to claim 1, characterized in that: