JPH07122270A - Manufacture of paste for lead acid battery - Google Patents

Abstract

PURPOSE:To improve a utilization factor without worsening life performance, in a method of manufacturing paste for a lead acid battery. CONSTITUTION:In manufacture of paste for a lead acid battery by adding water and dilute sulfuric acid to lead powder kneaded, sulfate of alkali metal and alkali earth metal is added at the time of kneading, to also set a maximum temperature at the time of kneading to 40 deg.C or less and further a paste water amount at the time of ending the kneading from 12 to 14.5wt.%. In this way, a utilization factor of an active material can be improved without worsening life performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a lead storage battery paste.

[0002]

2. Description of the Related Art Conventionally, the utilization of lead-acid batteries has been improved by increasing the amount of water in the paste, which increases the porosity of the active material after formation and increases the capacity. Is. However, if the amount of water is simply increased, the paste becomes too soft and it is difficult to fill the grid. Therefore, there has been a method of adding a sulfate of an alkali metal or an alkaline earth metal.

[0003]

However, even in the above-mentioned conventional method of adding a sulfate of an alkali metal or an alkaline earth metal, the deterioration of the life performance is reduced and the initial performance is reduced as compared with the case where the sulfate is not added. However, there is still a problem that the life performance is largely deteriorated. An object of the present invention is to solve such a problem, and to provide a battery having excellent initial performance (utilization rate) without impairing life performance.

[0004]

In order to solve the above-mentioned problems, the present invention provides a method for producing a lead-acid battery paste in which water and dilute sulfuric acid are added to lead powder and kneading, wherein an alkali metal and an alkaline earth metal are added during kneading. The metal sulfate is added, and the maximum temperature at the time of kneading is 40 ° C. or less and the paste water content at the end of kneading is in the range of 12 to 14.5% by weight.

[0005]

[Operation] While adding alkali metal and alkaline earth metal sulfates during kneading, the maximum temperature during kneading is 40 ° C.
Below and 12 to 14 of paste moisture content at the end of kneading.
By adjusting the range to 5% by weight, the pH at the time of kneading is increased and the solubility of PbO and PbSO ₄ is increased.
Shape of the resulting particles when changing from ₄ to 3PbO · PbSO ₄ · H ₂ O becomes acicular, even by increasing the amount of water can fill without paste is soft, as the carbon particles in the active material Since it does not contain any substances that decompose, the cycle life is not significantly reduced.

[0006]

EXAMPLE An example of the present invention will be described. The relationship between the water content of the paste and the usage rate is shown in FIG. 2, and the usage rate improves as the water content increases. Therefore, it is necessary to manufacture the electrode plate with a paste having a large water content. However, simply increasing the amount of paste moisture causes a problem that the paste becomes soft and the filled paste is deformed and drops. Therefore, a method of adding an alkali metal or alkaline earth metal sulfate to the paste has been used. This is because when added, the sulfate reacts with lead powder (PbO) and the pH of the paste rises, so that the formation of lead sulfate at the time of adding sulfuric acid and promotion of its conversion to tribasic lead sulfate are acicular. It is considered that a hard paste can be obtained even if the amount of water is increased due to the generation of particles. Further, since the shape of the paste particles is not changed and the pore diameter of the active material after chemical conversion is not increased, even if the water content is increased, the life performance is deteriorated by simply adding the water content without adding lead sulfate. Was smaller than if

However, it has been revealed that the life performance is improved by setting the maximum temperature of the paste at the time of kneading the paste to 40 ° C. (50 to 60 ° C. in the past) as shown in FIG. This is the result of the JIS light load life test of the battery using the electrode plate made of the paste that was kneaded so that the maximum temperature of the paste during the kneading and the amount of paste moisture at the end of the kneading would meet the conditions shown in FIG. From now on, the maximum paste temperature is
It is considered necessary to keep the temperature below 40 ° C.

The utilization factor of the battery using the electrode plate filled with the paste prepared under the same conditions was also as shown in FIG. 2 when the maximum paste temperature was 30, 40, 50 and 60 ° C. When the paste water content is 12% by weight or less, the utilization factor is largely reduced. Therefore, the maximum paste temperature during kneading is 40 ° C or less and the paste water content is 12 to 14.5% by weight.
By doing so, a battery with high utilization rate can be obtained without impairing the life performance.

[0009]

INDUSTRIAL APPLICABILITY As described above, in the production of a lead storage battery paste in which water and dilute sulfuric acid are added to the lead powder according to the present invention and kneaded, the alkali metal and alkaline earth metal sulfates are added during kneading. , The maximum temperature during kneading is 40
The amount of paste water is 12 to 1 below ℃ and at the end of kneading.
Since it is 4.5% by weight, it is superior to the conventional method of adding a sulfate in that the utilization factor of the active material can be further improved without impairing the life performance.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the amount of paste water and the number of times of charge and discharge.

FIG. 2 is a diagram showing a relationship between a paste water content and a utilization rate.

Claims (1)

[Claims] 1. A method for producing a lead-acid battery paste, comprising adding water and dilute sulfuric acid to lead powder and kneading, adding a sulfate of an alkali metal and an alkaline earth metal at the time of kneading, and increasing the maximum temperature at the time of kneading to 40. A method for producing a lead storage battery paste, characterized in that the paste water content at a temperature of not more than 0 ° C. and at the end of kneading is in the range of 12 to 14.5 wt%.