JPH10144306A - Manufacture of pole plate for lead acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a maturing time of a pole plate by sticking alkali solution to a collector and specifying the maturing condition of the pole plate full of pasted therein. SOLUTION: The maturing temperature is set to 60 to 100 deg.C. Then, drying times required in a constant rate drying process or in a reducing rate drying process can be shortened. Also, in the processes of constant rate drying and the process of reaction, such reactions take place that lead in a collector becomes ions and dissolves from the collector in paste and lead makes reaction with oxide in the air to become a lead oxide (equations I, III) so that the collector and the active material make connection between themselves. Namely, for the purpose of advancing reactions supply of lead solution and oxygen must take place simultaneously. Meanwhile, since alkaline material is stuck to the collector, even if hydro-oxide ion is consumed in equation III, pH does not drop so much and the lead dissolution is in its state liable to progress. Since the pole plates matures in this state in an atmosphere with the oxygen concentration from 30% to 100%, the oxygen is sufficiently supplied and the reaction shown in equation II may progress smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an electrode plate for a lead storage battery, and more particularly to a method for aging an electrode plate in which a lead-calcium alloy current collector is filled with an active material. .

[0002]

2. Description of the Related Art Lead-acid batteries are relatively inexpensive and have stable performance, and are used for various purposes such as for automobiles and stationary. Then, the electrode plate used for the lead storage battery is filled with a lead oxide paste in a lead alloy current collector, left in a high humidity atmosphere for several days, gradually evaporates moisture, and matures.
The connection between the current collector and the active material and between the active material itself were ensured.

[0003]

As a current collector of a recent lead storage battery, a calcium-based lead alloy has been used in order to improve performance such as self-discharge characteristics and liquid reduction characteristics. Also, in order to improve productivity, raise the temperature,
The aging time is shortened by lowering the humidity.

In a battery using an electrode plate aged under such conditions, the bond between the current collector and the active material is poor, so that the active material is separated from the current collector at an early stage, or the current collector is And the active material was discharged intensively, the capacity was reduced early, and the life performance was deteriorated. In the case of self-discharge or over-discharge due to standing, high resistance lead sulfate is similarly generated near the current collector, and the charge recovery performance deteriorates.

For this reason, for example, Japanese Patent Application Laid-Open No. 58-19766
No. 3 proposes a manufacturing method in which a liquid film of an aqueous alkaline solution is formed on the surface of a current collector, and then a lead paste is filled. However, even in the paste-type electrode plate manufactured in this manner, a sufficient bond between the active material and the current collector can be obtained unless the paste-type electrode plate is aged at a temperature of 40 to 60 ° C. and high humidity for 24 hours or more. As a result, it was not possible to obtain an electrode plate that did not cause an early capacity decrease.

The present invention has been made in view of the above problems, and has as its object to reduce the aging time without reducing the bonding between the active material and the current collector and between the active materials. An object of the present invention is to provide a method for manufacturing an electrode plate for a storage battery.

[0007]

In order to achieve the above-mentioned object, the present invention provides a current collector comprising a lead-calcium-based alloy, wherein an alkaline solution is adhered to the current collector, and the current collector is filled with a paste. Aging is performed in an atmosphere at 60 to 100 ° C. and an oxygen concentration of 30% or more.

In general, the aging step is a constant-rate drying step in which water in the paste is gradually reduced and oxygen is easily diffused, a reaction step in which water is rapidly evaporated by oxidative heating of lead particles, and is followed by a ripening step. It is divided into three stages of the decreasing rate drying process. To shorten the aging time, it is first necessary to increase the drying rate in the constant-rate drying process. For this purpose, the drying temperature may be increased, but if the temperature is simply increased, the evaporation of water becomes too fast, the reaction at the interface between the current collector and the active material cannot catch up, and the bond between the current collector and the active material is poor. Become. Therefore,
The present invention is characterized in that an alkaline solution is previously adhered to a current collector made of a lead-calcium alloy, and aging is performed in an atmosphere in which the temperature is increased and the oxygen concentration is 30 to 100% as compared with the conventional case.

[0009]

Since the temperature is higher than in the prior art, the drying time in the constant-rate drying process and the reduced-rate drying process can be reduced. In addition, in the constant-rate drying process and the reaction process, the following occurs: a reaction in which lead of the current collector becomes ions from the current collector and dissolves in the paste; It is believed that the body and the active material combine.

[0010] The dissolution reaction ^{Pb → Pb 2+ + 2e - ···} (1) 1 / 2O 2 + H 2 O + 2e - → 2OH - ··· (2) precipitation reaction ^{Pb 2+ + 2OH - → Pb (} OH) 2 → PbO + H ₂ O (3) Total reaction Pb + 1 / 2O ₂ + H ₂ O → PbO + H ₂ O (4) In other words, in order for the reaction to proceed, it is necessary that the dissolution of lead and the supply of oxygen occur simultaneously. is there.

In the present invention, since a large amount of the alkaline substance adheres to the surface of the current collector, the dissolution of lead always proceeds without greatly lowering the pH even when OH ^- ions are consumed in the formula (3). It is easy to do. Further, in this state, aging is performed in an atmosphere having an oxygen concentration of 30% or more, so that even if lead particles in the paste are oxidized and oxygen is consumed, a necessary amount of oxygen is supplied at the interface between the paste and the current collector, The reaction of equation (2) proceeds smoothly.

[0012]

Embodiments of the present invention will be described below.

0.1% by weight of calcium and 1.5% by weight
A lead-calcium-tin-based alloy sheet comprising tin and the balance of lead was expanded to obtain a current collector for a positive electrode. An electrode plate is filled with a lead oxide paste having a density of 4.0 g / cc and containing lead oxide as a main component, and the electrode plate is aged under the conditions shown in Table 1 to form a positive electrode plate.
He got. Thereafter, batteries A to F having a rated capacity of 55 AH and a voltage of 12 V were assembled using the positive electrodes A to F by a usual method.

[0014]

[Table 1]

(Test) After forming these batteries A to F in a battery case,
The solution was replaced with dilute sulfuric acid having a specific gravity of 1.28 and subjected to a cycle life test. The result is shown in FIG.

The cycle life test condition is a temperature of 60.
At 10 ° C., the battery was discharged to 10.2 V at a constant current of 11 A, and charged to 120% of the immediately preceding discharge capacity at a constant current of 8 A.

FIG. 1 shows that the batteries A and B have substantially the same cycle life as the battery F according to the conventional method. In addition, it can be seen that the capacity of the batteries C, D, and E is reduced earlier than the capacity of the battery F. As described above, the batteries A and B using the electrode plates in which the alkaline solution is adhered to the surface of the current collector and aged in an atmosphere having an increased oxygen concentration have a aging time of about 1 compared with the battery F according to the conventional method. / 200, which can increase the productivity of the electrode plate.

In this embodiment, an expanded grid is used as the current collector. However, a grid formed by casting may be used, and an alkaline substance may be a solid powder that is dissolved and shows alkalinity. The immersion time in the aqueous sodium hydroxide solution is
The same effect is obtained not only for 5 seconds but also for 0.5 seconds, for example.

[0019]

As described above, according to the present invention, a battery having the same life performance as that of a conventional battery can be manufactured by greatly shortening the aging time of the electrode plate.

[Brief description of the drawings]

FIG. 1 is a graph showing the cycle life of batteries A to F in an example and a comparative example.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takamasa Yoshida 6-6 Josaicho, Takatsuki-shi, Osaka Inside Yuasa Corporation

Claims (1)

[Claims] 1. A method of manufacturing an electrode plate for a lead storage battery, comprising: attaching an alkaline solution to a current collector made of a lead-calcium alloy; filling the current collector with a paste to form an electrode; and aging the electrode. A method for producing an electrode plate for a lead storage battery, wherein the aging is performed in an atmosphere at a temperature of 60 to 100 ° C. and an oxygen concentration of 30 to 100%.