JP2956114B2 - Anode plate for lead-acid battery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an anode plate for a lead storage battery and a method for producing the same.

2. Description of the Related Art An unformed anode plate of a lead-acid battery is usually prepared by adding water and sulfuric acid to a lead powder composed of lead oxide and metallic lead, kneading the paste, filling this into a grid, and then aging and drying. It is manufactured by performing. The aging and drying here are generally performed under such conditions that tribasic lead sulfate is produced in the active material of the unformed anode plate. It is also widely known that lead powder contains lead in order to improve the formation efficiency of the anode plate, and the mixing ratio is suitably from 10 to 30% by weight.

On the other hand, there is known a method in which the temperature and humidity of aging and drying are made higher to generate tetrabasic lead sulfate having a much larger crystal form than tribasic lead sulfate in an unformed anode plate. According to this method, since the aging and drying are performed at a high temperature, the aging and drying time of the electrode plate can be reduced. Further, the battery using the anode plate containing tetrabasic lead sulfate has a longer life than the conventional battery containing tribasic lead sulfate. However,
This electrode plate had the disadvantage that the formation efficiency was poor, several times the amount of formation electricity was required, and the initial battery capacity was low.

Recently, as a method for solving these problems, Pavlov et al. Disclosed a technique using an unformed electrode plate containing both lead and tetrabasic lead sulfate. Although this is an attempt to improve the formation efficiency with leadtan, it is possible to make the chemical electricity equivalent to the conventional electrode plate that does not use leadtan,
As compared with an electrode plate containing both lead gallium and tribasic lead sulfate at the same time, it also requires at least 1.5 to 2 times the amount of formation electricity, which has been a major obstacle in industry.

In addition, when a paste containing no lead red is used, tribasic lead sulfate and tetrabasic lead sulfate can be mixed by aging and drying. However, in such an electrode plate, tribasic lead sulfate or tetrabasic lead sulfate is localized between and within the electrodes due to variations in aging and drying conditions. In this case, during the chemical conversion step, the chemical conversion is concentrated on the tribasic lead sulfate portion having a high chemical conversion efficiency, and local softening of the active material may occur locally, which makes it difficult to be put to practical use.

Problems to be Solved by the Invention That is, in the method of producing tetrabasic lead sulfate in an unformed anode plate, the time can be reduced by aging and drying at a high temperature. In this case, the anode plate has an excellent property of a long life, but even if it contains lead red, its formation efficiency is poor. On the other hand, ripening and drying using a paste containing no lead red and tribasic lead sulfate And a mixture of tetrabasic lead sulfate, a nonuniformity of the obtained anode plate causes a bias in formation.

Means for Solving the Problems As means for solving the above problems, in the present invention, water and sulfuric acid are added to a lead powder composed of lead oxide and metallic lead, and kneaded to prepare a paste-like active material. An anode plate for a lead-acid battery filled with this paste in a grid and aged and dried, wherein the lead powder contains lead tin and 4-basic lead sulfate is generated during the aged and dried, This is a lead storage battery anode plate in which basic lead sulfate and tetrabasic lead sulfate are mixed.

According to the anode plate for a lead storage battery in which tribasic lead sulfate and tetrabasic lead sulfate are mixed in the pasty active material of the present invention,
The surface area of the active material is equivalent to the conventional one in which no tetrabasic lead sulfate is present. Accordingly, the amount of electricity required to form the conventional electrode plate can be sufficiently formed, and the initial battery capacity has the same or higher performance as the conventional one. In addition, regarding the state of the formation of the electrode plate, the defect seen in the anode plate mixed with tribasic lead sulfate and tetrabasic lead sulfate obtained by aging and drying from a paste containing no lead, that is, active material No local formation of lead sulfate or early softening was observed. This is because even if tribasic lead sulfate or tetrabasic lead sulfate is locally formed during aging and drying, lead tin with high electron conductivity is uniformly distributed, so that it is evenly distributed on the formation electrode. This is probably because current flows. On the other hand, the tetrabasic lead sulfate in the anode plate is present to some extent as a main skeleton of the active material, and the life characteristics of the battery are based on the excellent lifetime of the battery using the anode plate containing the tetrabasic lead sulfate. It conforms to the characteristics. This can be explained from the idea of Pavlov et al. That it is caused by a microstructure composed of crystals of tetrabasic lead sulfate which is much larger than that of tribasic lead sulfate. By the way, the content of lead red in the lead powder in the present invention is 10
~ 30% by weight. A paste containing lead tin in an amount of 30% by weight or more tends to have an increased hardness, making it difficult to fill the lattice. Therefore, the lead red content is preferably 10 to 30% by weight. In addition, the content of the tribasic lead sulfate and the tetrabasic lead sulfate in the active material that embodies the effects of the present invention is between about 10 to 30% by weight and about 15 to 40% by weight, respectively.

Examples Hereinafter, examples of the present invention will be described.

4% by weight of sulfuric acid and an appropriate amount of water are added to a lead powder mixed with 20% by weight of lead, and kneaded to prepare a paste. After this was applied to a lattice, aging and drying were performed under three conditions as shown in Table 1 to obtain anode plates A, B and C.

Observation of these three types of anode plates by a scanning electron microscope revealed that the anode plate A was composed of an active material containing tribasic lead sulfate having a crystal size of several μm, and the anode plate B had a crystal size of 20 to 50 μm.
This was an active material having a network structure formed of m-basic lead sulfate. The anode plate C of the present invention contains both tribasic lead sulfate of several μm and tetrabasic lead sulfate of 20 to 50 μm, and the tetrabasic lead sulfate formed a certain degree of network structure. . As a result of analyzing the composition by X-ray diffraction, the active material of A was composed of lead oxide, lead tin, etc., and tribasic lead sulfate was used as a component. The active material of B was tribasic lead sulfate. It was not recognized, and the composition contained 4-basic lead sulfate. The active material of C was composed of about 20% of a tribasic lead sulfate and about 25% of a tetrabasic lead sulfate in addition to lead oxide and lead red.

Next, using these anode plates, a chemical conversion in a battery case was performed. However, the formation was unified with the necessary amount of electricity to satisfy the formation of the anode plate A. The content of lead dioxide and lead sulfate in the electrode plate C after formation was almost the same as that of the electrode plate A, and no locally softened active material was observed. On the other hand, the electrode plate B after the formation has a lead dioxide content of not more than one half of that of the electrode plate A, and it has three times or more lead sulfate and remains without being formed. Basic lead sulfate was observed. That is, the anode plate B still needs a considerable amount of electricity to be completely formed, and requires more time. By the way, apart from these anode plates, an anode plate D obtained by preparing a paste containing no lead in the above-mentioned lead powder, filling this into a lattice, and performing aging and drying under the same conditions as the anode plate C Was an active material in a state similar to that of C, but the anode plate B
It was a near chemical formation.

Table 2 shows the results of measuring the initial capacity of a battery equivalent to type 36B20 constituted by using these anode plates.
As is clear from the results, the initial capacity of the battery comprising anode plate B containing 4-basic lead sulfate is about 30% inferior to that of the battery comprising anode plate A. The initial capacity of the battery consisting of is equal to that of A.

Further, FIG. 1 shows the results of a life test of JIS 5301 for a battery composed of each of these three types of anode plates. As is apparent from FIG. 1, the life of the battery comprising the anode plate C of the present invention is slightly inferior to that of the battery comprising the anode plate B, but about the same as that of the battery comprising the conventional anode plate A.
120%. This is because a network structure that is difficult to be maintained by an active material containing tribasic lead sulfate that does not contain tetrabasic lead sulfate at all can be formed because it contains tetrabasic lead sulfate. It is considered that this is maintained even if is repeated.

On the other hand, as is clear from Table 1, the aging drying for obtaining the anode plate C can be performed in almost half the time required for the aging drying for obtaining the anode plate A which is a conventional method.

Next, an anode plate in which tribasic lead sulfate and tetrabasic lead sulfate were mixed at various contents was obtained by changing only the aging time in the same manner as described above. FIG. 2 shows the results of initial capacity and JIS 5301 life tests for batteries of type 36B20 using these anode plates.

The anode plate obtained by aging for 4 hours has 3
The contents of the basic lead sulfate and the tetrabasic lead sulfate were about 33% and about 8%, respectively, and the initial capacity and life characteristics of the battery comprising the same were different from those of the battery comprising the conventional anode plate A. The results were almost the same and good results were not obtained. In addition, in the anode plate obtained by aging for 16 hours, the contents of the tribasic lead sulfate and the tetrabasic lead sulfate were about 3% and about 42%, respectively. On the other hand, the battery was about 130% of the battery of the anode plate A, but the initial capacity was inferior by 20% or more. On the other hand, the performance of the batteries composed of the anode plates obtained by the aging time of 7 hours, 10 hours and 13 hours corresponding to the anode plate of the present invention is slightly different depending on the batteries. In comparison, the initial capacities were almost the same, and the life was about 120% or more.

In other words, in a battery using an anode plate having a tribasic lead sulfate content of about 10% or less, the initial capacity is reduced because the surface area of the active material is small and the formation of the active material is difficult to occur. This is considered to be because it is difficult for an anode plate having a lead sulfate content of about 15% or less to form a network structure having long life characteristics.

Effect of the Invention The lead powder according to the present invention contains lead red in an amount of 10 to 30% by weight,
The active material contains 10 to 30% by weight of tribasic lead sulfate and 15 to 30% by weight.
An anode plate for a lead-acid battery containing 40% by weight of tetrabasic lead sulfate can be sufficiently formed by an amount of electricity sufficient to form a conventional anode plate in which no tetrabasic lead sulfate is present. In addition, the capacity of the battery at the initial stage has characteristics equal to or better than those of the conventional battery, and has a performance equivalent to the excellent life characteristics of the battery composed of the anode plate containing tetrabasic lead sulfate. Things. According to the present invention,
Local softening of the active material and generation of lead sulfate which occur when basic lead sulfate and tribasic lead sulfate coexist can be avoided, and only the advantages when both are mixed can be brought out.

[Brief description of the drawings]

FIG. 1 is a view showing the results of a life test performed on a battery constituted by using each of the anode plates obtained by three types of aging and drying, and FIG. 2 is a diagram showing the results of the anode active material obtained by various aging times. It is a figure which shows the relationship between the content of tribasic lead sulfate and tetrabasic lead sulfate, and the initial capacity and the life characteristic of the battery which consists of each anode plate.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Katsuhiro Takahashi 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-63-318071 (JP, A) JP-A-63-63 269456 (JP, A) JP-A-54-93427 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01M 4/14 H01M 4/20-4/21 H01M 4/56- 4/57

Claims (2)

(57) [Claims] 1. An anode plate for a lead-acid battery, which is prepared by filling a paste-like active material in a grid and aged and dried, wherein the lead powder of the active material contains 10 to 30% by weight of lead and 3 basic components. Lead sulfate and 4
Anode plate for lead-acid batteries containing basic lead sulfate. 2. The lead-acid battery according to claim 1, wherein the active material contains 10 to 30% by weight of tribasic lead sulfate and 15 to 40% by weight of tetrabasic lead sulfate. Anode plate.