JPS6097552A - Lead storage battery - Google Patents

Abstract

PURPOSE:To obtain a light lead storage battery of good performance by using an expanded grid made of a lead alloy containing small percentages of antimony and arsenic. CONSTITUTION:A grid is made by heating a lead alloy sheet containing 0.8- 2.0% of antimony and 0.01-0.2% of arsenic to 190-300 deg.C, then quenching the heated alloy before it is expanded. When the content of antimony is at least 0.8% of the alloy sheet, its strength and corrosion resistance are improved by performing the heating and quanching. When the content of antimony exceeds 2.0% of the alloy sheet, its corrosion resistance is deteriorated and self discharge develops in a higher possibility in a battery constituted using the grid of this invention. Although the strength of the grid is widely improved by adding at least 0.01% of arsenic in forming the alloy sheet, addition of more than 0.2% of antimony can not achieve any higher effect and will result in a deteriorated corrosion resistance. In addition, the alloy sheet is required to be heated to a higher temperature as the content of antimony is lower.

Description

[Detailed description of the invention] The present invention relates to lead acid batteries.

In general, lead-acid batteries that have little self-discharge and do not require refilling use a lattice of a lead-low antimony alloy containing little antimony or a lead-calcium-tin alloy that does not contain antimony. Conventionally, these lattice bodies have been obtained by casting, but as the demand for lighter batteries increases, attempts are being made to make the lattice bodies thinner and lighter. If the lattice becomes thin, the temperature of the hot water will deteriorate during casting, making it difficult to reduce weight.Recently, a method has been developed to obtain a lightweight lattice by expanding a thin lead alloy sheet. There is. However, in order to obtain a lattice body using this method, the sheet must have appropriate strength and elongation. This is because if the strength is low, deformation will easily occur during expansion processing or when pasting the active material, which will cause a high defect rate, and if the elongation is low, wires and node parts will be likely to break during expansion processing. It's for a reason.

In the case of lead-calcium-tin alloys, the strength and elongation of sheets obtained by plastic processing such as rolling or extrusion, or sheets obtained by direct casting, which are drawn from molten alloy using a cooling drum, are suitable for expanded processing. .

On the other hand, in the case of a lead-low antimony alloy, the strength decreases significantly when plastic working such as rolling or extrusion is performed. In addition, this alloy has a large temperature difference from the start to the end of solidification, so it is difficult to obtain a sheet with a uniform thickness by direct casting.

Therefore, lead-calcium-tin alloy sheets obtained by the above method are used in current extended band lattice bodies. However, when this expanded lattice of lead-calcylum-tin alloy is used for the positive electrode plate, it has a drawback that it is susceptible to overcharging and repeated deep charging and discharging.

The present invention aims to improve the above-mentioned drawbacks and to provide a lead storage pond with a negative value and good performance.

Its characteristics are 0.8-2.0% antimony, 0.01
190-500 lead alloy sheets containing ~0.2% arsenic
The purpose is to use a lattice body that is heated to ℃, then rapidly cooled, and processed into an expanded band.

Next, the present invention will be explained by examples.

Table 1 shows the tensile strength, elongation, and corrosion resistance of low antimony alloy sheets with typical compositions. The alloy sheet was cast into a plate having a thickness of 10 mm using a roll belt type continuous casting machine, and then rolled to a thickness of j MY using a rolling mill. The lead-low antimony alloy sheet was heated for 10 minutes and then rapidly cooled in water at 18°C. Tensile strength and elongation were measured by performing a tension test, and corrosion resistance was expressed by weight loss in the corrosion test. Corrosion tests were carried out at 30”A in sulfuric acid with a specific gravity of 1.28.
/. A cycle of oxidizing the V4 electrode for 45 minutes at the high current of d and then resting for 15 minutes was repeated for 200 hours. After the test, the sample was immersed in an alkaline solution to remove oxidation products, washed with water, and dried to reduce weight.

Table 1 As shown in Table 1, in the case of ship-low antimony alloy sheets, when the antimony content is less than 0.8%, there is almost no improvement in strength by heating and quenching treatment, and the strength is low. Not suitable for

However, when the content is 0.8% or more, the strength and corrosion resistance are improved by heating and quenching treatment. Moreover, if the antimony content (■) exceeds 2.0%, the corrosion resistance will deteriorate and the self-electrification of the battery will increase. Therefore, the appropriate antimony content is 0.8 to 2.0%. Arsenic is toxic and less is better, but
When not added, the strength is low. The amount of arsenic added is 0.
If it is 0.01% or more, the strength will be greatly improved, but if it is 0.01% or more, the strength will be greatly improved.
Even if more than 2% is added, no further effect will be seen and the corrosion resistance will deteriorate. Therefore, the arsenic content is 0.01-0.2%
is appropriate. Regarding the heating temperature, the heating temperature suitable for forming an expanded lattice body differs depending on the antimony content. The lower the antimony content, the higher the heating temperature required. FIG. 1 shows the antimony content and the optimum heating temperature range when the heating time is 30 minutes or less. The shaded area in the figure is the optimal temperature range, and if it is higher than this, the elongation will be small and the wires and node parts will easily break during expansion processing, and if it is lower, the strength will be weak and it is not suitable for lattice bodies.

If the heating time is increased, the heating temperature can be lowered, but prolonged heating reduces production efficiency.

The antimony-low antimony alloy sheet before heating may be obtained by extrusion in addition to rolling.

Moreover, the method of rapid cooling after heating may be performed by using oil or cooling air instead of water.

Next, in order to investigate battery performance, a 35AH automobile battery was assembled and a life test was conducted. Battery A is an embodiment according to the present invention, and the negative plate contains PB-1, 5% 5BO, 3%
After heating the rolled sheet of A-day alloy at 250°C for 10 minutes,
A lattice body that had been rapidly cooled in water at 18°C and subjected to an expand band process was used.

Battery B has Pb-0,09% 0a-0,5% on the positive and negative electrode plates.
This is a conventional product using a lattice body obtained by expanding a rolled Sn alloy sheet. The life test is 1 with a discharge current of 20A.
A cycle of time discharging and charging at a current of 5 A for 5 hours was used. In this life cycle test, the battery number was 148~, and the battery B was 78~. A lead-acid battery using an expanded lattice of a lead-low antimony-arsenic alloy according to the present invention has a much better lifespan than a lead-acid battery using a conventional expanded lattice of a lead-calcium-tin alloy. There is. Furthermore, since the antimony content is 2.0% or less, self-discharge is also small.

In the examples, the lattice body according to the present invention was used for both the positive and negative electrode plates, but the lattice body according to the present invention may be used for the positive electrode plate, and the expanded lattice body of lead-calcium alloy may be used for the negative electrode plate.

As described above, since the present invention uses an expanded lattice of lead-low antimony-arsenic alloy, it is possible to reduce the weight without deteriorating the battery performance, and the production efficiency is good, and its industrial value is great. be.

[Brief explanation of drawings]

FIG. 1 shows the relationship between the antimony content and the heating temperature suitable for obtaining an expanded lattice according to the invention. Applicant Yuasa Battery Co., Ltd.

Claims (1)

[Claims] Use a grid body obtained by heating a lead alloy sheet containing 0.8 to 2.0% antimony and 0.01 to 0.2% arsenic to 190 to 300°C, then rapidly cooling it, and processing it into an expanded band. A lead-acid battery characterized by