JPS59177864A - Electrode material for lead-acid battery - Google Patents

Abstract

PURPOSE:To provide electrode material for a lead-acid battery having increased strength, corrosion resistance, electrolyte decreasing property, and casting property by adding small amount of alkali metal such as Li, K, Na to lead alloy containing Sb. CONSTITUTION:0.11-0.5% either one of Li, K, or Na is added to lead alloy containing 0.2-1.0wt% Sb and this material is used to cast a plate for a lead- acid battery. This material has good strength, corrosion resistance, and electrolyte decreasing property and also has good casting property. A battery having a grid manufactured by using this material has features that, for example, current in completion of charging is small.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a PB gold alloy electrode material which is excellent in strength and corrosion resistance as an electrode material in a lead-acid battery, and is characterized by a small current value at the end of charging.

There are currently various electrode materials for lead-acid batteries that have been proposed or widely used.
0.005 to 0.01 weight ft to PB with approximately Sb added
% of Ca is added. The properties required for electrode materials for lead-acid batteries include appropriate strength and corrosion resistance, as well as a small current at the end of charging and little loss of liquid.
Castability or workability is also required for applications such as grids. The above-mentioned pb-Sb alloys have excellent strength, but are not satisfactory in terms of corrosion resistance and liquid reduction. On the other hand pb
-Ca alloy is excellent in liquid reduction and has poor corrosion resistance, especially when repeated deep charging and discharging.

The present invention causes a decrease in strength (PB with excellent castability).
The purpose is to improve the corrosion resistance and liquid reduction properties of -3b alloy-based electrode materials.

The easiest way to improve corrosion resistance and liquid reduction properties in pb-Sb alloys is to reduce the Sb content to at most 2% I. This is known to improve corrosion resistance and liquid reduction properties by eliminating the eutectic structure of pb-sb.

However, when the Sb content is less than 2%, the strength is insufficient, and when the Sb content is in the range of 1% to 2%, the incidence of hot cracking during casting is high, making it difficult to cast. be.

The main points of the present invention can be summarized in a nutshell: Sb-containing @ with good castability
By using an alloy of 1.0% or less, the lack of strength was improved by making the structure uniform and finer due to the addition of alkali metal. Furthermore, as a result of experimental studies, improvements in corrosion resistance and liquid reduction properties were also obtained.

For alkali metals I, i, K, N aSRb.

C8, Rb, and Cs are excluded because their melting points are low and there are difficulties in adding them. In the present invention, the amount of one kind of Li5K1Na added is below 05 weight factor, 011 weight factor
Specify that it is greater than or equal to i%.

Here, the upper limit was set at 0.05 wt.ffi% because addition of more than this not only deteriorates castability, but also deteriorates corrosion resistance and liquid reduction properties. The lower limit is 0.11 times ffi
% because if it is less than this, the effect of addition is poor and the strength is insufficient. Further, the pb-Sb alloy to be subjected to the above addition treatment is specified to have an Sb content of 0.2% by weight or more and 1.0% by weight or less. Here S
The reason why the upper limit of the amount of b is set at 1.0 weight factor is that addition of more than this not only deteriorates castability but also is unnecessary for the purpose of the present invention. The reason why the lower limit is set at 0.2 times ffi% is that below this, even if Lt, K, and Na are added, the strength is insufficient.

Example Tensile strength was measured by adding Li and 1Na to a pb-Sb alloy. Table 1 shows the measurement results. The addition resulted in an increase in strength of about 3 times.

Next, a pb-Sb alloy to which Li, K, and Na had been added was anodized at 20 mA/sheet for 240 hours (20°C, sulfuric acid specific gravity 1.28), and compared with other alloy compositions. Table 1 shows the results. As is clear from Table 1,
It can be seen that this scrapped product is superior in corrosion resistance.

Regarding the amount of corrosion, pb-S containing 4% Sb ff1%
This is the ratio when the amount of corrosion of alloy b is set to 100.

Table 1 In addition, the hydrogen generation potential (at the time of current application of 0.43 mA/m) of the pb-Sb alloy to which Na was added at t and t was measured. The results are shown in Figure 2.

The invented product behaves almost the same as pure pb and pb-Ca alloys, and the current at the end of charging is small, and pure pb and pb-Ca
It is possible to achieve liquid reduction properties equivalent to alloys.

A battery was fabricated using a lattice made of a CPB-3B alloy (CPB-3B alloy) with 1N a added to it, and a charge/discharge cycle test was conducted. As a result, no early capacity reduction was observed due to deep charging and discharging unlike in batteries with a pb-Ca alloy lattice.

As explained above, the electrode material for lead-acid batteries of the present invention has extremely high industrial value, such as excellent strength, corrosion resistance, liquid reduction properties, and castability.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the present invention in which Li is applied to a pb-Sb alloy.
, a graph showing the relationship between the tensile strength and the amount of KSNa added, and FIG.
, K, and Na are added to the hydrogen generation potential. Patent applicant Lj, No's daily weight (vehicle volume %p Fig. 2 Li, , No's multi-day power mouth 14 (weight% La 307

Claims (1)

[Claims] It is characterized by adding 0.11 to 0.5% by weight of one type of PB gold alloy alkali metal Li, K, Nal7) containing 0.2 to 1.0% by weight of Sb as a basic composition. Electrode material for lead-acid batteries.