CA1055735A - Lead alloy for battery plate screen - Google Patents

Abstract

Lead alloy poor in antimony for accumulator plate grid including tellurium in an amount by weight of 0.001% and 0.2%, 1 to 3.5% of antimony, 0.01 to 0.2% of arsenic. 0.005 to 0.05% tin and 0 to 0.3% silver.

Description

The present invention has for ob ~ and a lead alloy for grids of accumulator plates, and in particular an alloy low in antimony.
Lead acid battery grids are generally consisting of an alloy with an antimony content of the order of 3.5%
at 11% by weight. Such allies ~ es have the advantage of having a mechanical resistance ~
sufficient nique and good quality of casting. They also present many disadvantages; thus, the electrochemical corrosion entered ~ does the presence of antimony in the positive and negative active ingredients, and it a significant sulfation of the plates appears during storage of the drums. In addition, at the level of the negative plates, the over-voltage of hydro-~ gene is weak because the active ingredient is poisoned by antimony from ; ~ positive plates, negative grids also have an overvoltage low. On the one hand, this results in significant electrolyte consumption.
when the battery is overcharged at constant voltage, and others share a j auto ~ fast discharge of this battery. ~ -"s ~ The present invention aims to achieve an alloy for avoid the disadvantages of alloys with a high antimony content and keep their benefits as much as possible.
The present invention has for ob ~ and a lead alloy for grid of accumulator plague, characterized in that it contains 1% 3 3.5%
antimony, 0.001% to 0.2% tellurium, 0.01% to 0.2% arsenic, 0.005% to 0.05%
tin, and lead.
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Without the arsenic, tellurium and tin impurities in the proportions tions defined above, an alloy comprising 2.5% to 3.5% of antimony would soft and an alloy comprising 1% to 2.5% would be both soft and brittle. The tellurium a ~ outed in a quantity chosen between 0.001% and 0.2% depending on the content antimony eliminates the risk of cracking of the alloy and improve its mechanical properties such as hardness, resistance to bending and tensile. Adding tin improves the quality of casting of the alloy and the addition of arsenic further improves the mechanical properties niquss.

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Can be used advantageously for grids of posi-tives et negatives ~ es lead alloys containing the following elements:
1sr example antimony: 1 ~
tellurium: 0.1%
arsenic: 0.0 ~%
tin: 0.03%
2nd example antimony: 2%
tellurium: 0.075%
arsenic: 0 ~ 08%
. tin: 0.03%
3rd example antimony: 2.5%
tellurium: 0.001%
arsenic: 0.05 to O, OB%
tin: 0.03%
: ~ For the grids of positive plates, and in particular those dss traction and semi-fixed battsries, preferably add a quantity 1 20 of silver between 0.02% and 0.3% to reduce electrochemical corrosion.
. ~. Thus, the following alloy can be advantageously used:
antimony: 2.5%
tellurium: 0.001%
j arsenic: 0.05% to 0.0 ~%
tin: 0.03%
silver: 0.10% to û, 13%
We measured that a grid made of the previous alloy lost less weight by electrochemical corrosion than a grid made in one classic alloy containing 6% antimony and 0.13% silver.
Tests have made it possible to verify that an alloy according to the invention i presented a ~ onne quality of casting for the molding of thin grids and that the latter had a hardness and mechanical tensile strength

- 2 sufficient. However, in order to increase the hardness of the grates, it is possible to subject them to additional heat treatment such as water quenching as soon as it leaves the mold ~ this treatment also makes it possible to stretch towards a supersaturated solid solution limiting the departure of antimony ~
i It is observed that, in batteries now containing alloy grids according to the invention, the antimony pollution of positive plates st negative and the release of hydrogen is lower than in batteries known up to now. The charging fln voltage is much higher both for new batteries and for used batteries. The consumption of electrolyts is reduced and, for starter batteries, ~
it is not necessary to add water during their lifetime, without ~ -'''5 ~ t however increase their electrolyte reserve ~ the conservation of their capacity is also markedly improved during a storage of several month.
7 Of course, the use of the alloy according to the invention is not limited to the manufacture of grids of the types of batteries mentioned above.
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Claims (6)

The embodiments of the invention about which an exclusive right of property or privilege is claimed, are defined as follows: 1. Lead alloy for battery plate grid reader, characterized in that it contains lead, 1% a 3.5% antimony, 0.001% to 0.2% tellurium, 0.01% to 0.2%
arsenic, 0.005% to 0.05% tin, and 0 to 0.3% silver. 2. Lead alloy according to claim 1, charac-terrified by the fact that it contains 1% antimony, 0.1%
tellurium, 0.08% arsenic and 0.03% tin. 3. Lead alloy according to claim 1, charac-terrified by the fact that it contains 2.5% antimony, 0.001%
tellurium, 0.05% to 0.08% arsenic, and 0.03% tin. 4. Lead alloy according to claim 1, charac-terrified by the fact that it contains 2% antimony, 0.075%
tellurium, 0.08% arsenic and 0.03% tin. 5. Lead alloy according to claim 1, charac-terrified by the fact that it contains money in a proportion between 0.02% and 0.3%. 6. Lead alloy according to claim 5, charac-terrified by the fact that it contains 2.5% antimony, 0.001%
tellurium, 0.08% arsenic, 0.03% tin, and 0.10% to 0.13%
silver.