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Why are lead-antimony alloys used in lead-acid batteries?

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Metallurgy — lead processing A zinc-lead blast furnace and lead-splash condenser. This technology is utilized mainly for producing zinc while managing both lead and zinc from raw materials, a technique that was highly influential in 20th-century smelting.

Lead-antimony alloys are primarily used in lead-acid storage batteries because the addition of antimony significantly improves the hardness and strength of the lead.12

In the context of battery manufacturing, this alloy—often referred to as "hard lead"—is used to cast the grids and terminals of the battery plates. By providing increased structural integrity, the alloy ensures that these components can withstand the physical demands of the battery environment. Additionally, the performance of these grids can be further enhanced by the inclusion of small amounts of silver.3124

While traditional batteries utilize these antimonial lead alloys, modern "maintenance-free" automotive batteries often use different compositions, such as lead-calcium alloys, for their plates to reduce maintenance requirements.1