Battery Technology Reference · Last reviewed 2026-09-16
| Material | Formula | Role |
|---|---|---|
| Leady oxide (litharge mix) | PbO + free Pb | The paste starting material |
| Lead dioxide | PbO₂ | Positive-plate active material (after formation) |
| Spongy lead | Pb | Negative-plate active material (after formation) |
| Red lead | Pb₃O₄ | Additive that speeds formation |
Two industrial routes produce the fine lead-oxide powder used in paste:
The resulting "leady oxide" is a mix of lead monoxide (PbO) and free metallic lead. Its particle size and oxidation level matter directly: finer, more oxidized powder pastes better and forms a more porous, higher-surface-area plate — which is part of what determines CCA and capacity.
The lead oxide is the battery's energy-storing ingredient; the grid is only the conductor. The particle-size and paste quality control here decide how much active surface area the plate presents, which feeds directly into cranking performance — see plate & grid design.
My position: The lead oxide is the part of a lead-acid battery that actually does the work — and it is also the most under-appreciated, because everyone looks at the grid and the case instead of the powder inside them.
Why I think so: Capacity and CCA both trace back to active-material surface area and porosity, which are set at the oxide and paste stage. Two batteries with identical grids can perform very differently based on the oxide alone.
This is the author's editorial view, not a purchasing guarantee.
Return to Battery Technology Reference · World Battery Hub. Informational, not purchasing advice.