All rechargeable batteries have current collectors. These do not store the energy themselves. Although they do play an important role in the electrochemistry that happens inside them. But these thin metal sheets are not all the same. So how do current collectors vary between batteries?
How Do Current Collectors Work?
A current collector is like a highway for electricity. It gathers the electric current from the battery’s active electrode, and carries it to the battery terminals.
When the battery re-charges, it also helps move electrical energy back to the other electrode in the battery. Without current collection, batteries could not deliver their power efficiently, if indeed at all.
Dual Collectors Inside Batteries
Many modern batteries use dual current collectors. One is at the positive electrode, and the other at the negative electrode. Manufacturers choose metals that conduct electricity efficiently, resist corrosion, and add as little weight as possible.
Current collectors improve battery performance in several ways. They help electricity move quickly through the battery, reduce energy losses, and support the battery’s internal structure. Good current collectors also improve reliability and extend battery life.
Lithium-Ion and Sodium-Ion Collectors
We asked earlier how current collectors vary between batteries. Lithium-ion and sodium-ion batteries use very similar designs, but they differ in their materials:
- Lithium-ion batteries normally use aluminum as their positive current collector and copper as the negative current collector. Copper works well in lithium-ion cells, because the negative electrode remains stable at low voltages.
- Sodium-ion batteries often use aluminum for both current collectors. This costs less than copper, weighs less, and remains stable. This gives sodium-ion batteries a cost advantage, especially in large energy-storage projects.
The Efficient Lead-Acid Difference
Our sealed deep-cycle lead-acid batteries use lead-alloy grids as their current collectors. These support the active material, but also carry electrical current to the terminals.
In this way, they combine structural support and current collection, using the same component. This also enhances their value for bulk energy storage.
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