What are the requirements for surface roughness of copper and aluminum foils for lithium batteries?

For the lithium ion battery current collector, in addition to its thickness and weight having an influence on the battery, the surface performance of the current collector has a greater influence on the production and performance of the battery.

Especially for the negative electrode current collector, due to the defects of the preparation technology, the copper foils on the market are mainly single-sided hair, double-sided hair, and double-sided roughened varieties.

This asymmetry of the two-sided structure leads to asymmetric contact resistance of the coating on both sides of the negative electrode, which in turn prevents the negative electrode capacity on both sides from being evenly released.

At the same time, the asymmetry on both sides also leads to the inconsistency of the bonding strength of the negative electrode coating. It is that the charge and discharge cycle life of the negative electrode coating on both sides is seriously unbalanced, which further accelerates the decline in battery capacity.

More information at the Aotelec.com.