Surface treatment method for copper foil
By immersing and drying the copper foil in a surface treatment solution, the surface roughness of the copper foil is controlled within the range of 0.8-2.8 μm. This solves the problem of performance degradation of lithium-ion secondary batteries caused by uneven surface roughness of copper foil, and improves the bonding strength between the copper foil and the negative electrode coating and the uniformity of the battery.
Patent Information
- Application Number
- CN202311591952.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-24
- Publication Date
- 2026-04-07
- Estimated Expiration
- 2043-11-24
AI Technical Summary
In the prior art, the uneven surface roughness of the copper foil leads to a decrease in the charging and discharging efficiency of lithium-ion secondary batteries and inconsistent bonding strength of the negative electrode coating, which in turn accelerates the capacity decay of the battery.
A roughening treatment solution using deionized water as the main solvent, containing copper trifluoroacetate hydrate and peracetic acid, is used to improve the surface roughness of copper foil to the range of 0.8-2.8 μm through soaking and drying, while controlling the roughness difference between the two sides to within 0.1 μm. This increases the specific surface area and active sites of the copper foil, thereby enhancing its adhesion.
It effectively improves the bonding strength between copper foil and negative electrode coating, reduces the probability of coating peeling, uniformizes battery performance, and extends battery life.