A High-end Product: lithium Ion Battery Aluminum Foil

Aluminum foil acts as a positive current collector in lithium batteries due to its good properties. Lithium ion battery aluminum foil has good conductivity, soft texture, cost advantage, stable performance at high potential and is not easy to oxidize, and the above characteristics are well adapted to the requirements of power batteries for current collectors.

The aluminum foil used for current collectors is mainly 1060, 1070, 1100, 1235, 3003 and other alloys. The mainstream thickness specification is 10-20μm. Some battery manufacturers use 8μm battery aluminum foil. The future direction is to continue to thin it, and it may even be reduced to 6μm.

1235 pure aluminum foil has a relatively high purity and good conductivity, so it is often used as battery foil. The minimum thickness of 1235 battery foil is 0.014mm, the strength is >180Mpa, and the surface dyne value is very high.

Dyne value is a popular name, which should be the surface tension coefficient to be more precise. Surface wetting tension is one of the most important technical indicators of battery foil. It affects the adhesion quality of the coating, especially the coating firmness of carbon-coated foil. When the dyne value is low, the aluminum foil is not firmly bonded to the adhesive material, and there are defects such as missing coating. The dyne value of the aluminum foil surface should be greater than 32dyn/mm, and some high-requirement carbon-coated products should even reach 34dyn/mm.

Compared with ordinary aluminum foil, the requirements for battery grade aluminum foil are higher, among which the thickness is required to be controlled at 10~50 microns, and some battery factories even use 8-micron aluminum foil. At the same time, the battery current collector is also required to have lower roughness, better conductivity, tensile strength, and elongation. In addition, there are also high requirements for product consistency and stability. Therefore, battery aluminum foil has high requirements for equipment and processes and has certain entry barriers.

The price of battery aluminum foil is affected by many factors: 1. fluctuations in the price of aluminum ingot; 2. technical added value (processing fee). 9/10μm battery aluminum foil has high technical content with larger usable area per ton; 3. different companies have different product cost control capabilities and technical quality, and their prices are also different.