Coat both sides of a 4.5 μ m PET film with 1 μ m copper to form a 6.5 μ m PET copper plated film

PET copper plated filmIt is a technology of vacuum nano coating on PET base film, using copper with a purity of 99.999% as the target material, and then depositing a metal copper film on its surface by changing the working pressure, temperature, and evaporation time in the vacuum chamber. Combining the performance of PET film with the conductivity and thermal conductivity of copper. You can choose single-sided copper plating orDouble sided copper plating.

A 4.5 μ m PET film is coated with 1 μ m copper on each side to form a 6.5 μ m PET copper plated film, also known asPET copper foilThat is, composite copper foil. Replacing metallic copper with PET, a polymer substrate material with low density, low Young's modulus, high compressibility, and low cost, is characterized by thinner thickness, smaller copper usage, and effectively improving the safety and energy density of lithium batteries.

Lithium ion copper foil processIt can be divided into electrolytic copper foil and PET copper foil, among which electrolytic copper foil is the mainstream process in the market, and PET copper foil is a new process; The biggest difference between PET copper foil and traditional copper foil is that traditional copper foil is mostly prepared by electrolysis, while the core of PET copper foil process is vacuum coating and ion exchange.

1. Vacuum coating

Vacuum magnetron sputtering is one of the main techniques for preparing thin films and has a wide range of applications. Magnetron sputtering coating is achieved through the action of electric and magnetic fields. The working gas generates glow discharge, and ions bombard the target material to sputter material particles to form a thin film. The purpose is to create a metal layer on the surface of the plastic film, metalizing non-metallic materials. It has the advantages of good coating stability, high repeatability, good uniformity, suitable for large-area coating, dense film layer, good adhesion, and high process flexibility. Its main application industries include consumer electronics, automotive, optics, and glass industries.

2. Horizontal copper plating

After the plastic film is attached with a metal layer by vacuum magnetron sputtering, the copper layer is thickened to 1 μ m by aqueous medium electroplating to produce composite copper foil. The PET copper plating technology originates from PCB electroplating, but compared to PCB electroplating, the difficulty in developing PET copper plating equipment lies in meeting the requirements of film material manufacturers for PET composite film materials that are not deformed, have good uniformity, and have no perforation when the film is very thin.

Compared with traditional copper foil, PET composite copper foil has four major advantages:

1. High safety: The plastic separator layer in the middle of the composite copper foil can greatly improve the combustion safety of the battery.

2. High specific capacity: Under the same conditions, the amount of copper used is only 1/3-1/5 of the original, and some copper is replaced with plastic, which reduces the weight of the battery and increases its energy density;

3. Long lifespan: reduces the shedding of active substances caused by metal shrinkage, which can improve battery cycle life;

4. Strong compatibility: suitable for environments with lithium batteries.

The vast space and increasing demand in the new energy vehicle market have driven power batteries to become the main driving force for the increase in demand for lithium battery copper foil. For battery factories, the thinner the copper foil, the less copper is used, and the lower the cost; For copper foil factories, they are the first to achieve ultra-thin andComposite copper foilEnterprises producing high-end products will enjoy higher technological premiums and stronger profitability, and copper foil manufacturers have a strong willingness to produce high gross profit margin products. Therefore, both battery and copper foil factories will vigorously promote the development of ultra-thin copper foil, and PET copper foil is thinner and uses less copper compared to traditional copper foil, effectively improving the safety and energy density of lithium batteries.