Surface treatment technology of battery shell

Why is surface coating important in lithium ion batteries?

A major function of surface coatings in conventional lithium-ion batteries (discussed in section 3) is to provide a physical barrier between cathode and liquid electrolyte and thus suppressing the un-wanted side reactions, which may result in the formation of unstable SEI layer.

What is a battery coating & how does it work?

The primary role of such coatings is to act as a protective passivation film which prevents the direct contact of the cathode material and the electrolyte, thus mitigating the detrimental side reactions that can degrade the battery performance.

Why do battery cells need a protective film?

In the conventional way, battery cells, especially prismatic cells, are protected by a film. This process is costly and time-consuming and contains several sources of error. For example, condensation can accumulate under the protective film or the formation of unevenness in the bonding process can impair functionality.

How to protect a battery cell?

For reliable and efficient electrical insulation, a newly developed process is used to apply a protective coating instead of film wrapping the cells. In addition, ultra-fine cleaning of the bare battery cell ensures that the coating adheres completely and without gaps.

How are the prismatic battery cells coated?

In the second step, the prismatic battery cells at Venjakob are coated with a special 100 % UV protective coating in a fully automated, contact-free process. It is essential to protect the so-called terminals from overspray during the coating process.

How does a UV cured battery work?

After automatically passing through a UV channel and repeating these two steps in the continuous process, the coated cells are discharged. Thanks to immediate curing, they can be processed directly. This speeds up the entire battery manufacturing process.