Surface treatment with plasma technology can increase efficiency, lower costs, and reduce environmental harm within battery manufacturing.
Plasma applications make it possible to optimise battery manufacturing for electric vehicles (EVs). Besides vacuum plasma, the atmospheric plasma technology Openair-Plasma for pretreatment of surfaces is used in various processes to help make a number of production steps more efficient and more eco-friendly.
Mobility-related changes mean that the need for high-performance batteries for EVs is rapidly increasing. Plasmatreat’s plasma technology is based on a simple physical principle: The addition of energy causes the states of matter to change. Solids become liquids, and liquids become gases. If additional energy is added to a gas, it ionises and becomes energised plasma, the fourth state of matter. If the plasma, with its high energy level, subsequently comes into contact with materials, the surface properties of those materials may change. The wettability of the surface increases and a hydrophobic surface may become hydrophilic. As a result, adhesives, paints, varnishes or seals adhere optimally to the surface.
Plasma pretreatment is the key technology for microfine cleaning, activation, and coating of practically all materials. In that sense, it is a universal problem-solver: Plasma facilitates the industrial use of entirely new materials and material combinations, as well as the use of solvent-free paints and adhesives. It also makes processes more efficient and environmentally friendly, particularly battery manufacturing.
Openair-Plasma is Plasmatreat’s atmospheric plasma nozzle technology. If Openair-Plasma is not sufficient for optimum adhesion, a plasma coating can provide a remedy in many cases. One example is the PlasmaPlus technology developed by Plasmatreat, which uses nanocoatings to create specifically functionalised surfaces on various die casting alloys or aluminium materials. These can be both superhydrophobic and superhydrophilic, for example. Specific additives are added to the plasma via a special nozzle head, depending on the application. This plasma polymerisation allows the substances to optimally adhere to the material surface during plasma coating, to bind firmly and to crosslink with each other. The result is a nanolayer with functional surface properties that can be individually tailored to the process. One example is the PlasmaPlus application AntiCorr for anti-corrosion coatings on sealing and adhesive grooves on battery housings.
Plasma treatment for battery manufacturing
These days, Plasmatreat’s plasma technology is used for all kinds of batteries: prismatic, cylindrical and pouch cells. These areas of application are extremely wide. For example, optimisation of electrical insulation can be achieved via plasma cleaning prior to coating or the covering of individual cells with PET film. In cell-to-cell bonding - adhesion of individual cells to the battery module - plasma treatment activates the cell surfaces after application of the coating or the film covering, thereby improving adhesion and thus thermal conductivity.
The adhesiveness of structural bonding in a battery module, for example of the side walls, can be increased through plasma treatment of the components. Plasma technology is also used for cleaning battery terminals before contact (wire bonding) as well as for coating the overall housing of the battery module for active corrosion protection or treatment of power electronics prior to application of the protective coating (conformal coating).
Integration is key
Plasmatreat’s plasma systems and system components for its Openair-Plasma technology can be integrated into existing production lines and require only pressurised air and electricity for operation. In many cases, they represent an alternative that is less harmful to the environment. In battery manufacturing, for example, they replace solvent-containing processes in adhesion or aggressive chemical processes that are used to protect against corrosion, such as galvanisation. Supplemented by the high-tech plasma control unit (PCU) and innovative add-on modules for monitoring and diagnosing all process parameters, Plasmatreat offers its customers seamless process controlling, consistently high quality and precise reproducibility of applications.
Lukas Buske is the Head of Plasma Applications at Plasmatreat