Adhesives for Electric Vehicle Batteries
What are the biggest challenges in developing adhesives for the e-mobility market?
I have to say it is balancing features. Many of the adhesive features battery manufacturers require play off each other.
Following is a partial list of commonly requested features:
- Low Weight – Expandable adhesive products
- Good Heat Dissipation – Thermal Conductivity
- Low Cost – Efficient process and
- Electrical Resistance – High Dielectric Strength
- Safety – Fire Retardant Products
- Environmental Resistance – Encapsulants
- Adhesion – Durable or controlled
- Temperature swings – Thermal Expansion and Contraction
As battery manufacturers work to improve safety, reduce weight, increase performance and lower costs of battery-powered vehicles and machines, adhesive chemists are rapidly developing new products with unique features to allow the advancement of e-mobility.
The features of these products are dialed in to meet unique specifications. The challenge comes in balancing one or more characteristics against the others.
For example, high thermal conductivity is a common requirement. Batteries can get extremely hot while charging, and the faster the charge – the higher the heat. Dissipating the heat between the battery cells and bond the modules to the heat sink is one goal of the adhesive. The adhesive ensures no water ingress which could cause short circuits or damage to components. A key feature the adhesive must have is high dielectric strength to provide good electrical resistance and prevent arcing.
High thermal conductivity is easy to achieve in adhesives. However, it must be balanced with increased cost, increased viscosity, increased weight, and a potential reduction in electrical resistance.
In high-speed manufacturing lines, the adhesive is automatically dispensed. Very high viscosity adhesives can be difficult to dispense.