Thermal Interface Selection Criteria for Prismatic Battery Modules
Optimal prismatic module thermal interface selection balances bulk conductivity against rheology and compliance to accommodate swelling without dielectric rupture.
Outgassing Volatility
Meaning
Release of volatile compounds from non-metallic materials occurs when they are exposed to heat or reduced pressure. This property of outgassing volatility is a critical parameter for adhesives and thermal pads used in enclosed electronic assemblies. If a compound releases significant gas, it can condense on sensitive surfaces.
Measuring this behavior helps ensure long-term reliability in sealed battery packs.
Thermal Release
High temperatures inside operating battery modules accelerate the release of low-molecular-weight species. These volatiles escape from the polymer matrix of thermal pads or structural adhesives as gas. The rate of release depends on the temperature, the surface area exposed, and the chemical stability of the polymer.
This process can lead to material shrinkage and loss of physical properties over time.
Contamination Risk
Condensation of outgassed molecules on electrical contacts can form insulating films that increase contact resistance. In optical or sensing systems, this film can cloud lenses and degrade performance. Inside sealed battery enclosures, the accumulated gas can also increase pressure and create corrosive mixtures if it reacts with moisture.
Preventing this accumulation requires materials with low volatile content.
Material Selection
Standardized tests such as ASTM E595 measure the total mass loss and collected volatile condensable materials to screen products. Suppliers must provide these metrics to qualify materials for automotive and aerospace designs.