Metallized film current collectors in batteries improves safety and reduces weight
Increasing adoption of electric vehicles, renewable energy, and proliferation of consumer electronics is driving Lithium-ion battery demand. However, traditional designs have well-known safety issues from thermal runaway. This can occur in Li-ion batteries when the internal temperature and pressure rises from an electrical short caused by manufacturing defects or from mechanical damage, which on many occasions have led to fire/explosion.
Metallized plastic film to replace conventional metal-foil current collectors is an innovation patented by the Soteria Battery Innovation Group to address the safety challenges. This is very similar in concept to the self-healing capability of metallized-film capacitors.
The concept of a polymer film coated with metal on both sides enables new design goals to be successfully implemented. On the one hand, the specific power density of the battery can be further increased and the cell also becomes intrinsically safe against flammability in the event of a short circuit. Copper and aluminum electrodes are currently being tested. The layer thicknesses are 20 times thicker than usual for evaporation technology and are in the range of 0.5 to 1 µm on a substrate that is thinner 8 µm.
Soteria has successfully validated the concept by introducing Steinerfilm metallized film in actual products made by established Li-ion battery producers. It’s a drop-in replacement, and in addition to safety, it also offers weight and volume reductions, critical to all Li-ion battery applications and growth. Steinerfilm is an active member of the Soteria industry consortium.
Consortium member SVolt Energy has built NMC 811 cells demonstrating the enhanced safety of the Soteria aluminum metallized film current collector produced by Steinerfilm against control cells with standard aluminum foils.