Effect of Ceramifiable Silicone Rubber Composite based Thermal Insulators in Battery Packs

Silicone and rubber composite, often called Ceramifiable Silicone Rubber (CSR) has proven to show excellent mechanical and thermal properties. CSR materials have been mainly used in industrial applications like electrical insulating cables, decorations, and fire-proof materials. The mechanical and ceramifiable properties of CSR can be altered by changing the silicone rubber matrix and by adding the right additives or fillers. In this work, we prove the potential of CSR composites as thermal insulating materials in battery packs. Specifically, we explore the usage of CSR inside the battery pack to improve safety during thermal events. We also characterize the material properties before and after exposing the CSR composite to elevated temperatures and flame. Finally, we investigate the effectiveness of the CSR composite sheet in preventing or delaying cell-to-cell thermal propagation during a thermal runaway event inside the battery pack. Our experiments show that the CSR composite sheet significantly reduces the propagation of thermal runaway between cells, improving the safety of the battery pack used in electric vehicles and energy storage applications.