Studies on 8.4 W/m·K thermally conductive silicone rubber with high compressibility, high electrical insulation, high thermal reliability, and low cost

Thermally conductive silicone rubber (TCSR) has been widely used to enhance heat dissipation in electronics and energy storage devices. Currently, it is a challenge to produce TCSR which combines high thermal conductivity, high compressibility, high thermal reliability, high electrical insulation, and low cost. Here, we report a state-of-the-art TCSR which achieves such a combination. Owing to the optimized alumina gradation, the loading level of alumina in the TCSR reaches 96 wt%. The TCSR reaches a high and isotropic thermal conductivity of 8.4 W/m·K, a high compression ratio of 48 % (under a pressure of 6 psi or 42.4 kPa), and a high dielectric strength (>6 kV/mm). After heating at 180 °C for 100 h, little oil bleeding is observed. More importantly, these properties remain stable (variation < 10 %) after 2000 h of thermal aging at 135 °C, indicating high thermal reliability.