Shear Stiffening-Reinforced Conductive Nickel Metal Composite Foam for Impact-Thermal Protection and High-Performance Electromagnetic Shielding

As the most common hazards in daily life, impact-thermal shock and electromagnetic radiation inevitably negatively affect national security and economic development. The development of high-performance and multifunctional protective materials is highly important since a single protective material is no longer sufficient to meet the demands of complex and extreme environments. In this work, a multi-protective composite material with high-performance impact resistance, thermal insulation and electromagnetic shielding was developed by integrating shear stiffening gel (SSG) with conductive Ni-coated foam. The conductive Ni-coated foam served as the conductive component and heat insulation medium, while the SSG was used as the reinforcing phase to further enhance its mechanical performance. The resulting SSG/Ni composite foam effectively attenuated external impact forces, and the absorption rate of the impact energy exceeded 90%. Owing to the low thermal conductivity of the conductive Ni-coated foam (0.039 W m⁻¹ K⁻¹), the SSG/Ni composite foam exhibited excellent thermal insulation properties over a wide temperature range from 50 to 200 °C. At a thickness of 5 mm, the SSG/Ni composite foam showed superior electromagnetic shielding performance, with a maximum shielding effectiveness of 80 dB, which far exceeded the commercial and industrial requirements. This work provides a feasible strategy for the development of next-generation multimodal functional protective materials.