Dielectric‐Conductive Dual‐Shell Structure Design Overcome the Lightweight‐High Strength and Electrical‐Thermal Conductance Trade‐Off

ABSTRACT The advancement of modern electronic devices toward lightweighting, high‐frequency, and integrated designs has escalated the demand for multifunctional materials that can combine microwave and thermal management capabilities with mechanical load‐bearing capacity. However, inherent trade‐offs exist between electrical conductivity and thermal insulation, as well as between mechanical strength and lightweight properties. Herein, attempts have been made to innovatively embed lightweight, high‐strength dielectric shells and highly conductive, low‐infrared‐emissivity metallic shells into hollow structure design. Specifically, heterogeneous dual‐shell hollow microspheres (DSHM) were constructed using glass as the model dielectric material and copper as the conductive material. By optimizing the ratio of dielectric‐to‐conductive phases, the shell microstructure, and macroscopic structural parameters, we achieved a synergistic combination of lightweight and high strength (density: 0.4456–1.0991 g cm − 3 , survival rate under 2 MPa uniaxial compression: 87.1%. Crucially, leveraging the distinct structural dependence of conductive and thermal networks, the integration of low thermal conductivity (0.1134–0.1478 W m − 1 K − 1 ) with broadly tunable electrical conductivity (299.6–2625.7 S cm − 1 ) and infrared emissivity (0.218–0.493) in a single microsphere was achieved for the first time. These properties endow the hollow microspheres with exceptional microwave attenuation and thermal regulation performance.