Hierarchical thermal-conductive polymer nanocomposites for thermal management

•A hierarchical thermal-conductive interface material consisting of heterogeneous atomic layer ceramic and aligned polymer dielectric fiber array.•The heterogeneous material exhibits lightweight, high thermal conductivity and dielectric strength, on which a scalable manufacturing of crystalline ultrahigh molecular weight polymer with atomic layer deposited ceramic interface is reported with the increase of 200% thermal conductivity and 180% dielectric constant and strength.•The mechanistic understanding of heat dissipation from ceramic-polymer interface is carried out using finite element modeling to confirm the temperature and heat flux evolution under dynamic electric load conditions.•The ceramic-UHMWPE encapsulated conductor exhibits a low surface temperature with temperature difference of 17.8 °C at 10.8 W input power.