Mechanically Robust and Flexible Nitride Ceramic Nanofibers Enabling Advanced Thermal Management

Nitride ceramics with high thermal conductivity can effectively dissipate localized heat and prevent hotspot formation in advanced electronics. However, their intrinsic brittleness and limited deformability render them susceptible to structural damage under multiaxial mechanical loading, disrupting the continuity of heat transfer pathways and compromising long‐term device reliability. Here, a multiscale structural optimization strategy based on organic–inorganic hybrid chains is proposed to produce high‐strength, flexible, yet highly thermally conductive nitride ceramic nanofibers. This achievement arises from an optimized grain structure with high crystallinity at the microscopic scale, coupled with a continuous, defect‐minimized fibrous architecture at the mesoscale, collectively striking an optimal balance between stress transfer and phonon scattering to achieve rapid stress dissipation and efficient heat transport. Building on this feature, the nitride ceramic nanofibers exhibit excellent flexibility and a mechanical strength of up to 528.3 MPa despite possessing high crystallinity, a characteristic that typically leads to brittleness. Meanwhile, large‐area, free‐standing aligned fiber membranes fabricated via electrospinning achieve a high thermal conductivity of 16.58 W m − 1 K − 1 and structural stability during bending. This work offers new opportunities for high‐performance fibrous materials in next‐generation electronic systems.