▎ 摘　　要

NOVELTY - Polymer-based composite material comprises a three-dimensional woven body formed by composite fibers (100), where the composite fiber includes a one-dimensional carbon material (120) and a polymer matrix (110), and the polymer matrix is oriented in the length direction of the one-dimensional carbon material. The composite fiber is subjected to a slurry treatment with a thermally conductive slurry before forming the three-dimensional woven body. The thermally conductive slurry includes a two-dimensional thermally conductive material. The thermally conductive slurry includes graphene. USE - The polymer-based composite material is used in a thermal management device. The composite material or the thermal management device is used in a device (all claimed). ADVANTAGE - The composite material has at least: that the organic molecular chains of the polymer matrix and the one-dimensional carbon material are co-orientated, so that the composite fiber exhibits ultra-high thermal conductivity in a single dimension; simultaneously treating the composite fiber with a thermally conductive slurry to synergistically improve the thermal conductivity of the composite fiber; and three-dimensionally weaving to obtain a three-dimensional woven body, so that the overall composite material exhibits obvious high thermal conductivity in three-dimensional directions. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a preparation method of the polymer-based composite material, involving mixing the polymer matrix with an organic solvent, and ultrasonically treating to obtain a dispersion, mixing the dispersion with the one-dimensional carbon material, and ultrasonically treating to obtain the mixed material, spinning the mixed material to obtain the composite fiber, and slurrying the composite fiber by using a thermally conductive slurry to obtain a slurried composite fiber, where the sizing composite fiber is three-dimensionally woven to obtain a three-dimensional woven body; (2) a thermal management device comprising the polymer-based composite material; and (3) a device comprising the polymer-based composite material or the thermal management device. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic partial cross-sectional view of the composite fiber structure in a polymer-based composite material. Composite fibers (100) Polymer matrix (110) One-dimensional carbon material (120)