▎ 摘　　要

NOVELTY - Preparation of three-dimensional graphene composite material involves (1) fixing polyimide paper on substrate, laser inducing to produce laser-induced graphene (LIG) substrates, (2) paving polymer powder on the surface of the substrate LIG, (3) using carbon dioxide laser to laser-selective carbonizing the paved polymer powder substrate, forming a pre-designed single-layer graphene film, (4) paving a layer of polymer powder on the surface of the formed graphene film, (5) using carbon dioxide laser to laser-selective carbonizing the paved polymer powder substrate, forming a pre-designed single-layer graphene film, (6) repeating steps (4) and (5), obtaining three-dimensional graphene structure, (7) soaking the three-dimensional graphene structure in filling material and curing. The thickness of powder layer is calculated by using correlation coefficient and laser power. In step (2) and (4), the thickness of the powder layer is 60-80% of the growth height of graphene. USE - Preparation of three-dimensional graphene composite material. ADVANTAGE - The method is economical, and produces product with high efficiency and simple steps. The method does not require the use of chemical reagents, additional processing technology assistance or processing in a special atmosphere, and achieves rapid prototyping. In this method, the structure of the prepared three-dimensional graphene composite material is controllable, and the printing of multi-scale complex three-dimensional graphene structure can be realized, and the obtained composite material has excellent comprehensive properties. DETAILED DESCRIPTION - Preparation of three-dimensional graphene composite material involves (1) fixing polyimide paper on substrate, laser inducing to produce LIG substrates, (2) paving polymer powder on the surface of the substrate LIG, (3) using carbon dioxide laser to laser-selective carbonizing the paved polymer powder substrate, forming a pre-designed single-layer graphene film, (4) paving a layer of polymer powder on the surface of the formed graphene film, (5) using carbon dioxide laser to laser-selective carbonizing the paved polymer powder substrate, forming a pre-designed single-layer graphene film, (6) repeating steps (4) and (5) until printing is completed, obtaining three-dimensional graphene structure, (7) soaking the three-dimensional graphene structure in filling material, and curing. The thickness of powder layer (L) is calculated by using formula: a(93.5x-15.5), where a is correlation coefficient which is 60-80%, x is laser power (W), and L is thickness of the powder layer (mum). In step (2) and (4), the thickness of the powder layer is 60-80% of the growth height of graphene.