Onion carbon/cured fiber composite material and preparation method and application thereof, composite electrothermal film and preparation method and application thereof

The invention provides a preparation method of an onion carbon/cured fiber composite material, which comprises the following steps: distributing carbon nano onions on the surface and inside of precursor fibers which are obtained by electrostatic spinning and have a three-dimensional network cross-linked structure, and carrying out pre-oxidation treatment to improve the stability, thereby obtaining the onion carbon/cured fiber composite material. The onion carbon clusters are utilized to increase the specific surface area of the composite material, a large number of adsorption sites are provided, the adsorption capacity of the composite material is improved, carbonization treatment is continued, the onion carbon clusters construct a conductive network again in a three-dimensional network cross-linked structure constructed by carbon fibers, and the conductivity of the composite material is improved. The composite electrothermal film with good conductivity and high electrothermal conversion efficiency is obtaine