Copper Prussian blue/carbon nanotube fiber compound as well as preparation method and application thereof

The invention provides a copper prussian blue/carbon nanotube fiber compound and a preparation method and application thereof. Relates to the technical field of nano materials, and the preparation method of the copper Prussian blue/carbon nanotube fiber compound comprises the steps that carbon nanotube fibers serve as a substrate conducting layer material, and the copper Prussian blue/carbon nanotube fiber compound is obtained on the surfaces of the carbon nanotube fibers through a multi-step synthesis method. According to the technical scheme, the copper prussian blue nanosheets are synthesized on the surfaces of the carbon nanotube fibers through chemical processes of in-situ deposition, oxidation and organic acid mixed etching, so that the copper prussian blue nanosheets uniformly grow on the surfaces of the carbon nanotube fibers, and the copper prussian blue/carbon nanotube fiber compound is formed. And when being used as a positive electrode material of a water-based magnesium ion battery, the composite