Flexible sodium ion battery negative electrode, preparation method thereof and flexible sodium ion battery

The invention provides a flexible sodium ion battery negative electrode, a preparation method thereof and a flexible sodium ion battery. The flexible sodium ion battery negative electrode comprises a carbon nanotube film and a nickel sulfide negative electrode material grown on the carbon nanotube film in situ, wherein the mass of the nickel sulfide negative electrode material grown on the carbon nanotube film in situ is 0.3-1mg/cm < 2 >; and the thickness of the carbon nanotube film is 1-5 [mu] m. The flexible sodium-ion battery negative electrode is prepared by taking a carbon nanotube film as a current collector and growing a nickel sulfide negative electrode material on the carbon nanotube film in situ through a one-step hydrothermal method; the flexible sodium-ion battery assembled by the flexible sodium-ion battery negative electrode prepared by the preparation method disclosed by the invention does not have a stripping phenomenon in a cycle process, is stable in cycle, and has the advantages of high en