Application of nitrogen-doped carbon nanotube in lithium ion battery negative electrode material

The invention discloses an application of a nitrogen-doped carbon nanotube in a lithium ion battery negative electrode material. The preparation method of the nitrogen-doped carbon nanotube comprises the following the step: carrying out irradiation reaction on a mixed solution of a carbon nanotube and an unsaturated compound to prepare the nitrogen-doped carbon nanotube, wherein the carbon nano tube is an acid-washed carbon nano tube; the unsaturated compound comprises an unsaturated amide compound and/or an unsaturated nitrile compound; and the mass ratio of the carbon nanotubes to the unsaturated compound is 1: (1-100). When the nitrogen-doped carbon nanotube prepared by the preparation method is used as a lithium ion battery negative electrode material, the specific capacity has a trend of gradually increasing along with the increase of the charging and discharging times in the charging and discharging processes under different multiplying powers, and when the charging and discharging times are 350-500 tim