Carbon nanotube composite structure and method for making the same

A carbon nanotube composite structure, comprising:

• a carbon nanotube network structure comprising a plurality of carbon nanotubes;
• and
• a sulfur, nitrogen-codoped carbon layer coated on outer surfaces of the plurality of carbon nanotubes, wherein the sulfur, nitrogen-codoped carbon layer comprises nitrogen elements (N), sulfur elements (S), and carbon elements (C);
• a polyaniline is a dopant source of the carbon elements and the nitrogen elements, and an ammonium persulphate is both an initiator that initiates the polyaniline and a dopant source of the nitrogen element and the sulfur element:
• the sulfur, nitrogen-codoped carbon layer is formed by carbonizing a carbon nanotube composite structure preform consisting of carbon nanotubes, the polyaniline, and the initiator;
• the atomic percentage of the carbon elements, the nitrogen elements, and the sulfur elements is C:N:S=95.4%:3.2%:1.4%;
• and a Young's modulus of the carbon nanotube composite structure is 810.12 MPa.