Method for manufacturing graphene-metal composite wire

A method for manufacturing a graphene-metal composite wire, comprising the steps of:

• (1) growing graphene on a surface of a metal wire through a chemical vapor deposition process;
• (2) twisting the wire;
• (3) heat-treating the wire at 600-1100° C. for 30-60 minutes so that the wire becomes slack, then subjecting the wire to a pre-tensioning operation immediately after the heat treatment, and then cooling the wire to below 200° C. for a pre-straining operation;
• (4) cold-drawing the wire to obtain a densified structure;
• and
• (5) subjecting the wire to a chemical vapor deposition process,
• wherein the wire is subjected to steps (2) to (5) successively and cycled n times, wherein f wires obtained in step (1) are used in the first cycle, f wires obtained from previous cycle are used in subsequent cycle, and finally a graphene-metal composite wire with fn strands is obtained, and wherein (a) f is an integer of 2-9;
• and (b) n is an integer of 6 or more.