▎ 摘　　要

NOVELTY - Method for preparing nitrogen-doped graphene-carbonized fiber composite sponge, involves (i) preparing experimental materials and instruments, (ii) washing and drying natural cotton, mixing with urea solution in a mold, and freeze-drying to obtain cotton-urea block, and (ii) heating the block in a tube furnace at 600 degrees C at a rate of 1 degrees C/minute for 1 hour, increasing the temperature at a rate of 900 degrees C for 1 hour, and cooling to room temperature. USE - The method is useful for preparing nitrogen-doped graphene-carbonized fiber composite sponge. ADVANTAGE - The method improves the strength of the graphene sponge.