▎ 摘　　要

NOVELTY - The preparation method of nano-carbon fiber involves adding nano-manganese dioxide to aqueous solution of sodium alginate and then mixing, ultrasonically agitating the mixture, adding graphene oxide to the mixture and then adjusting pH value to 10-11, adding purified lignin to the mixture and then spinning at 200-250 degrees C, increasing the temperature at 280-300 degrees C for 1-6 hours and then heating at 1000-2000 degrees C and carbonizing for 0.5-12 hours. USE - The method is useful for preparation of nano-carbon fiber, which is useful for supercapacitor electrode. ADVANTAGE - The method enables preparation of nano-carbon fiber with high energy density.