▎ 摘　　要

NOVELTY - Sodium borohydride/nitrogen-doped graphene hydrogen storage composite material comprises nitrogen-doped graphene (NG) as additive mixed with sodium borohydride (NaBH4). The mass ratio of NaBH4 and NG is 9:1. USE - Used as sodium borohydride/nitrogen-doped graphene hydrogen storage composite material. ADVANTAGE - The composite material has greatly lower initial hydrogen release temperature (60 degrees C) than pure NaBH4 under the same ball milling conditions, fast dehydrogenation, simple preparation technique, wide raw material sources, low cost, and improved hydrogen storage performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the composite material comprising under ultrasonic vibration, respectively mixing 75.53 ml graphene dispersion liquid with three kinds of nitrogen source (0.05 mol melamine (C3N3(NH2)3)+0.05 mol pyrrole(C4H5N):0.1 mol C3N3(NH2)3:0.1 mol C4H5N), fully mixing, obtaining mixed samples S1, S2 and S3, respectively, transferring the mixed samples S1, S2, and S3 to hydrothermal reaction kettle, calcining at 180 degrees C for 5 hours, filtering, washing, and drying the mixture at 80 degrees C, sequentially placing the three groups of powder sample in a tubular furnace, annealing in argon (Ar) atmosphere at 500 degrees C for 8 hours, obtaining three different nitrogen-doped graphene NGX (X=1, 2, 3), reacting NaBH4 powder with the prepared NGX (X=1, 2, 3) powder at 9:1 mass ratio, putting into a ball milling tank, and mechanically ball milling under Ar atmosphere at 1000 revolutions/minute (rpm) and grinding media to material ratio of 30:1 for 2 hours, where to avoid overheating of sample in the ball milling process, the ball mill stops for cooling for 15 minutes after each operation for 1 hour.