Effects of Nitrogen-Doping or Alumina Films on Graphene as Anode Materials of Lithium-Ion Batteries Verified by In Situ XRD

Abstract

First, graphene is directly grown on nickel foil without additional catalysts by chemical vapor deposition (CVD). Next, the graphene is modified by nitrogen-doping, and alumina is deposited onto the graphene by magnetron sputtering. The charge-specific capacity of N-doped graphene is higher than that of graphene since 2 Theta of in situ XRD characteristic peaks for N-doped graphene moves toward a lower angle (about 24) which is smaller than that (about 25) for graphene, and then the gap between graphene layers for N-doped graphene is larger than that for graphene according to Bragg’s Law, and N-doped graphene demonstrates the additional in situ XRD characteristic peak (LiC6) in comparison to graphene only with the in situ XRD characteristic peak (LiC12). Furthermore, because 2 Theta of in situ XRD characteristic peaks for Al2O3/graphene also moves toward a lower angle (about 24) and Al2O3/graphene also shows the additional in situ XRD characteristic peak (LiC6), the charge-specific capacity of Al2O3/graphene is also higher than that of graphene.