Three-dimensional holey-graphene/niobia composite architectures for ultrahigh-rate energy storage

As with donuts, the holes matter Improving the density of stored charge and increasing the speed at which it can move through a material are usually opposing objectives. Sun et al. developed a Nb 2 O 5 /holey graphene framework composite with tailored porosity. The three-dimensional, hierarchically porous holey graphene acted as a conductive scaffold to support Nb 2 O 5 . A high mass loading and improved power capability were reached by tailoring the porosity in the holey graphene backbone with higher charge transport in the composite architecture. The interconnected graphene network provided excellent electron transport, and the hierarchical porous structure in the graphene sheets facilitated rapid ion transport and mitigated diffusion limitations. Science , this issue p. 599