Tailoring Hollow Nanostructures by Catalytic Strategy for Superior Lithium and Sodium Storage.

Nowadays, a novel catalyzed strategy for designing 3D carbon nanosheet frameworks is a wide concern in the field of energy storage. Herein, a 3D hollow structure with nickel and nanographitic domains is presented for fabrication of functionalized hollow microporous carbon embedded with expanded defective nanographitic domains or hollow nickel oxide composites. The hollow microporous carbon coupling nanographitic domains exhibits excellent long-term cycling (4000 cycles for lithium storage, 2000 cycles for sodium storage), which is mainly due to the formation of defects in the nanographite for catalytic strategy. The hollow nickel oxide composites show the capacities of 1093 mA h g-1 after 400 cycles with the high Coulombic efficiency at a current density of 200 mA g-1 for lithium storage and superior rate performance at different current densities for sodium storage. Stable and great energy storage features stem from the fact that the hollow structure can provide more active sites for ionic diffusion/storage and a free shuttle space for electrons.