Pomegranate-like structured Nb₂O₅/Carbon@N-doped carbon composites as ultrastable anode for advanced...

The distinctive pomegranate-like Nb₂O₅/Carbon@N-doped carbon (Nb₂O₅/C@NC) composites are fabricated using hydrothermal method integrated with nitrogen doped carbon coating procedure. For the SIBs anode, the Nb₂O₅/C@NC composites present superior rate character and sustainable capacity (117 mAh g^-1 upon 1000 cycles at 5 A g^-1). The in-situ X-ray diffraction (XRD) is utilized to research its sodium storage mechanism. Furthermore, for PIBs, the Nb₂O₅/C@NC composites present sustainable capacity (81 mAh g^-1 upon 1000 cycles at 1 A g^-1). The outstanding performance of Nb₂O₅/C@NC composites is ascribed to its unique architecture, in which Nb₂O₅ nanocrystals embedded in porous carbon can restrain agglomeration of Nb₂O₅ nanocrystals, enhance electron/ion diffusion kinetics, and ensure electrolyte accessibility, and moreover, NC shell layer can provide effective active sites and further increase ions/electrons transfer.