Hierarchical flower-like N-doped Nb2O5@N-doped carbon composites as superior anodes for advanced lithium-ion batteries

Niobium pentoxide (Nb2O5) has garnered significant interest as a viable anode material for lithium-ion batteries (LIBs) owing to its ability to function at high rates with improved safety and large capacity. Its applications, however, are limited by its inherent poor electron conductivity. This study describes the effective fabrication of flower-shaped N-doped Nb2O5 microspheres coated with N-doped carbon via a hydrothermal technique, followed by a carbonization procedure that utilizes polydopamine as a nitrogen and carbon source. When employed as the anode for LIBs, the N-Nb2O5@N-C demonstrated exceptional rate capability of 158 mAh g-1 at 20 C. It also demonstrated exceptional cycling stability by retaining 81% of its original capacity at 10 C after 2500 cycles. Additionally, the lithium-ion full battery using the N-Nb2O5@N-C anode exhibited also excellent electrochemical properties. The remarkable electrochemical performance of the N-Nb2O5@N-C composites can be attributed to the synergistic effect of the N-doped carbon coating, N doping, and a unique hierarchical structure. These factors collectively enhanced the electrochemical reaction kinetics of the N-Nb2O5@N-C composite.