Oxygen vacancy-assisted construction of phosphorus-doped layers to improve the lithium storage performance of T-Nb2O5

Abstract

T-Nb₂O₅ is a promising anode material for high power density lithium-ion batteries (LIBs) due to its fast lithium storage capacity and safe lithiation potential. However, its practical application is hindered by its low electronic conductivity. In this work, we improved the electrochemical performance of T-Nb₂O₅ by surface P-doping and the N-doped carbon substrate. Surface P-doping guided by defects enhances the electronic conductivity of the material, which can synergize with N-doped carbon substrates to form a conductive network and accelerate the lithiation/delithiation process. More importantly, surface P-doping does not destroy the internal crystal structure of the material, ensuring the stability of the Nb₂O₅ during the charge/discharge process. When used as the anode for LIBs, the Nb₂O₅-P/N-C exhibits great cycling stability and high-current charge/discharge performance. The specific capacity of Nb₂O₅-P/N-C exceeds 116 mAh g⁻¹ after 1000 cycles at 1000 mA g⁻¹. This work presents a novel approach to improve the electrochemical performance of T-Nb₂O₅.