Facile formation of tetragonal-Nb2O5 microspheres for high-rate and stable lithium storage with high areal capacity

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2020,（14）
• 页码范围: 1154-1162
• 页数: 9页
• 语种: 英文

摘要

Niobium pentoxide (Nb2O5) has attracted great attention as an anode for lithium-ion battery,which is attributed to the high-rate and good stability performances.In this work,TT-,T-,M-,and H-Nb2O5 microspheres were synthesized by a facile one-step thermal oxidation method.Ion and electron transport properties of Nb2Os with different phases were investigated by both electrochemical analyses and density functional theoretical calculations.Without nanostructuring and carbon modification,the tetragonal N b2Os (M-Nb2O5) displays preferable rate capability (121 mAh g-1 at 5 A g-1),enhanced reversible capacity (163 mAh g-1 at 0.2 A g-1) and better cycling stability (82.3％ capacity retention after 1000 cycles)when compared with TT-,T-,and H-Nb2O5.Electrochemical analyses further reveal the diffusioncontrolled Li+ intercalation kinetics and in-situ X-ray diffraction analysis indicates superior structural stability upon Li+ intercalation/deintercalation.Benefiting from the intrinsic fast ion/electron transport,a high areal capacity of 2.24 mAh cm-2 is obtained even at an ultrahigh mass loading of 22.51 mg cm-2.This work can promote the development of Nb2Os materials for high areal capacity and stable lithium storage towards practical applications.