Binder-Free Hybrid Titanium-Niobium Oxide/Carbon Nanofiber Mats for Lithium-Ion Battery Electrodes

摘要

Free-standing, binder-free, titanium-niobium oxide/carbon hybrid nanofibers are prepared for Li-ion battery applications. A one-pot synthesis offers a significant reduction of processing steps and avoids the use of environmentally unfriendly binder materials, making the approach highly sustainable. Tetragonal Nb2O5/C and monoclinic Ti2Nb10O29/C hybrid nanofibers synthesized at 1000 degrees C displayed the highest electrochemical performance, with capacity values of 243 and 267mAhg(-1), respectively, normalized to the electrode mass. At 5Ag(-1), the Nb2O5/C and Ti2Nb10O29/C hybrid fibers maintained 78% and 53% of the initial capacity, respectively. The higher rate performance and stability of tetragonal Nb2O5 compared to that of monoclinic Ti2Nb10O29 is related to the low energy barriers for Li+ transport in its crystal structure, with no phase transformation. The improved rate performance resulted from the excellent charge propagation in the continuous nanofiber network.