Fluorine-Doped Carbon-Coated Mesoporous Ti<sub>2</sub>Nb<sub>10</sub>O<sub>29</sub> Microspheres as a High-Performance Anode for Lithium-Ion Batteries
Xiaoxu Ji, Yan Yang, Yanhua Ding, Zhenxiao Lu, Guangyin Liu, Yiyang Liu, Jianglong Song, Zhi-Zheng Yang, Xiaodi Liu
Abstract
Ti2Nb10O29 is a prospective anodic material for high-power batteries based on lithium ions owing to its excellent safety, cyclability, and exceptionally good performance. However, its low electrical conductivity restricts its potential uses. In this work, a uniform F-doped ultrathin carbon-based coating layer was introduced on mesoporous Ti2Nb10O29 microspheres via a convenient thermal treatment method, with polyvinylidene fluoride as the source of fluoride and carbon. The use of these mesoporous structures in a Li-ion battery as the anode could significantly promote the electrolyte permeation, architectural stability of Ti2Nb10O29, and e–/Li+ transportation efficiency. The Ti2Nb10O29@F-C microspheres manifested a superior cycling stability (202 mAh g–1 at 10 C after 500 cycles) and a remarkable high-rate capability (211 mAh g–1 at 30C), and they functioned quite well in a LiNi0.5Mn0.3Co0.2O2||Ti2Nb10O29@F-C full cell. These results indicate that for high-rate lithium-ion batteries, Ti2Nb10O29@F-C has proven to be appropriate for use as an anodic material.