Fluorine-Doped Carbon-Coated Mesoporous Ti₂Nb₁₀O₂₉ Microspheres as a High-Performance Anode for Lithium-Ion Batteries

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 LiNi_0.5Mn_0.3Co_0.2O₂||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.