As promising anode materials for lithium-ion batteries, titanium− niobium oxides still suffer from the bottleneck of ion transport, which severely limits their practical usage. In this work, the ion-transport kinetics of micrometersized Ti 2 Nb 10 O 29 is improved by crystallinity mediation. The crystallinity of Ti 2 Nb 10 O 29 is intrinsically reduced through cation substitution (Nb 5+ → Ti 4+ and W 6+ ), with Ti 2.5 Nb 9 W 0.5 O 29 obtained. The amorphous phases not only optimize the ion transport through isotropic ion diffusion path but also introduce more oxygen vacancies, which can serve as nucleation sites for phase changing and improve electron conductivity. As a result, Ti 2.5 Nb 9 W 0.5 O 29 exhibits superior kinetics and remarkable rate performance. Even with large particle sizes from 5 to 20 μm, Ti 2.5 Nb 9 W 0.5 O 29 can achieve a reversible specific capacity of 110 mAh g −1 at a high current density of 10 A g −1 , much higher than Ti 2 Nb 10 O 29 (11.1 mAh g −1 ). This work provides a novel view for the development of practical, high-performance anode materials for LIBs.