Oxygen‐deficient TiO₂ Yolk‐shell Spheres for Enhanced Lithium Storage Properties

Anatase TiO 2 is a promising anode material for lithium‐ion batteries (LIBs) owing to its low cost and stability. However, the intrinsically kinetic limits seriously hindered its lithium‐ion storage capability. Here we present that anatase TiO 2 with rich oxygen vacancies can enhance its lithium‐ion storage performance. We synthesize anatase TiO 2 with well‐retained hierarchical structure by annealing the H 2 Ti 5 O 11 ·3H 2 O yolk‐shell spheres precursor in nitrogen atmosphere. EPR and XPS data evidence that the oxygen‐deficient environment could generate abundant oxygen vacancies in the as‐derived anatase TiO 2 , which leads to improved electron conductivity and reduced charge‐transfer resistance. The rich oxygen vacancies and high structural integrity of the hierarchical yolk‐shell spheres enable the as‐derived anatase TiO 2 yolk‐shell spheres with a high specific capacity of 280 mAh g −1 at 100 mA g −1 and 71% of capacity retention after 5000 cycles at 2 A g −1 .