The zero-strain spinel Li4Ti5O12 stands out as a promising anode material for lithium-ion batteries due to its outstanding cycling stability. However, the limited theoretic specific capacity, low Li+ diffusion coefficient and electronic conductivity severely hinder its practical application. In this study, we demonstrate a strategy of introducing abundant oxygen vacancies not only on the surface and but also inside the bulk of Li4Ti5O12 particles via reductive thermal sintering. The oxygen vacancies can significantly enhance the electronic conductivity and lithium-ion diffusion coefficient of Li4Ti5O12, leading to a remarkable improvement in rate performance and a reduction in polarization. Moreover, additional lithium-ion accommodation sites can be created at the defective surface, contributing to a high specific capacity of over 200 mAh g−1.