Diffusion tunnel shortening and Oxygen-Vacancy boosting high rate and stable lithium ion storage of crystallographic self-healed Ti2Nb10O29 anode

Long lithium-ion (Li+) diffusion path and poor electronic conductivity pose tricky challenges for the attractive Wadsley-Roth phase Ti2Nb10O29 (TNO) bulk anodic material in high-rate and stable Li+ storage applications. Herein, a well-designed monoclinic TNO nanoparticle sample with high dispersity and crystallization was synthesized. Due to the simultaneously reduced particle size, shortened Li+ diffusion tunnels along the [0 1 0] direction and introduced lattice oxygen vacancies (Ov), the Ov-TNO-nanoparticle anode performed a low charge transfer resistance, significant pseudo-capacitance effect, high Li+ diffusion coefficient, reversible phase-transition and forceful crystal structural self-healing ability for the Li+ (de)intercalation. Consequently, the anode demonstrated an impressive Li+ storage performance, including a high capacity of 288 mAh/g at 0.05 A g−1 with initial coulombic efficiency of 95.62 %, high rate-capability of 162 mAh/g and cycling durability of 92.3 % retention at 5 A g−1. Our exploration can not only present a new Ov-TNO-nanoparticle anode material for the fast-rechargeable batteries, but also supply a versatile strategy to enhance the electrochemical energy storage performance of all Wadsley-Roth phase niobium-based materials.