Reducing Lithium‐Diffusion Barrier on the Wadsley–Roth Crystallographic Shear Plane via Low‐Valent Cation Doping for Ultrahigh Power Lithium‐Ion Batteries

Abstract

Abstract Rapid‐charging niobium–tungsten oxide Nb 14 W 3 O 44 (NbWO) anodes with a Wadsley–Roth crystallographic shear (WRCS) structure possess 3D interconnected open tunnels. However, the anisotropic Li + diffusion paths lead to a high lithium‐diffusion barrier of hooping between window sites across edge‐shared octahedrons, as the rate‐limiting step of hooping. To improve the rate capability of NbWO, doping it with low‐valent cations (with valences lower than W 6+ ) to reduce the high lithium‐diffusion barrier is proposed. Electron energy loss spectroscopy reveals that low‐valent V 5+ , V 4+ , Tb 4+ , and Ce 4+ tend to distribute on the crystallographic shear plane under electrostatic repulsion forces. The reduction in steric hindrance resulting from the increased long bond length ratio of doped edge‐shared octahedrons, coupled with coordination environment modification of [LiO 5 ] on the crystallographic shear plane due to the low energy level of V 5+ , enhances Li + diffusion kinetics and cyclic stability. V 5+ ‐ and Tb 4+ ‐doped NbWOs achieve rate capacities of 83 and 63 mAh g −1 , at 200 C (1C = 0.178 Ag −1 ) and retain 75.42% and 86.79% of their capacities, respectively, after 3700 cycles at 20 C. Thus, the proposed doping strategy is promising for preparing WRCS‐type niobium‐based oxides for ultrafast lithium storage.