Anion Sublattice Engineering Induced Niobium-Tungsten Oxide with Near-Zero Residual Strain for Stable 100 C Cycling Capability

Wadsley-Roth W3Nb14O44 is a fast-charging anode material but suffers from low electronic conductivity and electrochemical polarization. Here, anion-sublattice engineering is employed to regulate its electronic structure and Li+ storage kinetics. Density functional theory and kinetic analyses reveal that an appropriate concentration of oxygen vacancies enhances electronic conductivity, moderates Li+ adsorption, and facilitates Li+ diffusion, thereby reducing charge-transfer and diffusion impedances at low temperatures. In situ XRD and synchrotron radiation X-ray 3D nanocomputed tomography reveal reversible structural evolution with near-zero residual strain after cycling. Consequently, WNO-x delivers 77.4 mAh g–1 at 200 C and retains 72.6% capacity after 6000 cycles at 100 C while exhibiting low-temperature electrochemical activity. Moreover, the WNO-x||LiNi0.8Co0.1Mn0.1O2 full cell delivers 85.8 mAh g–1 at 20 C and retains 77.1% capacity after 3000 cycles, with cycling capability at –30 °C. Such structure-property insight provides a strategy for designing niobium-based oxide anodes toward fast-charging and low-temperature batteries.