Crystallographically aligned Wadsley-Roth phase anodes with conductive agents for high-rate lithium-ion batteries

To realize high-energy density lithium-ion batteries, achieving fast-charging capabilities for electrodes with high areal mass loadings is a significant challenge. Traditional anode materials such as graphite and lithium titanate face limitations in fast charging owing to safety risks and energy density constraints. Wadsley-Roth structured niobium-based oxides have attracted attention for their unique three-dimensional open tunnel structures, but their low electrical conductivity limits practical applications. This study innovatively proposes a two-phase structural design with crystallographic alignment, successfully preparing a niobium titanium oxide (TiNb₂O₇)-conductive agent titanium oxide (Ti₄O₇) anode material (TNO-CA). By precisely controlling the sintering temperature, TNO-CA achieves a crystallographic alignment between TNO and Ti₄O₇, significantly enhancing the electronic conductivity and ion transport properties of the material. TNO-CA exhibits excellent reversible areal capacity and cycling stability at high charging rates. Compared with solvothermally prepared TNO materials, TNO-CA delivers a reversible capacity of 152 mAh g ^-1 at 30 °C, while TNO delivers 6 mAh g ^-1. Moreover, TNO-CA retains a reversible areal capacity of 1 mAh cm^-2 at 3 °C even at a high mass loading of 12.9 mg cm^-2. The TNO-CA/lithium cobalt oxide full cell demonstrates outstanding fast-charging performance (1.8 mAh cm^-2 at 3 °C) and good cycling stability (1.85 mAh cm^-2 after 300 cycles at 1 °C), proving the great potential of crystallographically aligned two-phase structural design in enhancing fast-charging performance.