Enhanced performance of W-Doped TiNb2O7 anodes via low-temperature spray drying synthesis for high-power lithium-ion batteries

The advancement of lithium-ion battery technology necessitates large-scale production of electrode materials with high energy density, power density, and safety. TiNb2O7 (TNO), a promising anode material with a Wadsley-Roth structure, offers high theoretical capacity (387.6 mAh g- 1), suitable voltage (1.65 V vs Li+/Li), and structural stability. However, the practical application of TNO is hindered by its low electronic conductivity and slow lithium-ion diffusion coefficient, necessitating performance enhancement through strategies such as nanosizing, morphology control, conductive material decoration, and ion doping. This study presents a novel precursor preparation approach using acidified hydrogen peroxide-assisted spray drying, which significantly lowers the subsequent heat treatment temperature, enabling the successful synthesis of tungsten (W6+)-doped TNO porous spherical nanomaterials at a lower calcination temperature of 750 degrees C. Optimal W6+ doping enhances the material's crystallinity, reduces the charge transfer resistance, accelerates lithium-ion transport, and markedly improves the charge-discharge performance at high rates. The prepared W0.1Ti0.9Nb2O7 material achieves a high specific capacity of 167.7 mAh g- 1 at a 20C rate and maintains a capacity retention of 93.4 % after 250 cycles at a 1C rate. This approach enables scalable production of high-performance TNO anodes.