The Role of Mo in Nucleating Large Niobate Crystals for Li-ion Battery Anodes

Abstract

High-power Wadsley-Roth anodes such as Nb 16 W 5 O 55 and Nb 18 W 16 O 93 show strong promise for safe, high-performance Li-ion batteries, driving significant interest and exploration of Nb-based oxide materials. However, these materials typically require high synthesis temperatures (e.g. 1200 °C) while previous studies on Nb-Mo-O materials show their formation at far lower temperatures (near 700 °C). Herein, high-throughput methods were used to systematically explore the entire Nb-W-Mo-O pseudoternary for the first time, and this revealed high performers in the ternary space at the modest synthesis temperature of 725 °C. Two solid-solution regions were identified, with Mo incorporation yielding much larger crystallites than along the Nb-W-O pseudobinary, demonstrating its ability to accelerate crystal growth in the sol-gel synthesis. Optimal materials exhibit initial capacities over 300 mAh g -1 alongside sustained cycling performance, particularly at 37 °C. These findings establish Nb-W-Mo-O as promising high-power anodes and demonstrate a cost-effective low temperature pathway toward high-performance materials.