Architecting Hierarchical WO₃ Agglomerates Assembled With Straight and Parallel Aligned Nanoribbons Enabling High Capacity and Robust Stability of Lithium Storage

The pursuit of electrochemical energy storage has led to a pressing need on materials with high capacities and energy densities; however, further progress is plagued by the restrictive capacity (372 mAh g^-1) of conventional graphite materials. Tungsten trioxide (WO₃)-based anodes feature high theoretical capacity (693 mAh g^-1), suitable potential, and affordable cost, arousing ever-increasing attention and intense efforts. Nonetheless, developing high-performance WO₃ electrodes that accommodate lithium ions remains a daunting challenge on account of sluggish kinetics characteristics and large volume strain. Herein, the well-designed hierarchical WO₃ agglomerates assembled with straight and parallel aligned nanoribbons are fabricated and evaluated as an anode of lithium-ion batteries (LIBs), which exhibits an ultra-high capacity and excellent rate capability. At a current density of 1,000 mA g^-1, a reversible capacity as high as 522.7 mAh g^-1 can be maintained after 800 cycles, corresponding to a high capacity retention of ∼80%, demonstrating an exceptional long-durability cyclic performance. Furthermore, the mechanistic studies on the lithium storage processes of WO₃ are probed, providing a foundation for further optimizations and rational designs. These results indicate that the well-designed hierarchical WO₃ agglomerates display great potential for applications in the field of high-performance LIBs.