Tailoring three-dimensional hierarchical porosity in Wadsley–Roth Nb14W3O44: A dual-role ethylenediaminetetraacetic acid combustion strategy for ultra-stable and high-rate lithium storage

The Wadsley–Roth phase Nb 14 W 3 O 44 emerges as a potential anode candidate for fast-charging lithium-ion batteries, featuring intrinsic crystalline tunnels that theoretically enable ultrafast ion transport. However, realizing this potential highlights a persistent challenge that conventional microstructures fail to reconcile the fundamental trade-off between rapid kinetics and durable interfacial stability. Herein, we address this limitation through an innovative dual-role ethylenediaminetetraacetic acid (EDTA) combustion strategy that directly constructs Nb 14 W 3 O 44 with precisely engineered multi-scale three-dimensional (3D) hierarchical porosity. By serving simultaneously as a chelating agent and a previously overlooked in situ pore-former, EDTA ensures molecular-scale precursor homogenization and gas-foamed architecture in a single process. This tailored architecture concurrently establishes continuous ion pathways and a robust framework, enabling exceptional rate capability (90 mAh g −1 at 9 A g −1 ) coupled with outstanding cycling stability (120 mAh g −1 after 1000 cycles at 3 A g −1 with merely 0.019% capacity decay per cycle). Systematic electrochemical diagnostics further reveal concurrent enhancement of Li + diffusion kinetics and interfacial charge transfer. Collectively, this multi-scale microstructure engineering approach successfully reconciles the long-standing kinetics-stability dilemma in intercalation electrodes, thereby establishing a new design paradigm for durable fast-charging batteries.