Mixed‐Phase Niobium Oxide as a Durable and Ultra‐Fast Charging Anode for High‐Power Lithium‐Ion Batteries

Abstract The development of low‐cost, high‐power lithium‐ion batteries requires durable anode materials that can store and release lithium quickly. Here a mixed phase of H‐Nb 2 O 5 and M‐Nb 2 O 5 (denoted as d‐H,M‐Nb 2 O 5 ) that demonstrates excellent performance as an anode material for lithium storage is reported. Experimental and computational analyses reveal several salient features of d‐H,M‐Nb 2 O 5 . First, the edge‐sharing arrangement between the mixed niobium oxygen polyhedral block structures helps alleviate volume expansion during cycling, thereby enhancing stability and reversibility. Second, the mixed‐phase structure facilitates a continuous pathway for lithium ion adsorption These characteristics allow for sequential transport of lithium ions, enabling fast charging. As a result, the d‐H,M‐Nb 2 O 5 electrode material exhibits a high capacity of 142 mAh g −1 at an ultra‐fast charging rate of 100 C, while maintaining 85% of its initial capacity after 5000 cycles. Moreover, its practical feasibility is established by demonstrating full‐cell performance at a 5 C discharge/charge rate (13 mA cm −2 ), maintaining 79% of its capacity over 1000 cycles.