Topological confinement and built-in electric field at F‑Nb2CTx/Nb2O5 heterointerfaces enable fast electron/ion kinetics for lithium-ion batteries

A topological confinement strategy is developed to construct atomically matched F-Nb 2 CT x /Nb 2 O 5 heterointerfaces. • The strongly coupled heterointerface enables 0.16068 |e| charge transfer and generates a built-in electric field. • The built-in electric field synergistically accelerates electron migration and Li + diffusion kinetics. • Excellent rate capability (257.7 mAh g −1 at 5.0 A g −1 ) and cycling stability (125.2% after 550 cycles) are achieved. • This work establishes a new heterointerface engineering paradigm for high-power, long-life lithium-ion battery anodes. Niobium pentoxide (Nb 2 O 5 ) is regarded as a promising anode material for lithium-ion batteries owing to its open-framework structure, competitive theoretical capacity, and intrinsic operational safety. However, its practical application is impeded by intrinsically low electronic conductivity and sluggish lithium-ion diffusion, leading to unsatisfactory rate capability and cycling stability. Herein, we propose a novel topological confinement strategy to construct atomically matched few-layer Nb 2 CT x /Nb 2 O 5 (F‑Nb 2 CT x /Nb 2 O 5 ) heterointerfaces for enhanced electron/ion kinetics. By leveraging the unique two-dimensional geometry of F‑Nb 2 CT x , a natural topological confinement space is established, inducing the in-situ derivation of well-ordered ultrafine Nb 2 O 5 nanocones with atomic-level lattice matching through the shared niobium element. This strongly coupled heterointerface enables electron transfer of 0.16068 |e| from F‑Nb 2 CT x to Nb 2 O 5 and establishes a built-in electric field, synergistically optimizing electron/ion transport kinetics. Benefiting from the strong interfacial coupling, the resulting electrode delivers a high reversible capacity of 430.0mAh g −1 at 0.2 A g −1 and maintains a remarkable rate capability of 257.7mAh g −1 even at 5.0 A g −1 . Moreover, it exhibits exceptional cycling stability with a capacity retention of 125.2% after 550 cycles at 1.0 A g −1 . This work establishes a new paradigm for overcoming the kinetic bottlenecks of oxide anodes through rational heterointerface engineering. A topological confinement strategy is developed to construct atomically matched few-layer Nb 2 CT x /Nb 2 O 5 (F-Nb 2 CT x /Nb 2 O 5 ) heterointerfaces. The unique two-dimensional geometry of F‑Nb 2 CT x provides a natural topological confinement space, directing the in-situ derivation of well-defined ultrafine Nb 2 O 5 nanocones with atomic-level lattice matching through the shared niobium element. This strongly coupled heterointerface enables electron transfer of 0.16068 |e| from F‑Nb 2 CT x to Nb 2 O 5 and establishes a built-in electric field, synergistically optimizing electron/ion transport kinetics. The resulting F‑Nb 2 CT x /Nb 2 O 5 heterostructured anode achieves an exceptional high-rate capacity of 257.7 mAh g −1 at 5.0 A g −1 and remarkable cycling stability, retaining 125.2% of its capacity after 550 cycles at 1.0 A g −1 . This work provides a new paradigm of heterointerface engineering to overcome the kinetic bottlenecks of oxide anodes for high-power, long-life lithium-ion batteries. Download: Download high-res image (207KB) Download: Download full-size image