The Preparation of Porous CuO@F‐GDY Nano‐Arrays for High‐Performance Sodium‐Ion Battery Anodes

ABSTRACT The growing demand for energy storage systems makes it crucial to develop high‐performance anode materials for sodium‐ion batteries. This study proposes an innovative strategy for constructing a porous CuO@ fluorinated graphdiyne (F‐GDY) composite anode guided by a F‐GDY coating. The synergistic effect of Cu(OH) ₂ core contraction and F‐GDY shell confinement led to the formation of a porous CuO structure while preserving the well‐defined linear array morphology. The interfacial charge transfer between F‐GDY and CuO modulates the electronic structure of CuO, significantly enhancing electron transport efficiency and sodium ion adsorption capacity. The porous structure effectively accommodates volume fluctuations during sodium‐ion insertion/extraction, thereby facilitating the formation of a stable solid electrolyte interphase. Electrochemical tests demonstrate that the composite anode exhibits high reversible capacity (681 mAh g ⁻¹ after 100 cycles at 50 mA g ⁻¹ ) and excellent long‐term cycling stability (maintaining 278 mAh g ⁻¹ after 1250 cycles at 2000 mA g ⁻¹ ). Mechanistic analysis further confirms that the sodium storage process is predominantly capacitive and possesses a high ionic diffusion coefficient. This study provides a new perspective for developing high‐stability anode materials for SIBs that can accommodate volume changes.