Self-Reinforcing Structural–Interfacial Evolution in LiCuFe ₂ (VO ₄ ) ₃ Anodes Enables Durable, High-Capacity Lithium Storage

Designing high-capacity and durable anodes for lithium-ion batteries (LIBs) remains a formidable challenge due to persistent structural degradation and sluggish interfacial kinetics. Herein, a polycationic vanadate-based compound, LiCuFe 2 (VO 4 ) 3, is engineered to address these issues through a coupled mechanism of electrochemical lattice reorganization and self-adaptive interface modulation. The electrode exhibits an exceptional cycling performance, retaining a specific capacity of 1178 mAh g −1 after 1000 cycles at 0.5 A g −1, accompanied by a continuous capacity elevation phenomenon. Advanced synchrotron radiation X-ray diffraction and first-principles calculations reveal that, during cycling, the precipitation of metallic Cu nanoparticles orchestrates charge percolation networks, while Fe 3+ -derived Fe 3 O 4 catalyzes dynamic electrolyte translation, yielding a polymer gel-like film. This dual-regulation framework simultaneously alleviates mechanical stress and enables high-rate surface-dominated storage. These findings shed light on an electrochemically induced optimization paradigm, positioning LiCuFe 2 (VO 4 ) 3 as a prototype material for next-generation high-performance LIB anode.