Design and Construction of Carbon-Coated Fe₃O₄/Cr₂O₃ Heterostructures Nanoparticles as High-Performance Anodes for Lithium Storage

Transition metal oxides, highly motivated anodes for lithium-ion batteries due to high theoretical capacity, typically afflict by inferior conductivity and significant volume variation. Architecting heterogeneous structures with distinctive interfacial features can effectively regulate the electronic structure to favor electrochemical properties. Herein, an engineered carbon-coated nanosized Fe3O4/Cr2O3 heterostructure with multiple interfaces is synthesized by a facile sol-gel method and subsequent heat treatment. Such ingenious components and structural design deliver rapid Li+ migration and facilitate charge transfer at the heterogeneous interface. Simultaneously, the strong coupling synergistic interactions between Fe3O4, Cr2O3, and carbon layers establish multiple interface structures and built-in electric fields, which accelerate ion/electron transport and effectively eliminate volume expansion. As a result, the multi-interface heterostructure, as a lithium-ion battery anode, exhibits superior cycling stability maintaining a reversible capacity of 651.2 mAh g(-1) for 600 cycles at 2 C. The density functionaltheory calculations not only unravel the electronic structure of the modulation but also illustrate favorable lithium-ion adsorption kinetics. This multi-interface heterostructure strategy offers a pathway for the development of advanced alkali metal-ion batteries.