MOF derived ZnFe2O4 nanoparticles scattered in hollow octahedra carbon skeleton for advanced lithium-ion batteries

Abstract Nanostructure design strategies are highly desired in lithium ion batteries due to the attractive properties of nanosizing. Herein, the hollow octahedra ZnFe2O4@C nanocomposites are synthesized through Zn-Fe MOFs as precursor and used as anode materials for lithium ion batteries. Notably, ZnFe2O4@C nanocomposites possess unique structure, where ZnFe2O4 nanoparticles (∼20 nm) well scatters in each surface of the hollow octahedra carbon skeleton (∼600 nm) and are also confined by coating carbon. This structure efficiently avoids particle agglomeration, buffers volume expansion, facilitates electron transfer and shortens diffusion lengths. Benefiting from above advantages, ZnFe2O4@C exhibits excellent electrochemical performance, including high specific capacity (1780 mAh g-1 at 1A g-1 after 400 cycles), superb rate capability (557 mAh g-1 at 15 A g-1) and ultra-long cycling stability (918 mAh g-1 at 3 A g-1 after 800 cycles). As much, this work may develop an effective nanostructure aiding in designing a variety of metal oxide/carbon composites of interest for energy storage applications.