MOF-Derived Long Spindle-like Carbon-Coated Ternary TransitionMetal-Oxide Composite for Lithium Storage

Fe3O4 is a promising alternative for next-generation lithium-ion batteries (LIBs). However, its poor cycle stability due to the large volume effect during cycling and poor conductivity hinders its application. Herein, we have successfully designed and prepared a carbon-coated ternary transition-metaloxide composite (noted as (FeCoNi)3O4@C), which is derived from FeCoNiMOF-74 (denoted as FeCoNi-211-24). (FeCoNi)3O4@C perfectly inherited the long spindle-shaped precursor structure, and (FeCoNi)3O4 particles grew in situ on the precursor surface. The ordered particles and the carbon-coated structure inhibited the agglomeration of particles, improving the material's cycle stability and conductivity. Therefore, the electrode exhibited excellent electrochemical performance. Specifically, (FeCoNi)3O4@C-700 presented excellent initial discharge capacity (763.1 mAh g-1 at 0.2 A g-1 ), high initial coulombic efficiency (73.8%), excellent rate capability, and cycle stability (634.6 mAh g-1 at 0.5 A g-1 after 505 cycles). This study provides a novel idea for developing anode materials for LIBs.