MOF-Derived Long Spindle-like Carbon-Coated Ternary Transition-Metal-Oxide Composite for Lithium Storage.

Fe 3 O 4 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-metal-oxide composite (noted as (FeCoNi) 3 O 4 @C), which is derived from FeCoNi-MOF-74 (denoted as FeCoNi-211-24). (FeCoNi) 3 O 4 @C perfectly inherited the long spindle-shaped precursor structure, and (FeCoNi) 3 O 4 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) 3 O 4 @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.