Engineering of Metal-Organic Framework-Derived CoTiO Micro-Prisms for Lithium-Ion Batteries.

Metal-organic framework (MOF)-derived transition metal compounds and their composites have attracted great interest for applications in energy conversion and storage. In this work, hexagonal micro-prisms of Ni-doped CoTiO composited with amorphous carbon (NiCTO/C) were synthesized using Ti-Co-based MOFs as precursors. The experimental results indicate the substitutional doping of Ni for Co in CoTiO (CTO), leading to improved conductivity, as further confirmed by density functional theory calculations. Thus, the carbon-free sample of Ni-doped CTO exhibits improved lithium storage properties compared to the pristine one. Furthermore, when coupled with in situ-formed carbon, the dually modified NiCTO/C micro-prisms demonstrated a significantly increased reversible capacity of 584.8 mA h g, excellent rate capability, and superior cycling stability at a high current density of 500 mA g. This enhanced electrochemical performance can be attributed to the synergistic effect of Ni doping and carbon coating.