Binary zinc-cobalt metal-organic framework derived mesoporous ZnCo2O4@NC polyhedron as a high-performance lithium-ion battery anode.

Abstract

Ternary transition metal oxides have attracted increasing attention due to their many merits, and will enhance electrochemical performance via the synergistic effects of the different single metal oxides. Herein, ZnCo2O4 nanoparticles encapsulated in nitrogen-doped carbon (ZnCo2O4@NC) polyhedrons have been successfully prepared through a facile two-step method. The as-prepared products had a uniform size and consisted mainly of interconnected ZnCo2O4 nanoparticles (NPs), which were uniformly distributed in the materials. As a result, the ZnCo2O4@NC polyhedrons of ZnCo-700 show a superb specific capacity of approximately 1601 mA h g-1 over 50 cycles at 0.1 A g-1. A reversible capacity of 1082 mA h g-1 was retained after 300 cycles at 1 A g-1, and a superb reversible capacity of 775 mA h g-1 was attained even when the current density was increased to 5 A g-1. These distinguished electrochemical properties could be ascribed mainly to the uniquely advantageous structural and compositional features.