MOF-Derived Hetero-Zn/Co Hollow Core-Shell TMOs as Anode for Lithium-Ion Batteries

Abstract

In this work, metal–organic frameworks (MOFs) were used as precursors to prepare Zn/Co oxide with a porous dodecahedral core-shell structure. Herein, a low-temperature self-assembly calcination and hydrothermal strategy of imidazole-based Zn-Co-MOF was used. As anode of lithium-ion batteries (LIBs), ZnO/Co3O4 has good cycling stability, the specific discharge capacity of ZnO/Co3O4 is stable at about 640 mAh g−1 after 200 cycles, and its coulombic efficiency (CE) is stable above 95% after the first 20 cycles. When the current density is 0.6 A/g, the discharge capacity is 420 mAh g−1. This excellent electrochemical performance is attributed to its unique porous hollow structure and unique heterojunction electrode interface, which improves the Li+ storage capacity, increases the contact area between the electrode and the electrolyte, and improves the overall electrochemical activity. In addition, the synergistic effect of ZnO and Co3O4 also plays an important role in improving the electrochemical performance.