Construction of Zinc MOFs-Derived Carbon-Based Zn–Co Oxides Porous Nanocages and Their Application as Electrodes for Electrochemical Energy Storage

Abstract

Metal–Organic frameworks (MOFs) and their derivatives have been widely used in lithium-ion batteries (LIBs) since their introduction because of their high porosity, large specific surface area, and structural and functional versatility. In this paper, the Zn–Co MOF-derived nanocages oxides with porous channel-crossing structure were successfully prepared by a low-temperature calcination self-assembly strategy. As anode of LIBs, the reduced graphene oxide (RGO)/ZnO/Co3O4 has excellent rating and cycling performances compared to the RGO/Co3O4. The RGO/ZnO/Co3O4 electrode maintains a reversible capacity of about 900 mAh g–1 after 500 cycles, which is 1.5 times higher than that of the RGO/Co3O4 electrode. At high current density of 2 A g–1, the discharge specific capacity of RGO/ZnO/Co3O4 is 500 mAh g–1, which is 1.25 times that of RGO/Co3O4. The superior electrochemical performance is attributed to its specific three-dimensional porous channel structure and internal Zn/Co oxide semiconductor heterointerface structure, which increases the effective active area of the electrode, improves the storage capacity and carrier transport efficiency of Li+, and enhances the overall structural stability as well as electrochemical activity. In addition, the improved electrochemical performance cannot be achieved without the synergistic effect of ZnO and Co3O4.

Recent Progress and Perspectives on Metal–Organic Framework-Based Electrode Materials for Metal-Ion Batteries and Supercapacitors

“…When combined with a commercial NCM 532 cathode to form a full battery, it could provide a high energy density of 611 W h kg –1 and a power density of 7600 W kg –1 . Meanwhile, Zheng et al had gained the Zn-Co MOF-derived nanocage oxide namely ZnO/Co 3 O 4 , which was further combined with rGO to form the composite material. When decorated as the LIB anode, it displayed outstanding electrochemical performance.…”