Metal-organic framework derived porous ternary ZnCo2O4 nanoplate arrays grown on carbon cloth as binder-free electrodes for lithium-ion batteries

Abstract

Metal-organic frameworks (MOFs) derived ternary transition metal oxide nanostructures have attracted considerable attention for their important applications in energy-related fields. However, most of the present reports on MOFs-derived materials are in the powder form, which should be further mixed with polymer binder and conductive agents before they are coated on current conductor. In this work, we demonstrate a facile solution method to grow the bimetallic zinc/cobalt zeolitic imidazolate frameworks nanoplate arrays (Zn/Co-ZIF NPAs) on carbon cloth (CC) substrate and then they are well converted to porous ternary ZnCo2O4 NPAs on CC after an annealing treatment in air. When investigated as binder-free electrodes for lithium-ion batteries (LIBs), the ZnCo2O4 NPAs/CC electrode exhibits a high area capacity of 3.01 mA h cm−2 (corresponding to 1341.7 mA h g−1 for the ZnCo2O4 NPAs) at the current density of 0.24 mA cm−2 for 100 cycles, which is much higher than that of the Co3O4 NPAs/CC electrode (1.93 mA h cm−2). Moreover, at a high current density of 1.20 mA cm−2, the ZnCo2O4 NPAs/CC electrode can still maintain a high capacity of 2.05 mA h cm−2. The excellent electrochemical performance could be attributed to the unique morphology, structure and composition of the porous ternary ZnCo2O4 NPAs, as well as directly grown on current collector.