ZIF-67 derived 3D nanocage-shaped FeCoNi layered double hydroxides as an electrocatalyst for improving the performance of LOBs

Layered double hydroxides (LDHs) with unique structure features are regarded as ideal materials for energy storage. Developing highly efficient cathode catalysts is crucial for improving the storage capacity and stability of lithium-oxygen batteries (LOBs). Herein, we proposed a facile solvothermal strategy to prepare different metal molar ratios of trimetallic FeCoNi LDHs using the zeolitic imidazolate framework-67 (ZIF-67) as a template. When the metal molar ratios of Fe/Ni = 1.7, the obtained FeCoNi LDH (FCN-C) exhibits a 3D nanocage-shaped structure with highly ordered flower-like nanosheets on the surface. The well-designed structures exhibit high specific surface areas and abundant mic-mesoporous channels, which are favored for the transport of electrons and ions diffusion. The synergistic effects of FeCoNi LDH components can effectively regulate the electronic structure and deliver striking electrochemical activities. Specifically, the LOBs with FCN-C cathode possess an excellent specific capacity of 17598.5 mAh g−1 at 0.05 mA cm−2. Under 0.05 mA cm−2 with a cutoff capacity of 500 mAh g−1, the LOBs assembled by FCN-C cathode can achieve 213 cycles, and it is much longer than that of other FeCoNi LDHs cathodes. This simple preparation method can provide new insight to design efficient electrocatalysts for energy applications.