A metal–organic-framework approach to engineer hollow bimetal oxide microspheres towards enhanced electrochemical performances of lithium storage

Abstract

Nanosized electrode materials with a hollow structure, larger specific surface area, and lower energy density as well as more void space are widely adopted for high-performance lithium-ion batteries. In this work, we obtained bimetal–organic frameworks of Fe/Mn-MOF-74 with a hollow microsphere morphology via a facile one-step microwave method and further used it to fabricate hollow Fe–Mn–O/C microspheres. Endowed with the metal–organic-framework-derived carbon-coated nanoparticle-assembled hollow structure with hierarchical porous characteristics and synergistic effects between two different metal species, the Fe–Mn–O/C electrode exhibits outstanding electrochemical performances as the anode of lithium-ion batteries. It achieves improved cycling performance (1294 mA h g⁻¹ after 200 cycles at 0.1 A g⁻¹) and good rate capability (722, 604, and 521 mA h g⁻¹ at 0.2, 0.5 and 1 A g⁻¹). The smart design of a hollow morphology with uniform two metal species can promote the synthesis of multimetal oxides and their carbon composites, as well as their further potential application for energy-storage.