Metal–organic framework mediated nickel doped copper ferrite for superior lithium storage

Abstract

The increasing demand for innovative lithium-ion batteries (LIBs) has significantly inspired the search for vigorous electrodes with higher specific capacity. Herein, a metal–organic framework (MOF) mediated approach was applied to fabricate a series of Cu_1−xNi_xFe₂O₄-based/carbon (Cu_1−xNi_xFe₂O₄@C) composites having diverse nanostructures. Starting from elegant Cu_1−xNi_xFe₂O₄ particles, the controlled growth of MOFs is then applied on their surfaces followed by carbonization, establishing a recognizable core/shell structure. The crystalline phase and morphology of as-obtained samples have been systematically characterized. Benefiting from a well-designed core/shell structure, all the optimized products displayed superior lithium (Li) storage performance in LIBs. The obtained Cu_1−xNi_xFe₂O₄@C provides a high reversible capacity of 813 mA h g⁻¹ with a current density of 100 mA g⁻¹ up to 100 cycles. Even under conditions of 500 mA g⁻¹ up to 500 cycles, the beneficial core/shell structure can still provide a discharge capacity of 722 mA h g⁻¹. Therefore, this work extends the scope of MOFs as coating materials and clarifies the Li storage performance of Cu_1−xNi_xFe₂O₄-based materials.