Core–shell copper-manganese oxide nanoparticles synthesized from a copper-manganese metal–organic framework with pyromellitic acid as ligand for lithium-ion battery anode

Abstract

Transition metal oxides (TMOs) applied to lithium-ion batteries have attracted increasing attention, but volume expansion during charging and discharging makes their application undesirable. To solve this problem, this paper reports for the first time that core–shell copper-manganese oxide nanoparticles, namely M-CuMn-600, consisting of metal oxides encapsulated in a carbon shell, were obtained by calcining a copper-manganese metal–organic framework (named CuMn-MOF) with pyromellitic acid (PMA) as a ligand at 600℃ under an inert atmosphere for lithium-ion battery applications. The M-CuMn-600 anode material was characterized by X-ray diffraction, field emission scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) theory, and X-ray photoelectron spectroscopy (XPS). It has an excellent cycle stability and reversible capacity (709.1 mA h g⁻¹ after 100 cycles at a current density of 200 mA g⁻¹) as an anode material for lithium-ion batteries. The results show that tailoring and optimizing the structure of TMOs is the key to having excellent electrochemical performance.