A MOF-derived flower-shaped CeCo-oxide as a multifunctional material for high-performance lithium-ion batteries and supercapacitors.

ABSTRACT

Precursor method is a well-known technology for preparing certain functional materials. In this work, a novel 3d-4f bimetallic organic framework, denoted as 45MCeCo (45 M representing 4,5-imidazole dicarboxylic acid), was successfully synthesized via a hydrothermal technique. The compound thus obtained has the molecular formula of C10H11CeCoN4O12. By meticulously controlling the amounts of the experimental materials, it was feasible to prepare flower-like crystals possessing identical single crystal structures and significantly larger specific surface areas. As a precursor for electrode materials, this structure underwent calcination at different temperatures to prepare Co3O4/CeO2 composites with in situ composite heterostructures. Post-electrochemical tests revealed that CeO2 remains unreactive across all potentials, thereby contributing to the stabilization of the electrode material structure. In contrast, Co3O4 participated in redox reactions to provide a specific capacity to the sample. In addition, when comparing the performance of the electrode material under different calcination conditions, it became evident that the material exhibited optimal electrochemical performance when subjected to a temperature of 700 °C for 2 h.