One-step hydrothermal synthesis of Co-MOF/Co3O4/rGO hybrid nanocomposite as high-performance anode of alkali metal-ion batteries

Abstract

Metal-organic frameworks (MOFs) frequently encounter issues such as inadequate conductivity and structural stability, constraining their utility in energy storage. Combining MOFs with other functional materials to form MOFs composites offers a promising approach to amalgamate advantages and address limitations. In this study, we developed a Co-MOF/Co₃O₄/rGO hybrid nanocomposite using a controlled one-step hydrothermal method. The pristine Co-MOF can be transformed into Co-MOF/Co₃O₄ by varying the amount of NaOH, and the final product Co-MOF/Co₃O₄/rGO can be obtained when reduced graphene oxide is added during the synthesis process. Due to the unique and synergistic structure consisting of Co-MOF, Co₃O₄, and rGO, Co-MOF/Co₃O₄/rGO exhibited excellent electrochemical performances. The Co-MOF/Co₃O₄/rGO composite demonstrated an initial charge capacity of 931 mAh g⁻¹ when utilized as an anode in lithium-ion batteries at 100 mA g⁻¹. Impressively, it maintained a reversible capacity of 1210 mAh g⁻¹ even after 300 cycles, showcasing its excellent cycling stability. Furthermore, its applicability was extended to sodium-ion and potassium-ion batteries, where it exhibited reversible capacities of 343 mAh g⁻¹ and 319 mAh g⁻¹, respectively, at the same current density after 300 cycles. These results highlight the versatility and promising performance of the Co-MOF/Co₃O₄/rGO composite as an electrode material across various types of batteries.