Efficient\nSynthesis of MOF-Derived Ni<sub>2</sub>CuO<sub>3</sub>/CuO Nanocomposites\nCathode and Fe<sub>2</sub>O<sub>3</sub>/N-rGO Composite Anode for\na High-Performance All-Solid-State Asymmetric\nSu

Recently,\nmetal–organic framework (MOF)-derived\nbinary transition-metal\noxide (BTMO) holds promise as an ideal electrode material for energy-storage\napplications. Here, we report a facile synthesis procedure of MOF-derived\nBTMO that commences with the preparation of Cu-MOF through the coordination\nof Cu<sup>2+</sup> with 2-MeIM. Subsequently, Ni<sup>2+</sup> is introduced\ninto the Cu-MOF to create Cu<sup>2+</sup> and Ni<sup>2+</sup> binary\nclusters, resulting in the formation of Ni-Cu-MOF. Finally, annealing\nof Ni-Cu-MOF led to the formation of a nanoflakes morphology of Ni<sub>2</sub>CuO<sub>3</sub>/CuO (denoted as NCO/CuO) composite that serves\nas an efficient pathway for both ion and electron transportation,\ncreating plentiful active sites for the faradaic charge storage process.\nImpressively, the NCO/CuO composite demonstrates significantly higher\nspecific capacity (<i>C</i><sub>s</sub>) of 613.54 C/g compared\nto Ni-Cu-MOF (301.11 C/g) at a current density of 1 A/g and retains\n66.3% of its initial capacitance at 15 A/g. Similarly, the Fe<sub>2</sub>O<sub>3</sub>-doped nitrogen-doped reduced graphene oxide\n(denoted as Fe<sub>2</sub>O<sub>3</sub>/N-rGO) composite prepared\nthrough a facile hydrothermal method demonstrates a specific capacitance\n(<i>C</i><sub>sp</sub>) of 603.39 F/g at 1 A/g, surpassing\nits counterparts, Fe<sub>2</sub>O<sub>3</sub>, and N-rGO and retains\n39.6% of its initial capacitance even at a higher current density\nof 15 A/g. Finally, a flexible asymmetric supercapacitor (ASC) device\nwas designed and assembled using the Ni<sub>2</sub>CuO<sub>3</sub>/CuO composite as the positive electrode, Fe<sub>2</sub>O<sub>3</sub>/N-rGO as the negative electrode, and PVA-KOH gel as the electrolyte.\nThe Ni<sub>2</sub>CuO<sub>3</sub>/CuO//Fe<sub>2</sub>O<sub>3</sub>/N-rGO ASC device demonstrates an excellent energy density of 48.26\nWh/kg at 1 A/g and a maximum power density of 11 250 W/kg and\nretains 86% of its capacitance after 10 000 cycles at 1 A/g.\nThese findings provide valuable insights for high-performance energy-storage\nASC devices for next-generation portable electronics.