Hierarchical NiCo-LDH/NH₂-UiO-66 Nanoflower Composites for High-Performance Supercapacitors

NH₂-UiO-66 has been recognized as a promising porous material due to its large specific surface area (SSA) and excellent structural stability. However, their poor electrochemical performance hinders their application in supercapacitors. In this study, NH₂-UiO-66 was attached to the surface of NiCo-LDH nanoflower by employing the self-assembly strategy, which significantly inhibited the stacking of NiCo-LDH nanoflower, forming the NiCo-LDH/NH₂-UiO-66 (NC/NU) composite. Owing to weakening of the aggregation effect, abundant redox-active sites, and ion diffusion channels of NH₂-UiO-66, the obtained NC/NU composites exhibit a high specific capacitance of 867.4 F g^-1 at 1 A g^-1 and an outstanding cycling stability of 86.7% after 10,000 charge/discharge cycles. Additionally, derived 3D reticulated porous carbon (PCC) with ZIF-67 and sodium carboxymethyl cellulose (CMC) as precursors was synthesized by a two-step KOH activation strategy and used as an anode material. The hybrid supercapacitor (NC/NU-80//PCC-0.75) provides an energy density of 30.6 Wh kg^-1 at a power density of 800.6 W kg^-1, with a capacity retention of 96% after 5000 charge/discharge cycles. The obtained results demonstrate that NC/NU-80 nanoflower composites have considerable potential for application in the field of supercapacitors.