Ternary MOF-Based Redox Active Sites Enabled 3D-on-2D Nanoarchitectured Battery-Type Electrodes for High-Energy-Density Supercapatteries

Designing rationally combined metal-organic frameworks (MOFs) with multifunctional nanogeometries is of significant research interest to enable the electrochemical properties in advanced energy storage devices. Herein, we explored a new class of binder-free dual-layered Ni-Co-Mn-based MOFs (NCM-based MOFs) with three-dimensional (3D)-on-2D nanoarchitectures through a polarity-induced solution-phase method for high-performance supercapatteries. The hierarchical NCM-based MOFs having grown on nickel foam exhibit a battery-type charge storage mechanism with superior areal capacity (1311.4 μAh cm-2 at 5 mA cm-2), good rate capability (61.8%; 811.67 μAh cm-2 at 50 mA cm-2), and an excellent cycling durability. The superior charge storage properties are ascribed to the synergistic features, higher accessible active sites of dual-layered nanogeometries, and exalted redox chemistry of multi metallic guest species, respectively. The bilayered NCM-based MOFs are further employed as a battery-type electrode for the fabrication of supercapattery paradigm with biomass-derived nitrogen/oxygen doped porous carbon as a negative electrode, which demonstrates excellent capacity of 1.6 mAh cm-2 along with high energy and power densities of 1.21 mWh cm-2 and 32.49 mW cm-2, respectively. Following, the MOF-based supercapattery was further assembled with a renewable solar power harvester to use as a self-charging station for various portable electronic applications.