Engineering redox active sites enriched 3D-on-2D bimetallic double layered hydroxide electrode for supercapatteries

The functionalization of structural nanoengineered battery-type electrodes has aided the emergence of supercapattery (SCp) subclass, which enables a wide range of applications. Herein, our research work provides a platform for two-step fabrication of nanoengineered 3D-on-2D structure as a promising approach to obtain high-performance battery-type electrodes. The hierarchical 2D NiCo bimetallic LDH NC(12)40 electrode was fabricated using electrodeposition, while the nanoengineered 3D ZIF-67 on 2D LDH electrode was achieved via pseudomorphic replication techniques. The fabricated 3D-on-2D NC(12)40-30 electrode reveals a maximum areal capacity of 1044 mC cm⁻² at a current density of 4 mA cm⁻² in 6 M KOH electrolyte. Furthermore, NC(12)40-30//AC was integrated as a SCp device, achieving a maximum specific capacitance of 63 F/g and maximum specific energy and power of 20.5 W/h/kg and 8522.7 W/kg, respectively, with improved capacitance retention (85%) even after 10,000 cycles. Thus, the assembled SCp coin cell displays 18-LED illumination in four different commercial LED colors, indicating the viability of the battery-type electrode for SCp development.