Advancing supercapacitors with BaMn-LDH/BaMn-MOF composites: a synergistic pathway to enhanced energy storage

The rational reforming of transition metal layered double hydroxides (LDHs) has emerged as a key strategy for developing high-performance supercapacitor electrodes owing to their outstanding electrochemical activity and tunable chemical composition. Despite their potential, pristine LDHs are hindered by their inherent low electrical conductivity and significant particle agglomeration, which adversely affect their electrochemical performance. In this study, a BaMn-LDH/BaMn-MOF composite was synthesized by integrating BaMn-LDHs with BaMn-MOFs via a hydrothermal method. LDH- and MOF-based electrode materials were fabricated to facilitate comparative analyses of their morphological, structural, and electrochemical characteristics. The porous framework of BaMn-MOF provides large structural dimensions, high surface area, and numerous electrochemically active sites, leading to improved electrochemical performance of LDHs. The electrochemical behavior of the synthesized materials was investigated using both three- and two-electrode configurations. The three-electrode electrochemical experiment indicated that the BaMn-LDH/BaMn-MOF composite provided a significant specific capacity (Q _s) of 744C g^-1 compared to the pristine LDH electrode material. This was enabled by the particular design of the BaMn-LDH/BaMn-MOF composite, which has vertically oriented LDH nanosheets and porous MOFs with an abundance of active sites and effective ion transport. In addition, a hybrid supercapacitor (HSC) was made with the help of the BaMn-LDH/BaMn-MOF composite (cathode) and activated carbon (AC) (anode). The as-fabricated BaMn-LDH/BaMn-MOF‖AC HSC device showed a significantly high energy density (E _d) of 58.44 Wh kg^-1 and an outstanding power density (P _d) of 5100 W kg^-1. The device exhibits excellent cycling stability, retaining 92% of its initial capacitance after 5000 cycles. The kinetic analysis at a scan rate of 10 mV s^-1 revealed that the device delivered 10% capacitive contribution, complemented by 90% diffusion-controlled contribution. The electrochemical activity of the BaMn-LDH electrodes is very high, offering a new perspective on hybrid energy storage devices in the future.