Experimental modulation of electrochemical energy storage characteristics of cobalt metal-organic framework-based electrode materials via organic linker variance

Abstract

Metal-organic frameworks (MOFs) represent a class of materials characterized by metal ions coordinated with organic linkers, resulting in highly porous and adaptable microstructures. Their remarkable efficacy in ion exchange processes enables them to exhibit outstanding energy and power density capabilities. This study investigates the critical role of organic ligands Pyridine-2,6-dicarboxylic acid (H₂PDC) and 5-Nitroisophthalic acid (5-NIP) in enhancing the electrochemical energy storage performance of pristine Cobalt-based MOFs (Co-MOFs). The sonochemically synthesized Co-H₂PDC demonstrates a specific capacity of 1673.05 C/g at a scan rate of 2 mV/s and 1194.704 C/g at a current density of 2.8 A/g. Owing to its superior performance, a hybrid device was fabricated as Co-H₂PDC//AC. The electrochemical performance of the hybrid device was evaluated using a two-electrode configuration. The Co-H₂PDC//AC configuration achieved an impressive energy density of 82.18 Wh/kg and a power density of 4250 W/kg while maintaining 79% stability over 5000 consecutive galvanostatic charge-discharge cycles. Furthermore, the device's performance was further evaluated using simulation techniques to assess diffusive and capacitive contributions. The integration of MOFs as battery-type electrode materials paves the way for advanced energy storage devices.