Toward Superior Energy Storage Capacity: Using Cobalt Metal-Organic Frameworks in Synergy with High Surface Area Biocarbons

Growing global energy needs, along with environmental deterioration due to fossil fuel consumption, play a pivotal role in the development of renewable energy sources. Since energy storage systems play a key role in using these kinds of energy sources for portable electronics, supercapacitors, which interstitially behave between conventional capacitors and batteries, have drawn increasing attention in recent years. Receiving benefits of outstanding tunability of structures and high specific surface area (SSA) metal-organic frameworks (MOFs) sound immensely promising candidate for meeting the demands of developing high-performance energy storage systems. Among a large variety of MOFs, Co ones with high redox activity, ample availability, low-cost, and environmental compatibility are receiving growing research attention in recent years. Regarding the synergistic effect of the ۳D hierarchically structured assemblies on the stability of nanostructured electrode materials as well as their electrochemical performance, designing ۱D or ۲D supporting current collectors with high electrical conductivity, such as nano-sized binary metal compounds, is of special significance. Transition metal sulfides possessing outstanding electrical conductivity and superior electrochemical activity together with low electronegativity are prominent active materials for energy storage applications. Among a large variety of transition metal sulfides, binaries gained the benefits of abundant natural resources as well as unique redox activity. Herein, a facile room-temperature in-situ process was followed by a scalable electrochemical approach to prepare binary metal sulfide (BMS)-decorated Co-MOF electrodes. As evidenced in the Figure ۱, the field-emission electron microscopy (FESEM) images, provide convincing evidence of successful formation of electrode active materials onto the graphite-based current collectors. Cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy were conducted to investigate the electrochemical performance of the prepared electrodes. The fabricated electrodes exhibited remarkable electrochemical performance, including high specific capacity, reasonable rate capability, as well as remarkable cycle durability in ۳M KOH aqueous electrolyte, all of which showed the potential of prepared electrodes for high-performance supercapacitors.

کلیدواژه ها:

Metal Organic Frameworks ، Energy Storage Systems ، Aqueous Electrolytes ، Binary Metal Sulfide Nanostructures