Some Aspects of Preparations and Applications of Electrochemical Double‐Layer Capacitors (Supercapacitors)

High-performance asymmetric supercapacitor based on a CdCO3/CdO/Co3O4 composite supported on Ni foam – part II: a three-electrode electrochemical study

“…Due to both the growing request to obtain sustainable and renewable energy and intermittent energy sources such as solar and wind power, a technology that can store sustainable energy to ensure efficient, continuous, reliable and affordable energy supplies is required. 1–3 Furthermore, development of lightweight portable devices and consumer electronics has increased demand for faster sustainable energy storage systems. 1,2 Then, the main challenge is to attain an efficient and reliable electrical energy storage system, with electrochemical energy storage technologies serving as the key components.…”

“…1–3 Furthermore, development of lightweight portable devices and consumer electronics has increased demand for faster sustainable energy storage systems. 1,2 Then, the main challenge is to attain an efficient and reliable electrical energy storage system, with electrochemical energy storage technologies serving as the key components. 1–3 In this way, supercapacitors (SCs) are one of the devices belonging to these electrochemical energy storage technologies, which also include batteries, conventional capacitors and fuel cells.…”

“…1,2 Then, the main challenge is to attain an efficient and reliable electrical energy storage system, with electrochemical energy storage technologies serving as the key components. 1–3 In this way, supercapacitors (SCs) are one of the devices belonging to these electrochemical energy storage technologies, which also include batteries, conventional capacitors and fuel cells. 2 Supercapacitors are electric energy storage devices that can fill the energy/power gap between fuel cells/batteries (which have high energy storage) and conventional capacitors (which have high power output).…”

“…2 Supercapacitors are electric energy storage devices that can fill the energy/power gap between fuel cells/batteries (which have high energy storage) and conventional capacitors (which have high power output). 1,3–6 In comparison with conventional capacitors, SCs exhibit specific capacitance values from 6 to 9 orders of magnitude larger and SCs can store ten to a hundred times more energy. 7,8 In opposition to batteries, SCs can be effectively operated as advanced energy storing innovations.…”

“…7 Supercapacitors exhibit numerous appealing electrochemical merits such as: exceptional long cycle life, symmetrical (high reversibility) and sloping charge–discharge profiles, very short charge–discharge time (a few seconds), high power density and continuous variation of free energy with the conversion degree. 1,2,4,5,7,9–11 Supercapacitors are widely used in hybrid electric vehicles, portable electronic devices, medical and telecommunication devices. 8,12–14 On the basis of charge storage mechanism, SCs can be categorized into two groups: electric double layer capacitors, which use electrostatic accumulation of electrolyte ion to store energy and pseudocapacitors, which store energy by faradaic reactions.…”