Perspective on High‐Energy Carbon‐Based Supercapacitors

Abstract

Supercapacitors based on carbon materials have advantages such as high power density, fast charging/discharging capability, and long lifetime stability, playing a vital role in the field of electrochemical energy storage technologies. To further expand the practical applications of carbon-based supercapacitors, their energy density, which is essentially determined by the specific capacitance and operating voltage, should be improved. This review provides fundamental knowledge on achieving high energy density of supercapacitors. We first address the relationship of the features of carbon materials, such as the surface area, pore size distribution, and surface functional groups, with their electrochemical performances, such as the gravimetric and volumetric capacitance, surface pseudocapacitance, and operating voltage. Then, we discuss the properties of electrolytes from nonaqueous and aqueous to hybrid one from the thermodynamic and kinetic aspects, and present their effects on capacitance and operating voltage. Finally, we illustrate different cell design strategies and their basic principles for increasing operating voltage. We also highlight the recent advances related to these fields and provide our insight into high-energy supercapacitors.

Uniform Zn Deposition Achieved by Conductive Carbon Additive for Zn Anode in Zinc‐Ion Hybrid Supercapacitors

“…To investigate the electrochemical performance of Zn and C@Zn in ZIHS, we adopted AC, prepared in‐house, [ 51 ] which can provide extremely high specific capacity, as the cathode. [ 52–55 ] Such a high‐capacity cathode may lead to more zinc ions participating in the energy‐storage process, which is favorable for us to test the stability of anode when a large amount of zinc deposition occurs. As shown in Figure 2 a,b, the pore structure details of AC are revealed by the nitrogen adsorption−desorption measurements.…”

Molecular Understanding of Energy Storage in Supercapacitors with Porous Graphyne Electrodes: From Semiconductor to Conductor

“…5e), when the applied voltage reaches 3 V, the maximum energy density and power density are 58.71 Wh/kg (36.28 Wh/L) and 70.5 kW/kg (43.57 kW/L), respectively; as the applied voltage reaches 4V, the maximum energy density and power density could reach 98.50 Wh/kg (60.86 Wh/L) and 178.85 kW/kg (110.51 kW/L) respectively, which surpass most porous carbon supercapacitors. Particularly, the volumetric power density excels all the carbon electrode supercapacitors (Supplementary Ta ble 4) 2,[38][39][40] . These power and energy densities are both at the temperature of 400 K. We further calculated the capacitive performance at 300 K. As shown in Fig.…”

1D interconnected porous binary transition metal phosphide nanowires for high performance hybrid supercapacitors

“…The advancement of high performance electrochemical energy storage devices has received tremendous attention triggered by the emerging markets, increasing concerns in energy consumption, and global environmental change. 1,2 Among various energy storage devices, supercapacitors (SCs) are attractive owing to the high power density, rapid charging/discharging capability, extensive long durability, and eco-friendliness. [3][4][5] However, the low energy density (ED) of SCs remains a critical challenge for practical applications.…”