Carbon-Based Materials for Supercapacitors: Recent Progress, Challenges and Barriers

Abstract

Swift developments in electronic devices and future transportation/energy production directions have forced researchers to develop new and contemporary devices with higher power capacities, extended cycle lives, and superior energy densities. Supercapacitors are promising devices with excellent power densities and exceptionally long cycle lives. However, commercially available supercapacitors, which commonly use high-surface-area carbon-based electrodes and organic solutions as electrolytes, suffer from inferior energy densities due to the limited accessibility of surface area and constrained operating potential window of electrolytes. To address the issue of inferior energy densities, new high-capacity electrode materials and new/state-of-the-art electrolytes, such as ionic liquids, gel polymers, or even solid-state electrolytes, have been developed and evaluated vigorously in recent years. In this brief review, different types of supercapacitors, according to their charge storage mechanisms, have been discussed in detail. Since carbon-based active materials are the key focus of this review, synthesis parameters, such as carbonisation, activation, and functionalisation, which can impact a material’s physiochemical characteristics, ultimately affecting the performance of supercapacitors, are also discussed. Finally, the synthesis and applications of different carbon-based materials, i.e., carbon nanotubes, graphene, and activated carbon, have been reviewed, followed by conclusions and outlook.

Bioderived Laser-Induced Graphene for Sensors and Supercapacitors

“…PC, instead, exploits fast and reversible redox reactions happening close to or on the interfaces. In general, EDLC have quicker charge–discharge cycles, longer life cycles, and higher power densities. , Other relevant variables that may affect the performance are the pretreatment of the electrodes and the device architecture. The most common are the sandwich, which consists of two thin electrodes on top of each other incorporating an electrolyte layer between them, and the interdigitated, which are arrays of in-plane microelectrode fingers …”

“…They are adopted in electronic systems when high charge–discharge rates, long life cycles, and high power and energy densities are needed . Two classes of SC can be differentiated based on the charge/discharge mechanism of the device: electric double-layer capacitors (EDLC) (Figure a and b) and EDLC with pseudocapacitive behavior (PC) (Figure c) . EDLC relies on the physical storage of energy: when the electrodes are immersed in the electrolyte, the ions reorganize spontaneously in a double layer at the interface due to electrostatic attraction.…”

“…9 Two classes of SC can be differentiated based on the charge/discharge mechanism of the device: electric double-layer capacitors (EDLC) (Figure 9a and b) and EDLC with pseudocapacitive behavior (PC) (Figure 9c). 145 EDLC relies on the physical storage of energy: when the electrodes are immersed in the electrolyte, the ions reorganize spontaneously in a double layer at the interface due to electrostatic attraction. PC, instead, exploits fast and reversible redox reactions happening close to or on the interfaces.…”

Morphology-controlled synthesis of a NiCo-carbonate layered double hydroxide as an electrode material for solid-state asymmetric supercapacitors

“…The specific capacitances of the carbonbased electrode materials can be achieved up to 250 F g À1 because of their high specific surface area. 12 On the other hand, the transition metal oxides (NiO, MnO 2 , Co 3 O 4 ), [13][14][15] hydroxides (Co(OH) 2 @Cu(OH) 2 ), 16 carbonates (NiCo(CO 3 )(OH) 2 ), 17 chalcogenides, 18 and conductive polymers (PANI, PPy) 19,20 are found to show PC behavior. Although the specific capacitance and energy density are higher for PCs, their cycling stability remains lower than that of EDLCs because of the faradaic redox reaction.…”

An Aniline‐Complexed Bismuth Tungstate Nanocomposite Anchored on Carbon Black as an Electrode Material for Supercapacitor Applications

“…Additionally, carbon-based materials have been used for the SCs applications by different researchers. [12] Bismuth tungstate (BiW) and their nanocomposite-based materials have been broadly utilized for catalytic applications owing to their economic, improved electron transfer kinetics, quick reaction, easy availability, and superior resilience. [13] Scientists tried different kinds of preparation methods to design highly functional BiW and their nanocomposites, like sol-gel, [14] chemical vapor deposition, [15] the co-precipitation process, [16] and the hydrothermal process.…”