Designing Carbon Based Supercapacitors with High Energy Density: A Summary of Recent Progress

Abstract

Carbon based supercapacitors (CSCs), with high output power and long lifespan, are considered as promising power sources for modern electronic devices. The rush to find new approaches for optimizing their electrochemical behaviors is still vibrant, and particularly, widespread enthusiasm was focused on improving the energy density of CSCs through improving the specific capacitance and expanding the operating voltage. In this regard, this article provides a brief review about recent progress and new understanding about the assembly of CSCs with high energy density. Novel applied strategies were highlighted and discussed from the aspects of electrolyte, electrodes, and device modulation. Dynamic and mechanism factors associated with the energy storage process of CSCs are particularly emphasized. Finally, the opportunities and challenges are elaborated in the hope of guiding the promising direction for the design of high-energy CSCs.

Achieving high volumetric EDLC carbons via hydrothermal carbonization and cyclic activation

“…Nevertheless, their energy density, which is frequently expressed as watt-hours per kilogram (Wh kg −1 ) named gravimetric energy density, is relatively low at about 10 Wh kg −1 for commercial supercapacitors compared to ∼300 Wh kg −1 for lithium-ion batteries [11,12]. Therefore, the greatest challenges in supercapacitor research is improving the gravimetric energy density of supercapacitors, shifting it as close as possible to batteries [13].…”

Graphene‐Based Planar Microsupercapacitors: Recent Advances and Future Challenges

“…Supercapacitors (SCs) are of particular interest for their high power densities as shown in Figure , and ultralong cycle life with little capacity loss . They also have wide operational temperature range and can be operated environmental friendly as well as maintenance free . A supercapacitor is generally composed by one (or more) pair of electrodes similarly to an electrostatic capacitor, where the typical dielectric material is replaced by a liquid or solid‐state electrolyte.…”

Surface Engineering for Advanced Aqueous Supercapacitors: A Review

“…Nevertheless, the lower energy densities ( E ) of aqueous SCs as compared to batteries have impeded their range of commercial applications . According to the theoretical equation, E=(1/2)CV 2 , the E is directly determined by the capacitance ( C ) and the square of potential ( V ), which are two main focuses for nowadays researchers . In comparison with electrostatic mechanism, the faradaic one presents much higher energy storage because of the reversible reactions occurring near surface as well as on the surface of electrode .…”

“…[18] According to the theoretical equation, E = (1/2) CV 2 , the E is directly determined by the capacitance (C) and the square of potential (V), which are two main focuses for nowadays researchers. [19][20][21] In comparison with electrostatic mechanism, the faradaic one presents much higher energy storage because of the reversible reactions occurring near surface as well as on the surface of electrode. [22,23] Consequently, the surface properties are crucial for electrodes to achieve high capacitance and enlarge working potential.…”