Electrochemical Double‐Layer Capacitor Energized by Adding an Ambipolar Organic Redox Radical into the Electrolyte

Abstract

Figure 4. GCD curves at 1Ag À1 of the full capacitors (a) with (b) without TEMPO, along with the potentials of positive and negative electrodes. GCD curves at different current densitieso fthe full capacitors( c) with and (d) without TEMPO. Comparison of rate performance (e) and energy density (f)o fthe full capacitors. g) Cycling stability at 10 Ag À1 of the full capacitor with TEMPO. The current density,c apacity and energy density are normalized to the total mass of AC at the positive and negative electrodes.

Recent progress in polyaniline-based composites as electrode materials for pliable supercapacitors

“…9 SCs can be fabricated by putting together the following components, i.e., the current collector, electrolyte, electrode, and separator. Classification of SCs is based upon the two types of charging mechanism, i.e., electrochemical doublelayer capacitance (EDLC) [10][11][12] and pseudo-capacitance. [13][14][15][16] Carbon-based materials with high surface area fall under the category of materials exhibiting EDL capacitance, wherein the charge storage occurs via the reversible adsorption of electrolyte ions onto the electrode-electrolyte interface.…”

Commercial-Level Energy Storage via Free-Standing Stacking Electrodes

“…Furthermore, N-and O-mediated reversible active sites and accessible fast electron and ion transport channels endow the stackable OCN free-standing films electrodes with fast and high energy storage performances beyond weight limitations of conventional electrode fabrication to a commercial level. or radicals groups grafted on polymer backbones or covalent organic frameworks or coupled with conductive carbon nanostructures, e.g., quinone, 28,29 anthraquinone-2-sulfonate, 30 2,6-diaminoanthraquinone, 31 2,5-dimethoxy-1,4-benzoquinone, 32 9, 10-phenanthrenequinone, 33 carbonyl, 34,35 oligoanilines, [36][37][38] pyridine, 39 pyrene, 40 TEMPO, 41 and (tBu 2 MeSi) 3 EC [E = Si, Ge, and Sn]; 42 (3) redox active electrolytes, e.g., TEMPO molecules, 43 viologen, 44 hydroquinone (HQ), 45,46 and TEMPO grafted polymers or ionic liquids; [47][48][49][50] (4) heteroatom-enriched carbons (HECs), e.g., nitrogen, [51][52][53] oxygen, [54][55][56] boron, [57][58][59] sulfur, 60,61 fluorine, 62 and phosphorus 63,64 (doped or co-doped). Although these emerging charged organic molecules as active centers present an excellent approach to increase the pseudocapacitance by a multi-electron faradic process, the capacitance retentions after long charge/ discharge cycles still face a challenge due to the degradation of charged organic molecules leading to irreversi...…”

PEDOT:PSS and Its Composites for Flexible Supercapacitors

“…SCs are categorized into electrochemical double-layer capacitors (EDLCs), − pseudocapacitors, , and hybrid capacitors according to the charge–discharge mechanism. Parallel-plate and fiber-shaped SCs , can be identified according to the shape of the devices.…”