A Stable Polyaniline‐Benzoquinone‐Hydroquinone Supercapacitor

Abstract

A Polyaniline-Supercapacitor with quinone electrolytes remains stable over 50 000 galvanostatic charge-discharge cycles. The quinones provide superior stability by preventing the conversion of porous polyaniline to a highly reactive state. Our work shows that highly stable polymer-supercapacitors can be engineered by combining electrochemically active polymers and redox-active electrolytes with concerted electrochemical properties.

Supercapacitive properties of composite electrode consisting of activated carbon and a quinone-containing conducting additive

“…1b, to enhance the electrochemical performance of the supercapacitor. It should be notable that unlike other reports dealing with the electrolyte additives [12][13][14][15][16][17][18][19][20][21][22], this study uses the HBU as an additive to active electrode material that influences electrode morphology and its electrochemical performance. The HBU in the composite electrode may contribute to yield a surface morphology with comparatively more compact morphology than the active carbon electrode alone by partially filling the pores between the activated carbon particles (see the surface morphologies in Fig.…”

“…Of these, quinone and its derivatives have been known as characteristic examples of the organic redox species to involve the increase in the specific capacitance [10]. In particular, hydroquinone/quinone couple was intensively investigated as promising organic additives for electrochemical capacitors in forms of electrode material and electrolyte component [11][12][13][14][15][16][17][18][19][20][21][22] because of cost effectiveness, environmental friendliness, and highly reversible redox reactions. The reversibility of redox reaction is mainly dominated by the reaction mechanism [13,[23][24][25] that hydroquinone is oxidized to quinone by generation of 2H + (two-proton) with 2e À (two-electron) during the charging whereas quinone is reduced to hydroquinone via absorption of 2H + with 2e À during the discharging.…”

Pronounced improvement of supercapacitor capacitance by using redox active electrolyte of p-phenylenediamine

“…Vonlanthen et al prepared a stable polyaniline-benzoquinone supercapacitor, which gives simultaneously high pseudo-capacitance and unmatched cycling stability (>50,000). The increased capacitance is attributed to the fast and reversible charge-transfer process between the polyaniline-modified electrodes and the quinines (with the ability to store 2e -/2H + per quinone unit) [10]. Besides, hydroquinone was incorporated into H 2 SO 4 electrolyte to improve the performance by quick Faradaic reactions, and the resultant capacitance of 901 F g À1 is almost three times than the original one [11].…”

Review Article: Flow battery systems with solid electroactive materials

“…There is also significant research interest in hybrid supercapacitors, where one electrode functions as a supercapacitor and the other undergoes battery redox reactions. [40][41][42][43][44][45] More detailed discussion of supercapacitors can be found in a number of recent reviews. 29,40,[45][46][47] The electrical energy stored in batteries is primarily stored as chemical energy that is released by redox reactions, as opposed to within a surface double layer.…”

“…Research efforts have pursued new materials, flow cell designs, surface modification, and mathematical modeling. 42,44,92,[99][100][101][102] More detailed discussion on the current status and research perspectives for supercapacitors and EFCs can be found in these recent reviews. 29,40,45,46,103,104 Capacitive water deionization is another application where solid suspensions have been coupled into a system with electrodes and electrical potential driving forces.…”