The Synergistic Effect of Nitrile and Ether Functionalities for Gel Electrolytes Used in Supercapacitors

Abstract

This study examines the linear triblock copolymer design of poly(acrylonitrile)-b-poly(ethylene glycol)-b-poly(acrylonitrile) (PAN-b-PEG-b-PAN) for a gel polymer electrolyte (GPE) swollen with dimethylformamide dissolving LiClO 4 . The study demonstrates the synergistic effect of the nitrile and ether functionalities in facilitating ion transport in the carbon films of electric double-layer capacitors (EDLCs). A GPE with a tuned AN/EG ratio exhibits ionic conductivity at approximately 10 −2 S cm −1 . The linear configuration incorporates the GPE border into the carbon electrodes. The PAN chain promotes ion solvation and transport into the carbon interior, and the PEG chain coordinates the solvent molecules to form ion motion channels. The synergistic effect of the PAN and PEG blocks enables a GPE EDLC delivering more energy and power than EDLCs with a liquidphase electrolyte. The GPE EDLC delivers 20 Wh kg −1 (approximately 10 Wh L −1 ) at a high power of 10 kW kg −1 (approximately 5 kW L −1 ) when using a high-porosity carbon electrode derived from mesophase pitch activation.

A review of electrolyte materials and compositions for electrochemical supercapacitors

“…331,391 Using these organogel electrolytes, the ES cell voltages were increased up to 2.5-3 V, 331,391-394 which was much higher than those of hydrogel electrolyte-based ESs including asymmetric ones. 333,387,388,391 Interestingly, as reported by Schroeder et al in Fig. As a direct result of the high cell voltages, most of the reported maximum energy density of organogel electrolyte-based ESs had relatively high values from approximately 18 to 25 W h kg À1 .…”

“…These polymers can promote proton conduction since the protons in their side chains can be easily subtracted in an aqueous medium. In these organogel electrolytes, various polymer hosts, such as PEO, 333,387 PMMA, 388,389 polyvinylpyrrolidone (PVP), PEEK, 390 and copolymers, 331,[391][392][393] were reported in the literature as having been tested. 383 Because the performance of a pseudocapacitive electrode material depends on the properties of the electrolyte, the nature of the polymer host in a hydrogel electrolyte should have an influence on the performance of its associated pseudocapacitors.…”

“…383 Because the performance of a pseudocapacitive electrode material depends on the properties of the electrolyte, the nature of the polymer host in a hydrogel electrolyte should have an influence on the performance of its associated pseudocapacitors. 331,391 For example, Hsueh et al 391 reported a synergistic effect between PAN and PEG when they were used as the GPE host. 385,386 Several studies showed that ESs using Nafion s as an electrolyte could support high potential scan rates.…”

Electrolyte selection for supercapacitive devices: a critical review

“…[210][211][212][213][214][215][216] Copolymers with various constituent units such as poly(acrylonitrile)-block-poly(ethylene glycol)block-poly(acrylonitrile) (PAN-b-PEG-b-PAN) have shown to be most promising polymeric hosts in organogel electrolytes-based supercapacitors. Hsueh et al 213 stated a synergistic effect between poly(ethylene glycol) and poly(acrylonitrile) when used as the gel polymer electrolyte host. The carbon-based EDLCs using these copolymer based organogel electrolytes could deliver higher energy and power densities (20 W h kg À1 at 10 kW kg À1 ) than EDLCs using organic liquid electrolytes.…”

A Flexible Ionic Liquid Gelled PVA‐Li2SO4 Polymer Electrolyte for Semi‐Solid‐State Supercapacitors

“…Therefore, PVA:BMIMCl:Li 2 SO 4 = 1:3:2.2 is optimal proportion in PVA-BMIMCl-Li 2 SO 4 FGPE, which is selected for further investigations. The maximum ionic conductivity value (37 mS cm −1 ) is higher than that of any other reported lithium salt GPEs, [32][33][34][35][36] and IL GPEs [ 1,37 ] ( Table 1 ).…”