Full-cell quinone/hydroquinone supercapacitors based on partially reduced graphite oxide and lignin/PEDOT electrodes

Abstract

The development of new, scalable and inexpensive materials for low-cost and sustainable energy storage devices is intensely pursued. The combination of redox active biopolymers with electron conducting polymers has shown enhanced charge storage properties. However, their performance has just been investigated at the electrode level. Herein, we move a step further by assembling full-cell supercapacitors based on natural lignin (Lig) and partially reduced graphite oxide (prGrO) electrode materials. Both materials evidenced that quinone/hydroquinone redox moieties are able to store and release charge reversibly. The redox properties of lignin were improved by combining it with poly(3,4-ethylenedioxythiophene) (PEDOT).Analysis of the capacitive contributions to the charge storage proved that PEDOT enhanced the lignin's capacitive contribution to the current by 22%. The capacitive contributions were equal to 66% and 75% in Lig/ PEDOT blend and prGrO electrodes, respectively. We also show for the first time that by distributing equally charges in carbon-biopolymer composite electrodes, a higher capacitance retention, up to 79% after 1000 cycles, is achieved.

Functional‐Group Modification of Kraft Lignin for Enhanced Supercapacitors

“…Figure a shows CV curves recorded in the potential range of 0–0.8 V at a scan rate of 10 mV s −1 , in the three electrode systems with 1.0 m H2SO4 solution as the electrolyte. All curves show two pairs of redox peaks at 0.3 and 0.52 V. The redox reaction at 0.3 V is triggered by the oxygen‐containing functional groups on the TAC surface, whereas the redox peaks at 0.52 V resulted from the hydroquinone/quinone moieties in KL and OKL, which store and release electrons/protons through the reaction displayed in the Scheme a during the charge–discharge process in acidic solution …”

Enhancing Energy Storage Devices with Biomacromolecules in Hybrid Electrodes

“…The highly stable lignin/PEDOT electrode was easily synthesized using chemical polymerization and electrochemical polymerization, showing a specific capacitance of 170 F g −1 and excellent capacitance retention (83% after 2000 cycles) . Mecerreyes´s group moved a step further by assembling two full‐cell supercapacitors . Their asymmetric device, which contains lignin/PEDOT as the positive electrode and partially reduced graphite oxide ( p ‐rGrO) as the negative electrode exhibited capacitance values of 34.6 F g −1 .…”

“…[101] Mecerreyes´s group moved a step further by assembling two full-cell supercapacitors. [102] Their asymmetric device, which contains lignin/PEDOT as the positive electrode and partially reduced graphite oxide (p-rGrO) as the negative electrode exhibited capacitance values of 34.6 F g −1 . Additionally, a symmetric supercapacitor in which lignin/PEDOT and p-rGrO were combined into a homogenous composite electrode material in both electrodes showed specific capacitance of 36 F g −1 and capacitance retention up to 79% after 1000 cycles.…”

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...…”