Fe³⁺ Cross-Linked Polyaniline/Cellulose Nanofibril Hydrogels for High-Performance Flexible Solid-State Supercapacitors

Abstract

Cellulose contains abundant oxygen-containing functional groups and can be used to fabricate hydrogel matrixes for supercapacitors (SCs). However, conventional bacterial cellulose-based SCs need a large amount of carbon materials with high electrical conductivity and mechanical strength to construct a three-dimensional network. Therefore, it is challenging to use cellulose as an electrode material with high electrochemical performance. Herein, Fe 3+ is used to prepare cross-linked polyaniline/cellulose nanofibril hydrogels. The Fe 3+ has two functions: it forms cross-links between cellulose nanofibril and polyaniline (PANI) through carboxylate anions and initiates aniline polymerization. The cross-links between the PANI and cellulose nanofibrils via Fe 3+ form a porous and mechanically robust three-dimensional conductive hydrogel. The as-prepared PANI/cellulose nanofibril hydrogel as an SC electrode has a high areal capacitance of 3060 mF cm −2 and an energy density of 106 μW h cm −2 at 0.5 mA cm −2 . Moreover, the convened flexible solid-state supercapacitor delivers a satisfactory areal capacitance of 185 mF cm −2 at 0.2 mA cm −2 and excellent flexibility. This green method extends the application of cellulose to SCs.

Connecting PEDOT Nanotube Arrays by Polyaniline Coating toward a Flexible and High-Rate Supercapacitor

“…Considering the device thickness of 100 μm, the maximal areal energy density of the device is 0.16 mWh cm –2 with an areal power density of 1.8 mW cm –2 . Although the energy stored in the Ti@PEDOT-PANi-based capacitor is slightly lower than that of N-doped graphene/PANi (26.5 mW h cm –3 ) and N-doped holey graphene (22.4 mW h cm –3 ), it is still higher than the recent results of PANi-based devices constructed with 3D graphene/PANi (14.2 mW h cm –3 ), PANi nanorods/graphene fiber (5.7 mW h cm –3 ), PANi monolithic (1.7 mW h cm –3 ), p -phenylenediamine intercalated graphene (15.4 mW h cm –3 ), MoS 2 /PANi/CNTs (13 mW h cm –3 ), ACM/MWCNTs@PANi (2.14 mW h cm –3 ), PANi-modified CNTs and carbon fibers (29.4 and 131 μW h cm –2 ), , PANi-decorated supramolecular hydrogel (8.48 μW h cm –2 ), 3D PANi nanoweb (12.7 μW h cm –2 ), PANi/cellulose nanofibril hydrogel (106 μW h cm –2 ), and other PANi-based electrodes (Table S1 and Figure e).…”

Stretchable supercapacitor based on a hierarchical PPy/CNT electrode and hybrid hydrogel electrolyte with a wide operating temperature

“…The galvanostatic charge/discharge (GCD) tests were carried out on a NEWARE battery testing system. The area‐specific capacitance for the combination device was calculated from the GCD test according to the following formula 30 : where C , I , t , Δ V , and S are the specific capacitance, discharge current, discharge time, voltage window, and device area in the chemical reaction, respectively. The energy density and power density were further calculated using Equations () and () 31 : where E , C , Δ V , P , and Δ t are the energy density, specific capacitance, voltage window, power density, and discharge time, respectively.…”

“…The galvanostatic charge/discharge (GCD) tests were carried out on a NEWARE battery testing system. The area-specific capacitance for the combination device was calculated from the GCD test according to the following formula 30 :…”

Recent Progress in Metal‐Organic Frameworks@Cellulose Hybrids and Their Applications

“…Generally, lengths of CNFs are in the micron scale, and their widths are from tens to hundreds of nanometers. [ 107‐110 ] CNFs were first introduced by Turbak et al . [ 111‐112 ] and Herrick et al .…”