Flexible Conductive Cellulose Network-Based Composite Hydrogel for Multifunctional Supercapacitors

Abstract

With the continuous development of energy storage devices towards sustainability and versatility, the development of biomass-based multi-functional energy storage devices has become one of the important directions. In this study, a symmetric dual-function supercapacitor was constructed based on a cellulose network/polyacrylamide/polyaniline (CPP) composite hydrogel. The presented supercapacitor, with excellent electrochemical performance and an areal capacitance of 1.73 mF/cm2 at 5 mV/s, an energy density of 0.62 µW h/cm2 at a power density of 7.03 µW/cm2, a wide electrochemical window of 1.6 V and a promising cycling stability, can be achieved. The transmittance of the supercapacitor at 500 nm decreased by 9.6% after the electrification at 3 V, and the device can exhibit periodic transmittance change under the square potential input between 0.0 V and 3.0 V at regular intervals of 10 s. The present construction strategy provides a basis for the preparation of multifunctional devices with natural renewable materials and structures.

Polymer Cross‐Linking on Highly Continuous Carbon for High‐power Supercapacitor

“…[15][16][17][18][19] The hierarchical CSC electrode materials have some advantages of improving charge transfer speed, maintaining strength of electrode, optimizing ion transfer path and reducing diffusion resistance, as follows: i) Continuous skeleton network of CSC can reduce the high resistance interface between electrode and optimize the distribution of electron transfer path throughout the electrode, so the charge and discharge capacity of electrode is enhanced at high speeds; ii) Uniform electrons distribution through conductive skeleton can effectively avoid charge aggregation toward the uniform electric field and the substantial reduction of electrode shedding or pore collapse caused by electrons or ions aggregation; iii) electron movement and ion transporting of supercapacitor devices are constrained mutually and synergistically, the fast and uniform electron movement could further enhance ion transporting and reduce ineffective active sites, thereby specific capacity of supercapacitor is increased. [20][21][22][23][24][25] Although many previously-reported methods such as template method and polymerization method can effectively realize the continuity of skeleton carbon, [26][27][28][29][30][31] they require expensive raw materials and harsh reaction conditions and difficultly control the polymerization process of precursor precisely. These methods intrinsically have limitations such as high production cost, inability to control the microstructure of carbon directionally, low porosity or uneven pore size distribution of carbon, and low energy density.…”

Wide-Temperature-Range Flexible Supercapacitors Using a Multipurpose Organogel Electrolyte

“…First of all, traditional hydrogel electrolytes contain a large amount of solvent water, which will inevitably freeze at subzero temperatures, significantly weakening the ionic conductivity or even losing. Second, at high temperature or room temperature, the internal water molecules cannot exist stably and are volatile, resulting in a loss of performance. − Finally, the operating voltage of hydrogel electrolytes is generally just within a relatively small potential window (0.8–1.0 V), which is because when the voltage reaches 1.23 V, the water will split, limiting its energy density. , At present, the study of wide-temperature-resistant hydrogel electrolytes has made a breakthrough, but there are still some places that can be improved in this field. − The most common strategy is to introduce organic solvent (glycerin, dimethyl sulfoxide, and ethylene glycol) into hydrogels, , but the introduction of organogels using novel antifreeze is rarely reported. , At the same time, the introduction of organic solvents usually weakens the mechanical properties and ionic conductivity of the hydrogel electrolytes . So, designing a new gel electrolyte with a wide temperature range, excellent mechanical properties, and capacitive properties is a great challenge.…”

Silicone Rubber Based-Conductive Composites for Stretchable “All-in-One” Microsystems

“…As for the conductive fillers, different kinds of conductive nanomaterials have been exploited, such as carbon black (CB), , silver nanoparticles (AgNPs), , carbon nanotubes (CNTs), silver nanowires (AgNWs), copper nanowires (CuNWs), graphene, reduced graphene oxide (rGO), graphene nanoflakes (GNFs), silver nanoflakes (AgNFs), and hybrid conductive fillers − such as rGO@CB. For the polymer matrix, poly­(dimethylsiloxane) (PDMS), − Ecoflex rubber, , SEBS, , polyurethane (PU), , poly­(vinyl alcohol) (PVA), , and others − are good matrices for stretchable conductive components.…”