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For modern high‐tech flexible energy storage devices, it becomes important to synthesize micro‐/nanostructures as per the required shape and morphology with superior physical and electro‐active characteristics. This work shares the fabrication and characterization of ZnSn(OH)6 (Zinc hydroxystannate [ZHS]) prepared by facile microwave‐assisted technique and furthermore converted into flexible sheets by employing lignocelluloses (LC) known as natural fibers, collected from Carica papaya leaf petiole as a substrate to provide the flexible matrix. X‐ray diffraction measurements confirm the successful crystalline structure of ZHS. Scanning electron microscopy and transmission electron microscopy showed the solid spherical structure of ZHS microspheres. Fourier transform infrared spectrometry and Raman spectroscopy confirmed the composite formation of ZHS and LC‐based composite sheets (ZHS/LC sheets). Electrochemical measurements that is, cyclic voltammetry (CV), Galvanostatic charge/discharge, and electrochemical impedance (EIS) spectroscopy revealed the electroactive behavior of ZHS/LC paper sheets as working electrode for energy storage applications. CV measurements revealed the specific capacitance of 100 F/g and EIS measurements confirmed the decrease in the resistance of LC fiber after the growth of ZHS microspheres. Presented flexible ZHS based paper sheets will be highly feasible for the modern bendable/flexible/disposable energy storage applications. [ABSTRACT FROM AUTHOR]

Functional materials, in the combination of lignocelluloses, known as natural fibers, with oxide materials, can result in cultivating functional properties such as flexibility, relativity good electrical conduction, good electrical charge storage capacity, and tunable electric permittivity. This study presents the morphological, dielectric, and impedance properties of lignocellulose–lead oxide (LC/PbO2) composite sheets electrodeposited with silver metallic nanoparticles for various time spans. The uncoated samples show a rather simple behavior where the impedance data fit well to the two-system model with different relaxation times. On the other side, the impedance spectra of the electrodeposited sample have varying features, which mainly depend upon the deposition thickness of the Ag particles. The common feature is the drift of conductive species, as seen from the straight-line behavior in the Nyquist plots, which were fitted using a Warburg element in the equivalent circuit model. [ABSTRACT FROM AUTHOR]

In recent era of modern and bendable technology, energy dearth arises as a paramount subject around the globe with a dire demand of flexible and lightweight energy storage devices. This study targets fabrication of reduced graphene oxide (rGO) and utility of abundantly available, cost effective, and environment friendly lignocelluloses (LC) fibers extracted from Carica papaya source, as a binder to bind active material (rGO) as robust and compact paper sheet. Fabricated samples were analyzed by X-ray diffraction for crystallographic analysis, Scanning electron microscopy, Transmission electron microscope for morphology, Fourier transform infrared spectroscopy for structural bonding, and Raman spectroscopy for vibrational modes. Robust and bendable rGO/LC paper electrode was tested for energy storage application by employing in different characterizations, i.e., cyclic voltammetry for capacitive behavior, galvanostatic charge–discharge for symmetric EDLC, and electrochemical impedance spectroscopy for resistive charge kinetics, respectively. rGO/LC composite sheet employed as working electrode in 3-electrode CV measurements and revealed specific capacitance of 591 F/g at a scan rate of 5 mV/s by keeping the undistorted shape of voltammograms at higher scan rates which present it as a suitable candidate for modern flexible and energy storage devices. rGO/LC-based symmetric cell revealed the highest specific capacitance of 228 F/g at applied current density of 0.1 A/g, the energy density of 6.3 Wh/kg, and power density of 129 W/kg, respectively. rGO/LC-based symmetric cell confirmed the cycling stability by revealing capacitance retention of 82% after 200 cycles. It can conclude that biomass-based rGO paper sheet can be a potential candidate as environmentally safe with remarkable electrochemical activity in energy storage applications. [ABSTRACT FROM AUTHOR]

In this modern age of technology, flexible, light-weight, environment-friendly and low-cost electrodes are vastly feasible for applications in energy storage devices and disposable electronics. This study presents a comprehensive report on the morphological, dielectric, and impedance characteristics of lignocellulose (LC) fibers, PbO2, and LC/PbO2 sheets. The dielectric analysis shows that the dielectric constant depends on space charge polarization in the case of LC/PbO2 composite sheets. It can be concluded from impedance spectroscopy results that LC fibers show semiconductor-like behavior and fibers appear to consist of one type of dielectric species whose impedance behavior can be modeled by a parallel combination of a resistor and a capacitor. However, the impedance response of PbO2 consists of two types of dielectric species, which can be identified as grains and grain boundaries, both of which show a small temperature dependence. The impedance behavior of LC/PbO2 composite is different in comparison to individual LC fibers and PbO2. The presented study also reveals that impedance parameters of fabricated LC/PbO2 composites are temperature-independent, which might be due to counteracting the characteristics of LC fibers and PbO2 particles. This temperature-independence of the composite is important for their use in applications in flexible devices. [ABSTRACT FROM AUTHOR]

In the new era of modern flexible and bendable technology, graphene-based materials have attracted great attention. The excellent electrical, mechanical, and optical properties of graphene as well as the ease of functionalization of its derivates have enabled graphene to become an attractive candidate for the construction of flexible devices. This paper provides a comprehensive review about the most recent progress in the synthesis and applications of graphene-based composites. Composite materials based on graphene, graphene oxide (GO), and reduced graphene oxide (rGO), as well as conducting polymers, metal matrices, carbon–carbon matrices, and natural fibers have potential application in energy-harvesting systems, clean-energy storage devices, and wearable and portable electronics owing to their superior mechanical strength, conductivity, and extraordinary thermal stability. Additionally, the difficulties and challenges in the current development of graphene are summarized and indicated. This review provides a comprehensive and useful database for further innovation of graphene-based composite materials. [ABSTRACT FROM AUTHOR]

Flexible, lightweight, and environment friendly energy storage devices are in high demand of modern disposable technology. This study presents the coating of directly collected lignocelluloses fibers from self‐growing plant, Monochoria vaginalis with conducting layers of polypyrrole and polyaniline. Fabricated paper electrodes were conductive, electroactive, all‐organic constituents, flexible, and can be cut with help of scissor in any shape. Paper electrodes were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis for morphology, structural, and thermal characteristics, respectively. Furthermore, fabricated paper electrodes were characterized by cyclic voltammetry to confirm the electroactive behavior and showed excellent electrochemical performance. Paper sheets comprising lignocelluloses fibers and polypyrrole coating (LC/PPy) were employed as electrodes of symmetric cell and showed specific capacitance of 230.35 Fg−1 at current density 0.25 mA g−1 for LC/PANI, while LC/PPy showed 9.042 W h kg−1 and 91.33 W kg−1 energy density and power density, respectively. This paper electrodes are highly feasible for environmentally safe and flexible energy storage applications, particularly in era of modern disposable technology. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47282. [ABSTRACT FROM AUTHOR]

In an era of modern smart technology, flexible electrodes are of great interest for different energy conversion as well as energy storage applications like solar cells, all solid-state batteries, and supercapacitors. Flexible metal oxide-based paper electrodes are advantageous in comparison to conventional electrodes due to their economical synthesis, biocompatibility, and environment-friendly characteristics. However, the electrical conductivity of paper electrodes is limited because of the insulating nature of natural fibers employed as a binder for the flexible matrix of metal oxides. The current study is an attempt to tune the electrical properties of lignocelluloses (natural fibers) and titanium dioxide (TiO 2) based paper electrodes by facile electrodeposition technique. The crystalline parts (e.g., TiO 2 , Ag, and Au) of the prepared composite sheets were characterized by XRD analysis while the surface morphology was studied by SEM. FTIR was used to characterize the organic matter in LC fibers by identifying various molecular stretching and vibrational modes of C, H, and O-containing molecules. Electric permittivity was measured as a function of electric field frequency at room temperature which revealed the value of 23. 5 (at 1 kHz) for the sample LC/TiO 2 /Ag 9000s indicating the best charge storing capability of the sample. Impedance analysis was employed to identify various charge carrier mechanisms active in the sheets. It was found through impedance analysis that there is an active diffusion-controlled impedance mechanism of Au-coated samples causing an increased conductivity via the ionic diffusion. This diffusion-controlled conduction was modeled by the Warburg element. The enhanced conductivity due to ionic diffusion makes these samples more useful as electrodes. Cyclic voltammetry (CV) measurements of the electrodeposited samples established the increase in conductive properties and efficient kinetics of LC/TiO 2 paper sheets. The current study suggests that Ag and Au-coated paper electrodes can be potential candidates for energy conversion and storage applications. [ABSTRACT FROM AUTHOR]