Biopolymer Electrolytes Research Articles

Influence of NH4F in Dextran Based Biopolymer Electrolytes: Conductivity and Electrical Analysis

Dextran polymer host was doped with different concentrations of ammonium fluoride (NH4F) via casting technique. In this present work, dextran-NH4F film has been employed to investigate the ionic conductivity using electrochemical impedance spectroscopy from 50 to 5 MHz. The highest room temperature conductivity is achieved at (2.33 ± 0.76) × 10-3 S cm-1 with 40 wt.% NH4F. The electrolyte is found to obey Arrhenius rule at high temperature with activation energy of 0.21 eV. Dielectric analysis has been performed to obtain better understanding on the conductivity pattern. The dielectric parameters e.g. ɛreal, ɛimag, Mreal, and Mimag have been tested as a function of frequency at various temperature. The potential stability obtained for the highest electrolyte in this study is 1.58 V.

Conductivity and Electrochemical Behavior of Plasticized Polymer Electrolyte for Dye-Sensitized Solar Cell Integrated Supercapacitor

Abstract The current energy situation requires not only enormous energy in a brief period of time but clean energy as well. In this direction, a dye-sensitized solar cell (DSSC)—supercapacitor (SC) integrated energy device has been fabricated. This embedded energy system has a specific advantage such as easy manufacturing, low manufacturing costs, and flexible substrates compatibility. A natural photosensitizer was extracted from readily available beetroots and characterized using ultraviolet (UV)-visible spectroscopy. The zinc oxide semiconductor was synthesized using microwave technique and regarded as the DSSC photoanode material. The ZnO’s phase, purity, and morphology were investigated using X-ray diffraction (XRD) spectroscopy and scanning electron microscope. The iodine-doped cellulose acetate propionate (CAP) biopolymer electrolyte functions as the DSSC and supercapacitor electrolyte. The solid polymer electrolyte conductivity and dielectric studies were performed using electrochemical impedance spectroscopy (EIS). The laser-induced technique was used to synthesize graphene that plays a dual purpose as photocathode in DSSC and supercapacitor electrodes. The embedded energy unit from the DSSC-supercapacitor demonstrates a 6.75% fill factor representing its decent efficiency.

Characterizations of Pectin/Lithium Sulfate Solid Biopolymer Electrolytes

In the present study, Pectin based Lithium sulfate added biopolymer electrolytes have been prepared by using Solution casting technique. Surface morphology of the prepared sample is investigated by Scanning Electron microscopy and crystalline nature is investigated by X-ray Diffraction. These films have a smooth surface and amorphous nature with good transparency. The Pectin is biopolymer which is ecofriendly and great abundance in earth. The maximum ionic conductivity value is obtained for 85Pectin:15Li2SO4 system. The change in ionic conductivity related to concentration of salt is also analyzed. The dielectric properties of the Pectin based system are also discussed.

Investigation on favourable ionic conduction based on CMC-K carrageenan proton conducting hybrid solid bio-polymer electrolytes for applications in EDLC

In the present work, a proton-conducting hybrid solid biopolymer electrolytes (HSBEs) system was successfully prepared via the solution casting approached. The HSBEs comprised of CMC blended with kappa carrageenan and doped with NH4NO3. The HSBEs system was characterized to evaluate the structural and the proton conduction properties using FTIR, XRD and EIS techniques. The FTIR analysis showed that a complexation occurred between the CMC-KC and H+ moiety of the NH4NO3 via the –OH, C–O–C as well as –COO- groups with associated changes observed to their wavenumbers and peak intensities. At the 80:20 ratio of the CMC:KC hybrid system, the optimum value of the ionic conductivity was found to be ~10−7 S/cm. However, the addition of 30 wt % of NH4NO3 to the system markedly increased the ionic conductivity to ~10−4 S/cm due to the increase in the amorphous phase in the HSBEs system as revealed by the XRD analysis. Meanwhile, the IR-deconvolution approach revealed an increase of the protonation (H+) from NH4NO3 towards the co-ordinating site on the hybrid CMC-KC system and this in turn, led to the increment in the ionic mobility and diffusion of ions for transportation. An EDLC was fabricated using the highest conducting HSBEs sample developed in the present study and it exhibited favourable characteristics as a capacitor with a reasonably good stability with regards to its electrochemical properties.

Enhancement of Electrical and Optical Properties of Sodium Bromide Doped Carboxymethyl Cellulose Biopolymer Electrolyte Films

Biodegradable ion conducting solid polymer electrolyte films of carboxymethyl cellulose (CMC) doped with sodium bromide (NaBr) with various weight percentages were prepared by a solution casting technique. Their structural, optical and electrical properties were studied by various experimental techniques in order to understand the impact of the sodium metal salt on the biopolymer CMC’s properties. The optical parameters namely the optical bandgap energy and the refractive index, showed a significant variable variation with the metal salt concentration. The maximum dc conductivity was found to be ∼5.15 × 10−4 S cm−1 at room temperature for the sample with 20 wt% of NaBr content in the CMC matrix. The ionic conductivity and dielectric constant in general, increased with increase in metal salt content, affirming the increase in ion concentration. The calculated transference number showed that the conductivity was mainly due to ions. The increase in conductivity was due to an increase in degree of amorphousness of the polymer upon doping, as analyzed by their XRD spectra.

Eco-friendly biopolymer kappa carrageenan with NH4Br application in energy saving battery

Preparation of biopolymer electrolyte based on kappa-Carrageenan with ammonium bromide (NH4Br) by means of solution casting manufacturing method using condensed back H2O as a solvent. Non crystalline characterization between the biopolymer (kappa-Carrageenan) and salt (NH4Br) has been investigated by XRD (X-ray diffraction) characterization. Glass transition temperature of the prepared sample is studied by DSC and its 32.08 °C for highest conducting biopolymer membrane. The conductivity value measured by the conductivity study for 1 gm kappa-Carrageenan with 300 mg NH4Br is 2.80 × 10−3 S/cm. The proton conducting battery has been fabricated and the measured output voltage is 4.29 V.

Ionic transport studies of solid bio-polymer electrolytes based on carboxymethyl cellulose doped with ammonium acetate and its potential application as an electrical double layer capacitor

CMC-NH4CH3CO2 complexes were characterized via theoretical and experimental approaches using molecular dynamics (MD) calculation, Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), and electrical impedance spectroscopy (EIS) analysis. These analyses successfully disclosed the structural and ion conduction properties of the bio-polymer electrolytes (BPE) system. The FTIR analysis further revealed that an interaction exists between the carboxylate anion group (COO–) from CMC and the H+ substructure of NH4CH3CO2. The ionic conductivity value at ambient temperature was found to achieve an optimum value of 5.07× 10–6 S/cm for a system containing 10 wt% NH4CH3CO2. The ionic conductivity improvement was demonstrated via the increment on the amorphous phase of the BPEs system as shown in the XRD analysis upon the inclusion of NH4CH3CO2. Based on the IR-deconvolution approach, the mobility (µ) and diffusion coefficient (D) were found to influence the ionic conductivity and aligned with the theoretical molecular dynamic (MD) calculation. To evaluate the potential application of the CMC-NH4CH3CO2, an electrical double-layer capacitor (EDLC) was fabricated from the BPE and tested using cyclic voltammetry (CV), and charge-discharge (GCD) for 300 cycles and the BPE exhibited a specific of capacitance~ 2.4 F/g.

Conducting biopolymer electrolyte based on pectin with magnesium chloride salt for magnesium battery application

Currently, biopolymer electrolytes are attracting a great deal of interest as substitute for synthetic polymer electrolytes in electrochemical devices, as they are carbon neutral, sustainable, reduce dependency on non-renewable fossil fuels and easily biodegradable. Some of the biopolymers under research are chitosan, pectin, agar–agar, cellulose acetate and carrageenan. The current work deals with the study of ion conducting polymer electrolyte, pectin with magnesium chloride salt for magnesium battery application. Biopolymer electrolytes of different compositions of pectin with different concentrations of magnesium chloride salt are prepared by solution casting technique and subjected to various studies like by X-ray diffraction (XRD), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), AC impedance spectroscopy and linear sweep voltammetry (LSV). XRD analysis has been used to identify the amorphous/crystalline nature of the sample. The complex formation between the polymer pectin and the magnesium chloride salt has been analyzed by FTIR spectroscopy. DSC analysis is a thermo-analytical technique which is used to observe the glass transition temperature (Tg) of the samples. AC impedance technique has been used to find the ionic conductivities of the sample. The electrochemical stability of the polymer electrolyte has been analyzed by linear sweep voltammetry. Among the prepared polymer electrolytes, 30 M wt% pectin: 70 M wt% MgCl2 offers the highest ionic conductivity of 1.14 × 10−3 S cm−1. The electrochemical stability of the highest conducting sample is 2.05 V. The primary magnesium battery has been constructed using the highest conducting sample, 30 M wt% pectin: 70 M wt% MgCl2, and the battery performance has been studied.

Biopolymer Electrolyte Membranes (BioPEMs) for Sustainable Primary Redox Batteries

AbstractThe proliferation of portable electronic devices has resulted in an increase of e‐waste that is generated after their use. One of the most hazardous components in e‐waste are batteries, due to their content of heavy metals and toxic chemicals. Fuel cells and redox flow batteries have been recognized as more sustainable alternatives to Li‐based batteries for powering portable applications. Although they provide comparable energy and power densities, they still face some challenges because they rely on proton exchange membranes based on nonenvironmentally friendly, high‐priced perfluorosulfonic acid copolymers that require energy‐intense manufacturing and recycling procedures. In this work, eco‐friendly and sustainable biopolymer electrolyte membranes (BioPEMs) are synthesized from biopolymers like chitosan, cellulose, and starch. These BioPEMs bring forth advantages in performance, sustainability, and cost. Additionally, they present good chemical and mechanical stability, high ionic conductivity in the same order of magnitude as Nafion membranes. Two alternatives of cellulose–chitosan based BioPEMs are successfully applied into primary redox batteries using benign eco‐friendly redox chemistries, delivering open circuit voltages above 0.75 V and power output up to 2.5 mW cm−2. These results demonstrate BioPEMs capability to improve biodegradable batteries in sectors requiring a transient electrical energy, such as environmental monitoring, agriculture, or packaging.

Influence of $$\hbox {NH}_{4}$$Br as an ionic source on the structural/electrical properties of dextran-based biopolymer electrolytes and EDLC application

Biopolymer electrolytes (BPEs), consisting of ammonium bromide ( $$\hbox {NH}_{4}\hbox {Br}$$ ) as the ionic provider and dextran (Leuconostoc mesenteroides) as the polymer host, are prepared by the solution cast technique. Interactions of cations from the salt have been confirmed with hydroxyl (OH) and glycosidic linkage (C–O–C) groups of dextran via Fourier transform infrared analysis. Electrolyte with 20 wt% $$\hbox {NH}_{4}\hbox {Br}$$ maximized the ionic conductivity up to ( $$1.67 \pm 0.36)\times 10^{-6}$$ S $$\hbox {cm}^{-1}$$ . The trend of conductivity has been verified by field emission scanning electron microscopy, where the electrolyte surface became rough as the concentration of $$\hbox {NH}_{4}\hbox {Br}$$ exceeded 20 wt%. The contribution of ions as the main charge carrier in the BPE is confirmed by transference number analysis as $$t_{\mathrm{ion}} = 0.92$$ and $$t_{\mathrm{e}} = 0.08$$ . From linear sweep voltammetry, it is found that the highest conducting BPE in this work is electrochemically stable from 0 to 1.62 V. The fabricated electrochemical double-layer capacitor (EDLC) has been tested for 100 charge–discharge cycles and verified by cyclic voltammetry.

Studies on structural and ionic transport in biopolymer electrolytes based on alginate-LiBr

The development of solid biopolymer electrolytes (SBEs) system based on alginate doped with LiBr was successfully prepared via solution casting. The structural and ionic conduction of SBEs were conducted to correlate the effect of LiBr in alginate by means of Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and impedance spectroscopy. From the infrared study, SBEs exhibited the occurrence of complexation between lithium-ion and carboxylate ion (COO−) of alginate through the peak intensity and wavenumber shift. The alginate doped with 15 wt.% LiBr achieved the highest ionic conductivity of 7.46 × 10−5 S/cm at ambient temperature, suggesting its good conduction stability as well as amorphous phase. The IR-deconvolution approach revealed that the ionic conductivity of SBEs system is influenced by both the ionic mobility and diffusion coefficient of transport properties. Based on LSV analysis, it’s implies that the present SBEs have the potentiality to be applied in electrochemical devices.

Correlation between structural, ion transport and ionic conductivity of plasticized 2-hydroxyethyl cellulose based solid biopolymer electrolyte

In this study, the relation between structural, ion transport and ionic conductivity of solid biopolymer electrolyte (SBE) is discussed in details. The SBE containing 2-hydroxyethyl cellulose (2-HEC) doped with ammonium nitrate (AN) and plasticized with ethylene carbonate (EC) are prepared via solution casting method and studied according to different weight percentage (wt.%) of EC. X-ray diffraction (XRD) analysis reveals amorphous nature of SBE while Fourier transforms infrared spectroscopy (FTIR) and Transference number measurement (TNM) are used for complexation and ionic species confirmation respectively. Based on these investigations, the enhancement of ionic conductivity, σ at room temperature can be deduced due to higher amorphous nature. The addition of EC with sufficient amount has increased the flexibility of 2-HEC chain to facilitate free H+ ion transport. A weak bonding created through EC … NH4+ allows easier movement of H+ ion from one site to another complex site of 2-HEC, which is also validated theoretically via Gaussian analysis software. This has increased the mobility, μ and diffusion coefficient, D of H+ ions, as proven from TNM analysis and thus enhance the ionic conductivity, σ of plasticized 2-HEC SBE to about 10−3 Scm−1.

Determining the potential of 55 wt.% chitosan-45 wt.% NH4I biopolymer electrolyte for application in dye-sensitized solar cells

Solution casting technique has been used to prepared chitosan-based polymer electrolyte films. The polymer electrolyte (PE) film containing 55 wt.% of biopolymer chitosan, 45 wt.% of NH4I salt and 80 wt.% of 1-butyl-3-methylimidazolium iodide (BMII) displayed the highest room temperature ionic conductivity of 3.02 × 10−4 S cm−1. The interaction between components in the biopolymer electrolyte has been optically investigated. The configuration of indium tin-oxide (ITO)/TiO2/Ru-complex (N3) dye/biopolymer electrolyte/Pt/ITO dye-sensitized solar cells (DSSCs) were fabricated. DSSC with chitosan-based PE consist of 80 wt.% BMII exhibited the highest efficiency of 1.2%.

A Sub-10 nm Vertical Organic/Inorganic Hybrid Transistor for Pain-Perceptual and Sensitization-Regulated Nociceptor Emulation.

Pain-perceptual nociceptors (PPN) are essential sensory neurons that recognize harmful stimuli and can empower the human body to react appropriately and perceive precisely unusual or dangerous conditions in the real world. Furthermore, the sensitization-regulated nociceptors (SRN) can greatly assist pain-sensitive human to reduce pain sensation by normalizing hyperexcitable central neural activity. Therefore, the implementation of PPNs and SRNs in hardware using emerging nanoscale devices can greatly improve the efficiency of bionic medical machines by giving them different sensitivities to external stimuli according to different purposes. However, current most-normal organic/oxide transistors face a great challenge due to channel scaling, especially in the sub-10 nm channel technology. Here, a sub-10 nm indium-tin-oxide transistor with an ultrashort vertical channel as low as ≈3 nm, using sodium alginate bio-polymer electrolyte as gate dielectric, is demonstrated. This device can emulate important characteristics of PPN such as pain threshold, memory of prior injury, and pain sensitization/desensitization. Furthermore, the most intriguing character of SRN can be achieved by tuning the channel thickness. The proposed device can open new avenues for the fascinating applications of next-generation neuromorphic brain-like systems, such as bio-inspired electronic skins and humanoid robots.

Investigation of seaweed derivative iota-carrageenan based biopolymer electrolytes with lithium trifluoromethanesulfonate

In the present work, iota-carrageenan (i-carrageenan) biopolymer derived from edible seaweed has been chosen as the host polymer material for battery electrolyte. Ionic salt of lithium trifluoromethanesulfonate (LiCF3SO3) commonly known as lithium triflate has been added with the host polymer as a source of charge carriers. The polymer membranes of 1.0 g i-carrageenan with LiCF3SO3 of various compositions (0.1 wt% to 0.5 wt%) have been prepared by solution casting technique. X-ray diffraction (XRD) results indicate the enhancement in amorphous nature of polymer membranes due to the addition of LiCF3SO3. Complex formation between the salt and polymer has been studied by Fourier Transform Infrared (FTIR) spectroscopy. The high ionic conductivity of 1.27 × 10−3 S cm−1 at room temperature is achieved with the combination of 1.0 g i-carrageenan : 0.4 wt% LiCF3SO3 by AC impedance analysis. Total ion transference number estimated for the highest conducting sample is 0.95 by Wagner’s DC polarization method and electrochemical stability of the same is 3.52 V by Linear Sweep Voltammetry (LSV) measurement. Lithium ion conducting battery has been fabricated using the highest conducting polymer membrane. Its open circuit voltage is measured as 1.70 V and its performance is studied.

Synthesis and Characterization of Reduced Graphene Oxide for Supercapacitor Application with a Biodegradable Electrolyte

The possibility of synthesizing a proton-conducting biopolymer electrolyte of polyvinyl alcohol (PVA) doped with 1-ethyl-3-methylimidazolium ethyl sulphate ([EMIM][EtSO4]) ionic liquid and ammonium acetate (CH3COONH4) by solvent casting has been investigated. The ionic conductivity of electrolyte membrane increased with addition of IL and fairly good ionic conductivity of 6.56 × 10−4 S cm−1 has been attained. The conductivity studies of the biopolymer electrolyte membrane have been carried out in coplanar configuration. Graphene oxide (GO) and reduced graphene oxide (rGO) have been synthesized by a chemical method. The prepared rGO has been characterized using ultraviolet–visible (UV–Vis) absorption spectroscopy, x-ray diffraction, Raman and x-ray photoelectron spectroscopy analysis. The surface area of rGO has been increased from 2.69 m2 g−1 to 203.78 m2 g−1. In this work, a supercapacitor with a symmetric electrode has been fabricated using PVA-doped ionic liquid as a biopolymer electrolyte and rGO as electrode materials. Its electrochemical performance has been verified, and the device exhibited a good specific capacitance of 138 F g−1. This combination was found to be very useful to improve the capacitance of supercapacitor.

Study on the effect of lithium nitrate in ionic conduction properties based alginate biopolymer electrolytes

In this present work, the conduction properties of biopolymer electrolytes (BEs) based alginate incorporation with LiNO3 was studied. FTIR analysis showed there is complexation occurred when incorporation with LiNO3 via COO− group of alginate. The interaction between alginate and LiNO3 shown an improvement in ionic conductivity of BEs where was increased from 3.24 × 10–7 S cm−1 for un-doped sample and achieved optimum value at 1.14 × 10–4 S cm−1 for sample containing with 15 wt. % LiNO3. The prepared samples shown that it has thermally assisted when the temperature is increased and shown Arrhenius behavior. Deconvolution approached revealed that the present ionic conduction of BEs influenced by ionic mobility and diffusion coefficient.

Preparation and Characterization of Biopolymer Electrolytes Based on Pectin and NaNO3 for Battery Applications

Pectin based biopolymer electrolytes have been prepared with different concentrations of sodium nitrate by solution casting technique using distilled water as solvent. The amorphous nature of all the prepared biopolymer electrolytes is confirmed by X-ray diffraction studies. The FTIR studies confirm the complexation between polymer and salt. The ionic conductivity (2.7 × 10–9 S/cm) of pure pectin is enhanced to 4.2 × 10–6 S/cm by doping of NaNO3 salt. The dielectric properties of the pectin/NaNO3 electrolytes are also discussed. The prepared biopolymer electrolytes obey Arrhenius behavior with respect to temperature. The high ionic conductivity, low relaxation time (41.2 mS) and maximum cationic transference number are achieved for 9% of NaNO3 doped biopolymer electrolyte. This highest conductivity polymer electrolyte has been used to construct a battery.

Solid-state double layer capacitors and protonic cell fabricated with dextran from Leuconostoc mesenteroides based green polymer electrolyte

Glycerolized dextran-ammonium nitrate (NH4NO3) biopolymer electrolytes are prepared by solution cast technique. The addition of 20 wt% glycerol has increased the conductivity value from (3.00 ± 1.60) × 10−5 S cm−1 to (1.15 ± 0.08) × 10−3 S cm−1. The study of ionic conductivities at high temperature is carried out from 298 K to 353 K and found that the conductivities harmonized with the Arrhenius rule. Results from dielectric analysis have proved that the dielectric constant of the electrolytes has increased as the glycerol concentration is increased. The trend of dielectric analysis follows the conductivity pattern at high temperature. Transference number of the highest conducting electrolyte is found to be 0.97, which proves that ion is the dominant conducting species. From conduction mechanism analysis, the electrolytes obey the correlated barrier hopping (CBH) model. Linear sweep voltammetry (LSV) confirms that the highest conducting electrolyte is suitable to be applied in electrochemical devices with potential stability up to 1.75 V. The fabricated supercapacitor is stable over 1000 cycles with the highest specific capacitance (Cs) of ~15.7 F g−1. The open circuit potential (OCP) for the fabricated protonic cell is ~ (1.40 ± 0.01) V with capacity of 11.6 ± 0.5 mAh.

Bio-host pectin complexed with dilithium borate based solid electrolytes for polymer batteries

Solid state polymer batteries have become the center of focus to fulfill the goal towards the accomplishment of storage systems with high power and energy densities in affordable cost and safety. In this connection, a new Solid Biopolymer Electrolyte (SBE) membrane, pectin complexed with dilithium borate, was prepared using solution casting technique and investigated by XRD, AC impedance and LSV techniques. The ion conductivity to a maximum of 1.69 × 10−5 Scm−1 for 60 (M.wt%) pectin: 40 (M.wt%) Li2B4O7 composition was attributed to the addition of Li2B4O7, which increases the number of conducting ion species. Increase in conductivity with temperature can be correlated with the free volume model. The lowest value of activation energy and an electrochemical stability window of 3.11 V were obtained for the highest ion conducting sample, indicating that this composition is a promising biopolymer membrane electrolyte in all solid state batteries.