Non suitability of silver ion conducting polymer electrolytes based on chitosan mediated by barium titanate (BaTiO3) for electrochemical device applications

Drude-Lorentz classical oscillator model and Tauc's approach to study the localized density of states and energy band gap of polymer composites based on chitosan integrated with green synthesized Pb-metal complexes: Improvement of linear and non-linear optical parameters

In the current work, green-synthesized metal complexes were combined with chitosan to fabricate polymer composites with controlled optical properties. The dye extracted from green tea was enriched with ligands to capture heavy metal ions and producing metal complexes. The FTIR bands associated with chitosan reduced in intensity and shifted in position when the Pb-metal complex (Pb-MC) was inserted. The XRD pattern illustrates that chitosan transformed into an amorphous material after the insertion of Pb-MC. FESEM revealed enhanced surface roughness in CS films containing high concentration of Pb-MC particles. The optical properties indicate that the bandgap energy was reduced from 5.1 eV to 1.68 eV. Urbach energy values were correlated with the amorphous nature of the films. The Eo and Ed values estimated from W-D models were used to compute the M-1 and M-3 optical moments. The optical parameters of CS:Pb-MC, including N/m, εL, NC, μopt, ρopt, and ωp, were determined based on the Lorentz oscillator model. The Sellmeier parameters (λo and So) were successfully calculated. The determined phase (vp) and group (vg) velocities establish that the composite media are dispersive. Kirchhoff's thermal emission and surface resistance were studied for all the films. Volume and surface energy losses were determined from the data on optical dielectric properties. The susceptibilities (χ(1)), (χ(2)), and (χ(3)) correspondingly represent the linear, second-order, and third-order nonlinear optical susceptibilities.

Gamma-ray shielding effectiveness, optical, mechanical, dielectric properties of nanofiller-reinforced PVA/PVP polymeric blend nanocomposites

The aqueous solution cast method was used to create the biodegradable polymer nanocomposite (PNC) films from a blend of poly (vinyl alcohol) PVA and poly (vinyl pyrrolidone) PVP (70/30 wt %) and Fe2O3 nanoparticles (NPs). These PNC films were characterized using X-ray diffraction, scanning electron microscopy SEM, Fourier transform infrared spectroscopy FTIR, and ultraviolet-visible spectroscopy. XRD and FTIR results indicate that Fe+ 3 NPs interact with the host polymer. Optical, electrical, mechanical, and radiation shielding measurements were performed on the PNC films. From the optical measurements, the indirect optical band gap drops from 4.86 eV for the pure blend to 4.26 eV at the greatest NPs concentration. Optical limiting characterization shows that the output power of He-Ne and solid-state green laser beams is reduced from 22.98 to 3.6 mW and 6.59 to 1.4 mW, respectively, when the Fe2O3 NPs content in the blend matrix is increased to 6 wt %. The NGCal software was utilized to calculate nuclear radiation shielding properties. The findings demonstrated that when the concentration of Fe2O3 rose, the PNC films half-value layer and mean free path decreased. Mechanical measurements demonstrate that increasing the Fe2O3 content significantly improves nanocomposite films' yield and tensile strength. Tensile strength is measured at 27.03 MPa for the composite film containing 6 wt % Fe2O3, which is significantly higher than the 8.66 MPa of the pure (PVA-PVP) film. Compared to the other samples under examination, the 6 wt % Fe2O3 sample yielded the best results (based on the analyzed optical, electrical, mechanical, and radiation shielding properties).

Cellulose acetate-based polymer electrolyte for energy storage application with the influence of BaTiO3 nanofillers on the electrochemical properties: A progression in biopolymer-EDLC technology

The bio-based solid polymer electrolyte serves as a promising choice for the next generation of energy storage devices to meet the requirement of green chemistry. In the current research, a green plasticized magnesium ion-conducting biopolymer electrolyte was developed using simple solution casting method for Electric Double Layer Capacitors (EDLC) applications. The biopolymer Cellulose Acetate (CA) as the host polymer, with varying concentrations of BaTiO3 as the nanofiller, Mg(CF3SO3)2 as the ionic dopant, and PEG as the plasticizer. A 2 wt% addition of BaTiO3 to the biopolymer electrolyte exhibits maximum conductivity measuring 2.4 × 10-3 S/cm. Linear Sweep Voltammetry (LSV) analysis demonstrates maximum stability voltage of 3.51 V. The ionic transference number (tion) and (tMg2+) were determined to be 0.99 and 0.41 respectively. The fabricated EDLC device with the same electrolyte showed polarisation curve without any noticeable peaks in the Cyclic Voltammetry (CV) plot, indicating no redox reactions occurring at the electrode-electrolyte interface. Galvanostatic Charge Discharge (GCD) results showed excellent coulombic efficiency, stability and Energy Density and Power Density performance over 2000 cycles. The incorporation of BaTiO3 into biopolymer membranes presents a viable approach towards sustainable energy storage solutions by enhancing the energy storage capacity of EDLC devices.

Ultrasound-Sensitive Intelligent Nanosystems: A Promising Strategy for the Treatment of Neurological Diseases

Neurological diseases are a major global health challenge, affecting hundreds of millions of people worldwide. Ultrasound therapy plays an irreplaceable role in the treatment of neurological diseases due to its noninvasive, highly focused, and strong tissue penetration capabilities. However, the complexity of brain and nervous system and the safety risks associated with prolonged exposure to ultrasound therapy severely limit the applicability of ultrasound therapy. Ultrasound-sensitive intelligent nanosystems (USINs) are a novel therapeutic strategy for neurological diseases that bring greater spatiotemporal controllability and improve safety to overcome these challenges. This review provides a detailed overview of therapeutic strategies and clinical advances of ultrasound in neurological diseases, focusing on the potential of USINs-based ultrasound in the treatment of neurological diseases. Based on the physical and chemical effects induced by ultrasound, rational design of USINs is a prerequisite for improving the efficacy of ultrasound therapy. Recent developments of ultrasound-sensitive nanocarriers and nanoagents are systemically reviewed. Finally, the challenges and developing prospects of USINs are discussed in depth, with a view to providing useful insights and guidance for efficient ultrasound treatment of neurological diseases.

Preparation and Characterization of Self-Healing PVA-H2SO4 Hydrogel for Flexible Energy Storage

In the past decade, hydrogels have attracted growing interest for emerging applications in flexible electronic devices, human-machine interactions, energy supply, or energy storage. Developing a multifunctional gel architecture with superior ionic conductivity and good mechanical flexibility is a bottleneck to overcome. Herein, poly(vinyl alcohol)/sulfuric acid (PVA-H2SO4) hydrogels were prepared via a freeze-thaw method. With the aim of tuning the formulation in view of a possible application in energy storage, the effects of different combinations in terms of the molecular weight (MW) of PVA and PVA-H2SO4 weight ratio were investigated. Moreover, exploiting the self-healing properties of these hydrogels and the easy possibility of functionalizing them, i.e., introducing a conducting polymer such as poly(2-acrylamido-2-methyl-1-propane) sulfonic acid doped polyaniline (PANI_PAMPSA), a sandwiched all-in-one double-layer hydrogel (electrode/electrolyte configuration) was prepared (PVA-H2SO4-PANI_PAMPSA/PVA-H2SO4). Results showed that the water content is independent of the PVA amount and MW; the polymer concentration has a significant effect on the formation of crystalline domains and therefore on swelling degree, whereas the cross-linking degree depends on the MW. The PVA MW has the maximum effect on the swelling percentage normalized with respect to the polymer fraction and the tensile properties of the hydrogel. The assembled all-in-one electrode/electrolyte shows promising ionic conductivity (439.7 mS cm-1) and specific capacitance performance (0.297 mF cm-2 at a current density of 0.025 mA cm-2), as well as excellent flexibility and considerable self-healing properties. These results will promote the development of self-healing symmetrical supercapacitors for storage devices in wearable electronics.

Advances in the Use of Conducting Polymers for Healthcare Monitoring

Conducting polymers (CPs) are an innovative class of materials recognized for their high flexibility and biocompatibility, making them an ideal choice for health monitoring applications that require flexibility. They are active in their design. Advances in fabrication technology allow the incorporation of CPs at various levels, by combining diverse CPs monomers with metal particles, 2D materials, carbon nanomaterials, and copolymers through the process of polymerization and mixing. This method produces materials with unique physicochemical properties and is highly customizable. In particular, the development of CPs with expanded surface area and high conductivity has significantly improved the performance of the sensors, providing high sensitivity and flexibility and expanding the range of available options. However, due to the morphological diversity of new materials and thus the variety of characteristics that can be synthesized by combining CPs and other types of functionalities, choosing the right combination for a sensor application is difficult but becomes important. This review focuses on classifying the role of CP and highlights recent advances in sensor design, especially in the field of healthcare monitoring. It also synthesizes the sensing mechanisms and evaluates the performance of CPs on electrochemical surfaces and in the sensor design. Furthermore, the applications that can be revolutionized by CPs will be discussed in detail.

Ultrasensitive Surface Plasmon Resonance Sensor with a Feature of Dynamically Tunable Sensitivity and High Figure of Merit for Cancer Detection

Cancer is one of the leading causes of death worldwide, and it is well known that an early detection of cancer in a human body will provide an opportunity to cure the cancer. Early detection of cancer depends on the sensitivity of the measuring device and method, where the lowest detectable concentration of the cancerous cell in a test sample becomes a matter of high importance. Recently, Surface Plasmon Resonance (SPR) has proven to be a promising method to detect cancerous cells. The SPR method is based on the detection of changes in refractive indices of samples under testing and the sensitivity of such a SPR based sensor is related to the smallest detectable change in the refractive index of the sample. There exist many techniques where different combinations of metals, metal alloys and different configurations have been shown to lead to high sensitivities of the SPR sensors. Based on the difference in the refractive index between a normal healthy cell and a cancerous cell, recently, SPR method has been shown to be applicable to detect different types of cancers. In this work, we propose a new sensor surface configuration that comprises of gold-silver-graphene-black phosphorus to detect different cancerous cells based on the SPR method. Additionally, recently we proposed that the application of electric field across gold-graphene layers that form the SPR sensor surface can provide enhanced sensitivity than that is possible without the application of electrical bias. We utilized the same concept and numerically studied the impact of electrical bias across the gold-graphene layers combined with silver and black Phosphorus layers which forms the SPR sensor surface. Our numerical results have shown that electrical bias across the sensor surface in this new heterostructure can provide enhanced sensitivity compared to the original unbiased sensor surface. Not only that, our results have shown that as the electrical bias increases, the sensitivity increases up to a certain value and stabilizes at a still improved sensitivity value. Such dependence of sensitivity on the applied bias provides a dynamic tunability of the sensitivity and figure-of-merit (FOM) of the sensor to detect different types of cancer. In this work, we used the proposed heterostructure to detect six different types of cancers: Basal, Hela, Jurkat, PC12, MDA-MB-231, and MCF-7. Comparing our results to work published recently, we were able to achieve an enhanced sensitivity ranging from 97.2 to 1851.4 (deg/RIU) and FOM values ranging from 62.13 to 89.81 far above the values presented recently by other researchers.

Antibacterial Activity of the Green Synthesized Plasmonic Silver Nanoparticles with Crystalline Structure against Gram-Positive and Gram-Negative Bacteria

Nanoparticles (NPs) have attracted considerable interest in numerous fields, including agriculture, medicine, the environment, and engineering. The use of green synthesis techniques that employ natural reducing agents to reduce metal ions and form NPs is of particular interest. This study investigates the use of green tea (GT) extract as a reducing agent for the synthesis of silver NPs (Ag NPs) with crystalline structure. Several analytical techniques, including UV-visible spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and X-ray diffraction (XRD), were used to characterize the synthesized Ag NPs. The results of UV-vis revealed that the biosynthesized Ag NPs exhibited an absorbance plasmonic resonance peak at 470 nm. According to FTIR analyses, the attachment of Ag NPs to polyphenolic compounds resulted in a decrease in intensity and band shifting. In addition, the XRD analysis confirmed the presence of sharp crystalline peaks associated with face-centered cubic Ag NPs. Moreover, HR-TEM revealed that the synthesized particles were spherical and 50 nm in size on average. The Ag NPs demonstrated promising antimicrobial activity against Gram-positive (GP) bacteria, Brevibacterium luteolum and Staphylococcus aureus, and Gram-negative (GN) bacteria, Pseudomonas aeruginosa and Escherichia coli, with a minimal inhibitory concentration (MIC) of 6.4 mg/mL for GN and 12.8 mg/mL for GP. Overall, these findings suggest that Ag NPs can be utilized as effective antimicrobial agents.

Structural, Optical, and Electrical Investigations of Nd2O3-Doped PVA/PVP Polymeric Composites for Electronic and Optoelectronic Applications

In this present work, a PVA/PVP-blend polymer was doped with various concentrations of neodymium oxide (PB-Nd+3) composite films using the solution casting technique. X-ray diffraction (XRD) analysis was used to investigate the composite structure and proved the semi-crystallinity of the pure PVA/PVP polymeric sample. Furthermore, Fourier transform infrared (FT-IR) analysis, a chemical-structure tool, illustrated a significant interaction of PB-Nd+3 elements in the polymeric blends. The transmittance data reached 88% for the host PVA/PVP blend matrix, while the absorption increased with the high dopant quantities of PB-Nd+3. The absorption spectrum fitting (ASF) and Tauc's models optically estimated the direct and indirect energy bandgaps, where the addition of PB-Nd+3 concentrations resulted in a drop in the energy bandgap values. A remarkably higher quantity of Urbach energy for the investigated composite films was observed with the increase in the PB-Nd+3 contents. Moreover, seven theoretical equations were utilized, in this current research, to indicate the correlation between the refractive index and the energy bandgap. The indirect bandgaps for the proposed composites were evaluated to be in the range of 5.6 eV to 4.82 eV; in addition, the direct energy gaps decreased from 6.09 eV to 5.83 eV as the dopant ratios increased. The nonlinear optical parameters were influenced by adding PB-Nd+3, which tended to increase the values. The PB-Nd+3 composite films enhanced the optical limiting effects and offered a cut-off laser in the visible region. The real and imaginary parts of the dielectric permittivity of the blend polymer embedded in PB-Nd+3 increased in the low-frequency region. The AC conductivity and nonlinear I-V characteristics were augmented with the doping level of PB-Nd+3 contents in the blended PVA/PVP polymer. The outstanding findings regarding the structural, electrical, optical, and dielectric performance of the proposed materials show that the new PB-Nd+3-doped PVA/PVP composite polymeric films are applicable in optoelectronics, cut-off lasers, and electrical devices.

The EDLC Energy Storage Device Based on a Natural Gelatin (NG) Biopolymer: Tuning the Capacitance through Plasticizer Variation

A solution casting method has been utilisedto fabricate plasticisednatural gelatin (NG)-based polymer electrolyte films. The NG electrolyte with 50 wt.% glycerol and 13 wt.% sodium nitrate (NaNO₃) attained the highest ionic conductivity of 1.67 × 10^-4 S cm^-1. Numerous techniques were used to characterisethe NG films to assess their electrochemical performance. The data obtained from impedance spectroscopy for the plasticisedsystem, such as bulk resistance (Rb), arerelatively low. Thiscomprehensive study has been focused on dielectric characteristics and electric modulus parameters. The plasticisedsystem has shown eligibility for practice in energy storage devices with electrochemical strength up to 2.85 V. The TNM data based on ion transference number (tion) and electron transference number (te) determine the identity of the main charge carrier, ion. The redox peaks in the cyclic voltammograms have not been observed as evidence of charge accumulation other than the Faradaic process at the electrode-electrolyte interface. The GCD plot reveals a triangle shape and records arelatively low drop voltage. The high average efficiency of 90% with low ESR has been achieved over 500 cycles, indicating compatibility between electrolyte and electrode. The average power density and energy density of the plasticisedare 700 W/kg and 8 Wh/kg, respectively.

Characteristics of Methyl Cellulose Based Solid Polymer Electrolyte Inserted with Potassium Thiocyanate as K+ Cation Provider: Structural and Electrical Studies

The attention to a stable and ionic conductive electrolyte is driven by the limitations of liquid electrolytes, particularly evaporation and leakage, which restrain their widespread use for electrochemical device applications. Solid polymer electrolyte (SPE) is considered to be a potential alternative since it possesses high safety compared to its counterparts. However, it still suffers from low device efficiency due to an incomplete understanding of the mechanism of ion transport parameters. Here, we present a simple in situ solution casting method for the production of polymer-based electrolytes using abundantly available methylcellulose (MC) doped at different weight percentages of potassium thiocyanate (KSCN) salt. Fourier transform infrared (FTIR), and electrochemical impedance spectroscopy (EIS) methods were used to characterize the prepared samples. Based on EIS simulation and FTIR deconvolution associated with the SCN anion peak, various ion transport parameters were determined. The host MC medium and KSCN salt have a strong interaction, which was evident from both peak shifting and intensity alteration of FTIR spectra. From the EIS modeling, desired electric circuits correlated with ion movement and chain polarization were drawn. The highest ionic conductivity of 1.54 × 10^-7 S cm^-1 is determined from the fitted EIS curve for the film doped with 30 wt.% of KSCN salt. From the FTIR deconvoluted peak, free ions, ions in contact with one another, and ion aggregates were separated. The extracted ion transport parameters from the EIS method and FTIR spectra of the SCN anion band confirm that both increased carrier concentration and their mobility were crucial in improving the overall conductivity of the electrolyte. The dielectric investigations were further used to understand the conductivity of the films. High dielectric constants were observed at low frequencies for all MC:KSCN systems. The dispersion with a high dielectric constant in the low-frequency band is ascribed to the dielectric polarization. The wide shift of M″ peak towards the high frequency was evidenced by the MC-based electrolyte impregnated with 30 wt.% of KSCN salt, revealing the improved ionic movement assisted with chain segmental motion. The AC conductivity pattern was influenced by salt concentration.

Study of MC:DN-Based Biopolymer Blend Electrolytes with Inserted Zn-Metal Complex for Energy Storage Devices with Improved Electrochemical Performance

Stable and ionic conducting electrolytes are needed to make supercapacitors more feasible, because liquid electrolytes have leakage problems and easily undergo solvent evaporation. Polymer-based electrolytes meet the criteria, yet they lack good efficiency due to limited segmental motion. Since metal complexes have crosslinking centers that can be coordinated with the polymer segments, they are regarded as an adequate method to improve the performance of the polymer-based electrolytes. To prepare plasticized proton conducting polymer composite (PPC), a simple and successful process was used. Using a solution casting process, methylcellulose and dextran were blended and impregnated with ammonium thiocyanate and zinc metal complex. A range of electrochemical techniques were used to analyze the PPC, including transference number measurement (TNM), linear sweep voltammetry (LSV), cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The ionic conductivity of the prepared system was found to be 3.59 × 10^-3 S/cm using the EIS method. The use of glycerol plasticizer improves the transport characteristics, according to the findings. The carrier species is found to have ionic mobility of 5.77 × 10^-5 cm² V^-1 s^-1 and diffusion coefficient of 1.48 × 10^-6 cm² s^-1 for the carrier density 3.4 × 10²⁰ cm^-3. The TNM revealed that anions and cations were the predominant carriers in electrolyte systems, with an ionic transference value of 0.972. The LSV approach demonstrated that, up to 2.05 V, the film was stable, which is sufficient for energy device applications. The prepared PPC was used to create an electrical double-layer capacitor (EDLC) device. The CV plot exhibited the absence of Faradaic peaks in the CV plot, making it practically have a rectangular form. Using the GCD experiment, the EDLC exhibited low equivalence series resistance of only 65 Ω at the first cycle. The average energy density, power density, and specific capacitance values were determined to be 15 Wh/kg, 350 W/kg, and 128 F/g, respectively.

The Study of Ion Transport Parameters in MC-Based Electrolyte Membranes Using EIS and Their Applications for EDLC Devices

A solution cast technique was utilized to create a plasticized biopolymer-based electrolyte system. The system was prepared from methylcellulose (MC) polymer as the hosting material and potassium iodide (KI) salt as the ionic source. The electrolyte produced with sufficient conductivity was evaluated in an electrochemical double-layer capacitor (EDLC). Electrolyte systems’ electrical, structural, and electrochemical properties have been examined using various electrochemical and FTIR spectroscopic techniques. From the electrochemical impedance spectroscopy (EIS), a maximum ionic conductivity of 5.14 × 10⁻⁴ S cm⁻¹ for the system with 50% plasticizer was recorded. From the EEC modeling, the ion transport parameters were evaluated. The extent of interaction between the components of the prepared electrolyte was investigated using Fourier transformed infrared spectroscopy (FTIR). For the electrolyte system (MC-KI-glycerol), the t_ion and electrochemical windows were 0.964 and 2.2 V, respectively. Another electrochemical property of electrolytes is transference number measurement (TNM), in which the ion predominantly responsibility was examined in an attempt to track the transport mechanism. The non-Faradaic nature of charge storing was proved from the absence of a redox peak in the cyclic voltammetry profile (CV). Several decisive parameters have been specified, such as specific capacitance (C_s), coulombic efficiency (η), energy density (E_d), and power density (P_d) at the first cycle, which were 68 F g⁻¹, 67%, 7.88 Wh kg⁻¹, and 1360 Wh kg⁻¹, respectively. Ultimately, during the 400th cycle, the series resistance ESR varied from 70 to 310 ohms.

Na2SnO3 functions as outstanding magnesium alloy passivator by synergistic effect with trace carboxymethyl chitosan for Mg–air batteries for standby protection

Coordination of Na2SnO3 with trace carboxymethyl chitosan contributes to standby protection and high utilization efficiency of the AZ61 anode.

Impedance, Electrical Equivalent Circuit (EEC) Modeling, Structural (FTIR and XRD), Dielectric, and Electric Modulus Study of MC-Based Ion-Conducting Solid Polymer Electrolytes

The polymer electrolyte system of methylcellulose (MC) doped with various sodium bromide (NaBr) salt concentrations is prepared in this study using the solution cast technique. FTIR and XRD were used to identify the structural changes in solid films. Sharp crystalline peaks appeared at the XRD pattern at 40 and 50 wt.% of NaBr salt. The electrical impedance spectroscopy (EIS) study illustrates that the loading of NaBr increases the electrolyte conductivity at room temperature. The DC conductivity of 6.71 × 10⁻⁶ S/cm is obtained for the highest conducting electrolyte. The EIS data are fitted with the electrical equivalent circuit (EEC) to determine the impedance parameters of each film. The EEC modeling helps determine the circuit elements, which is decisive from the engineering perspective. The DC conductivity tendency is further established by dielectric analysis. The EIS spectra analysis shows a decrease in bulk resistance, demonstrating free ion carriers and conductivity boost. The dielectric property and relaxation time confirmed the non-Debye behavior of the electrolyte system. An incomplete semicircle further confirms this behavior model in the Argand plot. The distribution of relaxation times is related to the presence of conducting ions in an amorphous structure. Dielectric properties are improved with the addition of NaBr salt. A high value of a dielectric constant is seen at the low frequency region.

Chitosan as a matrix of nanocomposites: A review on nanostructures, processes, properties, and applications

Chitosan is a biopolymer that is natural, biodegradable, and relatively low price. Chitosan has been attracting interest as a matrix of nanocomposites due to new properties for various applications. This study presents a comprehensive overview of common and recent advances using chitosan as a nanocomposite matrix. The focus is to present alternative processes to produce embedded or coated nanoparticles, and the shaping techniques that have been employed (3D printing, electrospinning), as well as the nanocomposites emerging applications in medicine, tissue engineering, wastewater treatment, corrosion inhibition, among others. There are several reviews about single chitosan material and derivatives for diverse applications. However, there is not a study that focuses on chitosan as a nanocomposite matrix, explaining the possibility of nanomaterial additions, the interaction of the attached species, and the applications possibility following the techniques to combine chitosan with nanostructures. Finally, future directions are presented for expanding the applications of chitosan nanocomposites.

Characteristics of Plasticized Lithium Ion Conducting Green Polymer Blend Electrolytes Based on CS: Dextran with High Energy Density and Specific Capacitance

The solution cast process is used to set up chitosan: dextran-based plasticized solid polymer electrolyte with high specific capacitance (228.62 F/g) at the 1st cycle. Fourier-transform infrared spectroscopy (FTIR) pattern revealed the interaction between polymers and electrolyte components. At ambient temperature, the highest conductive plasticized system (CDLG-3) achieves a maximum conductivity of 4.16 × 10-4 S cm-1. Using both FTIR and electrical impedance spectroscopy (EIS) methods, the mobility, number density, and diffusion coefficient of ions are measured, and they are found to rise as the amount of glycerol increases. Ions are the primary charge carriers, according to transference number measurement (TNM). According to linear sweep voltammetry (LSV), the CDLG-3 system's electrochemical stability window is 2.2 V. In the preparation of electrical double layer capacitor devices, the CDLG-3 system was used. There are no Faradaic peaks on the cyclic voltammetry (CV) curve, which is virtually rectangular. Beyond the 20th cycle, the power density, energy density, and specific capacitance values from the galvanostatic charge-discharge are practically constant at 480 W/Kg, 8 Wh/Kg, and 60 F g-1, for 180 cycles.

Characteristics of a Plasticized PVA-Based Polymer Electrolyte Membrane and H+ Conductor for an Electrical Double-Layer Capacitor: Structural, Morphological, and Ion Transport Properties

Poly (vinyl alcohol) (PVA)-based solid polymer electrolytes doped with ammonium thiocyanate (NH4SCN) and glycerol were fabricated using a solution casting method. Lithium-based energy storage devices are not environmentally friendly materials, and they are toxic. Thus, proton-conducting materials were used in this work as they are harmless and are smaller than lithium. The interaction between PVA and the electrolyte elements was shown by FTIR analysis. The highest conductivity of 1.82 × 10-5 S cm-1 was obtained by the highest-conducting plasticized system (PSP_2) at room temperature. The mobility, diffusion coefficient, and number density of anions and cations were found to increase with increasing glycerol. FESEM was used to investigate the influence of glycerol on film morphology. TNM showed that the cations and anions were the main charge carriers. LSV showed that the electrochemical stability window of the PSP_2 system was 1.99 V. The PSP_2 system was applied in the preparation of an electrical double layer capacitor device. The shape of the cyclic voltammetry (CV) curve was nearly rectangular with no Faradaic peaks. From the galvanostatic charge-discharge analysis, the power density, energy density, and specific capacitance values were nearly constant beyond the first cycle at 318.73 W/Kg, 2.06 Wh/Kg, and 18.30 F g-1, respectively, for 450 cycles.

Improving EDLC Device Performance Constructed from Plasticized Magnesium Ion Conducting Chitosan Based Polymer Electrolytes via Metal Complex Dispersion

The current work shows the preparation of plasticized chitosan-magnesium acetate Mg(CH3COO)2-based polymer electrolyte dispersed with nickel (Ni) metal complexes via solution casting. Investigations of electrical and electrochemical properties of the prepared polymer composite electrolyte were carried out. The structural and optical properties of the samples were studied using X-ray diffraction (XRD) and UV-Vis spectroscopy techniques. The structural and optical outcomes revealed a clear enhancement in both absorbance and amorphous nature of the samples upon the addition of Ni metal complexes. Through the simulation of impedance data, various ion transport parameters were calculated. The electrochemical performance of the sample was examined by means of transference number measurement (TNM), linear sweep voltammetry (LSV) and cyclic voltammetry (CV) measurements. The TNM analysis confirmed the dominance of ions as the main charge carrier in the electrolyte with tion of (0.96) compared to only (0.04) for tel. The present electrolyte was stable in the range of 0 V to 2.4 V, which was obtained from linear sweep voltammetry (LSV). A result from CV proved that the electrical double-layer capacitor (EDLC) has a capacitive behavior as no redox peaks could be observed. The presence of Ni improved the charge-discharge cycle of the EDLC due to its amorphous behavior. The average performances of the EDLC were recorded as 41.7 F/g, 95%, 5.86 Wh/kg and 628 W/kg for specific capacitance, coulombic efficiency, energy and power densities, respectively. The fabricated EDLC device was found to be stable up to 1000 cycles.

Plasticized Polymer Blend Electrolyte Based on Chitosan for Energy Storage Application: Structural, Circuit Modeling, Morphological and Electrochemical Properties

Chitosan (CS)-dextran (DN) biopolymer electrolytes doped with ammonium iodide (NH₄I) and plasticized with glycerol (GL), then dispersed with Zn(II)-metal complex were fabricated for energy device application. The CS:DN:NH₄I:Zn(II)-complex was plasticized with various amounts of GL and the impact of used metal complex and GL on the properties of the formed electrolyte were investigated.The electrochemical impedance spectroscopy (EIS) measurements have shown that the highest conductivity for the plasticized system was 3.44 × 10⁻⁴ S/cm. From the x-ray diffraction (XRD) measurements, the plasticized electrolyte with minimum degree of crystallinity has shown the maximum conductivity. The effect of (GL) plasticizer on the film morphology was studied using FESEM. It has been confirmed via transference number analysis (TNM) that the transport mechanism in the prepared electrolyte is predominantly ionic in nature with a high transference number of ion (t_i)of 0.983. From a linear sweep voltammetry (LSV) study, the electrolyte was found to be electrochemically constant as the voltage sweeps linearly up to 1.25 V. The cyclic voltammetry (CV) curve covered most of the area of the current–potential plot with no redox peaks and the sweep rate was found to be affecting the capacitance. The electric double-layer capacitor (EDLC) has shown a great performance of specific capacitance (108.3 F/g), ESR(47.8 ohm), energy density (12.2 W/kg) and power density (1743.4 W/kg) for complete 100 cycles at a current density of 0.5 mA cm⁻².

Ghareeb H, Dannoun EMA, M. Abdullah R, Hamsan MH, Kadir MFZ. Plasticized Sodium-Ion Conducting PVA Based Polymer Electrolyte for Electrochemical Energy Storage-EEC Modeling, Transport Properties, and Charge-Discharge Characteristics

This report presents the preparation of plasticized sodium ion-conducting polymer electrolytes based on polyvinyl alcohol (PVA)via solution cast technique. The prepared plasticized polymer electrolytes were utilized in the device fabrication of electrical double-layer capacitors (EDLCs). On an assembly EDLC system, cyclic voltammetry (CV), electrical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), transfer number measurement (TNM) and charge-discharging responses were performed. The influence of plasticization on polymer electrolytes was investigated in terms of electrochemical properties applying EIS and TNM. The EIS was fitted with electrical equivalent circuit (EEC) models and ion transport parameters were estimated with the highest conductivity of 1.17 × 10-3 S cm-1 was recorded. The CV and charge-discharging responses were used to evaluate the capacitance and the equivalent series resistance (ESR), respectively. The ESR of the highest conductive sample was found to be 91.2 Ω at the first cycle, with the decomposition voltage of 2.12 V. The TNM measurement has shown the dominancy of ions with tion = 0.982 for the highest conducting sample. The absence of redox peaks was proved via CV, indicating the charge storing process that comprised ion accumulation at the interfacial region. The fabricated EDLC device is stable for up to 400 cycles. At the first cycle, a high specific capacitance of 169 F/g, an energy density of 19 Wh/kg, and a power density of 600 W/kg were obtained.

Performance-tuning of PVA-based gel electrolytes by acid/PVA ratio and PVA molecular weight

The significant breakthroughs of flexible gel electrolytes have attracted extensive attention in modern wearable electronic gadgets. The lack of all-around high-performing gels limits the advantages of such devices for practical applications. To this end, developing a multi-functional gel architecture with superior ionic conductivity while enjoying good mechanical flexibility is a bottleneck to overcome. Herein, an architecturally engineered gel, based on PVA and H3PO4 with different molecular weights of PVA for various PVA/H3PO4 ratios, was developed. The results show the dependence of ionic conductivity on molecular weight and also charge carrier concentration. Consequently, fine-tuning of PVA-based gels through a simple yet systematic and well-regulated strategy to achieve highly ion-conducting gels, with the highest ionic conductivity of 14.75 ± 1.39 mS cm-1 have been made to fulfill the requirement of flexible devices. More importantly, gel electrolytes possess good mechanical robustness while exhibiting high-elasticity (%766.66 ± 59.73), making it an appropriate candidate for flexible devices.

The Study of Plasticized Sodium Ion Conducting Polymer Blend Electrolyte Membranes Based on Chitosan/Dextran Biopolymers: Ion Transport, Structural, Morphological and Potential Stability

The polymer electrolyte system of chitosan/dextran-NaTf with various glycerol concentrations is prepared in this study. The electrical impedance spectroscopy (EIS) study shows that the addition of glycerol increases the ionic conductivity of the electrolyte at room temperature. The highest conducting plasticized electrolyte shows the maximum DC ionic conductivity of 6.10 × 10⁻⁵ S/cm. Field emission scanning electron microscopy (FESEM) is used to investigate the effect of plasticizer on film morphology. The interaction between the electrolyte components is confirmed from the existence of the O–H, C–H, carboxamide, and amine groups. The XRD study is used to determine the degree of crystallinity. The transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D) of ions are determined using the percentage of free ions, due to the asymmetric vibration (υ_as(SO₃)) and symmetric vibration (υ_s(SO₃)) bands. The dielectric property and relaxation time are proved the non-Debye behavior of the electrolyte system. This behavior model is further verified by the existence of the incomplete semicircle arc from the Argand plot. Transference numbers of ion (t_ion) and electron (t_e) for the highest conducting plasticized electrolyte are identified to be 0.988 and 0.012, respectively, confirming that the ions are the dominant charge carriers. The t_ion value are used to further examine the contribution of ions in the values of the diffusion coefficient and mobility of ions. Linear sweep voltammetry (LSV) shows the potential window for the electrolyte is 2.55 V, indicating it to be a promising electrolyte for application in electrochemical energy storage devices.

Solid-State EDLC Device Based on Magnesium Ion-Conducting Biopolymer Composite Membrane Electrolytes: Impedance, Circuit Modeling, Dielectric Properties and Electrochemical Characteristics

The polymer electrolyte based on Dx:Cs:Mg(CH3COO)2:Ni with three different glycerol concentrations have been prepared. The impedance study has verified that the electrolyte with 42 wt.% of glycerol (A3) has the highest ionic conductivity of 7.71 × 10-6 S cm-1 at room temperature. The ionic conductivity is found to be influenced by the transport parameters. From the dielectric analysis, it was shown that the electrolytes in this system obeyed the non-Debye behavior. The A3 electrolyte exhibited a dominancy of ions (tion > te) with a breakdown voltage of 2.08 V. The fabricated electrochemical double layer capacitor (EDLC) achieved the specific capacitance values of 24.46 F/g and 39.68 F/g via the cyclic voltammetry (CV) curve and the charge-discharge profile, respectively. The other significant parameters to evaluate the performance of EDLC have been determined, such as internal resistance (186.80 to 202.27 Ω) energy density (4.46 Wh/kg), power density (500.58 to 558.57 W/kg) and efficiency (92.88%).

Energy Storage Behavior of Lithium-Ion Conducting poly(vinyl alcohol) (PVA): Chitosan(CS)-Based Polymer Blend Electrolyte Membranes: Preparation, Equivalent Circuit Modeling, Ion Transport Parameters, and Dielectric Properties

Plasticized lithium-ion-based-conducting polymer blend electrolytes based on poly(vinyl alcohol) (PVA):chitosan (CS) polymer was prepared using a solution cast technique. The conductivity of the polymer electrolyte system was found to be 8.457 × 10-4 S/cm, a critical factor for electrochemical device applications. It is indicated that the number density (n), diffusion coefficient (D), and mobility (μ) of ions are increased with the concentration of glycerol. High values of dielectric constant and dielectric loss were observed at low frequency region. A correlation was found between the dielectric constant and DC conductivity. The achieved transference number of ions (tion) and electrons (te) for the highest conducting plasticized sample were determined to be 0.989 and 0.011, respectively. The electrochemical stability for the highest conducting sample was 1.94 V, indicated by linear sweep voltammetry (LSV). The cyclic voltammetry (CV) response displayed no redox reaction peaks through its entire potential range. Through the constructing electric double-layer capacitor, the energy storage capacity of the highest conducting sample was investigated. All decisive parameters of the EDLC were determined. At the first cycle, the specific capacitance, internal resistance, energy density, and power density were found to be 130 F/g, 80 Ω, 14.5 Wh/kg, and 1100 W/kg, respectively.

Saeed S, Brza MA, Abdulwahid RT, Hamsan MH, M. Abdullah R, Kadir MFZ, Muzakir SK. Investigation of Ion Transport Parameters and Electrochemical Performance of Plasticized Biocompatible Chitosan-Based Proton Conducting Polymer Composite Electrolytes

In this study, biopolymer composite electrolytes based on chitosan:ammonium iodide:Zn(II)-complex plasticized with glycerol were successfully prepared using the solution casting technique. Various electrical and electrochemical parameters of the biopolymer composite electrolytes' films were evaluated prior to device application. The highest conducting plasticized membrane was found to have a conductivity of 1.17 × 10-4 S/cm. It is shown that the number density, mobility, and diffusion coefficient of cations and anions fractions are increased with the glycerol amount. Field emission scanning electron microscope and Fourier transform infrared spectroscopy techniques are used to study the morphology and structure of the films. The non-Debye type of relaxation process was confirmed from the peak appearance of the dielectric relaxation study. The obtained transference number of ions (cations and anions) and electrons for the highest conducting sample were identified to be 0.98 and 0.02, respectively. Linear sweep voltammetry shows that the electrochemical stability of the highest conducting plasticized system is 1.37 V. The cyclic voltammetry response displayed no redox reaction peaks over its entire potential range. It was discovered that the addition of Zn(II)-complex and glycerol plasticizer improved the electric double-layer capacitor device performances. Numerous crucial parameters of the electric double-layer capacitor device were obtained from the charge-discharge profile. The prepared electric double-layer capacitor device showed that the initial values of specific capacitance, equivalence series resistance, energy density, and power density are 36 F/g, 177 Ω, 4.1 Wh/kg, and 480 W/kg, respectively.

Characteristics of Glycerolized Chitosan: NH4NO3-Based Polymer Electrolyte for Energy Storage Devices with Extremely High Specific Capacitance and Energy Density Over 1000 Cycles

In this work, plasticized polymer electrolyte films consisting of chitosan, ammonium nitrate (NH₄NO₃) and glycerol for utilization in energy storage devices was presented. Various microscopic, spectroscopic and electrochemical techniques were used to characterize the concerned electrolyte and the electrical double-layer capacitor (EDLC) assembly. The nature of complexation between the polymer electrolyte components was examined via X-ray diffraction analysis. In the morphological study, field emission scanning electron microscopy (FESEM) was used to investigate the impact of glycerol as a plasticizer on the morphology of films. The polymer electrolyte (conducting membrane) was found to have a conductivity of 3.21 × 10^-3 S/cm. It is indicated that the number density (n), mobility (μ) and diffusion coefficient (D) of ions are increased with the glycerol amount. The mechanism of charge storing was clarified, which implies a non-Faradaic process. The voltage window of the polymer electrolyte is 2.32 V. It was proved that the ion is responsible for charge-carrying via measuring the transference number (TNM). It was also determined that the internal resistance of the EDLC assembly lay between 39 and 50 Ω. The parameters associated with the EDLC assembly are of great importance and the specific capacitance (C_spe) was determined to be almost constant over 1 to 1000 cycles with an average of 124 F/g. Other decisive parameters were found: energy density (18 Wh/kg) and power density (2700 W/kg).

The Study of Structural, Impedance and Energy Storage Behavior of Plasticized PVA:MC Based Proton Conducting Polymer Blend Electrolytes

In this study, structural characterization, electrical properties and energy storage performance of plasticized polymer electrolytes based on polyvinyl alcohol/methylcellulose/ammonium thiocyanate (PVA/MC-NH₄SCN) were carried out. An X-ray diffraction (XRD) study displayed that the plasticized electrolyte system with the uppermost value of direct current (DC) ionic conductivity was the most amorphous system. The electrolyte in the present work realized an ionic conductivity of 2.903 × 10⁻³ Scm⁻¹ at room temperature. The main charge carrier in the electrolyte was found to be the ions with the ionic transference number (t_ion) of 0.912, compared to only 0.088 for the electronic transference number (t_elec). The electrochemical stability potential window of the electrolyte is 2.1 V. The specific capacitance was found to reduce from 102.88 F/g to 28.58 F/g as the scan rate increased in cyclic voltammetry (CV) analysis. The fabricated electrochemical double layer capacitor (EDLC) was stable up to 200 cycles with high efficiency. The specific capacitance obtained for the EDLC by using charge–discharge analysis was 132.7 F/g at the first cycle, which is slightly higher compared to the CV plot. The equivalent series resistance (ESR) increased from 58 to 171 Ω throughout the cycles, which indicates a good electrolyte/electrode contact. Ions in the electrolyte were considered to have almost the same amount of energy during the conduction process as the energy density is approximately at 14.0 Wh/kg throughout the 200 cycles. The power density is stabilized at the range of 1444.3 to 467.6 W/kg as the EDLC completed the cycles.

The Study of Plasticized Solid Polymer Blend Electrolytes Based on Natural Polymers and Their Application for Energy Storage EDLC Devices

In this work, plasticized magnesium ion-conducting polymer blend electrolytes based on chitosan:methylcellulose (CS:MC) were prepared using a solution cast technique. Magnesium acetate [Mg(CH₃COO)₂] was used as a source of the ions. Nickel metal-complex [Ni(II)-complex)] was employed to expand the amorphous phase. For the ions dissociation enhancement, glycerol plasticizer was also engaged. Incorporating 42 wt% of the glycerol into the electrolyte system has been shown to improve the conductivity to 1.02 × 10⁻⁴ S cm⁻¹. X-ray diffraction (XRD) analysis showed that the electrolyte with the highest conductivity has a minimum crystallinity degree. The ionic transference number was estimated to be more than the electronic transference number. It is concluded that in CS:MC:Mg(CH₃COO)₂:Ni(II)-complex:glycerol, ions are the primary charge carriers. Results from linear sweep voltammetry (LSV) showed electrochemical stability to be 2.48 V. An electric double-layer capacitor (EDLC) based on activated carbon electrode and a prepared solid polymer electrolyte was constructed. The EDLC cell was then analyzed by cyclic voltammetry (CV) and galvanostatic charge–discharge methods. The CV test disclosed rectangular shapes with slight distortion, and there was no appearance of any redox currents on both anodic and cathodic parts, signifying a typical behavior of EDLC. The EDLC cell indicated a good cyclability of about (95%) for throughout of 200 cycles with a specific capacitance of 47.4 F/g.

The Study of Electrical and Electrochemical Properties of Magnesium Ion Conducting CS: PVA Based Polymer Blend Electrolytes: Role of Lattice Energy of Magnesium Salts on EDLC Performance

Plasticized magnesium ion conducting polymer blend electrolytes based on chitosan (CS): polyvinyl alcohol (PVA) was synthesized with a casting technique. The source of ions is magnesium triflate Mg(CF3SO3)2, and glycerol was used as a plasticizer. The electrical and electrochemical characteristics were examined. The outcome from X-ray diffraction (XRD) examination illustrates that the electrolyte with highest conductivity exhibits the minimum degree of crystallinity. The study of the dielectric relaxation has shown that the peak appearance obeys the non-Debye type of relaxation process. An enhancement in conductivity of ions of the electrolyte system was achieved by insertion of glycerol. The total conductivity is essentially ascribed to ions instead of electrons. The maximum DC ionic conductivity was measured to be 1.016 × 10-5 S cm-1 when 42 wt.% of plasticizer was added. Potential stability of the highest conducting electrolyte was found to be 2.4 V. The cyclic voltammetry (CV) response shows the behavior of the capacitor is non-Faradaic where no redox peaks appear. The shape of the CV response and EDLC specific capacitance are influenced by the scan rate. The specific capacitance values were 7.41 F/g and 32.69 F/g at 100 mV/s and 10 mV/s, respectively. Finally, the electrolyte with maximum conductivity value is obtained and used as electrodes separator in the electrochemical double-layer capacitor (EDLC) applications. The role of lattice energy of magnesium salts in energy storage performance is discussed in detail.

Marf A, Dannoun EMA, Brza MA, Abdullah RM. The Study of the Degree of Crystallinity, Electrical Equivalent Circuit, and Dielectric Properties of Polyvinyl Alcohol (PVA)-Based Biopolymer Electrolytes

This report presents a facile and efficient methodology for the fabrication of plasticized polyvinyl alcohol (PVA):chitosan (CS) polymer electrolytes using a solution cast technique. Regarding characterizations of electrical properties and structural behavior, the electrochemical impedance spectroscopy (EIS) and X-ray diffraction (XRD) are used, respectively. Crystalline peaks appear in the XRD pattern of the PVA:CS:NH4I while no peaks can be seen in the XRD pattern of plasticized systems. The degree of crystallinity is calculated for all the samples from the deconvoluted area of crystalline and amorphous phases. Considering the EIS measurements, the most conductive plasticized system shows a relatively high conductivity of (1.37 × 10-4) S/cm, which is eligible for applications in energy storage devices. The analysis of the EIS spectra reveals a decrease in bulk resistance which indicates an increase in free ion carriers. The electrical equivalent circuit (EEC) model is used in the analysis of EIS plots. Dielectric properties are modified with the addition of glycerol as a plasticizer. It is proved that the addition of glycerol as a plasticizer lowers ion association. It also shows, at the low-frequency region, a large value of a dielectric constant which is correlated with electrode polarization (EP). The distribution of relaxation times is associated with conducting ions.

Drawbacks of Low Lattice Energy Ammonium Salts for Ion-Conducting Polymer Electrolyte Preparation: Structural, Morphological and Electrical Characteristics of CS:PEO:NH4BF4-Based Polymer Blend Electrolytes

In the present work it was shown that low lattice energy ammonium salts are not favorable for polymer electrolyte preparation for electrochemical device applications. Polymer blend electrolytes based on chitosan:poly(ethylene oxide) (CS:PEO) incorporated with various amounts of low lattice energy NH4BF4ammonium salt have been prepared using the solution cast technique. Both structural and morphological studies were carried out to understand the phenomenon of ion association. Sharp peaks appeared in X-ray diffraction (XRD) spectra of the samples with high salt concentration. The degree of crystallinity increased from 8.52 to 65.84 as the salt concentration increased up to 40 wt.%. These are correlated to the leakage of the associated anions and cations of the salt to the surface of the polymer. The structural behaviors were further confirmed by morphological study. The morphological results revealed the large-sized protruded salts at high salt concentration. Based on lattice energy of salts, the phenomena of salt leakage were interpreted. Ammonium salts with lattice energy lower than 600 kJ/mol are not preferred for polymer electrolyte preparation due to the significant tendency of ion association among cations and anions. Electrical impedance spectroscopy was used to estimate the conductivity of the samples. It was found that the bulk resistance increased from 1.1 × 104 ohm to 0.7 × 105 ohm when the salt concentration raised from 20 wt.% to 40 wt.%, respectively; due to the association of cations and anions. The low value of direct current (DC) conductivity (7.93 × 10-7 S/cm) addressed the non-suitability of the electrolytes for electrochemical device applications. The calculated values of the capacitance over the interfaces of electrodes-electrolytes (C2) were found to drop from 1.32 × 10-6 F to 3.13 × 10-7 F with increasing salt concentration. The large values of dielectric constant at low frequencies are correlated to the electrode polarization phenomena while their decrements with rising frequency are attributed to the lag of ion polarization in respect of the fast orientation of the applied alternating current (AC) field. The imaginary part of the electric modulus shows obvious peaks known as conduction relaxation peaks.

Nofal M, San S, Abdulwahid RT, Raza Saeed S, Brza MA, Kadir MFZ, Mohammed SJ, Al-Zangana S. From Cellulose, Shrimp and Crab Shells to Energy Storage EDLC Cells: The Study of Structural and Electrochemical Properties of Proton Conducting Chitosan-Based Biopolymer Blend Electrolytes

In this study, solid polymer blend electrolytes (SPBEs) based on chitosan (CS) and methylcellulose (MC) incorporated with different concentrations of ammonium fluoride (NH₄F) salt were synthesized using a solution cast technique. Both Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results confirmed a strong interaction and dispersion of the amorphous region within the CS:MC system in the presence of NH₄F. To gain better insights into the electrical properties of the samples, the results of electrochemical impedance spectroscopy (EIS) were analyzed by electrical equivalent circuit (EEC) modeling. The highest conductivity of 2.96 × 10⁻³ S cm⁻¹ was recorded for the sample incorporated with 40 wt.% of NH₄F. Through transference number measurement (TNM) analysis, the fraction of ions was specified. The electrochemical stability of the electrolyte sample was found to be up to 2.3 V via the linear sweep voltammetry (LSV) study. The value of specific capacitance was determined to be around 58.3 F/g. The stability test showed that the electrical double layer capacitor (EDLC) system can be recharged and discharged for up to 100 cycles with an average specific capacitance of 64.1 F/g. The synthesized EDLC cell was found to exhibit high efficiency (90%). In the 1st cycle, the values of internal resistance, energy density and power density of the EDLC cell were determined to be 65 Ω, 9.3 Wh/kg and 1282 W/kg, respectively.

Aziz S, M. Nofal M, Hamsan MH, Brza MA, Yusof YM, Abdilwahid RT, Muzakir SK, Kadir MFZ. Glycerolized Li+ Ion Conducting Chitosan-Based Polymer Electrolyte for Energy Storage EDLC Device Applications with Relatively High Energy Density

In this study, the solution casting method was employed to prepare plasticized polymer electrolytes of chitosan (CS):LiCO₂CH₃:Glycerol with electrochemical stability (1.8 V). The electrolyte studied in this current work could be established as new materials in the fabrication of EDLC with high specific capacitance and energy density. The system with high dielectric constant was also associated with high DC conductivity (5.19 × 10⁻⁴ S/cm). The increase of the amorphous phase upon the addition of glycerol was observed from XRD results. The main charge carrier in the polymer electrolyte was ion as t_el (0.044) < t_ion (0.956). Cyclic voltammetry presented an almost rectangular plot with the absence of a Faradaic peak. Specific capacitance was found to be dependent on the scan rate used. The efficiency of the EDLC was observed to remain constant at 98.8% to 99.5% up to 700 cycles, portraying an excellent cyclability. High values of specific capacitance, energy density, and power density were achieved, such as 132.8 F/g, 18.4 Wh/kg, and 2591 W/kg, respectively. The low equivalent series resistance (ESR) indicated that the EDLC possessed good electrolyte/electrode contact. It was discovered that the power density of the EDLC was affected by ESR.

Metal Complex as a Novel Approach to Enhance the Amorphous Phase and Improve the EDLC Performance of Plasticized Proton Conducting Chitosan-Based Polymer Electrolyte

This work indicates that glycerolized chitosan-NH₄F polymer electrolytes incorporated with zinc metal complexes are crucial for EDLC application. The ionic conductivity of the plasticized system was improved drastically from 9.52 × 10⁻⁴ S/cm to 1.71 × 10⁻³ S/cm with the addition of a zinc metal complex. The XRD results demonstrated that the amorphous phase was enhanced for the system containing the zinc metal complex. The transference number of ions (t_ion) and electrons (t_e) were measured for two of the highest conducting electrolyte systems. It confirmed that the ions were the dominant charge carriers in both systems as t_ion values for CSNHG4 and CSNHG5 electrolytes were 0.976 and 0.966, respectively. From the examination of LSV, zinc improved the electrolyte electrochemical stability to 2.25 V. The achieved specific capacitance from the CV plot reveals the role of the metal complex on storage properties. The charge–discharge profile was obtained for the system incorporated with the metal complex. The obtained specific capacitance ranged from 69.7 to 77.6 F/g. The energy and power densities became stable from 7.8 to 8.5 Wh/kg and 1041.7 to 248.2 W/kg, respectively, as the EDLC finalized the cycles.

Electrochemical Characteristics of Glycerolized PEO-Based Polymer Electrolytes

In this article, poly(ethylene oxide)-based polymer electrolyte films doped with ammonium iodide (NH4I) and plasticized with glycerol were provided by a solution casting method. In the unplasticized system, the maximum ionic conductivity of 3.96 × 10-5 S cm-1 was achieved by the electrolyte comprised of 70 wt. % PEO:30 wt. % NH4I. The conductivity was further enhanced up to (1.77×10-4 S cm-1) for the plasticized system when 10 wt. % glycerol was added to the highest conducting unplasticized one at ambient temperature. The films were characterized by various techniques to evaluate their electrochemical performance. The results of impedance spectroscopy revealed that bulk resistance (Rb) considerably decreased for the highest plasticized polymer electrolyte. The dielectric properties and electric modulus parameters were studied in detail. The LSV analysis verified that the plasticized system can be used in energy storage devices with electrochemical stability up to 1.09 V and the TNM data elucidated that the ions were the main charge carrier. The values of the ion transference number (tion) and electron transfer number (tel) were calculated. The nonappearance of any redox peaks in the cyclic voltammograms indicated that the chemical reaction had not occurred at the electrode/electrolyte interface.

Structural, Morphological, Electrical and Electrochemical Properties of PVA: CS-Based Proton-Conducting Polymer Blend Electrolytes

Polymer blend electrolytes based on poly(vinyl alcohol):chitosan (PVA:CS) incorporated with various quantities of ammonium iodide were prepared and characterized using a range of electrochemical, structural and microscopic techniques. In the structural analysis, X-ray diffraction (XRD) was used to confirm the buildup of the amorphous phase. To reveal the effect of dopant addition on structural changes, field-emission scanning electron microscope (FESEM) was used. The protrusions of salt aggregates with large quantity were seen at the surface of the formed films at 50 wt.% of the added salt. The nature of the relationship between conductivity and dielectric properties was shown using electrochemical impedance spectroscopy (EIS). The EIS spectra were fitted with electrical equivalent circuits (EECs). It was observed that both dielectric constant and dielectric loss were high in the low-frequency region. For all samples, loss tangent and electric modulus plots were analyzed to become familiar with the relaxation behavior. Linear sweep voltammetry (LSV) and transference number measurement (TNM) were recorded. A relatively high cut-off potential for the polymer electrolyte was obtained at 1.33 V and both values of the transference number for ion (t_ion) and electronic (t_elec) showed the ion dominant as charge carrier species. The TNM and LSV measurements indicate the suitability of the samples for energy storage application if their conductivity can be more enhanced.

Design of Polymer Blends Based on Chitosan:POZ with Improved Dielectric Constant for Application in Polymer Electrolytes and Flexible Electronics

There is a considerable demand for the development and application of polymer materials in the flexible electronic- and polymer-based electrolyte technologies. Chitosan (CS) and poly(2-ethyl-2-oxazoline) (POZ) materials were blended with different ratios to obtain CS:POZ blend films using a straightforward solution cast technique. The work was involved a range of characteristic techniques, such as impedance spectroscopy, X-ray diffraction (XRD), and optical microscopy. From the XRD spectra, an enhancement in the amorphous nature in CS:POZ blend films was revealed when compared to the pure state of CS. The enhancement was verified from the peak broadening in CS:POZ blend films in relative to the one in crystalline peaks of the CS polymer. The optical micrograph study was used to designate the amorphous and crystalline regions by assigning dark and brilliant phases, respectively. Upon increasing POZ concentration, the dielectric constant was found to increase up to ɛ′ = 6.48 (at 1 MHz) at 15 wt.% of POZ, and then a drop was observed beyond this amount. The relatively high dielectric constant and dielectric loss were found at elevated temperatures. The increase of POZ concentration up to 45 wt.% made the loss tangent to shift to the lower frequency side, which is related to increasing resistivity. The increases of dielectric constant and dielectric loss with temperature were attributed to the increase of polarisation. The loss tangent peaks were found to shift to the higher frequency side as temperature elevated. Obvious relaxation peaks were observed in the imaginary part of electric modulus, and no peaks were found in the dielectric loss spectra. The concentration dependent of M″ peaks was found to follow the same trend of loss tangent peaks versus POZ content. The relaxation process was studied in terms of electric modulus parameters.

Fabrication of Interconnected Plasmonic Spherical Silver Nanoparticles with Enhanced Localized Surface Plasmon Resonance (LSPR) Peaks Using Quince Leaf Extract Solution

Interconnected spherical metallic silver nanoparticles (Ag NPs) were synthesized in the current study using a green chemistry method. The reduction of silver ions to Ag NPs was carried out with low-cost and eco-friendly quince leaves. For the first time, it was confirmed that the extract solution of quince leaves could be used to perform green production of Ag NPs. Fourier transform infrared spectroscopy (FTIR) was conducted to identify the potential biomolecules that were involved in the Ag NPs. The results depicted that the biosynthesis of Ag NPs through the extract solution of quince leaf was a low-cost, clean, and safe method, which did not make use of any contaminated element and hence, had no undesirable effects. The majority of the peaks in the FTIR spectrum of quince leaf extracts also emerged in the FTIR spectrum of Ag NPs but they were found to be of less severe intensity. The silver ion reduction was elaborated in detail on the basis of the FTIR outcomes. In addition, through X-ray diffraction (XRD) analysis, the Ag NPs were also confirmed to be crystalline in type, owing to the appearance of distinct peaks related to the Ag NPs. The creation of Ag NPs was furthermore confirmed by using absorption spectrum, in which a localized surface plasmon resonance (LSPR) peak at 480 nm was observed. The LSPR peak achieved in the present work was found to be of great interest compared to those reported in literature. Field emission scanning electron microscopy (FESEM) images were used to provide the morphology and grain size of Ag NPs. It was shown from the FESEM images that the Ag NPs had interconnected spherical morphology.

Ion Transport Study in CS: POZ Based Polymer Membrane Electrolytes Using Trukhan Model

In this work, analysis of ion transport parameters of polymer blend electrolytes incorporated with magnesium trifluoromethanesulfonate (Mg(CF₃SO₃)₂) was carried out by employing the Trukhan model. A solution cast technique was used to obtain the polymer blend electrolytes composed of chitosan (CS) and poly (2-ethyl-2-oxazoline) (POZ). From X-ray diffraction (XRD) patterns, improvement in amorphous phase for the blend samples has been observed in comparison to the pure state of CS. From impedance plot, bulk resistance (R_b) was found to decrease with increasing temperature. Based on direct current (DC) conductivity (σ_dc) patterns, considerations on the ion transport models of Arrhenius and Vogel–Tammann–Fulcher (VTF) were given. Analysis of the dielectric properties was carried out at different temperatures and the obtained results were linked to the ion transport mechanism. It is demonstrated in the real part of electrical modulus that chitosan-salt systems are extremely capacitive. The asymmetric peak of the imaginary part (M_i) of electric modulus indicated that there is non-Debye type of relaxation for ions. From frequency dependence of dielectric loss (ε″) and the imaginary part (M_i) of electric modulus, suitable coupling among polymer segmental and ionic motions was identified. Two techniques were used to analyze the viscoelastic relaxation dynamic of ions. The Trukhan model was used to determine the diffusion coefficient (D) by using the frequency related to peak frequencies and loss tangent maximum heights (tanδ_max). The Einstein–Nernst equation was applied to determine the carrier number density (n) and mobility. The ion transport parameters, such as D, n and mobility (μ), at room temperature, were found to be 4 × 10⁻⁵ cm²/s, 3.4 × 10¹⁵ cm⁻³, and 1.2 × 10⁻⁴ cm²/Vs, respectively. Finally, it was shown that an increase in temperature can also cause these parameters to increase.

The Anodic Behaviour of Bulk Copper in Ethaline and 1-Butyl-3-Methylimidazolium Chloride

The anodic dissolution of bulk metallic copper was conducted in ionic liquids (ILs)—a deep eutectic solvent (DES) ((CH3)3NC2H4OH) comprised of a 1:2 molar ratio mixture of choline chloride Cl (ChCl), and ethylene glycol (EG)—and imidazolium-based ILs, such as C4mimCl, using electrochemical techniques, such as cyclic voltammetry, anodic linear sweep voltammetry, and chronopotentiometry.To investigate the electrochemical dissolution mechanism, electrochemical impedance spectroscopy (EIS) was used. In addition to spectroscopic techniques, for instance, UV-visible spectroscopy, microscopic techniques, such as atomic force microscopy (AFM), were used. The significant industrial importance of metallic copper has motivated several research groups to deal with such an invaluable metal. It was confirmed that the speciation of dissolved copper from the bulk phase at the interface region is [CuCl3]− and [CuCl4]2− in such chloride-rich media, and the EG determine the structure of the interfacial region in the electrochemical dissolution process. A super-saturated solution was produced at the electrode/solution interface and CuCl2 was deposited on the metal surface.

Employing of Trukhan Model to Estimate Ion Transport Parameters in PVA Based Solid Polymer Electrolyte

In the current paper, ion transport parameters in poly (vinyl alcohol) (PVA) based solid polymer electrolyte were examined using Trukhan model successfully. The desired amount of lithium trifluoromethanesulfonate (LiCF₃SO₃) was dissolved in PVA host polymer to synthesis of solid polymer electrolytes (SPEs). Ion transport parameters such as mobility (μ), diffusion coefficient (D), and charge carrier number density (n) are investigated in detail using impedance spectroscopy. The data results from impedance plots illustrated a decrement of bulk resistance with an increase in temperature. Using electrical equivalent circuits (EEC), electrical impedance plots (ZivsZr) are fitted at various temperatures. The results of impedance study demonstrated that the resistivity of the sample decreases with increasing temperature. The decrease of resistance or impedance with increasing temperature distinguished from Bode plots. The dielectric constant and dielectric loss values increased with an increase in temperature. The loss tangent peaks shifted to higher frequency region and the intensity increased with an increase in temperature. In this contribution, ion transport as a complicated subject in polymer physics is studied. The conductivity versus reciprocal of temperature was found to obey Arrhenius behavior type. The ion transport mechanism is discussed from the tanδ spectra. The ion transport parameters at ambient temperature are found to be 9 × 10⁻⁸ cm²/s, 0.8 × 10¹⁷ cm⁻³, and 3 × 10⁻⁶ cm²/Vs for D, n, andμ respectively. All these parameters have shown increasing as temperature increased. The electric modulus parameters are studied in an attempt to understand the relaxation dynamics and to clarify the relaxation process and ion dynamics relationship.