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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. [ABSTRACT FROM AUTHOR]

In this report, the preparation of solid polymer electrolytes (SPEs) is performed from polyvinyl alcohol, methyl cellulose (PVA-MC), and ammonium chloride (NH4Cl) using solution casting methodology for its use in electrical double layer capacitors (EDLCs). The characterizations of the prepared electrolyte are conducted using a variety of techniques, including Fourier transform infrared spectroscopy (FTIR), electrical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV). The interaction between the polymers and NH4Cl salt are assured via FTIR. EIS confirms the possibility of obtaining a reasonably high conductance of the electrolyte of 1.99 × 10−3 S/cm at room temperature. The dielectric response technique is applied to determine the extent of the ion dissociation of the NH4Cl in the PVA-MC-NH4Cl systems. The appearance of a peak in the imaginary part of the modulus study recognizes the contribution of chain dynamics and ion mobility. Transference number measurement (TNM) is specified and is found to be (tion) = 0.933 for the uppermost conducting sample. This verifies that ions are the predominant charge carriers. From the LSV study, 1.4 V are recorded for the relatively high-conducting sample. The CV curve response is far from the rectangular shape. The maximum specific capacitance of 20.6 F/g is recorded at 10 mV/s. [ABSTRACT FROM AUTHOR]

The aim of this study is to synthesize Li1+xAlxTixSn2−2x(PO4) sodium super ion conductor (NASICON) -based ceramic solid electrolyte and to study the effect of dual metal substitution on the electrical and structural properties of the electrolyte. The performance of the electrolyte is analyzed based on the sintering temperature (550 to 950 °C) as well as the composition. The trend of XRD results reveals the presence of impurities in the sample, and from Rietveld Refinement, the purest sample is achieved at a sintering temperature of 950 °C and when x = 0.6. The electrolytes obey Vegard′s Law as the addition of Al3+ and Ti4+ provide linear relation with cell volume, which signifies a random distribution. The different composition has a different optimum sintering temperature at which the highest conductivity is achieved when the sample is sintered at 650 °C and x = 0.4. Field emission scanning electron microscope (FESEM) analysis showed that higher sintering temperature promotes the increment of grain boundaries and size. Based on energy dispersive X-ray spectroscopy (EDX) analysis, x = 0.4 produced the closest atomic percentage ratio to the theoretical value. Electrode polarization is found to be at maximum when x = 0.4, which is determined from dielectric analysis. The electrolytes follow non-Debye behavior as it shows a variety of relaxation times. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The preparation of a dextran (Dex)-hydroxyethyl cellulose (HEC) blend impregnated with ammonium bromide (NH4Br) is done via the solution cast method. The phases due to crystalline and amorphous regions were separated and used to estimate the degree of crystallinity. The most amorphous blend was discovered to be a blend of 40 wt% Dex and 60 wt% HEC. This polymer blend serves as the channel for ions to be conducted and electrodes separator. The conductivity has been optimized at (1.47 ± 0.12) × 10−4 S cm−1 with 20 wt% NH4Br. The EIS plots were fitted with EEC circuits. The DC conductivity against 1000/T follows the Arrhenius model. The highest conducting electrolyte possesses an ionic number density and mobility of 1.58 × 1021 cm−3 and 6.27 × 10−7 V−1s−1 cm2, respectively. The TNM and LSV investigations were carried out on the highest conducting system. A non-Faradic behavior was predicted from the CV pattern. The fabricated electrical double layer capacitor (EDLC) achieved 8000 cycles, with a specific capacitance, internal resistance, energy density, and power density of 31.7 F g−1, 80 Ω, 3.18 Wh kg−1, and 922.22 W kg−1, respectively. [ABSTRACT FROM AUTHOR]

In this research, a biopolymer-based electrolyte system involving methylcellulose (MC) as a host polymeric material and potassium iodide (KI) salt as the ionic source was prepared by solution cast technique. The electrolyte with the highest conductivity was used for device application of electrochemical double-layer capacitor (EDLC) with high specific capacitance. The electrical, structural, and electrochemical characteristics of the electrolyte systems were investigated using various techniques. According to electrochemical impedance spectroscopy (EIS), the bulk resistance (Rb) decreased from 3.3 × 105 to 8 × 102 Ω with the increase of salt concentration from 10 wt % to 40 wt % and the ionic conductivity was found to be 1.93 ×10−5 S/cm. The dielectric analysis further verified the conductivity trends. Low-frequency regions showed high dielectric constant, ε′ and loss, ε″ values. The polymer-salt complexation between (MC) and (KI) was shown through a Fourier transformed infrared spectroscopy (FTIR) studies. The analysis of transference number measurement (TNM) supported ions were predominantly responsible for the transport process in the MC-KI electrolyte. The highest conducting sample was observed to be electrochemically constant as the potential was swept linearly up to 1.8 V using linear sweep voltammetry (LSV). The cyclic voltammetry (CV) profile reveals the absence of a redox peak, indicating the presence of a charge double-layer between the surface of activated carbon electrodes and electrolytes. The maximum specific capacitance, Cs value was obtained as 118.4 F/g at the sweep rate of 10 mV/s. [ABSTRACT FROM AUTHOR]

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%). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In the present work, chitosan (CS) as a natural biopolymer was used to prepare nanocomposite polymer electrolytes (NCPEs) in order to reduce plastic waste pollution. The plasticized CS-based NCSPE has been prepared via the solution casting technique. The electrical properties of the films were investigated using AC conductivity, dielectric properties, electric modulus, and electrical impedance spectroscopy (EIS). The obtained results from the dielectric properties and electric modulus study confirm the non-Debye behavior of ion dynamics. The effect of glycerol plasticizer on ionic conductivity of the CS:AgNO3:Al2O3 system was investigated via AC conductivity and impedance studies. The conductivity of the samples was explained based on electrical equivalent circuits and Bode plots. The electrochemical properties such as transfer number measurement (TNM), linear sweep voltammetry (LSV), and cyclic voltammetry (CV) were carried out to inspect the sample suitability for electrochemical double-layer capacitor (EDLC) application. The highest conductivity was 3.7 × 10−4 S cm−1 with the electrochemical stability window up to 2.1 V at room temperature. Through the TNM study, the ionic conductivity of plasticized CS-based NCSPE was confirmed, and ion transport (tion) of the highest conducting sample was found to be 0.985. The activated carbon electrode with the highest conducting sample was employed in the EDLC device fabrication. Accordingly, it can be said that the highest conducting sample had capable performance to be applied in electrochemical device application. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 (tion) and electrons (te) were measured for two of the highest conducting electrolyte systems. It confirmed that the ions were the dominant charge carriers in both systems as tion 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. [ABSTRACT FROM AUTHOR]

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 tel (0.044) < tion (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. [ABSTRACT FROM AUTHOR]

This report presents the preparation and characterizations of solid biopolymer blend electrolyte films of chitosan as cationic polysaccharide and anionic dextran (CS: Dextran) doped with ammonium iodide (NH4I) to be utilized as electrolyte and electrode separator in electrical double-layer capacitor (EDLC) devices. FTIR and XRD techniques were used to study the structural behavior of the films. From the FTIR band analysis, shifting and broadening of the bands were observed with increasing salt concentration. The XRD analysis indicates amorphousness of the blended electrolyte samples whereby the peaks underwent broadening. The analysis of the impedance spectra emphasized that incorporation of 40 wt.% of NH4I salt into polymer electrolyte exhibited a relatively high conductivity (5.16 × 10−3 S/cm). The transference number measurement (TNM) confirmed that ion (tion = 0.928) is the main charge carriers in the conduction process. The linear sweep voltammetry (LSV) revealed the extent of durability of the relatively high conducting film which was 1.8 V. The mechanism of charge storage within the fabricated EDLC has been explained to be fully capacitive behavior with no redox peaks appearance in the cyclic voltammogram (CV). From this findings, four important parameters of the EDLC; specific capacitance, equivalent series resistance, energy density and power density were calculated as 67.5 F/g, 160 ohm, 7.59 Wh/kg and 520.8 W/kg, respectively. [ABSTRACT FROM AUTHOR]

In this report, a facile solution casting technique was used to fabricate polymer blend electrolytes of chitosan (CS):poly (ethylene oxide) (PEO):NH4SCN with high electrochemical stability (2.43V). Fourier transform infrared (FTIR) spectroscopy was used to investigate the polymer electrolyte formation. For the electrochemical property analysis, cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) techniques were carried out. Referring to the FTIR spectra, a complex formation between the added salt and CS:PEO was deduced by considering the decreasing and shifting of FTIR bands intensity in terms of functional groups. The CS:PEO:NH4SCN electrolyte was found to be electrochemically stable as the applied voltage linearly swept up to 2.43V. The cyclic voltammogram has presented a wide potential window without showing any sign of redox peaks on the electrode surface. The proved mechanisms of charge storage in these fabricated systems were found to be double layer charging. The EIS analysis showed the existence of bulk resistance, wherein the semicircle diameter decreased with increasing salt concentration. The calculated maximum DC conductivity value was observed to be 2.11 × 10−4 S/cm for CS:PEO incorporated with 40 wt% of NH4SCN salt. The charged species in CS:PEO:NH4SCN electrolytes were considered to be predominantly ionic in nature. This was verified from transference number analysis (TNM), in which ion and electron transference numbers were found to be tion = 0.954 and tel = 0.045, respectively. The results obtained for both ion transference number and DC conductivity implied the possibility of fabricating electrolytes for electrochemical double layer capacitor (EDLC) device application. The specific capacitance of the fabricated EDLC was obtained from the area under the curve of the CV plot. [ABSTRACT FROM AUTHOR]

Solid polymer blend electrolyte membranes (SPBEM) composed of chitosan and dextran with the incorporation of various amounts of lithium perchlorate (LiClO4) were synthesized. The complexation of the polymer blend electrolytes with the salt was examined using FTIR spectroscopy and X-ray diffraction (XRD). The morphology of the SPBEs was also investigated using field emission scanning electron microscopy (FESEM). The ion transport behavior of the membrane films was measured using impedance spectroscopy. The membrane with highest LiClO4 content was found to exhibit the highest conductivity of 5.16 × 10−3 S/cm. Ionic (ti) and electronic (te) transference numbers for the highest conducting electrolyte were found to be 0.98 and 0.02, respectively. Electrochemical stability was estimated from linear sweep voltammetry and found to be up to ~2.3V for the Li+ ion conducting electrolyte. The only existence of electrical double charging at the surface of electrodes was evidenced from the absence of peaks in cyclic voltammetry (CV) plot. The discharge slope was observed to be almost linear, confirming the capacitive behavior of the EDLC. The performance of synthesized EDLC was studied using CV and charge–discharge techniques. The highest specific capacitance was achieved to be 8.7 F·g−1 at 20th cycle. The efficiency (η) was observed to be at 92.8% and remained constant at 92.0% up to 100 cycles. The EDLC was considered to have a reasonable electrode-electrolyte contact, in which η exceeds 90.0%. It was determined that equivalent series resistance (Resr) is quite low and varies from 150 to 180 Ω over the 100 cycles. Energy density (Ed) was found to be 1.21 Wh·kg−1 at the 1st cycle and then remained stable at 0.86 Wh·kg−1 up to 100 cycles. The interesting observation is that the value of Pd increases back to 685 W·kg−1 up to 80 cycles. [ABSTRACT FROM AUTHOR]

Compatible green polymer electrolytes based on methyl cellulose (MC) were prepared for energy storage electrochemical double-layer capacitor (EDLC) application. X-ray diffraction (XRD) was conducted for structural investigation. The reduction in the intensity of crystalline peaks of MC upon the addition of sodium iodide (NaI) salt discloses the growth of the amorphous area in solid polymer electrolytes (SPEs). Impedance plots show that the uppermost conducting electrolyte had a smaller bulk resistance. The highest attained direct current DC conductivity was 3.01 × 10 -3 S/cm for the sample integrated with 50 wt.% of NaI. The dielectric analysis suggests that samples in this study showed non-Debye behavior. The electron transference number was found to be lower than the ion transference number, thus it can be concluded that ions are the primary charge carriers in the MC-NaI system. The addition of a relatively high concentration of salt into the MC matrix changed the ion transfer number from 0.75 to 0.93. From linear sweep voltammetry (LSV), the green polymer electrolyte in this work was actually stable up to 1.7 V. The consequence of the cyclic voltammetry (CV) plot suggests that the nature of charge storage at the electrode-electrolyte interfaces is a non-Faradaic process and specific capacitance is subjective by scan rates. The relatively high capacitance of 94.7 F/g at a sweep rate of 10 mV/s was achieved for EDLC assembly containing a MC-NaI system., Competing Interests: The authors declare no conflicts of interest.

This research paper investigates the electrochemical performance of chitosan (CS): dextran (DX) polymer-blend electrolytes (PBEs), which have been developed successfully with the incorporation of ammonium hexafluorophosphate (NH 4 PF 6 ). X-ray diffraction (XRD) analysis indicates that the plasticized electrolyte system with the highest value of direct current (DC) ionic conductivity is the most amorphous system. The glycerol addition increased the amorphous phase and improved the ionic dissociation, which contributed to the enhancement of the fabricated device's performance. Transference number analysis (TNM) has shown that the charge transport process is mainly by ions rather than electrons, as t ion = 0.957. The CS:DX:NH 4 system was found to decompose as the voltage goes beyond 1.5 V. Linear sweep voltammetry (LSV) revealed that the potential window for the most plasticized system is 1.5 V. The fabricated electrochemical double-layer capacitor (EDLC) was analyzed with cyclic voltammetry (CV) and charge-discharge analysis. The results from CV verify that the EDLC in this work holds the characteristics of a capacitor. The imperative parameters of the fabricated EDLC such as specific capacitance and internal resistance were found to be 102.9 F/g and 30 Ω, respectively. The energy stored and power delivered by the EDLC were 11.6 Wh/kg and 2741.2 W/kg, respectively.6 system was found to decompose as the voltage goes beyond 1.5 V. Linear sweep voltammetry (LSV) revealed that the potential window for the most plasticized system is 1.5 V. The fabricated electrochemical double-layer capacitor (EDLC) was analyzed with cyclic voltammetry (CV) and charge-discharge analysis. The results from CV verify that the EDLC in this work holds the characteristics of a capacitor. The imperative parameters of the fabricated EDLC such as specific capacitance and internal resistance were found to be 102.9 F/g and 30 Ω, respectively. The energy stored and power delivered by the EDLC were 11.6 Wh/kg and 2741.2 W/kg, respectively.

In this study, plasticized films of polyvinyl alcohol (PVA): chitosan (CS) based electrolyte impregnated with ammonium thiocyanate (NH 4 SCN) were successfully prepared using a solution-casting technique. The structural features of the electrolyte films were investigated through the X-ray diffraction (XRD) pattern. The enrichment of the amorphous phase with increasing glycerol concentration was confirmed by observing broad humps. The electrical impedance spectroscopy (EIS) portrays the improvement of ionic conductivity from 10 -5 S/cm to 10 -3 S/cm upon the addition of plasticizer. The electrolytes incorporated with 28 wt.% and 42 wt.% of glycerol were observed to be mainly ionic conductor as the ionic transference number measurement (TNM) was found to be 0.97 and 0.989, respectively. The linear sweep voltammetry (LSV) investigation indicates that the maximum conducting sample is stable up to 2 V. An electrolyte with the highest conductivity was used to make an energy storage electrical double-layer capacitor (EDLC) device. The cyclic voltammetry (CV) plot depicts no distinguishable peaks in the polarization curve, which means no redox reaction has occurred at the electrode/electrolyte interface. The fabricated EDLC displays the initial specific capacitance, equivalent series resistance, energy density, and power density of 35.5 F/g, 65 Ω, 4.9 Wh/kg, and 399 W/kg, respectively.

In the present work, a novel polymer composite electrolytes (PCEs) based on poly(vinyl alcohol) (PVA): ammonium thiocyanate (NH 4 SCN): Cd(II)-complex plasticized with glycerol (Gly) are prepared by solution cast technique. The film structure was examined by XRD and FTIR routes. The utmost ambient temperature DC ionic conductivity ( σ DC ) of 2.01 × 10 -3 S cm -1 is achieved. The film morphology was studied by field emission scanning electron microscopy (FESEM). The trend of σ DC is further confirmed with investigation of dielectric properties. Transference numbers of ions ( t ion ) and electrons ( t el ) are specified to be 0.96 and 0.04, respectively. Linear sweep voltammetry (LSV) displayed that the PCE potential window is 2.1 V. The desired mixture of activated carbon (AC) and carbon black was used to fabricate the electrodes of the EDLC. Cyclic voltammetry (CV) was carried out by sandwiching the PCEs between two carbon-based electrodes, and it revealed an almost rectangular shape. The EDLC exhibited specific capacitance, energy density, and equivalent series resistance with average of 160.07F/g, 18.01Wh/kg, and 51.05Ω, respectively, within 450 cycles. The EDLC demonstrated the initial power density as 4.065 × 10 3 W/Kg.

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 NH 4 BF 4 ammonium 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 × 10 4 ohm to 0.7 × 10 5 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 (C 2 ) 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.

In this study, the solution casting method was employed to prepare plasticized polymer electrolytes of chitosan (CS):LiCO 2 CH 3 :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 .