Polymer Blend Electrolytes Research Articles

Improving supercapacitor performance with novel potato starch-PVA solid polymer electrolyte blend modified by sodium perchlorate-glycerol additives

The synthesis and analysis of Solid Polymer Electrolytes (SPEs) derived from a blend of Potato Starch and Poly Vinyl Alcohol (PS-PVA), enhanced with Sodium perchlorate salt (NaClO4) and Glycerol (GCL) are explored in this work. Our focus is on their suitability for Electrical Double-Layer Capacitor (EDLC) devices. GCL, a non-toxic substance, served as the plasticizer, and sodium perchlorate was incorporated to enhance the ionic conductivity of the SPE film. The conductivity at room temperature for pure PS-PVA blend, in the absence of salt and GCL, was found to be 4.16 × 10−8 S cm−1. Upon adding an optimized quantity of NaClO4 salt, the conductivity increased to 1.02 × 10−5 S cm−1. Subsequent plasticization of the salt-polymer blend with GCL induced NaClO4 dissociation, further augmenting the conductivity by one order of magnitude. A conductivity value of 10.35 × 10−5 S cm−1 was achieved for the film with 30 wt% GCL. Morphological, electrical, and structural analyses revealed that synthesized polymer films exhibited favorable characteristics. The suitability of these electrolytes for Electric Double-Layer Capacitors (EDLC) was studied using electrochemical characterizations and cycling tests for 2000 cycles. The findings demonstrate their potential for use in energy storage devices, showcasing excellent performance in specific capacitance, energy, and power densities.

Ion Conduction Mechanism in Polymer Blend Electrolyte Films

AbstractThis paper presents the development of the blend polymer solid electrolyte films (BPSE) for potential applications in electrochemical devices. Two host polymers, polyvinyl alcohol (PVA) and polymethyl methacrylate (PMMA), along with the salt KI, are employed to create the solid polymer electrolytes (SPEs). The synthesis involves varying the weight percentage of salt within the SPEs to investigate its impact on the material properties. Conductivity measurements are conducted using AC impedance spectroscopy, unveiling the conductivity behavior of the BPSEs. Additionally, surface morphology is characterized using polarized optical microscopy (POM) at 10 pixel resolution, offering a detailed examination of the film's microstructure. This comprehensive study not only contributes to the understanding of the fundamental properties of BPSEs but also opens avenues for their utilization in various electrochemical applications.

Flexible magnesium-ion-conducting solid poly-blend electrolyte films for magnesium-ion batteries

Solid biodegradable polymer electrolyte systems are considered the optimal choice for energy storage devices because they are both cost-effective and energy-efficient. A solid blend polymer electrolyte (SBPE) membrane capable of transporting magnesium ions was prepared using a mixture of 70 wt% methylcellulose, 30 wt% chitosan, and varying wt% magnesium perchlorate salt. X-ray diffraction analysis revealed an increase in the amorphous nature caused by the inclusion of Mg(ClO4)2 salt in the polymer blend matrix. A Fourier transform infrared spectroscopy study of samples containing varying salt concentrations revealed secondary interactions between polymer segments and salt, which provides the basis for energy density. Moreover, through impedance analysis, it was determined that the bulk resistance decreased with increasing salt concentration. The SBPE containing 30 wt% magnesium perchlorate exhibited the highest ionic conductivity, with a value of 2.49 × 10–6 S cm−1. A comprehensive evaluation of the ion transport parameters, including mobility, carrier density, and diffusion, was conducted for the prepared electrolyte samples. Notably, an ionic transference number (tion) of approximately 0.83 was observed for the SBPE sample with 30 wt% magnesium salt, indicating ions’ prevalence as the system’s primary charge carriers. Electrochemical analyses demonstrated that the SBPE with the highest ion conductivity possessed an electrochemical stability window (ESW) of 1.92 V. Additionally, the thermal characteristics of the samples were evaluated using thermogravimetric analysis (TGA) to assess the thermal stability of the electrolyte. Finally, the highest conducting polymer electrolyte was employed to construct a primary magnesium battery, and its discharge profile with different cathode materials was studied. Based on these findings, the current study suggests an environmentally friendly, biodegradable, and economically viable electrolyte option suitable for separator cum electrolytes in magnesium-ion batteries.

Development of Eco‐Friendly Chitosan‐Dextran Polyblend Electrolyte for Enhanced Performance in Primary Magnesium Batteries

The potential of next‐generation batteries lies in solid biodegradable polymer electrolytes. This research delves into a solid blend polymer electrolyte (SBPE) for magnesium conduction, utilizing a chitosan‐dextran blend matrix doped with magnesium perchlorate (Mg(ClO4)2) salt. The electrolyte films are prepared using a conventional solution casting technique. Through techniques like X‐ray diffraction and Fourier transform infrared spectroscopy, the successful incorporation of Mg(ClO4)2 into the blend matrix is confirmed. Notably, the SBPE containing 30 wt% of Mg(ClO4)2 demonstrates the highest ionic conductivity of 6.99 × 10−4 S cm−1 and a prominent ionic transference number of 0.84. Thermogravimetric analysis is carried out to study thermal stability. Differential scanning calorimetry analysis of the electrolyte systems gives insight into their thermal properties. Additionally, it showcases favorable electrochemical stability of 2.66 V. The oxidation and reduction peaks are observed in the cyclic voltammetry curve of the highest conducting sample. Furthermore, the discharge performance of Mg/(CS + DN + Mg(ClO4)2)/cathode cells is explored with varied cathode materials, illustrating the SBPE's potential for magnesium‐ion batteries. This study unveils a sustainable, biodegradable, and economical electrolyte solution for advanced energy storage systems.

Studies on ionic conductivity, linear and non-linear optical properties of ecofriendly methyl cellulose: sodium bromide based solid polymer blend electrolytes

Biopolymer electrolytes based on methyl cellulose (MC) and sodium bromide(NaBr) have been prepared through solvent casting technique. Both the concentrations of MC and NaBr are varied. The prepared biopolymer electrolytes have been subjected to AC impedance and UV-Vis spectroscopic techniques. The ionic conductivity reached a maximum value of 4.84 × 10−8 Scm−1 for 0.8 g of MC and 0.2 g of NaBr. UV studies revealed that low direct and indirect band gaps have been observed for the maximum ionic conducting sample. Other optical parameters, such as refractive index, extinction coefficient, skin depth, and optical conductivity, have been estimated. The single-oscillator energy (Eo ) and dispersion energy (Ed ) for all the prepared biopolymer electrolyte samples were calculated with the help of Wemple and DiDomenico single oscillator model. The higher-order non-linear susceptibility values were also calculated. Polymer electrolytes are found to be suitable for optical and electronic devices.

Ionic liquid based NCPBE membranes for electrochemical capacitor applications: Structural, thermal and electrical transport properties

The current study focuses on the preparation and characterisation of imidazolium ionic liquid based plasticized nano-composite polymer blend electrolytes (NCPBEs). Semi-crystalline nature of the synthesized samples was observed using XRD analysis. ATR-FTIR results demonstrate the interaction among the carbonyl (CO) and hydroxyl (O–H) groups of polymers with ionic liquid (IL) and salt, NaI. Furthermore, thermo-gravimetric analysis (TGA) indicates multi-step decomposition process. Ion transport mechanism has been analysed using temperature dependent conductivity analysis, ac conductivity analysis and dielectric properties study. The sample containing 25 wt% IL i.e. NCPBE-25 has the ionic conductivity ∼9.30 × 10−4 Scm−1 with the optimum vale of charge carrier density, mobility, and ion diffusivity at 30oC. Ions are principal charge carriers in the present electrolytes. The sample NCPBE-25 has the electro-chemical stability window −3.6 to 1.5 V at room temperature. The fabricated electro-chemical capacitor has the specific capacitance, energy density and power density 363.27 Fg-1, 50.45 Whkg−1 and 18.16 kW/kg, respectively at the scan rate 5 mV/s.

AC Impedance Analysis of Blend Polymer Electrolyte of PVP – PPA with Magnesium Salts as an Ionic Dopant for Potential Battery Applications

Abstract Solid polymer electrolyte films containing blend polymer electrolyte of Polyvinylpyrrolidone (PVP) and Poly p - amino benzoic acid (PPA) with varying ratios of magnesium salts were synthesized by solution casting method. Their conduction and relaxation mechanisms were studied by impedance spectroscopy (AC) at room temperature. The dependence of electrical data on frequency was analyzed by Cole – Cole plot and Jonscher’s power law. The semicircle seen in the plot represents the double relaxation process and shows how bulk electrolyte and the interfacial effect contribute to non-Debye and electrical conduction. The ac and dc conductivity values were calculated and the conductivity variation for the blend polymer PVP – PPA doped with different concentrations of magnesium salts was explained by the ionic contribution of the electrolytes. The dielectric constant and dielectric loss were measured by the dielectric investigations. The relaxation phenomenon of these electrolytes is provided by the dissipation factor analysis and electric modulus value. The conductivity of the system determines the suitability of the thin film concentration for potential battery applications as a polymer electrolyte.

Strategy on enhancing ionic conductivity of biocompatible hydroxypropylmethylcellulose/polyethylene glycol polymer blend electrolyte with TiO2 nanofillers and LiNO3 ionic salt

Strategy on enhancing ionic conductivity of biocompatible hydroxypropylmethylcellulose/polyethylene glycol polymer blend electrolyte with TiO2 nanofillers and LiNO3 ionic salt

The ionic conductivity and electrochemical performance of Alginate-PVA based polymer electrolyte with Li+ charge carriers for supercapacitor

This study presents the synthesis and characterization of solid polymer blend electrolytes (SPBEs) using alginate (Alg) and polyvinyl alcohol (PVA) as host polymers, incorporating lithium bis(trimethanesulfonyl)imide (LiTFSI) as the ion-providing salt for potential application in EDLCs. The surface morphology of the SPBEs was revealed using scanning electron microscopy (SEM), while thermal gravimetric analysis (TGA) demonstrates enhanced thermal stability, characterized by reduced weight loss and a shift toward higher decomposition temperature. Complexation between Alg-PVA and LiTFSI was indicated by Fourier-transform infrared spectroscopy (FTIR), as evident by the transitions and intensity changes in FTIR bands corresponding to functional groups. Increasing LiTFSI content reduces bulk resistance, with Alg-PVA containing 20 wt% LiTFSI (Li-20) showing maximum room temperature ionic conductivity (3.31 × 10-4 S cm−1) and the lowest activation energy (0.05 eV). Transport properties, analyzed using the Arof-Noor (A-N) method, reveal that ionic conductivity in SPBEs is governed by ionic mobility and ions’ diffusion coefficient. Sample Li-20 displays predominantly ionic transport with a transference number (tion) 0.98 and electrochemical stability up to 2.55 V. The EDLC, employing activated carbon electrodes and the most conductive electrolyte, demonstrates notable performance features, including specific capacitance (87.51F/g at 2 mV/s, assessed from CV), energy density (25.17 Wh kg−1), and power density (1038.92 W kg−1). Testing at various current densities reveals the highest specific capacitance values associated with the lowest current density, measuring 51.15F/g for the EDLC cell based on the Li-20 sample.

Safety enhanced novel polymer electrolytes for lithium-ion battery: Anomalous output performance with long term cycling stability by doping and polymer blending

Electrolyte with better safety and stability are the primary concern in the present lithium-ion battery (LIB) technology. Herein, a unique polymer blend electrolyte of polyvinylidene difluoride (PVdF)/poly (acrylonitrile butadiene styrene) (ABS) (75: 25) is fabricated by the non-solvent induced phase inversion method. The structural, morphological, and electrochemical performance of the PVdF/ABS blend is enhanced by incorporating the silica nanoparticles as the ceramic filler by the in-situ method. The gel polymer electrolyte (GPE) constitutes 6 wt % of in-situ synthesised silica in PVdF/ABS blend (PASI-06) exhibits better microporous structure with 80 % porosity. The thermal shrinkage, thermogravimetric analysis (TGA) and flammability test safeguards the exceptional thermal stability of the polymer membrane in LIBs. The polymer membrane activated in the liquid electrolyte (1 M LiPF6 in EC:EMC:DMC (1: 1: 1 v/v)) reveals an electrolyte uptake of 400 %, high electrolyte retention (0.82) and a room temperature ionic conductivity of 5.7 mS cm−1. The better oxidative stability exhibited by the PASI-06 (4.5 V) ensures its applicability with high voltage cathodes. Moreover, the electrochemical performance of the coin cell constitutes of Li/GPE/LFP able to exhibits an initial discharge capacity of 143 mAh g−1 and retained a capacity of 115 mAh g−1 even after 200 cycles at 0.1 C-rate at 25 °C. The long term cycling stability evaluated over 500 cycles at 1 C shows that the cell can exhibit an initial discharge capacity 120 mAh g−1 with 77 % capacity retention over 500 cycles that corresponds to 99 % of coulombic efficiency. These excellent performances exhibited by the PASI-06 GPE guarantee its applicability in thermally stable LIBs with better safety and reliability.

Plasticised chitosan: Dextran polymer blend electrolyte for energy harvesting application: Tuning the ion transport and EDLC charge storage capacity through TiO2 dispersion

This study investigates the performance of biopolymer electrolytes based on chitosan and dextran for energy storage applications. The optimization of ion transport and performance of electric double-layer capacitors EDCL using these electrolytes, incorporating different concentrations of glycerol as a plasticizer and TiO2 as nanoparticles, is explored. Impedance measurements indicate a notable reduction in charge transfer resistance with the addition of TiO2. DC conductivity estimates from AC spectra plateau regions reach up to 5.6 × 10−4 S/cm. The electric bulk resistance Rb obtained from the Nyquist plots exhibits a substantial decrease with increasing plasticizer concentration, further enhanced by the addition of the nanoparticles. Specifically, Rb decreases from ∼20 kΩ to 287 Ω when glycerol concentration increases from 10 % to 40 % and further drops to 30 Ω with the introduction of TiO2. Specific capacitance obtained from cyclic voltammetry shows a notable increase as the scan rate decreases, indicating improved efficiency and stability of ion transport. The TiO2-enriched EDCL achieves 12.3 F/g specific capacitance at 20 mV/s scan rate, with high ion conductivity and extended electrochemical stability. These results suggest the great potential of plasticizer and TiO2 with biopolymers in improving the performance of energy storage systems.

Enhancement of salt solubility in a PVDF-PEO-based solid blend polymer electrolyte by gamma irradiation: effects on ion dynamics and relaxation properties

Enhancement of salt solubility in a PVDF-PEO-based solid blend polymer electrolyte by gamma irradiation: effects on ion dynamics and relaxation properties

Optimization and investigation polyvinyl pyrrolidone/polyacrylamide (PVP/PAM) blend electrolytes via optimal mixture design

In this paper, polymer blend electrolytes (PBEs) composed of polyvinyl pyrrolidone/polyacrylamide blend hosts (PVP/PAM) and sodium chloride salt (NaCl) were prepared via solution casting techniques and their ionic conductivity was optimized. PBEs with the maximum conductivity were characterized using FTIR, TGA, LSV, and CV to investigate the interactions between the polymer blend host and the salts, the thermal stability and electrochemical window potential stability of the optimized PBEs. Moreover, PBEs were characterized by electrochemical impedance spectroscopy to investigate their ionic conductivity. The FTIR analysis showed that NaCl has been complexed with PVP/PAM blend host. It was found that the conductivity of PBEs were strongly dependent on the concentrations of salts and polymer blend hosts. The conductivity of the PBEs boosted with the increase in salt concentration up to its optimal concentration but the reverse is true in the case of polymer blend host concentrations. The PBEs composed of 86.5 wt% of PVP/PAM and 13.5 wt% of NaCl exhibited an appreciable conductivity of 1.722 × 10−6 S/cm at ambient temperature, which is close to the predicted conductivity of 1.766 × 10−6 S/cm. The dielectric constant and loss of the PBEs increased with the increase in salt concentrations up to their optimum content. The optimized PBEs did not exhibit oxidation and reduction peaks in the range of -3 V–3 V window potential at 25 °C and are thermally stable up to 240 °C. Hence, the electrochemical performance and thermal stability of the PBEs demonstrated that the PBEs could be employed as electrolytes for sodium batteries.

Harnessing melt processing for the preparation of mechanically robust thermoplastic vulcanizate electrolytes

We report a new type of polymer blend electrolyte based on the principle of thermoplastic vulcanizates (TPV). TPV materials have been extensively used in the automotive and manufacturing sectors. However, to the best of our knowledge, TPV-based electrolytes have yet to be produced. These electrolytes, obtained via melt-processing, combine the high ionic conductivity and processibility of a thermoplastic phase with the improved mechanical strength of a crosslinked elastomeric phase. TPV electrolytes prepared with poly(caprolactone) (PCL) (thermoplastic phase) and hydrogenated nitrile butadiene rubber (HNBR) (elastomeric phase) are presented in this work. These materials deliver promising results in terms of ionic conductivity, electrochemical stability and mechanical strength. Further improvements in ionic conductivity are obtained by doping the TPV electrolyte with a flame-retardant solvent, triethyl phosphate. The crosslinked nature of the TPV allows both mechanical strength and electrochemical stability to be conserved upon doping which is not possible in non-crosslinked polymer blend electrolytes prepared with PCL and HNBR.

Electrolytic performance of sodium alginate-poly vinyl alcohol matrix with ammonium bromide for proton conduction: Applications in electrochemical systems

Polymer blend electrolytes based on poly(vinyl alcohol) (PVA) and sodium alginate (NaAlg) were prepared using the solution casting method. These electrolytes were doped with varying amounts of ammonium bromide (NH4Br). The compatibility of NH4Br with PVA:NaAlg polymers was examined through X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) studies. The FTIR assessment confirmed the formation of a complex between PVA:NaAlg and the added salt, as evidenced by modifications and reductions in the intensity of FTIR bands related to functional groups. The conductivity and dielectric behavior of the samples were analyzed using AC impedance spectroscopy. The sample with 20 wt% of added salt exhibited a higher ionic conductivity of 1.661×10−5 Scm−1. Activation energy and relaxation time were estimated, and dielectric studies revealed a non-Debye nature. The conduction mechanism was best described by the correlated overlapping large polaron tunneling model (OLPT). The highest conducting sample was found to be suitable for electrochemical devices, as demonstrated by transference number (TNM), cyclic volumetric (CV), and linear sweep voltammetry (LSV) analyses. This high-conductivity sample can be employed in electrochemical devices such as EDLC. The cyclic voltammetry (CV) curve exhibited a nearly rectangular shape with non-faradaic peaks. GCD(Galvanostatic charge-discharge) analysis yielded specific capacitance, power density, and energy density values of 125.01 Fg−1, 1037 WKg−1, and 14.06 WhKg−1 respectively. These results indicate that polymer electrolytes show great promise as electrolytes in proton-conducting electrochemical devices.

Phase Morphology Dependence of Ionic Conductivity and Oxidative Stability in Fluorinated Ether Solid-State Electrolytes.

Solid-state polymer electrolytes can enable the safe operation of high energy density lithium metal batteries; unfortunately, they have low ionic conductivity and poor redox stability at electrode interfaces. Fluorinated ether polymer electrolytes are a promising approach because the ether units can solvate and conduct ions, while the fluorinated moieties can increase oxidative stability. However, current perfluoropolyether (PFPE) electrolytes exhibit deficient lithium-ion coordination and ion transport. Here, we incorporate cross-linked poly(ethylene glycol) (PEG) units within the PFPE matrix and increase the polymer blend electrolyte conductivity by 6 orders of magnitude as compared to pure PFPE at 60 °C from 1.55 × 10-11 to 2.26 × 10-5 S/cm. Blending varying ratios of PEG and PFPE induces microscale phase separation, and we show the impact of morphology on ion solvation and dynamics in the electrolyte. Spectroscopy and simulations show weak ion-PFPE interactions, which promote salt phase segregation into-and ion transport within-the PEG domain. These polymer electrolytes show promise for use in high-voltage lithium metal batteries with improved Li|Li cycling due to enhanced mechanical properties and high-voltage stability beyond 6 V versus Li/Li+. Our work provides insights into transport and stability in fluorinated polymer electrolytes for next-generation batteries.

Exploring the potential of poly (caprolactone) and guar gum biodegradable blend film: an investigation for supercapacitor

A biodegradable polymer electrolyte comprising poly (caprolactone) (PCL) and guar gum (GG) doped with lithium perchlorate (LiClO4) was investigated for its application in supercapacitors. The films’ thermal properties, surface morphology, and tensile strength were determined to understand the interaction between the blend system and the salt. Scanning electron microscopic images showed a network of GG channels across the polymer matrix. A unique combo of THF/water as solvent was used for this study as they bring out relaxation in GG segments and compatibility between GG and PCL. The blend polymer electrolyte (BPE) was characterized using conductivity, dielectric, and biodegradation studies. Supercapacitors were fabricated, and electrochemical studies were performed. The optimized BPE was used to fabricate supercapacitors, producing a specific capacitance of 125 F g−1. The time constant was measured at 0.8 s, and a consistent cyclic pattern was observed during galvanostatic charge/discharge studies with 96% Coulombic efficiency. This novel amalgamation of polymeric films holds immense promise for supercapacitor applications.

Novel approach: Simultaneous application of ionic liquid doped polymer electrolyte in supercapacitor and dye-sensitized solar cells

The present study reports the synthesis, characterization, and application as energy devices of an ionic liquid blended polymer electrolyte film in which the host polymer polyvinyl alcohol (PVA) is mixed with low viscosity ionic liquid (IL) 1-ethyl-3-methylimidazolium thiocyanate. Various characterization tools have been used further to elaborate electrical, structural, and photoelectrochemical properties. X-ray diffraction (XRD) and polarized optical microscope (POM) affirm the reduction of crystallinity of polymer, while Fourier transform infrared spectroscopy (FTIR) shows complexation and composite nature. Electrochemical impedance spectroscopy shows an enhancement in ionic conductivity by IL doping, where the highest conductivity is achieved at 60 wt% of IL concentration with a conductivity value of 6.21 × 10⁻⁴ S/cm. The ionic transference number (tion) and electrochemical stability measurement show the film's predominantly ionic nature and a reasonable stability window. Using maximum conducting film sandwiched between electrodes, we have successfully fabricated two devices, i.e., an electrical double-layer capacitor (EDLC) and a dye-sensitized solar cell (DSSC). The fabricated EDLC capacitor shows a specific capacitance of 125 F/g, while DSSC shows an efficiency of 1.1 % at one sun condition.

Enhancing the Performance of Nanocrystalline TiO2 Dye-Sensitized Solar Cells with Phenothiazine-Doped Blended Solid Polymer Electrolyte

Enhancing the Performance of Nanocrystalline TiO2 Dye-Sensitized Solar Cells with Phenothiazine-Doped Blended Solid Polymer Electrolyte

Chitosan as a suitable host for sustainable plasticized nanocomposite sodium ion conducting polymer electrolyte in EDLC applications: Structural, ion transport and electrochemical studies

The challenge in front of EDLC device is their low energy density compared to their battery counter parts. In the current study, a green plasticized nanocomposite sodium ion conducting polymer blend electrolytes (PNSPBE) was developed by incorporating plasticized Chitosan (CS) blended with polyvinyl alcohol (PVA), doped with NaBr salt with various concentration of CaTiO3 nanoparticles. The most optimized PNSPBE film was subsequently utilized in an EDLC device to evaluate its effectiveness both as an electrolyte and a separator. Structural and morphological changes were assessed using XRD and SEM techniques. The PNSPBE film demonstrated a peak ionic conductivity of 9.76×10−5 S/cm, as determined through EIS analysis. The dielectric and AC studies provided further confirmation of structural modifications within the sample. Both TNM and LSV analyses affirmed the suitability of the prepared electrolyte for energy device applications, evidenced by its adequate ion transference number and an electrochemical potential window of 2.86 V. Electrochemical properties were assessed via CV and GCD techniques, confirming non-Faradaic ion storage, indicated by the rectangular CV pattern at low scan rates. The parameters associated with the designed EDLC device including specific capacitance, ESR, power density (1950 W/kg) and energy density (12.3 Wh/kg) were determined over 1000 cycles.