Enhancement Of Ionic Conductivity Research Articles

Metal-Halogen Interactions Inducing Phase Separation for Self-Healing and Tough Ionogels with Tunable Thermoelectric Performance.

Ionic liquid-based thermoelectric gels become a compelling candidate for thermoelectric power generation and sensing due to their giant thermopower, good thermal stability, high flexibility, and low-cost production. However, the materials reported to date suffer from canonical trade-offs between self-healing ability, stretchability, strength and ionic conductivity. Herein, we develop a self-healing and tough ionogel (PEO/LiTFSI/EmimCl) with tunable thermoelectric properties by tailoring metal-halogen bonding interactions. Different affinities between polymer matrix and salts are exploited to induce phase separation, resulting in simultaneous enhancement of ionic conductivity and mechanical strength. Molecular dynamics simulations and spectroscopic analyses show that Cl- ions impair the lithium-ether oxygen coordination, leading to changes in chain conformation. The migration difference between cations and anions is thus widened and a transition from n-type to p-type thermoelectric ionogels is realized. Furthermore, the dynamic interactions of metal-ligand coordination and hydrogen bonding yield autonomously self-healing capability, large stretchability (2000%) and environment-friendly recyclability. Benefiting from these fascinating properties, we apply the multifunctional PEO-based ionogels in sensors, supercapacitors, and thermoelectric power generation modules. The strategy of tuning solvation dominance to address the trade-offs in thermoelectric ionogels and optimize their macroscopic properties offers new possibilities for the design of advanced ionogels. This article is protected by copyright. All rights reserved.

Utilizing machine learning and phonon density of states for innovative approaches to design and optimize high-performance solid-state Mg-ion electrolytes

This study presents the development of machine learning (ML) model for the enhancement of ionic conductivity in solid-state electrolytes for Mg-ion batteries (MIBs), utilizing phonon density of states (PhDOS) as tool for predicting ionic conductivity. Data comprising compounds with PhDOS calculations are sourced from the Materials Project (MP) and processed to extract frequencies and PhDOS values, enabling the calculation of the total phonon band center, a practical proxy for ionic conductivity. Learning process involving three ML algorithms (Extra Random Trees (XT), Gradient Boosting (GB), Extreme Gradient Boosting (XGB)) is conducted using these band centers. Cross-validation results indicated the superior accuracy of XT-model where its performance, is validated through density functional theory (DFT)-based phonon calculations on Mg2Ge, Mg2Gd, MgSe2 and Mg3P2. The XT-model was further employed to predict total phonon band centers of ∼9 K Mg compounds obtained from MP with no previous PhDOS calculations containing Mg–O, Mg–S and Mg–Se compounds which show that the band center median of Mg–Se materials is the lowest of the systems. Additionally, Nudged Elastic Band (NEB) and Ab initio Molecular Dynamics (AIMD) calculations is used to calculate the migration energy of MgSe2 which shows potential as an Mg-ion solid electrolyte when compared to other Mg electrolytes.

Water-Capture Filter Paper Separator Realizing Ambient Li-Air Battery.

Lithium-air battery (LAB) is regarded as one of the most promising energy storage systems. However, the challenges arising from the lithium metal anode have significantly impeded the progress of LAB development. In this study, cellulose-based filter paper (FP) is utilized as a separator for ambient Li-air batteries to suppress dendrite growth and prevent H2O crossover. Thermogravimetric analysis and molecular spectrum reveal that FP enables ambient Li-air battery operation due to its surface functional groups derived from cellulose. The oxygen-enriched surface of cellulose not only enhances ion conductivity but also captures water and confines solvent molecules, thereby mitigating anode corrosion and side reactions. Compared with commercial glassfiber (GF) separator, this cellulose-based FP separator is cheaper, renewable, and environmentally friendly. Moreover, it requires less electrolyte while achieving prolonged and stable cycle life under real air environment conditions. This work presents a novel approach to realizing practical Li-air batteries by capturing water on the separator's surface. It also provides insights into the exploration and design of separators for enabling practical Li-air batteries toward their commercialization.

Efficient statistical approach for thermo-electrical properties of gadolinia-doped ceria thin films

The thermo-electrical properties of gadolinia-doped ceria (GDC) thin films play a vital role in solid oxide fuel cell (SOFC) applications. Nonetheless, the effects of temperature, dopant concentration, and thickness on thermal expansion, and ionic conduction remain ambiguous. In the present study, we propose an efficient theoretical approach to emphasize the roles of surface layers and surface vicinity (called next-surface layers) on the thermo-electrical properties of GDC thin films. Using statistical moment method, thermal expansion coefficient, and ionic conductivity are calculated as functions of temperature, dopant concentration, and thickness. The lattice strain and ionic disorder in the surface and next-surface layers cause an increase in thermal expansion coefficient and ionic conductivity of thin films. Compared with bulk GDC, the thermal expansion coefficient is slightly larger while the ionic conductivity is more than one to two orders of magnitude enhancement and exhibits the maximum value at the higher concentration. The ionic conductivity depends non-linearly on the dopant concentration and the maximum conductivity is shifted toward a higher value as the temperature increases. The enhancement in thermal expansion coefficient and ionic conductivity offers new opportunities for SOFC electrolytes whose efficiency can be effectively controlled by tailoring the thickness. The theoretical calculations are compared to measured results from experiments.

Filling Two Needs with One Deed: Supercapacitor and Dye-Sensitized Solar Cells using Ionic Liquid Doped Polymer Electrolyte

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 6.21x10⁻⁴ 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.

Macromolecular crosslinked poly(aryl piperidinium)-based anion exchange membranes with enhanced ion conduction for water electrolysis

Anion exchange membranes (AEMs) are essential in AEM water electrolysis, providing a cost-effective alternative to proton exchange membranes through the use of noble metal-free electrocatalysts. However, the “trade-off” between conductivity and dimensional stability in AEMs still hinders the development of high-performance water electrolysis. Herein, partially functionalized poly(phenylene oxide) (QPPO) is combined with poly(aryl piperidinium) (QPAP) to fabricate novel crosslinked AEMs (C-QPAP-x-QPPO), addressing the conductivity-stability issue. The crosslinked C-QPAP-x-QPPO AEMs show lower water swelling compared to their non-crosslinked QPAP membrane, mainly due to increased chain entanglements from the crosslinking process. C-QPAP-2-QPPO AEM exhibits a high conductivity of 139.4 mS cm−1 at 80 °C, attributed to the well-defined microphase separation structure. In addition, C-QPAP-2-QPPO AEM demonstrates exceptional alkaline durability, retaining over 86% conductivity and showing slight degradation after 2400 h in 1 M KOH at 60 °C. A water electrolyzer using the C-QPAP-2-QPPO achieves a maximum current density of 1440 mA cm−2 at 80 °C (2.0 V). These findings demonstrate the potential applications of crosslinked C-QPAP-x-QPPO AEMs in electrochemical devices.

Enhanced Ion Conductivity in a Poly(ionic liquid)-Grafted Nanoparticle-Based Single-Ion Conductor

Enhanced Ion Conductivity in a Poly(ionic liquid)-Grafted Nanoparticle-Based Single-Ion Conductor

Emerging trends and prospects in aqueous electrolyte design: Elevating energy density and power density of multivalent metal-ion batteries

Aqueous batteries, using multivalent metallic charge carriers (Zn2+, Mg2+, Ca2+, Al3+), show promise as next-generation electrochemical energy storage due to their adequate energy density, high power density, and cost-effectiveness. The electrolyte, serving as a bridge between the cathode and anode, plays a crucial role in functionality. However, the use of aqueous electrolytes introduces issues such as limited voltage range, slow kinetics of multivalent cations, and side reactions on metal surfaces. Electrolyte engineering has emerged as a key solution to overcome major challenges in multivalent metal-ion batteries. This innovative approach involves optimizing factors such as electrolyte concentration, specific additives, pH management, and manipulating the ligand effect of cation salts. Additionally, incorporating anti-freezing agents is crucial. A systematic review of this domain is crucial for further development and refinement of electrolyte engineering strategies. This review should primarily focus on assessing how these modifications can enhance energy and power densities, broaden the operational range of the batteries (by adjusting water activity and LUMO/HOMO energy levels), improve cation transport (via enhanced ion conductivity, dielectric constant, transference number, and solvation structure), and effectively mitigate detrimental side reactions, such as metal deposition, interphase formation, and hydrogen bonding regulation. The electrolyte design strategies in multivalent metal-ion systems are outlined in terms of their effectiveness in smoothing metal dendrites, managing solvation shells and free water molecules, and minimizing side reactions between the metal surface and electrolyte. The article proposes future innovation directions and development prospects for enhancing electrolyte design engineering in these systems.

Cationic cellulose nanofiber solid electrolytes: A pathway to high lithium-ion migration and polysulfide adsorption for lithium-sulfur batteries

Polyethylene oxide (PEO) solid electrolytes, acknowledged for their safety advantages over liquid counterparts, confront inherent challenges, including low ionic conductivity, restricted lithium ion migration, and mechanical fragility, notably pronounced in lithium‑sulfur batteries due to the polysulfide shuttling phenomenon. To address these limitations, we integrate a quaternary ammonium cation-modified cellulose (QACC) nanofiber, electrospun with cellulose acetate (CA) from recycled cigarette filters, into the PEO electrolyte matrix. The nitrogen atom within the quaternary ammonium group exhibits a pronounced affinity for polysulfide compounds, effectively curtailing polysulfide migration. Concurrently, Lewis acid-base interactions between quaternary ammonium groups and lithium salt anions facilitate the release of additional Li+, achieving a lithium-ion transference number 1.5 times higher than its pure PEO counterpart. Furthermore, the introduction of a larger trifluoromethanesulfonimide (TFSI) group on the QACC macromolecule (TFSI-QACC) disrupts the ordered arrangement of PEO macromolecules, resulting in a noteworthy enhancement in ionic conductivity, reaching 2.07 × 10−4 S cm−1 at 60 °C, thus addressing the challenge of low PEO electrolyte conductivity. Moreover, the nanofiber enhances the mechanical strength of the PEO electrolyte from 0.49 to 7.50 MPa, mitigating safety concerns related to lithium dendrites puncturing the electrolyte. Consequently, the composite PEO demonstrates exemplary performance in lithium symmetrical batteries, enduring 500 h of continuous operation and completing 100 cycles at both room and elevated temperatures. This integrated approach, transitioning from waste to wealth, adeptly addresses a spectrum of challenges in the efficiency of solid-state electrolytes, holding considerable promise for advancing lithium‑sulfur battery technology.

Enhancement of ionic conductivity and electrochemical stability of PVA/HPMC/PANI/CuSO4 gel polymer for rechargeable batteries electrolytes

Gel polymer electrolytes (GPEs) have drawn a lot of interest due to their special qualities, which include high conductivity that is comparable to liquid electrolytes, excellent mechanical stability, and high flexibility. Using the solution casting approach, we have synthesized copper ion conducting gel polymer electrolyte (GPE) films made of polyvinyl alcohol (PVA) as the polymer host. An ionic salt, copper sulphate (CuSO4), and a plasticizing solvent, PANI/ [BMIM] [BF4] polyionic liquid, were employed. The structural, electrical, and electrochemical properties of the GPE films were carefully examined. The significant XRD crystalline peak decreased and disappeared upon the addition of PANI/[BMIM] [BF4] polyionic liquid, suggesting that PIL is a useful plasticizer for the PVA/HPMC polymers.The conductivity of GPE films was determined by electrochemical impedance spectroscopy measurements. The sample containing 20% CuSO4 salt has the highest room temperature conductivity (σ = 5.11 × 10−3 S/cm). The measurements of transference numbers show that ions are primarily responsible for the transport of these electrolytes. It seems that the working voltage range is high enough to be used as an electrolyte in batteries, based on the results of using linear sweep voltammetry (LSV) and cyclic voltammetry to evaluate the electrochemical stability of the GPE films.

Enhanced structural, electrical, and electrochemical performance of polyethylene oxides (PEO)‐based polymer electrolytes for solid state K+ ion batteries

AbstractFlexible polymer electrolytes with effective electrochemical characteristics must be developed to meet smart electronic technology demands. The current investigation explores the solid polymer electrolytes (SPEs) prepared by solution‐casting technique, using polyethylene oxides (PEO) doped with KCl salt in different weight percentages. The effect of the dopant on the chemical interactions and structural, optical, thermal, electrical, and electrochemical properties were studied using various strategies. It was found that the incorporation of KCl salt to PEO results in a three order of magnitude enhancement in ionic conductivity of polymer matrix from 10−9 to 10−6 S cm−1. The PEO doped with 20 wt.% KCl salt exhibited the highest ionic conductivity (4.32 × 10−6 S cm−1) and low activation energy (0.25 eV). According to the thermal analysis, the thermal stability of the films improved as the dopant concentration increased. Further, the electrochemical strength improved with increasing dopant concentration, according to cyclic voltammogram experiments. From the results of all the characterizations, PEO loaded with 20 wt.% KCl SPE system is a suitable candidate for use as an electrolyte in energy storage devices such as solid‐state batteries.

Effects of Sodium Vacancies and Concentrations in Na3SO4F Solid Electrolyte.

The sodium-rich solid electrolyte, Na3SO4F (NSOF), holds promise for eco-friendly and resource-abundant energy storage. While the introduction of heterovalent dopants has the potential to enhance its suitability for battery applications by creating Na vacancies, the effect of vacancies and sodium concentrations on sodium conduction remains unclear. In this work, Mg2+ was introduced into Na+ sites in Na3SO4F, generating sodium vacancies with different contents by using solid-state synthesis method. Among the resulting materials, Na2.96Mg0.02SO4F exhibited an ionic conductivity that is two-order-of-magnitude higher than NSOF at 298 K. Notably, as the sodium concentration decreased, the ionic conductivity also declined, revealing an equilibrium between Na vacancies and concentrations. To further investigate the influence of sodium concentration, excess Na+ was introduced into NaMgSO4F, which inherently possesses a lower sodium content by using solid-state synthesis method. However, this adjustment only led to an approximately one-order-of-magnitude enhancement in optimal ionic conductivity at 298 K. Combined with an in situ X-ray diffraction analysis, our findings underscore the greater sensitivity of sodium conduction to variations in sodium vacancies. This study paves the way for the development of ultrafast sodium ion conductors, offering exciting prospects for advanced energy storage solutions.

Strain-Induced Phase Separation and Mechanomodulation of Ionic Conduction in Anisotropic Nanocomposite Ionogels.

Ionogels have great potential for the development of tissue-like, soft, and stretchable ionotronics. However, conventional isotropic ionogels suffer from poor mechanical properties, low efficient force transmission, and tardy mechanoelectric response, hindering their practical utility. Here, we propose a simple one-step method to fabricate bioinspired anisotropic nanocomposite ionogels based on a combination of strain-induced phase separation and mechanomodulation of ionic conduction in the presence of attapulgite nanorods. These ionogels show high stretchability (747.1% strain), tensile strength (6.42 MPa), Young's modulus (83.49 MPa), and toughness (18.08 MJ/m3). Importantly, the liquid crystalline domain alignment-induced microphase separation and ionic conductivity enhancement during stretching endow these ionogels with an unusual mechanoelectric response and dual-programmable shape-memory properties. Moreover, the anisotropic structure, good elasticity, and unique resistance-strain responsiveness give the ionogel-based strain sensors high sensitivity, rapid response time, excellent fatigue resistance, and unique waveform-discernible strain sensing, which can be applied to real-time monitoring of human motions. The findings offer a promising way to develop bioinspired anisotropic ionogels to modulate the microstructure and properties for practical applications in advanced ionotronics.

Rationalizing the Role of Polyoxometalate‐Based Gel–Polymer Electrolytes to Achieve Five‐Fold Increase in the Specific Capacitance of Hard‐Carbon‐Based Supercapacitors

Boosting the charge‐transport pathways in gel–polymer electrolytes (GPEs) is important to extract their full potential for non‐Faradaic, supercapacitive energy‐storage devices. Herein, a series of polyoxometalates (POMs) ([P6W18O79]20−, [PW9O34]9− and [PW12O40]3−) as electrochemical polarization promoters is demonstrated to achieve 15‐fold enhancement in ionic conductivity of 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide‐based GPEs. Fundamentally, the three POMs offer systematically differing charge densities (200, 45, and 6.5 e− nm−3) that are linearly correlated to the observed enhancements in ionic conductivities. The charge density on the POMs contributes to the formation of additional charge‐migrative pathways across the GPE, as evidenced from facile polarization characteristics. Importantly, the presence of POM beyond a critical concentration acts as charge‐trapping centers to impede the ionic conductivity of the GPEs. The insights obtained through such detailed spectroscopic and electrochemical techniques are integrated into full‐scale supercapacitive devices with a rationally designed porous hard carbon as the electrode material. The resulting electrode–electrolyte interface synergies achieve a best‐in‐class supercapacitor exhibiting energy density of 58 Wh kg−1, power density of 14 kW kg−1, and a relaxation time constant of 0.66 s, without compromising on cycling stability for direct integration with intermittent energy‐harvesting devices. Thus, the fundamental insights presented here outline the design principles for extracting high‐performance from GPE‐based energy‐storage devices.

Experimental Investigations on Highly Conducting Solid Bio‐Polymer Electrolytes Based on Latex of Calotropis gigantea Plant

AbstractThe study has prepared highly conducting polymer electrolyte films using solution cast technique with poly(vinylidene fluoride‐co‐hexafluoropropylene) PVDF‐HFP, mixture of ethylene carbonate (EC), and propylene carbonate (PC) as plasticizer and latex of Calotropis gigantea (CGL) as an ionic source. In this study, four films are prepared using PVDF‐HFP:CGL in ratio 1:1 with the increasing concentration of EC+PC as 1, 2, 3, and 4 M named as 1:1:1, 1:1:2, 1:1:3, 1:1:4. The prepared polymer electrolyte is examined by polarized optical microscopy (POM), elemental dispersive X‐ray technique (EDX), and complex impedance spectroscopy. EDX and POM are studied for the surface morphology of all prepared samples and to investigate the porous nature of films. The enhancement in ionic conductivity occurs due to CGL and increasing amount of EC‐PC. Conductivity of highest composition (1:1:4) polymer electrolyte film is found to be ≈10−3 S cm−1. The optimized polymer electrolyte film is considered as a promising candidate for application in supercapacitors.

Current Scenario and Future Prospective of Ionic‐Liquid Doped Polymer Electrolyte for Energy Application

AbstractSolid polymer electrolyte (SPE) films based on poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF–HFP) with salt and ionic‐liquid (IL) are synthesized using the solution‐cast technique and summarized in this review. Doping ILs or salts increases ionic conductivity up to the device level. This is further confirmed using differential scanning calorimetry (DSC) and X‐ray diffraction (XRD) measurements. Polarized optical microscopy (POM) affirms that enhancement in ionic conductivity is due to increase in amorphous nature of film. The complex nature of polymer electrolyte films is confirmed using Fourier transform infrared (FT‐IR) spectroscopy. Overall results show that doping IL into polyether matrix is advantageous material playing a dominant role in electrochemical devices.

Dual phase change separator combining cooling and thermal shutdown functions for Li-ion battery with enhanced safety

The rapid growth of electric vehicles raises an unmet need to enhance high-temperature performance and safety of Li-ion battery (LIB). Herein, polyethylene glycol/polyvinylidene fluoride (PEG/PVDF) core @ polybutylene succinate (PBS) shell separator with cooling and thermal shutdown functions was fabricated using a one-step coaxial electrospinning method. The separator exhibited superior electrochemical performance even at room temperature due to good wettability and high porosity. When battery temperature rises as discharging, PEG with 50 °C melting point (m.p.) will melt to store heat temporarily. Thus, the separator with cooling function can effectively enhance ion conductivity to alleviate specific capacity drop and polarization voltage increase. As temperature decreases after battery discharging, the separator will release thermal energy to prepare for the next working cycle. When thermal runaway happens and raises temperate above 100 °C rapidly, the PBS shell will melt at 110 °C without skeleton thermal shrinkage. Separator pores can be blocked by the melted PBS and Li+ ions transfer can be inhibited in time to prevent disastrous consequence. Thus, dual phase change of the separator provides a novel and effective strategy for synergistic performance and safety enhancement of high temperature LIB.

Decoupling of ion-transport from polymer segmental relaxation and higher ionic-conductivity in poly(ethylene oxide)/succinonitrile composite-based electrolytes having low lithium salt doping.

Only limited enhancement in room-temperature ionic-conductivity for poly(ethylene oxide), PEO, based electrolytes is possible due to coupling between ionic-conductivity and segmental relaxation. In the present study, we have achieved ionic-conductivity of 1.07 × 10-3 and 6.20 × 10-4 S cm-1 at 313 and 298 K, respectively, by adding 45 wt% of succinonitrile (SN) in PEO having low LiTFSI loading (Li : EO = 1 : 20). This enhancement in the ionic-conductivity is attributed to faster ion transport (diffusion coefficient, D = 3.63 × 10-5 cm2 s-1) occurring through the ion-transport channels as confirmed by positron annihilation lifetime spectroscopy. The ionic-transport through these channels is observed to be highly decoupled from the segmental relaxations as confirmed using broadband dielectric spectroscopy through Ratner's approach. The observed decoupling of ionic-conductivity from PEO segmental relaxation in PEO-SN composite-based electrolytes would be useful to design rather inexpensive all solid-state polymer electrolytes for Li ion batteries.

Synthesis and Characterization of 2,5 Polybenzimidazole-ZrO2 Nanocomposite Membrane Towards Improved Vanadium Redox Flow Battery Performance

Zirconium oxide (ZrO2) nanomaterials were synthesized by hydrothermal method using ZrOCl2,8H2O and KOH as precursors. The as-synthesized ZrO2 was characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Field Emission Gun Scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM) and Brunaur-Emmett-Teller (BET) surface analysis. The synthesized ZrO2 nanomaterial is used to prepare composite 2,5 polybenzimidazole (ABPBI) polymer membrane. The nanocomposite membrane was further gone through various characterisation processes as mechanical stability, X-ray diffraction (XRD), contact angle measurement, Electrochemical impedance spectroscopy (EIS) and Field Emission Gun Scanning electron microscopy (FEG-SEM). The influence of ZrO2 nanoparticle for preparing composite polymer membrane to use in Vanadium redox flow battery as a separator was studied. The investigation shows significant improvement in mechanical stability and robustness, enhancement in ionic conductivity of the nanocomposite membrane and excellent battery performance. Figure 1

Electrospun Sulfonated Silica/P(VDF-TrFE)-Based Composite Membranes for PEM Fuel Cells

Nafion® membranes are the most widely used commercially available membranes for PEM fuel cells due to their good chemical and mechanical stability as well as high ionic conductivity at fully humidified conditions. However, their high cost and inadequate conductivity at lower humidity levels can be addressed as the main drawbacks of Nafion® membranes which needs to be overcome. In this regard new strategies such as complete replacement of these membranes with alternative cost-effective membranes or modifying their properties via synthesizing of Nafion® containing composite membranes by incorporation of some inorganic additives such as silica were extensively investigated previously [1].In this study, we developed two types of electrospun composite membranes: in the first route: membranes were prepared with using P(VDF-TrFE) or PVDF as carrier polymers which are decorated with sulfonated silica (S-SiO2) nanoparticles, as a proton conducting additive. Here S-SiO2 nanoparticles were synthesized via hydrothermal method, then these nanoparticles were added to the electrospinning solutions to prepare the hybrid membranes. The effect of S-SiO2 amount in final properties of these membranes were investigated via preparing samples with three different S-SiO2/ carrier polymer ratios [2]. In the second approach, a combination of sol-gel and dual electrospinning methods were employed to fabricate proton conducting membranes comprising sulfonated silica network, Nafion®, and PVDF or P(VDF-TrFE) as the carrier polymers. For this purpose, the obtained S-SiO2 network via sol-gel method was incorporated into the Nafion®/carrier polymer mixed fibrous-mats during dual electrospinning process [3]. In both approaches after electrospinning all electrospun mats were transformed to compact membranes via hot-pressing process. Then fabricated mats and compact membranes, were characterized by various techniques including FTIR, XPS, SEM, TEM, ionic conductivity, ion exchange capacity (IEC), water uptake and mechanical tests. Finally, membrane-electrode-assemblies (MEAs) were prepared via composite electrospun membranes and fuel cell performance tests were performed. The results showed an enhancement in ionic conductivity for both set of membranes (102 and 132 mS/cm) compared to commercial Nafion® membranes at the same conditions. Moreover, the fuel cell test exhibited that presence of sulfonated silica in the composite membranes improved the performance at lower humidity conditions (344 mW/cm2 at 60% RH) due to enhanced water retention ability of the resultant composite membranes.