Temperature Dependence Of Ionic Conductivity Research Articles

Ionic conductivity improvement in poly (propylene) carbonate-based gel polymer electrolytes using 1-butyl-3-methylimidazolium iodide (BmimI) ionic liquid for dye-sensitized solar cell application

Gel polymer electrolytes (GPEs) are prepared by mixing poly (propylene) carbonate (PPC) with various weight percentages of 1-butyl-3-methylimidazolium iodide (BmimI) ionic liquid. The GPEs consist of PPC host polymer, NaI iodide salt, ethylene carbonate (EC), propylene carbonate (PC), BmimI ionic liquid, and iodine (I2). The optimum BmimI ionic liquid content was found to be 60 wt% with respect to the wt% of PPC polymer with the highest ionic conductivity of 4.79 × 10−3 S cm−1. Temperature-dependent ionic conductivity studies exhibited that gel polymer electrolytes obey Arrhenius thermal-activated model. X-ray diffraction (XRD) study confirms the complexation between host polymer (PPC polymer), sodium iodide salt, and BmimI ionic liquid. Dye-sensitized solar cells are fabricated and GPEs are sandwiched between the working and counter electrodes and tested under the one Sun illumination. The highest energy conversion efficiency of 6.14% is achieved with the addition of 60 wt% of BmimI.

Ionic conductivity of acceptor doped sodium bismuth titanate: influence of dopants, phase transitions and defect associates

The temperature dependent ionic conductivity of NBT results from an interplay of defect complex formation, phase coexistence, and dopant concentration.

Quasi-solid-state agar-based polymer electrolytes for dye-sensitized solar cell applications using imidazolium-based ionic liquid

Agar as a natural polymer is used to prepare quasi-solid-state polymer electrolytes (QSPEs). Two different iodide salts namely sodium iodide (NaI) and potassium iodide (KI) are incorporated. To enhance the ionic conductivity of the QSPE system, 1-methyl-3-propylimidazolium iodide (MPII) ionic liquid is added. The highest ionic conductivity of 1.48 × 10−3 S cm−1 was achieved after addition of 50 wt.% of KI and 3.0 g of MPII ionic liquid. QSPEs are studied for temperature-dependent ionic conductivity behavior. QSPEs are studied for structural properties using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The structural studies revealed that the complexation between agar polymer, iodide salts, and MPII ionic liquid has occurred. QSPEs are sandwiched between counter and working electrodes to fabricated DSSC and analyzed under sun simulator. The highest efficiency of 2.16% is achieved with incorporation of 3.0 g MPII ionic liquid.

Impedance study of PVA/PEG/LiClO4/TiO2 nanocomposite solid polymer blend electrolyte

Composite solid polymeric electrolytes (CSPE) of PVA/PEG/LiClO4 and nanocomposite solid polymeric electrolytes (NSPE) of PVA/PEG/LiClO4/TiO2 films were prepared via solution casting technique using water as the solvent. TiO2 nano powder was prepared from the sulfate process and characterized by the XRD and SEM techniques. The structural interactions of the prepared films were studied by FTIR. Ionic conductivity of the prepared CSPE and NSPE films were measured using AC impedance method at a wide temperature range from 298.15 to 348.15 K in frequency range 50–100 MHz. The measured ionic conductivity results from Nyquist plot were compared with calculations results from equivalent circuit model. The temperature dependence of ionic conductivity of the prepared CSPE and NSPE films was expressed by Arrhenius model and the ionic conductivity activation energy was reported to be 0.86 and 0.89 eV respectively.

Relationship between Ion Dissociation, Melt Morphology, and Electrochemical Performance of Lithium and Magnesium Single-Ion Conducting Block Copolymers

Single-ion conducting block copolymers, such as poly(ethylene oxide)-b-poly[(styrene-4-sulfonyltrifluoromethylsulfonyl)imide lithium] (PEO–P[(STFSI)Li]), represent an exciting new class of materials capable of improving the performance of solid-state batteries with metal anodes. In this work, we report on the synthesis and characterization of a matched set of lithiated (PEO–P[(STFSI)Li]) and magnesiated (PEO–P[(STFSI)2Mg]) single-ion conducting diblock copolymers. We measure the temperature dependence of ionic conductivity, and through analysis using the Vogel–Tamman–Fulcher (VTF) relation, demonstrate that ion dissociation is significantly lower for all PEO–P[(STFSI)2Mg] samples when compared to their PEO–P[(STFSI)Li] counterparts. The VTF parameter characterizing the activation barrier to ion hopping was similar for both cations, but the VTF prefactor that reflects effective charge carrier concentration was higher in the lithiated samples by an order of magnitude. We study the melt morphology of the sin...

Novel poly(vinylidene fluoride-co-hexafluoro propylene)/polyethylene oxide based gel polymer electrolyte containing fumed silica (SiO2) nanofiller for high performance dye-sensitized solar cell

Novel gel polymer electrolytes (GPEs) are prepared using poly(vinylidene fluoride-co-hexafluoro propylene) copolymer (PVdF-HFP) and polyethylene oxide (PEO) in presence of fumed silica nanofiller with the designated system of PVdF-HFP:PEO:EC:PC:NaI:SiO2:I2. GPEs are examined using electrochemical impedance spectroscopy (EIS) and the highest ionic conductivity of 8.84mScm−1 is achieved after incorporation of 13wt.% of fumed silica (SiO2). Temperature-dependent ionic conductivity study confirms that GPE system follows Arrhenius thermal activated model. GPEs are characterized for structural studies using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. GPEs are used to fabricate dye-sensitized solar cells (DSSCs) and tested under 1 Sun irradiation, obtaining the highest energy conversion efficiency of 9.44% after the incorporation of 13wt.% fumed silica. Cyclic voltammetry has been performed to analyse electrochemical properties of gel polymer electrolytes.

Preparation of Si/Ti Mesoporous Molecular Sieve and Its Application in P(VDF-HFP)-based Composite Polymer Electrolytes

The mesoporous Si/Ti molecular sieve was successfully synthesized from tetrabutyl titanate, tetraethoxysilane and EO20PO70EO20 by sol-gel combined with following pyrolysis processes and confirmed by XRD and TEM. The poly (vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with Si/Ti molecular sieve were fabricated by phase inversion method and the desirable CPEs were obtained after being activated in liquid electrolytes, which are investigated by SEM, XRD, TG, LSV and EIS measurements. The results show that the CPE doped with 10% Si/Ti molecular sieve (vs P(VDF-HFP) in weight) presents the most uniform surface with abundant interconnected micro-pores and possesses excellent mechanical tensile strength with high decomposition temperature about 400°C and wide electrochemical working window about 4.7V; adding Si/Ti molecular sieve into the system can significantly decrease the crystallinity and improve the ionic conductivity of the as-prepared CPEs, in which the ionic conductivity and lithium ion transference number at room temperature are up to 3.263mScm−1 and 0.4292, respectively, and the reciprocal temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher relation. Furthermore, the anti-shrinkage rate of the as-prepared CPE membrane distinctly outperforms the commercial polyolefin membrane at 120°C about 2h. The interfacial resistance of the assembled Li/CPE/Li simulated cell can rapidly increase to a steady value about 548Ω from the initial value about 362Ω at 30°C during 5days storage, and the assembled Li/CPE/LiCoO2 coin cell with the electrolyte also show excellent rate and cycle performance, which indicates that this kind of CPE is an exciting potential candidate as polymer electrolyte for the lithium ion battery.

Metal Organic Frameworks/Ionic Liquid Composites As Electrolytes for Li-Ion Batteries

Metal Organic Frameworks (MOFs), as a novel class of crystalline porous material have gained great attention in the fields of gas storage, separation, drug delivery, catalysis, sensors and so forth. The supramolecular design of MOFs allow a number of organic ligands, with two or more functional groups, to be linked to metal ion coordination centers giving myriad variations and tunable properties in synthesized structures. Metal Organic Frameworks (MOFs) are of great interest due to several unique features and their applications have been extended to the field of Li-ion batteries. Simultaneously, ionic liquids (ILs) are becoming popular in a range of areas including biphasic reaction catalysis, electromechanical actuator membranes and diluents and separation membranes. Many studies have been conducted for the application of MOFs in energy storage devices [1]-[3], but scarcely any investigation was performed to understand the effect of ionic liquid incorporated MOFs in electrochemical storage devices especially batteries. Hence, an attempt has been made by our group with ionic liquid incorporated modified MOFs to serve as a better electrolyte system for Li-ion batteries with increased thermal and electrochemical stability, high ionic conductivity and other electrochemical aspects. Further, dimensionally and morphologically controlled MOFs will be carefully used to ease the ion transport in the electrolyte system by the regulation of ion conductive path. MOF-1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (AMImTFSI), synthesized by a facile in-situ electrochemical method [4] was doped with a lithium salt, lithium bis (triflouromethylsulfonyl) imide (LiTFSI) by a modified procedure for electrochemical measurements. Morphological features and crystal size of these matrices were evaluated by TEM (Transmission Electron Microscopy) and XRD measurements. Temperature dependence of ionic conductivity of the MOF/ionic liquid matrix was studied by AC-impedance method. Combination of AC-impedance and DC-polarization method was used to determine the lithium ion transference number of the samples. Electrochemical window of different electrolyte compositions was studied by linear sweep voltammetry. A coin cell was fabricated to study the charge discharge characteristics of the resulting cell. Synthesis of MOF-5/ionic liquid matrix by electrochemical method - MOF was successfully synthesized by a mild in-situ electrochemical method using 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (AMImTFSI) as a templating agent employing a modified procedure of reported method [4]. Synthesis of the MOF (AMImTFSI) was achieved by a constant dissolution of Zn2+ ion from Zn anode. The dissolution was carried out by applying a constant direct current (DC) of 0.15A. A titanium electrode was employed as cathode. The electrolyte used in this procedure was a solution containing 0.07 M terephthalic acid and 0.04 M zinc nitrate hexahydrate in DMF. The electrochemical galvanostatic procedure was carried out for 3hrs. A white powder formed during the above mentioned procedure, was filtered and washed with DMF first and then, with chloroform. The sample was then dried in oven at 80 oC to get pure MOF (IL). For further electrochemical analysis, MOF (IL) was doped with lithium salt, LiTFSI. A set of samples were synthesized with varying content of MOF (IL) in ionic liquid system and ionic conductivity was measured by AC-impedance method. Three samples with different weight % of MOF (IL) in AMImTFSI were prepared and temperature dependent ionic conductivity measurements were performed by AC impedance method. All the samples showed linear profiles in Arrhenius plots. As expected the ionic conductivity decreased with increase in wt% of MOF (IL) because of change in state from liquid to gel. Interestingly a decrease in activation energy of ion transport was observed. The ionic conductivities of the samples were calculated by the Vogel-Fulcher-Tammann (VFT) equation, resulting out to be highest for the sample with 10 wt% of MOF (IL) in AMImTFSI i.e. 1.0 x 10-2 Scm-1 at 51 oC . The highest tLi + of 0.31 was observed for 20 wt% MOF (IL) in AMImTFSI. The systems showed a potential window of 5.22-5.55 V. Charge discharge studies were also carried out after fabricating a coin anodic half-cell composed of Si/electrolyte/Li which showed 90% coulombic efficiency in the presence of 30 mL of EC: DC=1:1 in electrolyte. Conclusion Modified MOF with ionic liquid framework was prepared in ionic liquid system by electrochemical method. Measurements of temperature dependence of ionic conductivity using AC impedance showed relatively high ionic conductivity. These encouraging results affirm the prepared modified MOF (IL) to be a prospective electrolyte in energy storage devices.

Ionic Conduction Mechanism Analysis for Neodymium Complex in Phosphonium Ionic Liquids and Potassium Bis(trifluoromethylsulfonyl)amide Melts

It is important to investigate the ionic conduction mechanism for neodymium complex; Nd(III) in ionic liquids and low-temperature molten salts. The temperature dependence of ionic conductivities in [P2225][TFSA] dissolving 0.05-0.50 M Nd(III) was evaluated from Vogel-Fulcher-Tammann (VFT) equation in this study. The concentration dependence of ionic conductivities for Nd(III) in [P2225][TFSA] was evaluated from Kohlrausch law. Considering from Walden plot, this result indicated that the ionic conduction was attributed to the transfer of [P2225]+ and Nd3+ cations, and [TFSA]- anions even in the presence of Nd(III). Moreover, The VFT parameters of the ionic conductivities in [Nd1/3,K][TFSA] melts with molar fraction of Nd; x Nd=0.010-0.075 were also estimated in this study. Furthermore, the self-diffusion coefficients of cation and anion in [P2225][TFSA] were calculated from molecular dynamics simulation. This tendency of diffusivity for each ion was consistent with the ionic conductivity.

Thermal, mechanical and conductive properties of imidazolium-containing thiol-ene poly(ionic liquid) networks

Abstract A series of imidazolium-based bis(trifluoromethylsulfonyl)imide [NTf2] poly(ionic liquid)s (PILs) were prepared by conducting the solventless thiol-ene ‘click’ photopolymerization of bisallylimidazolium [NTf2] and pentaerythritol tetrakis(3-mercaptopropionate) (PTMP). The thiol:ene molar ratio was varied in order to examine changes in the thermal, mechanical and conductive properties of the resulting polymer networks. The 1.0:2.0 thiol-ene PIL network exhibited the highest glass transition temperature (Tg of −5.0 °C) and storage modulus (E′ of 9.24 MPa at 100 °C) values. Temperature-dependent ionic conductivities were found to rely on both the Tg/crosslink density as well as the IL content, with the highest ionic conductivity observed for the 1.0:3.0 thiol-ene PIL network (1.42 × 10−5 S/cm at 25 °C). Application of Vogel-Fulcher-Tammann and Williams-Landel-Ferry theories revealed the impact of both Tg/crosslink density and free ion concentration on temperature-dependent conductivity data, and indicated lower free volumes and fragilities for the thiol-ene networks relative to other non-network PILs.

Covalent silica-PEO-LiTFSI hybrid solid electrolytes via sol-gel for Li-ion battery applications

Organic/inorganic hybrid membranes based on (3-glycidoxypropyl) trimethoxysilane (GPTMS) and ethylene glycol diglycidyl ether (EGDE), have been prepared by sol-gel method and organic polymerization as solid electrolytes for Li-ion batteries. Lithium bis(trifluoromethane)sulfonamide (LiTFSI) was used as Li salt. FTIR and Raman spectroscopies were used to confirm the hybrid structure formation and the interactions between Li ions and hybrid network. An Arrhenius-like temperature dependence of ionic conductivity was observed for solid hybrid electrolyte membranes, suggesting that the diffusion of charge carriers was assisted by the segmental motions of the organic network. The Li-ion transfer number was determined and correlated with their ionic conductivities. Maximum ionic conductivities for the solid hybrid electrolyte membrane with LiTFSI and a [Li+]/[O]=0.10 (class II hybrid) of 2.6×10−5S/cm was obtained at room temperature. A good value of electrochemical stability window (7V) and an excellent high rate performance after 500 cycles make these hybrids materials a promising electrolyte candidate for all-solid-state lithium battery applications.

Mathematical modeling of field-assisted Li ion conduction in nanocomposite solid polymer electrolyte systems

Nanocomposite solid polymer electrolyte films were prepared to study the effect of electric field on the ionic conductivity. The studies were carried out by varying the electric field from 0 to 100 V cm−1 at different temperatures and the results shows that conductivity increases with increase in electric field and temperature. A mathematical model is proposed to describe the electric field and temperature-dependent ionic conductivity in nanocomposite solid polymer electrolyte systems. The correlation between the proposed equation and the experimental observations showed high degree of correlation.

Ionic Liquid Based Polymer Gel Electrolyte Membranes for Lithium Ion Rechargeable Batteries

Li-ion conducting polymer gel electrolyte membranes (PGEMs) based on polymer poly(vinylidene fluoride-co-hexafluoropropylene) PVdF-HFP, ionic liquid, 1-butyl-3-methylimidazolium tetrafluroborate BMIMBF4 and Lithium bis(trifluoromethanesulfonyl)imide) LiTFSI salt (having different anion i.e. BF4 - and TFSI-) have been synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), complex impedance spectroscopy and cyclic voltammetry. After incorporation of IL in polymer electrolyte, (i.e. PVdF-HFP+20wt.% LiTFSI) different physicochemical properties such as melting temperature (Tm), glass transition temperature (Tg), thermal stability, degree of crystallinity (Xc), and ionic transport behaviour of these materials are found to change. The pristine PVdF-HFP possessed a semi-crystalline structure and its amorphicity increased with the addition of LiTFSI salt and BMIMBF4 ionic liquid. An impedance measurement indicated that the room-temperature ionic conductivity of the membranes increased with increasing IL content and attains a maximum value of 3.2 *10-3 S/cm at 30 °C and ~ 8.7*10-3 S/cm at 130 °C. An schematic representation exhibiting increase in ionic conductivity with increasing amount of dopant ionic liquid has been shown in the given figure. In addition, temperature dependent ionic conductivity seems to obey Arrhenius type thermally activated behaviour. A high total ionic transference number > 0.99 and the cationic transference number (tLi +) ~0.33 with a wider electrochemical window (ECW) ~4.0–5.0 V for the PGEMs containing higher loading of IL have been obtained. Fig. Schematic representation exhibiting increase in ionic conductivity with increasing amount of dopant Ionic Liquid. Figure 1

The effects of MgO nanofiller to the physicochemical and ionic liquid retention properties of PEMA‐MgTf2‐EMITFSI nanocomposite polymer electrolytes

Nanocomposite polymer electrolytes were prepared by dispersing different compositions of nanosized magnesium oxide (MgO) as ceramic nanofiller in poly(ethyl methacrylate) (PEMA)−20 wt% magnesium triflate (MgTf2)−40 wt% 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl) imide (EMITFSI) electrolytes. The role of ionic liquid, magnesium salt, and ceramic nanofiller were visualized by various physical and electrochemical analyses including scanning electron microscopy, thermogravimetric analysis, electrical impedance spectroscopy, and linear sweep voltammetry. The improvement of ionic liquid retention property has been observed by formation of free standing films of PEMA–40 wt% EMITFSI–20 wt% MgTf2 dispersed with MgO. The smoothness of the films’ surface observed in SEM images suggested the amorphous nature of the films. The room temperature ionic conductivity was improved up to 10−5 S/cm by the incorporation of 1 wt% of MgO nanofiller in the polymer electrolytes. Temperature dependent ionic conductivity showed the Arrhenius‐like behavior with ionic conductivity of 3.78 × 10−4 S/cm at 100°C. The polymer electrolyte also showed enhanced electrochemical stability window. POLYM. COMPOS., 39:1500–1506, 2018. © 2016 Society of Plastics Engineers

Poly(vinyl alcohol) Based Polymer Gel Electrolytes: Investigation on Their Conductivity and Characterization

Polymer gel electrolytes were prepared using poly(vinyl alcohol) (PVA) as polymer matrix. 1-methyl-2pyrrolidone (NMP) and γ-butyrolactone (GBL) were preferred as the organic solvents. The alkali metal iodide salt (KI) and iodine (I2) were used as the redox couple. Liquid electrolytes with different concentrations of KI were prepared by dissolving iodide salt/iodine in the binary NMP:GBL (volume ratio 7:3) solvent mixture. PVA was added into the liquid electrolytes and then the resulting mixture was stirred at 110 ◦C for 1 h. Gel form was obtained at room temperature. The highest ionic conductivity at room temperature is 8.41 mS/cm. The temperature dependence of ionic conductivity with respect to the all concentration of KI shows the Arrhenius behaviour. Characterizations of polymer gel electrolytes were performed using the Fourier transform infrared, thermal gravimetric analysis, and differential scanning calorimetry techniques.

A study of structural, electrical and electrochemical properties of PVdF-HFP gel polymer electrolyte films for magnesium ion battery applications

New magnesium ion conducting polymer electrolyte films are developed and their experimental investigations are reported. The polymer electrolyte films are composed of various poly(vinylidene fluoride-co-hexafluoropropylene):magnesium trifluoromethanesulfonate compositions (PVdF-HFP:Mg(Tf)2 in weight ratio) with different quantities of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid (EMITf). X-ray diffraction reveals that the pristine PVdF-HFP polymer film possesses a semi-crystalline structure and its amorphicity increases with increasing Mg(Tf)2 and EMITf concentrations. From thermal analysis, the melting temperature (Tm), relative crystallinity (χc) and thermal stability of the 90PVdF-HFP:10Mg(Tf)2 gel polymer electrolyte film doped with 40wt.% EMITf are obtained as 112°C, 21.8% and 355°C, respectively. The room-temperature ionic conductivity of the gel polymer electrolyte film increases with increasing EMITf concentration and reaches a high value of approximately 4.63×10−3Scm−1 at 40wt.% EMITf due to its amorphicity increase and interconnected pore structure. For the 40wt.% EMITf electrolyte film, the temperature dependence of ionic conductivity follows the Arrhenius relation with an activation energy of 0.35eV. The electrochemical stability window of the 40wt.% EMITf electrolyte film is determined as ∼4.8V. The findings from this study are promising and have great potential for practical ionic device applications, particularly in rechargeable magnesium ion batteries.

Effect of EMIMBF4 ionic liquid addition on the structure and ionic conductivity of LiBF4-complexed PVdF-HFP polymer electrolyte films

New polymer electrolyte films of lithium tetrafluoroborate (LiBF4)-complexed poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) embedded with different quantities of 1-ethyl-3methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid were prepared by solution casting. The prepared films were characterized using various techniques: X-ray diffraction, scanning electron microscopy, impedance spectroscopy and electrochemical measurements. The pure PVdF-HFP possessed a semi-crystalline structure and its amorphicity increased with the addition of LiBF4 salt and EMIMBF4 ionic liquid. The size and interconnection of pores in the films were enhanced by EMIMBF4. Impedance measurements indicated that the room-temperature ionic conductivity of the films increased with increasing EMIMBF4 concentration until 15 wt.%, being up to 0.202 × 10−4 S cm−1, and then decreased with further increasing EMIMBF4 concentration. In addition, the temperature-dependent ionic conductivity of the polymer electrolyte films followed an Arrhenius relation and the 15 wt.% EMIMBF4-incorporated gel polymer electrolyte film exhibited a low activation energy for ionic conduction, being about 0.28 eV. Finally, the electrochemical stability window of the 85PVdF-HFP:15LiBF4+15 EMIMBF4 gel polymer electrolyte films was evaluated as approximately 4.4 V, which is a promising value for ion battery applications.

Dynamics and relaxation of charge carriers in poly(methylmethacrylate)-based polymer electrolytes embedded with ionic liquid.

In the present paper, we have studied dynamics and relaxation of the charge carriers in polymethylmethacrylate-lithium bis(trifluoromethane sulfonyl)imide polymer electrolytes embedded with 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid. We have analyzed the frequency dependent conductivity spectra using the random free-energy barrier model coupled with the contribution of electrode polarization in the low frequency region. The temperature dependence of ionic conductivity, and relaxation time obtained from the analysis of the spectra exhibits Vogel-Tammann-Fulcher type behavior. The Barton-Nakajima-Namikawa relation is consistent with the results obtained from the random free-energy barrier model. The scaling of ac conductivity spectra has been performed to understand the effect of temperature as well as the composition on the relaxation mechanism. The analysis of the ac conductivity also clearly indicates the existence of a nearly constant loss phenomenon at low temperatures or at high frequencies.

Hydroxypropyl Cellulose Based Non-Volatile Gel Polymer Electrolytes for Dye-Sensitized Solar Cell Applications using 1-methyl-3-propylimidazolium iodide ionic liquid.

Gel polymer electrolytes using imidazolium based ionic liquids have attracted much attention in dye-sensitized solar cell applications. Hydroxypropyl cellulose (HPC), sodium iodide (NaI), 1-methyl-3-propylimidazolium iodide (MPII) as ionic liquid (IL), ethylene carbonate (EC) and propylene carbonate (PC) are used for preparation of non-volatile gel polymer electrolyte (GPE) system (HPC:EC:PC:NaI:MPII) for dye-sensitized solar cell (DSSC) applications. The highest ionic conductivity of 7.37 × 10−3 S cm−1 is achieved after introducing 100% of MPII with respect to the weight of HPC. Temperature-dependent ionic conductivity of gel polymer electrolytes is studied in this work. XRD patterns of gel polymer electrolytes are studied to confirm complexation between HPC polymer, NaI and MPII. Thermal behavior of the GPEs is studied using simultaneous thermal analyzer (STA) and differential scanning calorimetry (DSC). DSSCs are fabricated using gel polymer electrolytes and J-V centeracteristics of fabricated dye sensitized solar cells were analyzed. The gel polymer electrolyte with 100 wt.% of MPII ionic liquid shows the best performance and energy conversion efficiency of 5.79%, with short-circuit current density, open-circuit voltage and fill factor of 13.73 mA cm−2, 610 mV and 69.1%, respectively.

Hot pressed K+ ion conducting solid polymer electrolytes: synthesis, ion conduction and polymeric battery fabrication

Synthesis and ion transport studies of hot pressed K+ ion conducting solid polymer electrolytes (SPEs): (1 − x) PEO:x KBr, where 0 < x < 50 in wt%, are reported. The solvent-free/hot-press method is used for synthesis of the present SPEs. The two orders of conductivity enhancement achieved after the polymer-salt complexation in SPE composition: (70:30) with conductivity (σ) ~ 5.01 × 10−7 S cm−1 from the room temperature conductivity measurements. Materials characterization and polymer-salt complexations of present SPEs have been explained with the help of various techniques viz. X-ray diffraction, Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy technique. To explain the ion conduction in the present SPEs, temperature dependent ionic conductivity (σ), ionic mobility (μ), mobile ion concentration (n), ionic transference number (t ion ) and ionic drift velocity (v d ) have been calculated with the help of various experimental techniques. A solid state polymer battery is also fabricated by using the present SPE as an electrolyte and have been calculated their important cell parameters at room temperature.