Characterization Of Gel Polymer Electrolyte Research Articles

Preparation and characterization of gel polymer electrolyte based on porous poly(methyl methacrylate) and poly(vinylidene fluoride) films for lithium ion batteries

Preparation and characterization of gel polymer electrolyte based on porous poly(methyl methacrylate) and poly(vinylidene fluoride) films for lithium ion batteries

Synthesis and Characterization of Gel Polymer Electrolyte Based on Epoxy Group via Cationic Ring-Open Polymerization for Lithium-Ion Battery.

The polymer electrolytes are considered to be an alternative to liquid electrolytes for lithium-ion batteries because of their high thermal stability, flexibility, and wide applications. However, the polymer electrolytes have low ionic conductivity at room temperature due to the interfacial contact issue and the growing of lithium dendrites between the electrolytes/electrodes. In this study, we prepared gel polymer electrolytes (GPEs) through an in situ thermal-induced cationic ring-opening strategy, using LiFSI as an initiator. As-synthesized GPEs were characterized with a series of technologies. The as-synthesized PNDGE 1.5 presented good thermal stability (up to 150 °C), low glass transition temperature (Tg < −40 °C), high ionic conductivity (>10−4 S/cm), and good interfacial contact with the cell components and comparable anodic oxidation voltage (4.0 V). In addition, PNGDE 1.5 exhibited a discharge capacity of 131 mAh/g after 50 cycles at 0.2 C and had a 92% level of coulombic efficiency. Herein, these results can contribute to developing of new polymer electrolytes and offer the possibility of good compatibility through the in situ technique for Li-ion batteries.

Properties of Gel Polymer Electrolyte Based Poly(Vinylidine Fluoride-сo-Hexafluoropropylene) (PVdF-HFP), Lithium Perchlorate (LiClO&lt;sub&gt;4&lt;/sub&gt;) and 1-Butyl-3-Methylimmidazoliumhexafluorophosphate [PF&lt;sub&gt;6&lt;/sub&gt;

This study reported the preparation and characterization of gel polymer electrolyte (GPE) using poly (vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), lithium perchlorate (LiClO4) and 1-butyl-3-metilimmidazoliumhexafluorophosphate [PF6]. The GPE were prepared by solution casting technique. [Bmim] [PF6] ionic liquid is used as an additive for the purpose of increasing the ionic conductivity of GPE. Morphological analysis showed that the electrolyte gel polymer sample had a smooth and flat surface with the addition of [Bmim] [PF6] and no phase separation effect was observed. This shows the compatibility between PVdF-HFP and [Bmim] [PF6]. ATR-FTIR analysis showed that C-F bond related peaks experienced peak changes in terms of intensity and peak shifting. This proves the interaction of the imidazolium ion with the fluorine atom through the formation of coordinate bonds. Ionic conductivity analysis showed that PVdF-HFP-[Bmim][PF6] samples reached a maximum room temperature ionic conductivity value of 2.44 × 10-4 S cm-1 at 60 wt.% [Bmim] [PF6]. When 20 wt.% of LiClO4 added to the system, the ionic conductivity increased one magnitude order to 2.20 × 10-3 S cm-1.

Preparation and characterization of gel polymer electrolyte based on PVA-K2CO3

ABSTRACT In this study, electrolyte materials were synthesized by mixing a highly conducting salt (K2CO3) with the poly(vinyl alcohol) (PVA) in different proportions (from 10 to 50 wt.%). The synthesized electrolyte was characterized using Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) for their functional groups, morphology, thermal stability, glass transition temperature (Tg ), ionic conductivity, and potential window, respectively. Characterization results show that the complex formation between PVA and K2CO3 salt has been established by FTIR spectroscopic study, which indicates the detailed interaction between PVA and the salts in PVA-K2CO3 composites while the amorphous nature of the electrolyte after incorporation of the salts has been confirmed by FESEM analysis. Similarly, TGA and DSC analysis revealed that both decomposition temperature and Tg of the synthesized electrolytes decrease with the addition of K2CO3 due to the strong plasticizing effect of the salt. The results confirm that the electrolytes have sufficient thermal stability for supercapacitor operation, as well as an amorphous phase to effectively deliver high ionic conductivity. The highest ionic conductivity of 4.53 × 10−3 S cm−1 at 373 K and potential window of 2.7 V was exhibited by PK30 (30 wt.% K2CO3), which can be considered as high value for solid-state electrolytes which are superior to those electrolytes from PVA salts earlier reported. The results similarly show that the prepared electrolyte is temperature-dependent as conductivity increase with increase in temperature. Based on these properties, it can be imply that the PVA-K2CO3 gel polymer electrolyte (GPE) could be a promising electrolyte candidate for EDLC applications. The results indicate that the PVA-K2CO3 as a new electrolyte material has great potential in practical applications of portable energy-storage devices.

Characterization of Gel Polymer Electrolytes Based on Poly (Ionic Liquid)-Glyme Mixtures for Lithium Metal Batteries

Solid polymer electrolytes (SPE) have generated an extensive and sustained interest for its application in lithium metal batteries.[ 1 ] Compared with liquid electrolytes, solid polymer electrolytes have higher safety and thermal stability, since they can provide a physical barrier layer to prevent efficiently lithium dendrite growth and avoid thermal runaway under high temperature or impact. Despite the substantial benefits, some limitations remain to be improved, such as a low ionic conductivity at room temperature and low transference number. Several studies are being conducted to overcome these weaknesses and develop new generation of solid polymer electrolyte lithium metal batteries.[ 2 ] Most of the research on SPEs is focused on polyethylene oxide (PEO) mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt and its derivative. In general, PEO-based solid electrolytes have shown good dimensional stability, good safety, and can mechanically prevent dendritic growth. However, they exhibit low ionic conductivity and rather low cationic transference number (t+) of ca. 0.15. To achieve sufficient conductivity at low temperatures, polymers that are difficult to crystallize are proposed. Ionic liquids (IL) are poor crystal formers; therefore, polymers of IL are potentially good alternatives to PEO for lower temperature conductivity. An Iongel membrane based on the poly(dimethyldiallylammonium) polyDADMA-TFSI poly(ionic liquid) has gained attention in polymer metal batteries due to its favorable mechanical properties and stability against Li-metal.[ 3 ] The present study provides an insight into the properties of free-standing membranes using poly (ionic liquid)-glyme mixtures compared to typical polymer salt blends (PEO-LiTFSI) and PDADMA-LiTFSI. The benefit of tetraethylene glycol dimethyl ether (G4) is highlighted and appears to be the key component to obtain higher ionic conductivity regardless on the type of polymer used. The impact of the increase in LiG4TFSI/poly ionic liquid ratio within the electrolyte on the transference number, ionic conductivity and mechanical properties was further analyzed. For 33-66 wt% composition for PDADMAT-LiG4TFSI and PEO-LiG4TFSI membranes, a good compromise between the physicochemical and electrochemical properties was achieved.

Preparation and Characterization of Gel Polymer Electrolyte Based on PAN- NH4CF3SO4 and Nano ZrO2 Filler –Application as an Electrochemical cell

In the present investigation, the Nano Composite Gel Polymer Electrolyte (NCGPEs) based on nano fillers ZrO2, Polyacrylonitrile (PAN), and Ammonium Triflate (NH4CF3SO4) doped at various wt% ratios prepared with the help of solution cast technique. The better amorphous nature observed for the 70PAN:30NH4CF3SO4 composition with addition of 1-4 wt% of ZrO2 nano fillers and structural, complexation studies of NCGPEs were confirmed by XRD technique. The micro structural studies and particle size can be revealed by SEM technique. DC Conductivity studies reveal the ionic conductivity performance on effect of temperature and composition wt% of nano powder. The ionic conductivity studies observed for 70PAN:30NH4CF3SO4 with nano powder ZrO2 concentration ranging from 1-4 wt%. The sample containing 3wt% of ZrO2 exhibits the highest conductivity order of 4.20x10-4 S cm-1 at room temperature (303K) and 4.65x 10-3 S cm-1 at 373K. The cell parameters like Open Circuit Voltage, Short Circuit Current, energy density and power density were perfectly determined which were useful to explain electrochemical cell behaviour.

Preparation and characterization of gel polymer electrolyte based on electrospun polyhedral oligomeric silsesquioxane-poly(methyl methacrylate)8/polyvinylidene fluoride hybrid nanofiber membranes for lithium-ion batteries

As a kind of organic–inorganic hybrid materials with nanocage structure, polyhedral oligomeric silsesquioxane (POSS) has the advantages of good interaction with polymer and excellent thermal and mechanical stability. Star-shaped polyhedral POSS-poly(methyl methacrylate) (POSS-(PMMA n )8) with different molecular weights had been synthesized by sequential atom transfer radical polymerization (ATRP) with POSS-(C3H6Cl)8 as the initiator. Electrospun polyvinylidene fluoride (PVDF) composite gel polymer electrolytes (GPEs) modified by POSS-(PMMA n )8 were prepared, and their electrochemical and mechanical properties were assessed. The POSS-(PMMA n )8 particles were found to improve thermal stability and mechanical strength of the GPEs without decreasing electrochemical properties. Among all composite GPEs studied, the best comprehensive performance was obtained from PVDF-[POSS-(PMMA46)8] GPE: the porosity was 60.0%, and the tensile strength and the elongation at break were 4.94 MPa and 52.2%, respectively. Besides, the ionic conductivity was 4.85 × 10−3S cm−1 at room temperature, the electrochemical window could reach 6.0 V, and the interfacial impedance with Li electrode was 256.15 Ω. The cells with POSS-(PMMA)8-modified composite electrolytes also have good cycle performance. These results suggest that the PVDF-[POSS-(PMMA)8] composite GPEs are suitable for lithium-ion battery applications.

Preparation and characterization of gel polymer electrolytes using poly(ionic liquids) and high lithium salt concentration ionic liquids

Poly(ionic liquids)-based gel polymer electrolytes containing high lithium salt concentration ionic liquids are demonstrated.

Preparation and Characterization of Gel Polymer Electrolytes based on Electrospun PLA/PHB Membranes for Lithium-Ion Batteries

Electrospun biodegradable polylactide/poly 3-hydroxybutyrate (PLA/PHB) membranes were prepared using the electrospinning method. The conformation of the biodegradable membranes was verified by SEM, attenuated total reflectance-Fourier transformation infrared spectroscopy (ATR-FTIR), XRD technique, and DSC. For all electrospun PLA/PHB biodegradable membranes a nonwovenen, fibers network structure was observed. The high level of absorption of the liquid phase were observed for blended PLA/PHB biodegradable polymer membranes. Gel polymer electrolytes with polymer matrices containing 70% PLA and 30% PHB showed the highest porosity and liquid phase absorption abilities, and, as a consequence, also the highest values of conductivity amongst all tested polymer electrolytes (1,5·10-2 Scm-1 at 25°C).

Characterization of gel polymer electrolyte for suppressing deterioration of cathode electrodes of Li ion batteries on high-rate cycling at elevated temperature

As one of obvious electrolyte design technologies of Li ion batteries (LIBs) to meet durable high-rate capability at elevated temperatures for battery electric vehicles, this study assesses the superiority of gel polymer electrolyte (GPE) based on experimental results supporting its working mechanism. Our previous study indicated that degradation of cathode electrode under high-rate cycling at elevated temperature was a major cause of the decrease in performance of LIBs, and the single full cells (SFCs) with a GPE designed from dipentaerythritol hexaacrylate and methyl ether methacrylate was re-verified to have superior 3.0C cycling performance at 80°C. The superiority of the GPE is studied from comparing mid-voltages of discharge profiles of the SFCs, observing the cross-sectional morphology of the electrodes by field emission scanning electron microscopy, assessing the interacting force among the electrolyte components by thermogravimetric analysis, and examining each resistance component of the SFCs by electrochemical impedance spectroscopy. Gel polymerization of liquid electrolyte results in a significant increase of durable high-rate capability of LIBs due to the mechanisms of not only its buffering effect on solvating process of Li+ ions being extracted from the active materials during high rate operation, but also higher thermal stability of electrolyte components, lower susceptibility of the ionic conductivity of the electrolyte to a temperature change, and lower energy barrier to breakup of solvated structures during conducting of Li+ ions in gel polymer matrix.

Polyacrylamide-methanesulfonic acid gel polymer electrolytes for tin-air battery

The present work describes the synthesis and characterization of gel polymer electrolytes containing methanesulfonic acid (MSA) with Polyacrylamide (PAAm). The PAAm–MSA gel electrolytes were prepared with different concentrations of MSA. Addition of 0.5 M of MSA into the electrolyte increased the ionic conductivity of PAAm from 1.35 × 10−3 to 1.56 × 10−2 S cm−1. The maximum ionic conductivity of 7.0 × 10−1 S cm−1 was obtained with 3 M MSA at room temperature. The chemical interaction between PAAm and MSA was studied by Fourier transformed infra-red. The performance as a polymer electrolyte was evaluated from the cell discharge and open circuit potential measurements of a tin-air cell. The tin-air cell supported relatively high current, up to 12 mA cm−2 with a maximum power density of 5 mW cm−2. The open-circuit potential of the cell was 1.27 V for 24 h.

Preparation and electrochemical characterization of gel polymer electrolyte based on electrospun polyacrylonitrile nonwoven membranes for lithium batteries

Electrospun membranes of polyacrylonitrile are prepared, and the electrospinning parameters are optimized to get fibrous membranes with uniform bead-free morphology. The polymer solution of 16 wt.% in N, N-dimethylformamide at an applied voltage of 20 kV results in the nanofibrous membrane with average fiber diameter of 350 nm and narrow fiber diameter distribution. Gel polymer electrolytes are prepared by activating the nonwoven membranes with different liquid electrolytes. The nanometer level fiber diameter and fully interconnected pore structure of the host polymer membranes facilitate easy penetration of the liquid electrolyte. The gel polymer electrolytes show high electrolyte uptake (>390%) and high ionic conductivity (>2 × 10 −3 S cm −1). The cell fabricated with the gel polymer electrolytes shows good interfacial stability and oxidation stability >4.7 V. Prototype coin cells with gel polymer electrolytes based on a membrane activated with 1 M LiPF 6 in ethylene carbonate/dimethyl carbonate or propylene carbonate are evaluated for discharge capacity and cycle property in Li/LiFePO 4 cells at room temperature. The cells show remarkably good cycle performance with high initial discharge properties and low capacity fade under continuous cycling.

Preparation and characterization of gel polymer electrolytes based on acrylonitrile–methoxy polyethylene glycol (350) monoacrylate–lithium acrylate terpolymers

The acrylonitrile (AN)–methoxy polyethylene glycol (350) monoacrylate (MPGA)–lithium acrylate (LiAc) copolymers (PAMGLiAc) was synthesized by emulsion polymerization. Phase inversion technique was used to prepare the PAMGLiAc microporous membrane. The gel polymer electrolytes (GPEs) with the PAMGLiAc were obtained by the copolymer microporous membrane soaking liquid electrolyte. The component and structure of the PAMGLiAc were characterized by IR, NMR and TGA/DSC measurement. The electrochemical characteristics of the PAMGLiAc gel electrolytes were investigated in terms of different composition. The ionic conductivity exceeded 2.0 × 10 −3 S/cm at ambient temperature, and this system also showed good mechanical properties and a sufficient electrochemical stability with a decomposition voltage as much as 5 V vs. Li to allow far wider operation in the rechargeable lithium-ion polymer batteries.

Preparation and characterization of gel polymer electrolytes for solid state magnesium batteries

Magnesium-ion conducting gel polymer electrolytes (GPE) were prepared and their electrochemical properties were characterized. The composition of GPE containing P(VdF- co-HFP), Mg(ClO 4) 2–EC/PC and SiO 2 was optimized in consideration of ionic conductivity and mechanical stability. Solid state magnesium cell employing magnesium anode, GPE, and vanadium oxide cathode was assembled and its cycling characteristics were investigated. The Mg/GPE/V 2O 5 cell showed low initial discharge capacity of 58 mAh/g based on active V 2O 5 material and poor cycling characteristics. At present, the results show that the Mg/GPE/V 2O 5 cell has an inferior cycling performance in comparison with that of well-developed, lithium metal polymer cells.

Preparation and characterization of gel polymer electrolytes based on methyl methacrylate–styrene copolymers

Gel polymer electrolytes (GPEs) are prepared with methyl methacrylate (MMA)–styrene (ST) copolymers and LiPF 6 or LiBF 4 in ethylene carbonate/dimethyl carbonate. Depending on the molar composition of the copolymer, these gel polymer electrolytes exhibit a different range of mechanical and electrical properties. On the aspect of ionic conductivity and mechanical property, the copolymer comprising about 33 mol% MMA is found to be most desirable. Lithium-ion polymer cells employing GPE containing different electrolyte solution are assembled and their cycling performances are evaluated.

Electrochemical characterization of gel polymer electrolytes prepared with porous membranes

A highly porous polymer membrane with high affinity for electrolyte solution is prepared and characterized. In preparing this membrane, a blend of P(VdF-co-HFP) and PAN is used as a matrix polymer in order to attain high ionic conductivity and good mechanical strength. Gel polymer electrolytes are prepared by soaking the porous membranes in an electrolyte solution, and their electrochemical characteristics are investigated. A lithium-ion polymer cell is assembled with the gel polymer electrolyte prepared in the porous membrane and the charge–discharge cycling performance is evaluated.