Ionic Conductivity Of Gel Electrolyte Research Articles

Building fast and selective Zn ion channels for highly stable quasi-solid-state Zn-ion batteries

Ordered ion channels constructed by confining a gel electrolyte in intercalated halloysite nanotubes exhibit fast and selective Zn ion transportation and therefore enhance the cycling stability of the quasi-solid-state Zn-ion batteries.

Optimization on Ameliorating an Ionic Conductivity of Gel Electrolyte and Mitigating the Self-Discharge of Flexible Supercapacitor

Optimization on Ameliorating an Ionic Conductivity of Gel Electrolyte and Mitigating the Self-Discharge of Flexible Supercapacitor

Review of PVA-based gel polymer electrolytes in flexible solid-state supercapacitors: Opportunities and challenges

Abstract Flexible solid-state supercapacitors with high power density and rate performance, long cycle life, high safety and ease of fabrication are highly desirable. They can be used in an emerging market of flexible and wearable electronic gadgets. Gel polymer electrolytes are being considered as one of the best candidates. They typically have higher ionic conductivity than solid electrolytes without safety concerns of liquid electrolytes. This article reviews the latest achievements in the application of PVA-based gel polymer electrolytes for flexible supercapacitors and new findings on the improvement of their ionic conductivity, mechanical properties, and overall electrochemical performance. Several current kinds of research attempt to overcome these challenges with the main goal of improving ionic conductivity and electrochemical properties. There is no limitation for ionic conductivity of gel electrolyte because high ionic conductivity can lead to higher specific capacitance and also sufficient electrochemical performance. A recent study of gel electrolytes has shown the highest ionic conductivity of 82 mS.cm−1 for PVA/H2SO4/Glutaraldehyde/H2O which results in a large areal capacitance of 488 mF.cm−2 (100 reference).

Enhanced Electrochemical Performance of the Cathode for a Lithium Ion Secondary Battery Using Lithium Ion Conductive Glass-Ceramics

Ceramics powder such as SiO2 and Al2O3 are incorporated in to the polymer electrolyte to form the composite film for the sake of improving ionic conductivity, mechanical and thermal properties. Though these filler enhanced ionic conductivity of gel electrolyte due to the disruption of polymer matrix and increasing micro pores, these are not ionic conductive material. We found that the gel electrolyte film (Pvdf based polymer) was enhanced ionic conductivity by adding LICGCTM. We have developed lithium ion conducting glass-ceramics LICGCTM with a NASICON type structure for solid lithium ion electrolyte.1- 3) The ionic conductivity of the glass ceramics with a Li1+x+yAlxTi2-yGeyPO4 composition shows over 1×10-4 Scm-1 at room temperature. Such ceramics have a very stable in ionic conduction. In addition, the ionic conductivity does not decrease, even if it was soaked in an aqueous of Li salt solution4-5), and does not lose the weight in boiling distilled-water for 1 h. The glass-ceramics with the crystalline form of Li1+x+yAlxTi2–xSiyP3–yO12 with a NASICON-type structure by heat-treated glass with a specific composition1-2). This glass-ceramics has a high lithium-ion conductivity that is equal to or more than 10–3 Scm–1at room temperature. Furthermore, because it is very stable in the atmosphere and even to exposure to moist air, it is possible to use this material to apply a solid-electrolyte for a lithium ion secondary battery using organic liquid electrolyte. In this work, the effect of LICGCTM as additive for a lithium ion secondary battery was investigated. We synthesized LiCoO2 cathode with 5wt.% LICGCTM filler and evaluated it the charge and discharge property using a half cell. We confirm the rate performance at room temperature is enhanced at 0.2-3.0C comparing pristine LiCoO2 cathode. The rate performance was indicated 20 percent increasing at 2.0C rate as compared to pristine LiCoO2 cathode. The charging performance was also enhanced at higher rate at room temperature.

Activation of Passive Nanofillers in Composite Polymer Electrolyte for Higher Performance Lithium‐Ion Batteries

Poor ionic conductivity in gel or solid electrolytes hinders the electrochemical performance and hence applications of solid‐state lithium‐ion batteries. In this work, a simple and efficient approach to increase the ionic conductivity of gel electrolytes is reported. Composite gel polymer electrolyte (CGPE) films, consisting of poly(vinylidene fluoride‐hexafluoropropylene) as the host polymer and the trilayer polypropylene membrane as the mechanical support, are prepared using charge‐modified acidic TiO2 and basic SiO2 nanoparticles as ionic conductors. Ionic conductivities of 1.56, 1, and 1 × 10−2 mS cm−1 for acidic CGPE, basic CGPE, and CGPE without nanofillers are achieved, respectively. The Li‐graphite cells employing the modified nanofillers incorporated CGPE show an enhanced electrochemical performance with the first cycle specific capacity of 412/408.5 mAh g−1 for the cell with acidic CGPE and 349/347.18 mAh g−1 with basic CGPE at the C/20 rate. After five cycles, each of C/8, C/4, C/2, and 1C, the acidic CGPE demonstrates a capacity retention of 78% compared to that of the basic one with 70%. This modification method has been demonstrated as a simple, facile, and scalable technique to improve electrolyte performance for solid‐state lithium‐ion batteries.

Effect of nano-dispersed silica on the ion-conducting behavior of PMMA-based polymer gel electrolytes containing LiPF6

Nano-sized silica poly(methylmethacrylate)-based gel electrolyte containing lithium hexafluorophosphate (LiPF6) was synthesized by using different binary solvent mixture (propylene carbonate(PC) and dimethylformamide (DMF) in different volume ratio). Role of DMF in PC: Higher DMF content in PC-based electrolyte shows higher ionic conductivity at all polymer content and at wide temperature regions (10-70 °C). A small increment in ionic conductivity at lower content of polymer in liquid/gel electrolyte was observed and having maximum conductivity of 13.12 mS/cm at 25 °C. Stability (mechanically and electrically), viscosity and ionic conductivity of gel electrolytes were improved with the addition of nano-sized silica at ambient temperature. Ionic conductivity of nano-sized silica-based gel electrolyte does not change much over 5o–70 °C temperature range and is factor-wise only which make indispensable in different electrochemical devices. Also polymer gel electrolyte membranes as such and with dispersed silica nano-particles were characterized through scanning electron microscope to study the morphology of gel matrix.

A highly stable and efficient quasi solid state dye sensitized solar cell based on Polymethyl methacrylate(PMMA)/Polyaniline Nanotube(PANI-NT) gel electrolyte

A novel polymer gel electrolyte (PGE) based on polymethyl methacrylate (PMMA)/polyaniline nanotube (PANI-NT) with LiI/I2 as a redox couple and 4-tertbutylpyridine as additive was prepared in a solvent mixture of N-methyl 2-pyrrolidone (NMP) and acetonitrile. PMMA and PANI-NT were characterized using Fourier transform infrared spectroscopy. Different amounts of PANI-NT (0.15, 0.20, 0.25 and 0.30wt%) were used to optimize the ionic conductivity of the polymer gel electrolyte. Electrochemical Impedance Spectroscopy (EIS) showed that the introduction of PANI-NT in the PMMA based gel electrolyte enhanced the ionic conductivity of the gel electrolyte. The surface morphology of gel electrolytes was studied using scanning electron microscopy. A series of Dye sensitized solar cells (DSSCs) were fabricated employing the foresaid gel electrolytes with different weight percentages of PANI-NT. The cell performance of the optimized DSSC was investigated by current density vs. voltage (J-V) characteristics. The optimized system exhibited an open circuit voltage of 0.75V, short circuit current density of 9.80mAcm−2, fill factor of 0.68 and the photo-conversion efficiency of 5.11% under irradiation of 100mWcm−2 and air mass (AM) 1.5. EIS was used to study the charge transfer processes in the DSSCs under irradiation. The increment of PANI-NT in the PMMA based gel electrolytes reduces the charge transfer (Rct) process, resulting enhancement of the device efficiency. The long term stability study of the DSSCs shows that the PMMA/PANI-NT based gel electrolyte have commendable durability as compared to the liquid electrolyte.

Influence of different silica gelling agents on the performance of aqueous gel electrolytes

In this study, gel electrolytes are prepared from silica gelling agents and aqueous electrolyte for application in the rechargeable hybrid aqueous battery for the first time. The required quantities of silica materials are in the range of 4–15wt.%. The gelling time is in the magnitude of minutes and the ionic conductivities of gel electrolytes are in the range of 50.6–60.6mScm−1. These batteries using these gel electrolytes exhibit higher rate capability, slower self-discharge (ca.15% after 24h), and up to 10–12% higher cyclability compared with the performance of the batteries using the conventional liquid electrolyte.

Hypergrafted nano-silica modified polymer gel electrolyte for high-performance solid-state supercapacitor

In the developing of wearable electronics and smart textiles, thin, lightweight, and flexible energy storage supercapacitor with high energy density has attracted the attention of many researchers in recent years. In this work, we prepared gel nano-composite electrolyte with the hypergrafted poly (amine-ester) nano-silica (HBPAE-SiO2) as inclusion. The electrochemical properties of the supercapacitor with the alkaline polymer electrolyte were evaluated by cyclic voltammetry, galvanostatic charge–discharge behavior, and electrochemical impedance spectroscopy. It was found that the incorporated HBPAE-SiO2 can greatly increase the specific capacitance of the supercapacitor, which was due to the enhanced ionic conductivity of gel electrolyte as well as good electrode–electrolyte contact. It is pointed out that the electroactivity of the inclusion may be also one reason. The best specific capacitance with 30 wt% HBPAE-SiO2 reached 160 F g−1, which was increased by 36.5 % compared with that of polyvinyl alcohol (PVA)-KOH system. Moreover, the capacity retention of solid-state supercapacitor can be 88 % after 10,000 cycles. The hypergrafted nano-silica modified polymer gel electrolyte is promising for the application of solid-state supercapacitor.

Structural, thermal and electrical characterizations of PVA:DMSO:NH 4SCN gel electrolytes

An attempt has been made in the present work to cast stable polymeric gel electrolytes by drying as-synthesized gel electrolytes which were prepared by sol gel process. The polyvinyl alcohol (PVA) has been used as matrix in the gel to hold ammonium thiocyanate (NH 4SCN) dissolved in dimethyl sulfoxide (DMSO). DSC studies reveal the presence of pristine materials along with PVA–NH 4SCN complexes. The FTIR spectral studies affirm complex formation. Ionic conductivity of gel electrolytes shows maxima at 6 wt.% of PVA. The conductivity response has been correlated to complexation behaviour. Temperature dependence of ionic conductivity revealed the existence of liquid like conduction at lower wt.% of incorporated PVA whereas contribution to conductivity by polymeric complexes enhanced at higher wt.% of polymer.

Electrical properties of fluorinated gel electrolytes using high ionic conducting solution and its application to secondary battery

Lithium ionic electrolytes of fluorinated gel materials have been found to show high ionic conductivity. We proposed to apply this gel electrolyte to a secondary battery. Non-crosslinking fluorinated gel materials were prepared by reacting fluoroalkanoyl peroxides with 2-acrylamid-2-methyl-propanesulfonic acid (AMPS) oligomer containing fluoroalkylated end-capped units {[R F(AMPS) q] p}. Four kinds of lithium salts were used for ionic electrolyte of fluorinated gel materials. The ionic conductivity of gel electrolytes depended on the chain length of R F, the lithium salt material and its concentration. The maximum conductivity was 2.1×10 −2 S/cm when used by the ionic solution, the lithium salt with LiN(CF 3SO 2) 2 and the concentration of 5.7 mmol/g, respectively. We also measured the charge and discharge characteristics of secondary batteries that were fabricated by a carbon negative electrode, fluorinated gel electrolyte and a positive electrode of LiCoO 2.

Synthesis and characterization of novel crosslinked polyurethane–acrylate electrolyte

AbstractFlexible, transparent, and crosslinked polymer films were synthesized by polymerization of PEG‐modified urethane acrylate using a simple method. A series of novel solid polymer electrolytes and gel electrolytes were prepared based on this type of polymer film. To understand the interactions among salt, solvent, and polymer, the swelling behaviors of the crosslinked polymer in pure propylene carbonate (PC) and liquid electrolyte solutions (LiClO4/PC) were investigated. The results showed that the swelling rate in the electrolyte solution containing moderate LiClO4 was greater than that in pure PC. Thermogravimetric analysis (TGA) also supported the interaction between the solvent and polymer. The morphology and crystallinity of the crosslinked polymer and polymer electrolytes were studied using atomic force microscopy (AFM) and wide‐angle X‐ray diffraction (WAXD) spectroscopy. The effects of the content of the electrolyte solution on the ionic conductivity of gel electrolytes were explored. The dependence of the conductivity on the amount of the electrolyte solution was nonlinear. With a different content of the plasticizer, the ionic conduction pathway of the polymer electrolytes would be changed. The best ionic conductivity of the gel electrolytes, which should have good mechanical properties, was 4 × 10r−3 S cm−1 at 25°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 340–348, 2003

Ionic conductivity of gel electrolyte based on polydiethylene glycol dimethacrylate and its copolymer

Gel electrolytes were prepared by thermal polymerization of diethylene glycol dimethacrylate (DIEGD) or its copolymer with methoxy polyethylene glycol monomethacrylate, molecular weight 400 (PEM 400), at a molar ratio of 3 1 in the presence of propylene carbonate (PC) and LiClO 4. Conductivity was measured by impedance spectroscopy. It was found that the conductivity data follow the Arrhenius equation in the homopolymer gel system, while the VTF equation holds true in the copolymer gel system. An increase in conductivity was observed in the copolymer gel system. However, whether in the homopolymer or in the copolymer gel system, a maximum ambient temperature conductivity was found at a salt concentration near 1.50 mol l . Further, the activation energy values calculated from Arrhenius plots for the homopolymer gel system tended to reach a minimum value with increasing salt concentration.

Ionic conduction in poly( N, N-dimethylacrylamide) gels complexing lithium salts

Ionic conductivities of gel electrolytes prepared from poly( N, N,-dimethylacrylamide) (PDMA) and lithium salts (perchlorate and trifluoromethanesulphonate), incorporating N, N-dimethylacetamide (DMAc) as plasticizer, were studied. The molar mass of the polymer was controlled by use of ethane thiol as a chain transfer agent. The salt-free and salt-containing materials free from added DMAc were tough, non-crystalline, transparent solids. Complexes of high molar mass PDMA and lithium salts, incorporating 60% by weight of DMAc were tacky resins exhibiting bulk ionic conductivities from 2 × 10 −4 S cm −1 at room temperature to 7 × 10 −3 S cm −1 at 393 K. Rubbery solids were obtained by crosslinking the highly plasticized gels, and these materials had bulk ionic conductivities above 10 −3 S cm −1 at room temperature.