Lithium Trifluoromethanesulfonate Research Articles

Plastic crystal as a plasticizer for enhancing Li+ ion conductivity in PMMA–LiTf polymer electrolyte

In this work, plastic crystal polymer electrolytes (PCPE) composed of polymethyl methacrylate (PMMA), lithium trifluoromethanesulfonate (LiTf), and succinonitrile (SN) were prepared using the solution casting method. The concentration of the plastic crystal SN was varied from 2 wt% to 20 wt%. The ionic conductivity of the PCPEs was measured at room temperature, with a maximum value of 5.75×10−5 S/cm observed for the PCPE with 10 wt% SN. An increase in the amorphous nature of the PCPE was noted from X-ray diffraction analysis, attributed to the interactions among PMMA, LiTf, and SN. FTIR analysis confirmed the presence of interactions among the components in the samples. A higher dielectric constant was obtained for the PCPE with 10 wt% SN. Dielectric tangent analysis revealed improved salt dissolution at higher concentrations of SN (20 wt%). The thermal stability of the PCPEs was also enhanced with the addition of SN.

Entropy-Driven 60mol% Li Electrolyte for Li Metal-Free Batteries.

Highly Li-concentrated electrolytes are acknowledged for their compatibility with Li metal negative electrodes and high voltage positive electrodes to achieve high-energy Li metal batteries, showcasing stable and facile interfaces for Li deposition/dissolution and high anodic stability. This study aims to explore a highly concentrated electrolyte by adopting entropy-driven chemistry for Li metal-free (so-called anode-free) batteries. The combination of lithium bis(fluorosulfonyl)amide (LiFSA) and lithium trifluoromethanesulfonate (LiOTf)salts in a pyrrolidinium-based ionic liquid is found to significantly modify the coordination structure, resulting in an unprecedented 60mol% Li concentration and a low solvent-to-salt ratio of 0.67:1 in the electrolyte system. This novel 60mol% Li electrolyte demonstrates unique coordination stricture, featuring a high ratio of monodentate-anion structures and aggregates, which facilitates an enhanced Li+ transference number and improved anodic stability. Moreover, the developed electrolyte provides a facile de-coordination process and leads to the formation of an anion-based solid electrolyte interface, which enables stable Li deposition/dissolution properties and demonstrates excellent cycling stability in the Li metal-free full cell with a Li[Ni0.8Co0.1Mn0.1]O2 (NCM811) positive electrode.

A Computational and Spectroscopic Analysis of Solvate Ionic Liquids Containing Anions with Long and Short Perfluorinated Alkyl Chains.

Anion-driven, nanoscale polar-apolar structural organization is investigated in a solvate ionic liquid (SIL) setting by comparing sulfonate-based anions with long and short perfluorinated alkyl chains. Representative SILs are created from 1,2-bis(2-methoxyethoxy)ethane ("triglyme" or "G3"), lithium nonafluoro-1-butanesulfonate, and lithium trifluoromethanesulfonate. Molecular dynamics simulations, density functional theory computations, and vibrational spectroscopy provide insight into the overall liquid structure, cation-solvent interactions, and cation-anion association. Significant competition between G3 and anions for cation-binding sites characterizes the G3-LiC4F9SO3 mixtures. Only 50% of coordinating G3 molecules form tetradentate complexes with Li+ in [(G3)1Li][C4F9SO3]. Moreover, the SIL is characterized by extensive amounts of ion pairing. Based on these observations, [(G3)1Li][C4F9SO3] is classified as a "poor" SIL, similar to the analogous [(G3)1Li][CF3SO3] system. Even though the comparable basicity of the CF3SO3- and C4F9SO3- anions leads to similar SIL classifications, the hydrophobic fluorobutyl groups support extensive apolar domain formation. These apolar moieties permeate throughout [(G3)1Li][C4F9SO3] and persist even at relatively low dilution ratios of [(G3)10Li][C4F9SO3]. By way of comparison, the CF3 group is far too short to sustain polar-apolar segregation. This demonstrates how chemically modifying the anions to include hydrophobic groups can impart unique nanoscale organization to a SIL. Moreover, tuning these nano-segregated fluorinated domains could, in principle, control the presence of dimensionally ordered states in these mixtures without changing the coordination of the lithium ions.

Novel mono substituted pyridoimidazoisoquinoliniums via a silver-catalyzed intramolecular cyclization and their applications in cellular imaging.

Cationic heterocycles, an important class of organic compounds soluble in polar solvents, have been gaining attention in the construction of fluorescent probes. This paper reports the quick synthesis of novel pyrido[1',2';2,3]imidazo[5,1-a]isoquinoliniums starting from 2-(2-ethynylphenyl)imidazo[1,2-a]pyridines at room temperature via intramolecular cyclization by employing a catalytic amount of silver trifluoromethanesulfonate in addition to lithium trifluoromethanesulfonate and silica gel as the counter anion source and additive, respectively. The designed pyridoimidazoisoquinoliniums consisted of an imidazo[1,2-a]pyridine fused isoquinolinium. The X-ray diffraction results revealed that pyrido[1',2';2,3]imidazo[5,1-a]isoquinolinium trifluoromethanesulfonate contained considerable planar parent skeletons and interacted by π-π stacking with neighbouring molecules. Furthermore, in a methanol solution the designed 6-phenyl derivative exhibited strong fluorescence in the 420-450 nm region in addition to strong mitochondrial specificity in a cell staining assay.

Divalent Viologen Cation‐Based Ionogels Facilitate Reversible Intercalation of Anions in PProDOT‐Me2 for Flexible Electrochromic Displays

AbstractThe electrochromic (EC) polymer poly (3,4‐(2,2‐dimethylpropylenedioxy)thiophene) (PProDOT‐Me2) is expected to be used in flexible e‐paper displays because of its great optical modulation ability and inherent flexibility. While the EC effect is primarily determined by the anions and cations in the electrolyte, yet suffers from inorganic salt based on monovalent Li+ cations and corresponding anions, such as lithium perchlorate(LiClO4), lithium bis(trifluoromethane sulfonyl) imide (LiTFSI), and lithium trifluoromethane sulfonate (LiTRIF), which may impact the overall EC performance of the EC device caused by insufficient ion doping/de‐doping processes. Herein, the divalent viologen cation‐based ionogel (VGE) is developed to tackle the challenge. Owing to its more anions design, the doping/de‐doping process in the PProDOT‐Me2 is more sufficient, thereby enhancing the optical modulation range (ΔR = 39.4%) of PProDOT‐Me2, compared to monovalent Li+ cation‐based ionogel (ΔR = 13.3%). Meanwhile, the VGE has good interface contact with PProDOT‐Me2 and the flexible electrode, which makes the VGE‐based EC device (V‐ECD) exhibit commendable mechanical stability. To demonstrate the potential application in flexible e‐paper displays, the simple eight‐digit EC display device is assembled from seven V‐ECDs, each of which hasa high switching speed, robust cycling stability, and low operating energy consumption.

Polyhydroxyurethane and Poly(ethylene oxide) Multiblock Copolymer Networks: Crosslinking with Polysilsesquioxane, Reprocessing and Solid Polyelectrolyte Properties.

This contribution reports the synthesis of polyhydroxyurethane (PHU)-poly(ethylene oxide) (PEO) multiblock copolymer networks crosslinked with polysilsesquioxane (PSSQ). First, the linear PHU-PEO multiblock copolymers were synthesized via the step-growth polymerization of bis(6-membered cyclic carbonate) (B6CC) with α,ω-diamino-terminated PEOs with variable molecular weights. Thereafter, the PHU-PEO copolymers were allowed to react with 3-isocyanatopropyltriethoxysilane (IPTS) to afford the derivatives bearing triethoxysilane moieties, the hydrolysis and condensation of which afforded the PHU-PEO networks crosslinked with PSSQ. It was found that the PHU-PEO networks displayed excellent reprocessing properties in the presence of trifluoromethanesulfonate [Zn(OTf)2]. Compared to the PHU networks crosslinked via the reaction of difunctional cyclic carbonate with multifunctional amines, the organic-inorganic PHU networks displayed the decreased reprocessing temperature. The metathesis of silyl ether bonds is responsible for the improved reprocessing behavior. By adding lithium trifluoromethanesulfonate (LiOTf), the PHU-PEO networks were further transformed into the solid polymer electrolytes. It was found that the crystallization of PEO chains in the crosslinked networks was significantly suppressed. The solid polymer electrolytes had the ionic conductivity as high as 7.64 × 10-5 S × cm-1 at 300 K. More importantly, the solid polymer electrolytes were recyclable; the reprocessing did not affect the ionic conductivity.

Pyridinium and trifluoromethanesulfonate bifunctional poly(ionic liquid)s for highly efficient and selective adsorption of anionic dyes

The efficient and selective removal of dyes from polluted water by low cost, durable, sustainable, and reusable adsorptions remain challenges. In this study, a pyridinium and trifluoromethanesulfonate bifunctional poly(ionic liquid)s, named Py-CF3SO3-PIL was prepared by co-polymerization of 4-vinyl pyridine (4VP), divinylbenzene (DVB) and styrene (ST), followed by quaternization with 1-bromobutane and anion exchange with lithium trifluoromethanesulfonate. The resulting bifunctional Py-CF3SO3-PIL exhibited remarkable adsorption capacity (2192 mg g−1) and efficiency (within 10 min) for selective removal (>99.9%) of methyl orange (MO) from (mixed) dye solutions. The superior adsorption capacity and selectivity of Py-CF3SO3-PIL towards the removal of MO was attributed to the strong electrostatic interactions and π-π stacking interaction between the adsorbent and MO dye. Detailed kinetic studies, adsorption isotherms, and thermodynamic experiments revealed an endothermic monolayer chemical adsorption mechanism of MO on Py-CF3SO3-PIL, which is perfectly matched with the Langmuir isotherm model (R2 > 0.999). Importantly, the Py-CF3SO3-PIL could be easily collected and regenerated for multiple repeated uses, highlighting its reusability. The exceptional adsorption capacity and selectivity towards anionic dyes make Py-CF3SO3-PIL a promising candidate for dye separation applications. Our findings will contribute to the rational design of functional poly(ionic liquid)s-based adsorbents for water purification.

Achieving stable interphases toward lithium metal batteries by a dilute and anion-rich electrolyte

It is necessary to find an ideal electrolyte suitable for high performance lithium metal batteries (LMBs). Herein, we construct a novel cluster-like and anion-rich dilute electrolyte system by using LiNO3 and trace lithium trifluoromethanesulfonate (LiOTf) in an ester-based electrolyte. In the designed system, NO3– is used as a modulator to regulate the coordination number of solvents and anions, and LiOTf is applied as a solubilizing agent of LiNO3 and trigger for the generation of large cluster. As a result, an anion-regulated solvation structure (ARSS) is obtained even in a dilute Li-ion concentration (<1.5 M), evidenced by various techniques, enabling the electrolyte a high ion-conductivity which vastly differs from a high concentration electrolyte system. Afterwards, the ARSS facilitates the formation of an inorganic-rich solid electrolyte interface (SEI) on both cathode and anode, ensuring the LMBs high stability and long cycling performance.

Impact of ionic liquid on structural, thermal and transport properties in gellan gum-lithium triflate solid polymer electrolyte

60 wt% gellan gum (GG) complexes with 40 wt% lithium trifluoromethanesulfonate (LiTf) solid polymer electrolytes (SPEs) with different concentrations of ethyl-dimethyl-propylammonium bis(tri-fluoromethylsulfonyl)imide, [EDPA][TFSI] ionic liquid (IL) have been prepared by solution casting technique. The aim of this work is to investigate the impact of IL in GG-LiTF SPEs on electrical, structural and thermal properties. The room temperature conductivity of 0.54 mS cm−1 has been obtained for the free IL sample. Addition of IL up to 20 wt% increases the conductivity to 2.18 mS cm−1. The contributing factors in the increase of conductivity were studied based on its structural characterisations. The addition of IL up to 20 wt% into the SPE has reduced the crystallinity nature to become more amorphous as can be seen in XRD deconvolution and DSC analysis. This change in structural nature has created more space between the polymer matrix for the free ions to dissociate and drive through the SPE, hence increasing conductivity. Nevertheless, the IL added seems not to affect the dissociation ratios of free ions, ion pairs and ion aggregates of LiTf, despite of clear complexation that occurred between GG and both ionic salts from FTIR analysis. Thus, the conductivity trend is governed by both charge carriers’ mobility and concentration in the electrolyte which can also be seen at elevated temperatures.

Na3V2O2(PO4)2F nanoparticles@reduced graphene oxide: a high-voltage polyanionic cathode with enhanced reaction kinetics for aqueous zinc-ion batteries

Na3V2O2(PO4)2F is characterized by a high theoretical specific capacity, high-voltage plateaus, large ion diffusion channels, and stable three-dimensional structure, which is a promising cathode candidate for rechargeable aqueous zinc-ion batteries (AZIBs). Nevertheless, the low electronic conductivity hinders its cycling and rate performance. In this work, a facile microwave-assisted solvothermal approach with postheat treatment has successfully produced Na3V2O2(PO4)2F nanoparticles with the dimension of 20–50 nm wrapped by reduced graphene oxide (rGO). The high pseudocapacitive contribution, high diffusion coefficient, low electrochemical impedance, favorable electrode wettability, and stable structure can be obtained by optimizing the chemical components of electrolyte and the content of rGO, facilitating the Zn2+ storage performance. Hence, Na3V2O2(PO4)2F@rGO delivers excellent electrochemical properties such as a high capacity of 127.0 mAh g−1 at 0.5C, a stable capacity of 63.9 mAh g−1 at 30C after 5000 cycles, and a high average voltage plateau of 1.50 V in hybrid aqueous electrolyte (2 M zinc trifluoromethane sulfonate (Zn(OTf)2) and 4 M lithium trifluoromethane sulfonate (LiOTf)). Furthermore, exceptional cycling performance in the soft-pack batteries with the size of 3 × 3.5 cm2 includes a reversible capacity of 84.1 mAh g−1 at 10C after 1000 cycles. In situ X-ray diffraction, ex situ X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy reveal reversible Zn2+ insertion/extraction process.

A nonequilibrium constitutive equation for the stress–strain behavior of water‐absorbed poly(methyl methacrylate)‐based materials

AbstractIn this work, the water absorption effects on the tensile behavior of a poly(methyl methacrylate) (PMMA) doped with lithium trifluoromethanesulfonate (LiCF3SO3) was investigated. It was found that the water content in the PMMA/LiCF3SO3system could be controlled using the salt content because of the system's remarkable water absorbability. Moreover, it was found that a dried PMMA/LiCF3SO3is more brittle compared to a pristine PMMA; however, PMMA/LiCF3SO3samples containing high water level demonstrated high drawability. The brittle‐to‐ductile transition was represented using a kinetic mechanism in which water spots accumulated around salts were spread throughout a whole sample specimen and stretched to a homogeneously water‐absorbed condition.

Investigation of flexible electrochemical storage with Li+/PVdF-HFP/PEO blend

ABSTRACT Design and development of lithium ion batteries with flexible solid polymer electrolyte along with high ionic conductivity is crucial and challenging so as to protect from electrical short circuits within electrochemical devices. The present research work describes the fabrication of lithium based solid polymer electrolytes (LSPEs) using polymer blends of poly (vinylidene fluoride- hexafluoropropylene) (PVdF-HFP), poly (ethylene oxide) (PEO) with selective weight ratios of lithium trifluoromethanesulfonate (LiCF3SO3) salt by using solution-cast approach. The scanning electron microscopy (SEM) exposed morphology of LSPE membranes depicts crosslinking of polymer network with salt elevates strong dissociation behavior of LiCF3SO3. The amorphous behavior of LSPEs explored using X-ray diffraction (XRD) crystallographs clearly accommodates reduction of average crystallite size from 10─6 m to 10─9 m. The complexation studies, bond length and force constants calculations, interaction of ions, ionic pairs and aggregates of LiCF3SO3 in LSPE films were briefly analyzed using Fourier transform infrared spectroscopy (FTIR). IR modes correspond to [δs (SO3)], [υas (SO3)], [υas (CF3)], and amorphous phase of PVdF-HFP results in complexation, whereas IR modes correspond to [δas (SO3)], [δs (CF3)], [δas (CF3)], [υs (SO3)], C=O and β-phase of PVdF-HFP attributes ionic pairs and aggregation phenomena. The [υs (SO3)] mode contribution toward ionic conductivity was detailed. The ionic conductivity (σionic) values were estimated using Electrochemical impedance spectroscopy (EIS). The σionic values were enhanced from 10─7 S/cm to 10─4 S/cm as salt concentration increases. Charge accumulation, ionic strength, and transference number analysis of LSPE membranes were investigated using Chronoamperometry and Cyclic Voltammetry. Further, we have fabricated flexible electrochemical storage device (FESD) which are accentuating carriers of smart electronics technology (SET) in terms of foldable and stretchable electronic devices. We have explored discharge characteristics of our FESD with an average discharge current of 3 mA for 25 hours and denoted using 0.04C rating.

Viscoelastic Properties of Water-Absorbed Poly(methyl methacrylate) Doped with Lithium Salts with Various Anions.

We investigated the effects of water absorption on the dynamic mechanical properties of poly(methyl methacrylate) doped with various generic lithium salts, such as lithium perchlorate trihydrate (LiClO4), lithium trifluoromethanesulfonate (LiCF3SO3), lithium nonafluorobutanesulfonate (LiC4F9SO3), and lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2)). The rates of weight change during water absorption of lithium salt-doped samples were higher in the following order: LiClO4, LiCF3SO3, LiC4F9SO3, and LiN(CF3SO2). Interestingly, the aforementioned order was the same as the order of the terminal relaxation times in the flow region of the viscoelastic measurement in the melting-state. This implies that the water absorption of the salt-doped PMMA occurs due to the factors that affect the pinning of the PMMA molecular chains in the places.

Preparation and Characterization of GG-LiCF3SO3-DMSO Gel Polymer Electrolyte for Potential Lithium-Ion Battery Application

This work uses gellan gum (GG) natural polymer as the base polymer to prepare gel polymer electrolytes (GPEs). Lithium trifluoromethanesulfonate (LiCF3SO3) salt is used as a charge supplier, and dimethyl sulfoxide (DMSO) acts as a plasticizer to keep the electrolyte in gel form. Two electrolyte systems are formed, which are LiCF3SO3-DMSO liquid electrolytes and GG-LiCF3SO3-DMSO GPEs. Liquid electrolyte with a composition of 12.42 wt.% LiCF3SO3-87.58 wt.% DMSO (LN3 electrolyte) revealed the highest room temperature conductivity (σrt) of 9.14 mS cm-1. The highest σrt value obtained by the LN3 electrolyte is strongly influenced by the charge carrier concentration (n) relative to the mobility (µ). To form GPEs, GG is added to the LN3 electrolyte since this sample composition gave the highest σrt. The electrolyte of 2.00 wt.% GG-12.18 wt.% LiCF3SO3-85.82 wt.% DMSO (GN3 electrolyte) showed the highest σrt of 9.96 mS cm-1. The highest σrt value obtained by GN3 electrolyte is strongly influenced by µ rather than n. The conductivity-temperature study showed that the increase in conductivity for GG-LiCF3SO3-DMSO GPEs is controlled by an increase in n, not µ. Linear sweep voltammetry (LSV) for the GN3 electrolyte showed high electrochemical stability up to 4.8 V. Cyclic voltammetry (CV) illustrated the redox process in the GN3 electrolyte is reversible. A lithium-ion battery fabricated with GN3 electrolyte showed a good discharge performance up to 480 hours with an average voltage of 1.50 V discharged at a current of 0.001 mA. Based on this work, it can be concluded that natural polymer GG-based GPE has great potential for use in LIBs as a charge transport medium.

Solvate Ionic Liquids: Assessing the Possibility of Determining the Composition by Means of Gas–Liquid Chromatography

A study is performed of the possibility of using gas–liquid chromatography (GLC) to determine the composition of solutions of lithium salts in aprotic dipolar solvents and solvate ionic liquids. The objects of study are solutions of lithium perchlorate and lithium trifluoromethanesulfonate in sulfolane and solvate complexes of lithium perchlorate with sulfolane obtained in two ways: direct interaction of the initial components in a given molar ratio and interaction of the components in a common solvent with its subsequent removal via evaporation. It is shown that GLC is a convenient way of determining the content of a solvating solvent in the composition of solutions and solvate ionic liquids. The presence of lithium salt in the analyzed solutions does not affect the period of retention; instead, it raises the degree of asymmetry of the chromatographic peak of the solvent and manifestation of the tailing effect. It is found that the presence of salt in the considered system also does not reduce the accuracy of determining the solvent content. The error in determining the content of solvent in solutions of lithium salts and solvate complexes by GLC is no greater than 1%.

Impact of charge carrier transport properties on conductivity-temperature dependence of gellan gum-LiCF3SO3 biopolymer electrolyte

Charge carrier density, mobility and diffusivity are three important transport properties in determining the ionic conductivity as well as the performance of solid polymer electrolyte. In this work, biopolymer electrolytes samples were prepared using the solution casting method by complexing gellan gum with different concentrations of lithium trifluoromethanesulfonate (3–15 wt.%). The values of charge carrier concentration, mobility, and diffusivity for electrolyte samples were estimated by fitting the Nyquist plot with an equation developed based on electrical impedance spectroscopy. At room temperature, the optimum electrolyte conductivity is 1.29×10−8 Scm−1 at 6 wt.% salt concentration. This result was supported by the highest percentage of free ions, 31.45%, observed in the FTIR method. As the temperature increases, the ionic conductivity increases to the optimum value before dropping. The highest conductivity of each sample was obtained at different temperatures (80°C–90°C) using the impedance method, whereas the percentage area of free ions was highest at 80°C for all samples with FTIR analysis. Overall, the ionic conductivity of this system has been dominated by the carrier charge density. Results suggest that, under these experimental conditions, electrical impedance spectroscopy is suitable for evaluating the charge transport properties at low temperatures.

An Ionically Conductive, Self-Powered and Stable Organogel for Pressure Sensing.

Gel-based ionic conductors are promising candidates for flexible electronics, serving as stretchable sensors or electrodes. However, most of them suffer from a short operating life, low conductivity and rely on an external power supply, limiting their practical application. Herein, we report a stable organogel ionic conductor with high conductivity and self-powering ability. Briefly, lithium trifluoromethanesulfonate, as a conductive salt, provides high conductivity and the poly(1,1-difluoroethylene) layers, as a self-powering system, supply stable energy output under the influence of pressure. Moreover, the proposed conductors withstand long-term and multi-cycle durability tests. The prepared auxiliary training device can withstand the impact of a basketball and detect the impact force, showing potential in passive sensing during practical applications.

A cost-effective water-in-salt electrolyte enables highly stable operation of a 2.15-V aqueous lithium-ion battery

Extensive efforts are currently underway to develop safe and cost-effective electrolytes for large-scale energy storage. In this regard, water-based electrolytes may be an attractive option, but their narrow electrochemical stability window hinders their realization. Although highly concentrated fluorinated electrolytes have been shown to be highly effective in suppression of water splitting, enabling significant widening of the applied potential range, they utilize expensive salts (e.g., lithium bis(trifluoromethane sulfonyl) imide [LiTFSI] or lithium trifluoromethane sulfonate [LiOTf]); hence, they cannot be considered for practical applications. Here, we demonstrate a cost-effective aqueous electrolyte solution combining 14 M LiCl and 4 M CsCl that allows stable operation of a 2.15-V battery comprising a TiO 2 anode and LiMn 2 O 4 cathode. Addition of CsCl to the electrolyte plays a double role in system stabilization: the added chloride anions interact with the free water molecules, whereas the chaotropic cesium cations adsorb at the electrified interface, preventing hydrogen formation. Mixed aqueous LiCl + CsCl electrolyte solution enables widely stable electrochemical window Cl − anions interact with the free H 2 O molecules and reduce their bulk activity The added chaotropic Cs + cations adsorb on the anode interface and prevent H 2 generation Long-term stable 2.15-V cell comprising TiO 2 anode and LiMn 2 O 4 cathode demonstrated The need for safe and cost-effective energy storage systems has advanced the development of aqueous batteries. Looking for a cost-effective electrolyte solution, Turgeman et al. propose saturated LiCl + 4 M CsCl. It is found that addition of CsCl significantly improves electrolyte stability and enables stable operation of a 2.15-V battery.

Performance enhancement of rechargeable magnesium–sulfur batteries based on a sulfurized poly(acrylonitrile) composite and a lithium salt

Research on magnesium-sulfur (Mg–S) batteries has gained great attention due to the high theoretical gravimetric and volumetric energy densities (1700 Wh kg−1 and 3200 Wh L−1), as well as because of their economic, ecologic and safety advantages. In this study, we present room-temperature Mg–S batteries with a sulfurized poly(acrylonitrile) composite (SPAN) cathode and a Mg2+/Li+ hybrid electrolyte (magnesium trifluoromethanesulfonate, (CF3SO3)2Mg), lithium trifluoromethanesulfonate, MgCl2 and AlCl3 in 1,2-dimethoxyethane (DME)). These cells deliver high discharge capacities and energy densities of 1100 mAh gs−1 and 700 Wh kgs−1 at 1 C, respectively, with >99.9% Coulombic efficiency. Electrochemical and kinetic measurements as well as post-mortem analysis revealed that utilization of SPAN and a lithium salt in the electrolyte is crucial and beneficial for the prevention of the polysulfide shuttle. It also dramatically reduces the cell resistance and the overpotential via the formation of MgLiSx species. Concomitantly, this system supports the formation of a solid electrolyte interface (SEI) layer, which greatly improves the reaction kinetics of the Mg2+ ions and the cycle performance.

Influence of PMMA on properties of polymer electrolyte based on epoxidized deprotenized natural rubber

The effect of co-polymer, i.e. poly(methyl methacrylate) (PMMA), and doping salt, i.e. lithium trifluoromethanesulfonate (LiCF3SO3) inthe epoxidized rubber-polymer blends preparation was evaluated. The electrolyte membrane was developed through solution castingmethod in the presence of 0-50wt.% of LiCF3SO3. The influence of LiCF3SO3 on chemical interaction and structure, ionic conductivity,mechanical properties, and glass transition temperature (Tg) of 45%-epoxidized deproteinized natural rubber (EDPNR45)-PMMA (80/20) membrane was determined using several techniques, i.e. F-IR, universal testing machine, multipotentiostat, and DSC. Infrared analysis showed that lithium salts might formed coordination bonds with the oxygen atoms of PMMA and EDPNR45. Ionic conductivity of EDPNR45/LiCF3SO3 blends have been evaluated and the highest conductivity (σ) was obtained in the presence of 35 wt.% of lithiumtrifluoromethanesulfonate (1.71 x 10-5S.cm-1). The PMMA content’s effect was also evaluated on the properties of EDPNR45/LiCF3SO3.The highest conductivity and mechanical strength values at EDPNR45/PMMA ratio of 80/20. Enhancing trend of Tg was obtained withthe increase of PMMA and salt concentration. FTIR characterization also confirms the interaction of salt with EDPNR45 and PMMA.