Poly Ethylene Oxide Research Articles

A method for deriving oligomers from sulfamide monomer and their application as electrolytes

This paper describes the development of a method of catalytic polymerization that was then applied to synthesize sulfate-based oligomers from sulfamide. Two molecules, copper triflate and copper acetate, catalyzed the formation of oligomers with diol monomers. Two oligomers were identified as products of the reactions. Oligomers with sulfate incorporated in the backbone proved to have an ability for ion diffusion. When the oligomers were doped with lithium salt, anion transportation was predominant, as shown by solid-state NMR. The lithium ion was found to be strongly bonded to the backbone, while the anion was highly mobile. To corroborate this finding, we conducted molecular dynamics (MD) simulations, which revealed the structural characteristics and static properties of two electrolytes containing LiTFSI and two different polyethylene oxide oligomers. Interactions between the anion and cation were analyzed through computation of the radial distribution function (RDF) and the spatial distribution function (SDF). Our findings indicate that while the anion presents weak interactions with the polymer chain, the cation interacts strongly with the oligomer backbone.

Diffusive Memristor with CuS Nanoparticles Embedded in Polymeric Film as Artificial Nociceptor.

The threshold behavior and the ion diffusion dynamics in diffusive volatile memristors have a very uncanny resemblance to the transduction process of biological nociceptors. Hence, the diffusive memristors are considered the most suited for making artificial nociceptive systems. To facilitate their widespread adoption, it is imperative to develop polymeric or organic-inorganic hybrid material-based diffusive memristors that are economical, biocompatible, and easily processable. In this study, we present a cluster-type polymeric diffusive memristor where copper is used as the active top electrode. The switching medium comprises copper(II) sulfide (CuS) nanoparticles embedded in poly(ethylene oxide) (PEO). The devices show electrochemical metalization (ECM)-type and bidirectional diffusive volatile memory with high nonlinearity (104) and turn-on slope (5.6 mV/dec). They reliably remain diffusive volatile with up to 10 wt % CuS in PEO and for a wide range of compliance (10-6 to 10-2 A) without transitioning to the bipolar nonvolatile type. The low reduction potential of CuS and optimal segmental dynamics of PEO work synergistically to ensure stable and reproducible diffusive memory. The CuS nanoparticles act as bipolar electrodes, undergoing local oxidation and reduction under the influence of the bias. The switching of resistance states in the CuS-PEO memristors is attributed to the formation of cluster-type filaments between CuS nanoparticles within the PEO matrix supported by the participation of copper ions from the top Cu electrode. The observation of low filament temperature and the independence of on-state resistance with respect to the device area and temperature further corroborate the cluster-type filament in CuS-PEO memristors. Using a 5 wt % CuS-based device, an artificial nociceptor is realized, which successfully mimics most of the nociceptive plasticities such as threshold, relaxation, no adaptation, and sensitization.

Review on Poly(ethylene oxide)-Based Solid Electrolytes: Key Issues, Potential Solutions, and Outlook

Review on Poly(ethylene oxide)-Based Solid Electrolytes: Key Issues, Potential Solutions, and Outlook

Ion Transport at Polymer-Argyrodite Interfaces.

Solid-state electrolytes, particularly polymer/ceramic composite electrolytes, are emerging as promising candidates for lithium-ion batteries due to their high ionic conductivity and mechanical flexibility. The interfaces that arise between the inorganic and organic materials in these composites play a crucial role in ion transport mechanisms. While lithium ions are proposed to diffuse across or parallel to the interface, few studies have directly examined the quantitative impact of these pathways on ion transport and little is known about how they affect the overall conductivity. Here, we present an atomistic study of lithium-ion (Li+) transport across well-defined polymer-argyrodite interfaces. We present a force field for polymer-argyrodite interfacial systems, and we carry out molecular dynamics and enhanced sampling simulations of several composite systems, including poly(ethylene oxide) (PEO)/Li6PS5Cl, hydrogenated nitrile butadiene rubber (HNBR)/Li6PS5Cl, and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/Li6PS5Cl. For the materials considered here, Li-ion exhibits a preference for the ceramic material, as revealed by free energy differences for Li-ion between the inorganic and the organic polymer phase in excess of 13 kBT. The relative free energy profiles of Li-ion for different polymeric materials exhibit similar shapes, but their magnitude depends on the strength of interaction between the polymers and Li-ion: the greater the interaction between the polymer and Li-ions, the smaller the free energy difference between the inorganic and organic materials. The influence of the interface is felt over a range of approximately 1.5 nm, after which the behavior of Li-ion in the polymer is comparable to that in the bulk. Near the interface, Li-ion transport primarily occurs parallel to the interfacial plane, and ion mobility is considerably slower near the interface itself, consistent with the reduced segmental mobility of the polymer in the vicinity of the ceramic material. These findings provide insights into ionic complexation and transport mechanisms in composite systems, and will help improve design of improved solid electrolyte systems.

Extensional rheology of elastoviscous aqueous PEO/PEG or DMS Boger fluids and weakly elastic alternatives for investigating viscoelastic flows and instabilities

Boger fluids that exhibit a rate-independent shear viscosity (typically ∼ 1 Pa∙s = 1000x water viscosity) and elasticity measurable using torsional rheometers (modulus, relaxation time, or first normal stress difference) are considered as the realization of viscoelastic fluids described by the Oldroyd-B model. However, Boger fluids, conventionally formulated as dilute solutions of high molecular weight (Mw) polymers in relatively high viscosity solvents (or solutions of oligomers or lower Mw polymer), are unsuitable for emulating polymeric fluids used in coating formulations that are lower in viscosity, appear inelastic in torsional shear rheometry, and yet appear prone to viscoelastic instabilities. Therefore, Dontula, Macosko, and Scriven (DMS) (AIChE J, 1998) chose to create an alternative model of elastic fluids by dissolving ultrahigh molecular weight (UHMw) poly(ethylene oxide) (PEO) in an aqueous solution of its lower Mw analog, often referred to as poly(ethylene glycol) or PEG. Even though numerous studies of printing and coating flow instabilities use this aqueous PEO/PEG or DMS Boger fluids as model viscoelastic fluids, only a few explicitly measured elastic properties, especially using relaxation time, and hardly any characterized extensional rheology. In this contribution, we recreate the DMS Boger fluids to examine their elasticity and extensional rheology response using dripping-onto-substrate (DoS) rheometry that relies on an analysis of capillarity-driven pinching dynamics. Though the aqueous PEG solution is often treated as a viscous and Newtonian solvent, we discover that in DoS rheometry, both the PEG solution and the DMS Boger fluid display power law response followed by elastocapillary, in contradiction with the assumptions and the response expected of the Oldroyd-B model. Furthermore, the solution of entangled PEG chains influences specific viscosity, pinching dynamics, and measured extensional rheology response in striking contrast with Newtonian solvents of the same viscosity. Lastly, we describe the possibility of using dilute, aqueous solutions of UHMw PEO as model viscoelastic fluids for coating flows, for both elasticity and extensional viscosity can be determined using DoS rheometry. Due to their water-like viscosity, the aqueous PEO solutions appeal as model fluids that have elasticity, emulate Newtonian fluids in the early stages of pinching, and have a relaxation time tunable by changing polymer Mw or concentration.

Biocompatible Native Hyaluronan Nanofibers Fabricated via Aqueous PEO-Assisted Electrospinning and Heat-Quench Process.

Hyaluronan (HA) is widely used in cosmetic and biomedical applications due to its excellent biocompatibility and potential to promote wound healing. Nanofibrous HA, mimicking the extracellular matrix (ECM), is considered promising for therapeutic and cosmetic applications. However, the electrospinning process of HA often necessitates cytotoxic solvents and chemical modifications, compromising its biocompatibility and advantageous properties. In this study, poly(ethylene oxide) (PEO) was added to an aqueous solution of natural HA to improve its spinnability, enabling HA to be electrospun into fibers. The HA was rendered water-insoluble by treatment with an acidic solution, and the amorphized PEO, achieved by heat-quenching, was removed through water washing. This method distinguishes it from previous reports of fibers blended with PEO or other water-soluble polymers. Consequently, the resulting HA gel fibers demonstrated suitability for mesenchymal stem cell adhesion due to the exposure of HA on the fiber surface. Additionally, HA fibers were successfully applied directly onto the skin using a hand-held electrospinning device, indicating the potential for point-of-care and home use applications.

Machine Learning‐Guided Design and Synthesis of Eco‐Friendly Poly(ethylene oxide) Membranes for High‐Efficacy CO2/N2 Separation

AbstractMachine learning (ML)‐guided polymer design and synthesis will enable the next‐generation membrane material discovery for CO2 capture. Herein, ML is leveraged to establish a structure‐performance relationship for the eco‐friendly poly(ethylene oxide) (PEO) membrane and guide its design for high‐efficacy CO2/N2 separation. Through a rational fragment representation method and knowledge sharing across membranes fabricated by different methods, the precise prediction of CO2/N2 separation performance for PEO membranes with high Pearson correlation coefficients (0.973 for permeability and 0.875 for selectivity) despite data scarcity is demonstrated. Expertise knowledge and external monomer databases are then utilized in a human‐in‐the‐loop workflow to effectively explore high‐performance PEO membranes in the design space. Several discovered thermally crosslinked PEO membranes achieve CO2/N2 separation performances close to the 2019 Robeson upper bound, which are promising for practical large‐scale carbon capture applications. Model interpretation techniques are employed to provide data‐driven insights into the design of PEO membranes for high‐efficacy CO2/N2 separation. Further life cycle assessment results reveal the outstanding advantage of discovered PEO membranes in terms of environmental friendliness. The work highlights the enormous potential of ML in expediting the discovery of high‐performance carbon capture membrane materials.

Application of drag-reducing polymers in forest firefighting: Effects on wood properties and mechanism study

Based on the successful utilization of polymer additives in drag reduction for long-distance transportation and the intricacies of their application in firefighting contexts, this study investigated the impact of additives on wood properties in forest fire suppression through a combination of experiments and molecular dynamics simulations, focusing on wettability, fluidity, and combustibility. Optimal concentrations of polymer solutions were determined through contact angle measurements and surface flow experiments. The effects of polymers on wood water retention, thermal stability, and microstructure were analyzed using thermogravimetric analysis, infrared spectroscopy, and wood impregnation experiments. Wetting and flow models of polymers on cellulose surfaces were simulated to elucidate the wetting mechanism and dynamic behavior of polymers during flow. The results revealed that polyacrylamide (PAM) and polyethylene oxide (PEO) promoted wood surface wetting, improved flowability, enhanced water retention, and delayed decomposition at optimal concentrations. PAM exhibited superior effects in flow stability, thermal stability, and liquid absorption enhancement, attributed to strong hydrogen bonding between PAM and surfaces, primarily through amide groups. During flow, PAM molecules gradually aggregated and moved as aggregates along the X-axis. In contrast, the PEO system relied on electrostatic forces between water and surfaces, with dynamic processes involving repeated stretching and shrinking of PEO molecular chains to facilitate water flow and enhance wetting. This research contributes to delineating the application conditions and benefits of polymer on wood surfaces, enhancing the efficacy and potential of drag-reducing agents in firefighting applications.

Lithium fluoride additive helps construct stable electrode-electrolyte interfaces to boost the performance of Mg-S batteries

Most magnesium electrolytes react with the Mg anode surface to form a non-favorable passive layer that inhibits shuttling of the Mg ions and results in the short cycle life of the Mg cells. In this work, we probe LiF as an effective electrolyte additive to address the challenges of electrolyte degradation, Mg anode passivation, and polysulfide shuttle. The key to our strategy lies in modifying the halogen-free electrolytes (HFE) electrolyte-based Mg(NO3)2·6H2O salt dissolved in acetonitrile (ACN) and tetra ethylene glycol dimethyl ether (G4) with LiF additives, which play a crucial role in engineering stable electrolyte interfaces. These additives alter the chemical composition of the solid electrolyte interface (SEI) layer on the surface of the Mg anode, enabling low overpotential of Mg2+ extraction/insertion, improving the Mg2+ transference, and enhancing the electrochemical performance of the electrolyte. The Mg-S cell with modified electrolyte delivers a high discharge capacity of over 400 mAh g−1 for >10 cycles, compared with the short cycle life in the case of using a blank electrolyte. This remarkable performance underscores the potential of our findings in advancing magnesium sulfur battery technology.

Unraveling the Effect of Strain Rate and Temperature on the Heterogeneous Mechanical Behavior of Polymer Nanocomposites via Atomistic Simulations and Continuum Models.

Polymer nanocomposites are characterized by heterogeneous mechanical behavior and performance, which is mainly controlled by the interaction between the nanofiller and the polymer matrix. Optimizing their material performance in engineering applications requires understanding how both the temperature and strain rate of the applied deformation affect mechanical properties. This work investigates the effect of strain rate and temperature on the mechanical properties of poly(ethylene oxide)/silica (PEO/SiO2) nanocomposites, revealing their behavior in both the melt and glassy states, via atomistic molecular dynamics simulations and continuum models. In the glassy state, the results indicate that Young's modulus increases by up to 99.7% as the strain rate rises from 1.0 × 10-7 fs-1 to 1.0 × 10-4 fs-1, while Poisson's ratio decreases by up to 39.8% over the same range. These effects become even more pronounced in the melt state. Conversely, higher temperatures lead to an opposing trend. A local, per-atom analysis of stress and strain fields reveals broader variability in the local strain of the PEO/SiO2 nanocomposites as temperature increases and/or the deformation rate decreases. Both interphase and matrix regions lose rigidity at higher temperatures and lower strain rates, blurring their distinctiveness. The results of the atomistic simulations concerning the elastic modulus and Poisson's ratio are in good agreement with the predictions of the Richeton-Ji model. Additionally, these findings can be leveraged to design advanced polymer composites with tailored mechanical properties and could optimize structural components by enhancing their performance under diverse engineering conditions.

Shell Distribution of Vitamin K3 within Reinforced Electrospun Nanofibers for Improved Photo-Antibacterial Performance.

Personal protective equipment (PPE) has attracted more attention since the outbreak of the epidemic in 2019. Advanced nano techniques, such as electrospinning, can provide new routes for developing novel PPE. However, electrospun antibacterial PPE is not easily obtained. Fibers loaded with photosensitizers prepared using single-fluid electrospinning have a relatively low utilization rate due to the influence of embedding and their inadequate mechanical properties. For this study, monolithic nanofibers and core-shell nanofibers were prepared and compared. Monolithic F1 fibers comprising polyethylene oxide (PEO), poly(vinyl alcohol-co-ethylene) (PVA-co-PE), and the photo-antibacterial agent vitamin K3 (VK3) were created using a single-fluid blending process. Core-shell F2 nanofibers were prepared using coaxial electrospinning, in which the extensible material PEO was set as the core section, and a composite consisting of PEO, PVA-co-PE, and VK3 was set as the shell section. Both F1 and F2 fibers with the designed structural properties had an average diameter of approximately 1.0 μm, as determined using scanning electron microscopy and transmission electron microscopy. VK3 was amorphously dispersed within the polymeric matrices of F1 and F2 fibers in a compatible manner, as revealed using X-ray diffraction and Fourier transform infrared spectroscopy. Monolithic F1 fibers had a higher tensile strength of 2.917 ± 0.091 MPa, whereas the core-shell F2 fibers had a longer elongation with a break rate of 194.567 ± 0.091%. Photoreaction tests showed that, with their adjustment, core-shell F2 nanofibers could produce 0.222 μmol/L ·OH upon illumination. F2 fibers had slightly better antibacterial performance than F1 fibers, with inhibition zones of 1.361 ± 0.012 cm and 1.296 ± 0.022 cm for E. coli and S. aureus, respectively, but with less VK3. The intentional tailoring of the components and compositions of the core-shell nanostructures can improve the process-structure-performance relationship of electrospun nanofibers for potential sunlight-activated antibacterial PPE.

A General Strategy toward Enhanced Electrochemical and Mechanical Performance of Solid‐State Lithium Batteries through Constructing Covalently Bonded Electrode Materials/Electrolyte Interfaces

AbstractSolid‐state lithium batteries (SSLBs) offer inherent safety and high energy density for next‐generation energy storage, but the large interfacial resistance and poor physical connection between electrode materials and the solid electrolyte (SE) severely impede their practical applications. This work reports a general strategy to introduce covalent bonds between electrode materials and SE, not only reducing interfacial resistance but also enhancing electrochemical stability and mechanical robustness of SSLBs. The covalent bonding is accomplished by functionalizing electrode surfaces with C═C groups, enabling in situ copolymerization with telechelic polymers in the SE. This approach is applicable to various cathode/anode materials and SEs. Particularly, the SSLBs comprising LiFePO4 cathode, Li6.75La3Zr1.75Ta0.25O12/(polyethylene oxide (PEO)/lithium bis(trifluoromethylsulfonyl)imide (LiTFSI)/silk composite SE and metallic lithium anode exhibit a specific capacity of 158.4 mAh g−1 and can be cycled at 2 C for 2200 times with >80% retention. Additionally, the SSLBs containing the high nickel‐content LiNi0.96Co0.03Mn0.01O2 cathode can afford a high specific capacity of 201.8 mAh g−1. Comprehensive experimental examination and theoretical simulations confirm that the lowered interfacial resistance and intimately contacted electrode materials/electrolyte interfaces facilitate Li+ transport at different stages of charge. Furthermore, the covalently bonded electrode/electrolyte interfaces also endow SSLBs with outstanding mechanical stability, enabling flexible SSLB pouch cells to operate under various bending states without performance decay.

A simple and efficient approach for pore structure optimization and hydrophilic modification of PTFE nanofiber membrane

Polytetrafluoroethylene (PTFE) membranes have great potential for treating wastewater in harsh environment due to their excellent stability. However, difficulties in the pore structure optimization and functional modification of biaxial stretched PTFE membrane have limited its further applications in liquid separation. Herein, we presented a simple and efficient approach for the preparation and hydrophilic modification of electrospun PTFE nanofiber membranes. This method involved optimizing the pore structure of PTFE nanofiber membranes through adjusting the mass ratio of the spinning carrier polyethylene oxide (PEO) and PTFE, followed by introducing the acetalized polyvinyl alcohol (PVA) on the membrane’s pore surface to improve the hydrophilicity. The average pore size changed from 288.5 to 161.3 nm, while the water contact angle reduced from 135.7° to 50.9°, which not only increased the water permeate flux from 68.56 to 1056.16 L·m−2·h−1, but also achieved high rejection rates of 99.3 % and 97.3 % for carbon (1 μm) and SiO2 (100 nm) particles respectively. Meanwhile, the obtained PTFE nanofiber membrane also exhibited excellent hydrophilic stability after long term exposure to harsh environments (pH=2 HCl, pH=12 NaOH, 1000 ppm NaClO) and 100 friction cycles (5 g weights on 1000 mesh sandpaper). This approach of preparing hydrophilic PTFE nanofiber membranes showed significant potential for practical applications in wastewater treatment.

Free Volume Mediated Decoupling of Ionic Conduction from Segmental Relaxation Leading to Enhancement in Ionic Conductivity of Polymer Electrolytes at Low Temperatures.

Coupling between segmental relaxation and ionic conduction has limited the ionic conductivity of flexible polymers like poly(ethylene oxide), PEO, based electrolytes especially at low temperatures where segmental relaxation becomes extremely slow. In the present study, we show that ionic conduction becomes decoupled from segmental relaxation in PEO-based electrolytes simply by loading succinonitrile (SN). As a result of SN interactions induced rigid chain packing of PEO, the semicrystalline morphology of PEO is completely altered along with the enhancement in number density of free volumes having smaller size and narrower size distribution. These free volumes provide additional pathways for ionic diffusion independent of segmental relaxations of PEO leading to decoupling of ionic diffusion from the segmental relaxation process. The decoupling finally leads to nearly two orders higher ionic conductivity (∼10-11 Scm-1)at glass transition temperature (Tg ∼ 210 K), than what is expected in the case of complete coupling.

Effects of Dye Addition on the Rheological Properties of Aqueous Polymer Solutions.

In many commercial applications, polymer-dye interactions are frequently encountered from food to wastewater treatment, and while shear rheology has been well characterized, the extensional properties are not well known. The extensional viscosity ηE and relaxation time λE are the extensional rheological parameters that provide valuable insights into how aqueous polymers respond during deformation, and this study investigated the effect of dyes on the extensional rheology of three different aqueous polymer solutions (e.g., anionic, cationic, and neutral) paired with two different dye salts (e.g., anionic and cationic) using drop pinch-off experiments. We have found that the influence of dyes on the pinch-off dynamics is complex but generally leads to a decrease in, for example, the apparent extensional relaxation time. We have utilized the dripping-onto-substrate method to probe the uniaxial deformation of widely used polymers such as xanthan gum (XG), poly(diallyldimethylammonium chloride) (PDADMAC), and poly(ethylene oxide) (PEO) as the anionic, cationic, and neutral polymers, respectively, paired with either fluorescein (Fl) or methylene blue (MB) as the anionic and cationic dyes, respectively. Polymer-dye pairs with opposite charges (e.g., XG-MB and PDADMAC-Fl) displayed a pronounced decrease in pinch-off times, but even PEO, which is a neutral polymer, resulted in decreased pinch-off times, which was restored by the addition of NaCl. The pinch-off times for the Boger fluid (mixture of poly(ethylene glycol) and PEO), however, were surprisingly uninfluenced by dyes. These results showed that not only did the small addition of dyes strongly decrease the polymer relaxation times, but the relative importance of the dye salts on the polymer pinch-off dynamics was also different from that of pure salts such as NaCl.

PEO kaolinite intercalation interface accelerates lithium-ion transfer for all-solid-state lithium metal batteries

The improvement of ionic conductivity and Li dendrite inhibition capability of poly(ethylene oxide)(PEO)-based solid polymer electrolytes(SPEs) is urgent for the development of all-solid-state lithium metal batteries (ASSLMBs). Here, intercalated composite consisted with PEO polymer chains inserted into the clay gallery of the formamide intercalated kaolinite (KM) is formed. Due to this alternating organic-inorganic layered structure, the crystallinity of PEO decreases to 26.2% and the ion conductivity of SPE with 3% KM of PEO mass added(PEO+KM-3) increased to 1.43 × 10−3 S cm−1 at 60 °C. Besides, bis (trifluoromethane) sulfonimide lithium salt (LiTFSI) interacts with formamide to form a complex, making the local solvated Li+ transports close to a quasi-solid model. PEO+KM-3 SPE exhibits a good inhibition effect on lithium dendrites due to the formation of organic silicon at lithium anode side, and Li/ PEO+KM-3/Li cell works steadily for more than 1600 h at 60 °C with 0.1 mA cm−2. The assembled Li//LiFePO4 cell provides a capacity of 118 mAh g−1 after 500 cycles at 0.5 C at 60 °C.

Single‐ion conducting polymer electrolytes with temperature‐independent modulus using cellulose nanocrystal‐MXene and Poly(tetramethylene glycol)‐based waterborne polyurethane and PEO

AbstractWith the rapid progress of electric vehicles, the focus on high‐energy‐density anodes has increased substantially. Lithium metal (Li) possesses a high energy density of 3800 mAh/g. However, it poses safety issues for liquid electrolytes, mandating the use of safer replacements like solid polymer electrolytes (SPEs). In this regard, polyethylene oxide (PEO), as the most prominent SPE, shows the highest ionic conductivity (σ) among polymers despite facing challenges including loss of thermomechanical stability around 60°C and low lithium‐ion (Li+) transference number (). Here, we designed SPEs consisting of PEO, poly (tetramethylene glycol)‐based waterborne polyurethane (WPU), cellulose nanocrystal (CNC), and MXene. The presence of WPU was quite effective at increasing (). High CNC loading () made elastic modulus () independent of temperature with terminal , while improving σ and . These achievements were attributed to CNCs competing with over oxygen atoms of PEO and the formation of a strong CNC network. was able to increase σ from attributed to intercalation of PEO into its interlayer spaces while also increasing to 0.897. The SPEs showed a high electrochemical stability window. The optimal electrolyte showed high Coulombic efficiency and stable cycling performance.Highlights Ionomeric units resulted in a high lithium‐ion transference number () Hydrogen bonding was partially responsible for increased Cellulose nanocrystals (CNCs) increased ionic conductivity and CNCs suppressed PEO spherulites' size and increased thermomechanical stability MXene disrupts PEO crystal growth and provides a new route for conduction

Advancements in Polyethylene Oxide (PEO)-Active Filler Composite Polymer Electrolytes for Lithium-Ion Batteries: A Comprehensive Review and Prospects.

Polyethylene oxide (PEO) has become a highly sought-after polymer electrolyte for lithium-ion batteries (LIBs) due to its high ionic conductivity, strong mechanical properties, and broad electrochemical stability range. However, its usefulness is hindered by its limited ionic conductivity at typical temperatures (<60 °C). Many researchers have delved into the integration of active fillers into the PEO matrix to improve the ionic conductivity and overall efficiency of composite polymer electrolytes (CPEs) for LIBs. This review delves deeply into the latest developments and insights in CPEs for LIBs, focusing on the role of PEO-active filler composites. It explores the impact of different types and morphologies of active fillers on the electrochemical behavior of CPEs. Additionally, it explores the mechanisms that contribute to the improved ionic conductivity and Li-ion transport in PEO-based CPEs. This paper also emphasizes the present obstacles and prospects in the advancement of CPEs containing PEO-active filler composites for LIBs. It serves as a valuable reference for scientists and engineers engaged in the domain of advanced energy storage systems, offering insights for the forthcoming development and enhancement of CPEs to achieve superior performance in LIBs.

A stationary phase of tetraethylene glycol-modified silica for separation of phenolic acids

AbstractSilica, as a stationary phase, has low separation efficiency accompanied by overlapping, broadened, and tailed peaks, so it needs to be modified to improve its efficiency. This study aims to develop a silica-based stationary phase modified by tetraethylene glycol (TEG) to separate phenolic compounds. Silica was modified by a chemical bond between silanol groups on the silica surface and TEG through a 3-glycidyloxypropylmethoxysilane reaction. The modified silica was packed into a capillary column and used to separate simple phenolic compounds consisting of phenol, pyrocatechol, and pyrogallol. A sample of 0.2 µL was injected into the capillary liquid chromatography and the mobile phase employed was acetonitrile 98% with a flow rate of 3 μL min−1. Elution was also done isocratically in this process and detection was carried out at a wavelength of 254 nm. The mixture of simple phenolic compounds was successfully separated in less than 7 min. The asymmetry factor and resolution were 1.43–2.12 and 1.72–5.43 respectively. The number of the theoretical plates ranged from 213 to 7,857. Columns containing Si-TEG stationary phase also separate phenolic compounds, which consist of gallic acid, syringic acid, ferulic acid, and caffeic acid. A sample of 0.2 µL was injected into the capillary liquid chromatography and successfully separated the mixture in less than 12 min. The samples were eluted isocratically using a mixture of methanol and 50 mM phosphate buffer pH 2.5 (8:92) with a flow rate of 3 μL min−1. The phenolic acids compounds were detected at a wavelength of 280 nm. The chromatogram showed four separate peaks. The asymmetry factor and resolution were 1.53–1.63 and 1.14–1.74, respectively, but the number of the theoretical plates was low, ranging from 190 to 796.

PVDF Binder in All-Solid-State Lithium Batteries with NCM/Sulfide/PVDF Cathode, Oxide/PEO SE Layer, and Li-metal Anode

Sulfide-based solid electrolyte such as Li6PS5Cl (LPSCl) is unstable in contact with Li metal electrode due to decomposing to by-product resulting in poor performance. Therefore, the introduction of an interlayer to suppress reactivity is essential. In this study, instead of an interlayer, an oxide/polymer composite electrolyte was applied to suppress side reactions, while a sulfide-based electrolyte was used at the cathode to improve interfacial control between the cathode and the electrolyte. All-solid-state lithium batteries (ASLBs) were prepared by applying sulfide-based solid electrolyte (argyrodite, Li6PS5Cl) including NCM424, polyvinylidene fluoride (PVDF), and Super-P in a composite cathode layer, and a composite solid electrolyte (CSE) layer by mixing an oxide-based solid electrolyte (garnet, Al-doped Li7La3Zr2O12 (LLZO)), polymer (PEO, polyethylene oxide) and lithium metal as the anode. In this study, NCM424 powder was coated with LiNbO3 to prevent chemical reaction with the sulfide electrolyte. As the PVDF binder was applied to the cathode of the ASLB, the discharge capacity of the cell was approximately 163 mAh g−1 at 70 °C, 0.1 C, and 4.2 V cut-off and its capacity retention was 83% after 50 cycles. The effects of the PVDF were evaluated using both pouch-type cells. The capacity and cycle retention are greatly dependent on the PVDF content of the cathode materials and the drying temperature during the fabrication of the cathode. When the cathode with PVDF binder was dried at 130 °C, initial cycling was required for activation of the pouch cell, and it was possible to overcome this by adding a plasticizer.