Nonvolatile Liquid Research Articles

Enhancing performance and sustainability of lithium manganese oxide cathodes with a poly(ionic liquid) binder and ionic liquid electrolyte

Current battery production involves various energy intensive processes and the use of volatile, flammable and/or toxic chemicals. This study explores the potential for using a water-soluble and functional binder, poly(diallyldimethylammonium) (PDADMA) with diethyl phosphate (DEP) as a counter anion, for lithium manganese oxide (LMO) cathodes. By replacing the traditional polyvinylidene fluoride (PVDF) binder and its associated toxic N-methyl-2-pyrrolidone (NMP) solvent, PDADMA-DEP offers a more sustainable and cost-effective solution. Notably, PDADMA-DEP electrodes do not require high-temperature calendaring to achieve high performance unlike PVDF electrodes. X-ray Photoelectron Spectroscopy (XPS) indicated significant interactions between the binder and LMO that enhance stability and ion conduction. The PDADMA-DEP binder demonstrated excellent electrochemical rate capability up to 10C with the conventional organic liquid electrolyte (LP30), outperforming PVDF electrodes. The performance of both binders using a safer and non-volatile ionic liquid electrolyte, specifically 50 mol% LiFSI in N-trimethyl-N-propylammonium bis(fluorosulfonyl)imide, was also investigated to enhance the overall safety and environmental impact of the battery system. IL-based cells utilizing a PDADMA-DEP cathode binder demonstrated a 58 % capacity retention over 500 cycles at 0.5C when cycled at room temperature.

Formulation and <i>in vitro</i> Evaluation of Liquisolid Compact of Celecoxib

<i>Introduction</i>: The liquisolid technique presents a promising avenue for enhancing the dissolution rate and bioavailability of poorly water-soluble drugs like celecoxib. This study investigated the formulation and evaluation of celecoxib tablets using this technique. <i>Aim</i>: To formulate and evaluate celecoxib tablets using the liquisolid technique, with the objective of enhancing its dissolution rate and bioavailability. <i>Methods</i>: Celecoxib tablets were prepared using the liquid-solid technique by incorporating a non-volatile liquid medication carrier and a suitable solid carrier. Various formulations were developed by altering the ratios of drug, carrier, and coating materials. The prepared tablets were characterized for their physical properties, drug content uniformity, <i>in vitro</i> dissolution behavior, and compatibility using Fourier-transform infrared (FTIR) spectroscopy. <i>Results</i>: The solubility profile showed that the maximum rate of solubility was recorded in PEG-400 (11.03 ± 0.01) when compared to other non-volatile solvents. The angle of slide, indicated that the excipients used were within the acceptable limit of 33°. The FTIR spectroscopy showed compatibility of the drug and excipients. The results of the SEM showed that spherically-shaped vesicles were formed. Evaluation of the pre-compression parameters indicated that the drug content was highest in batch F-11 hence its optimization (96.1 ± 0.90). The post compression evaluation indicated that the official tests were within the acceptable range for disintegration time (2.25 ± 0.35). The results of the <i>in vitro</i> release studies of the optimized formulation, conventional tablet and reference commercial tablet showed that the amount of drug released increased steadily with time over the 1-hour period. <i>Conclusion</i>: Our findings underscore its viability as a strategy to enhance the therapeutic efficacy of poorly water-soluble drugs, offering promising prospects for pharmaceutical formulation.

Recent Advances in Graphene Adaptive Thermal Camouflage Devices.

Thermal camouflage is a highly coveted technology aimed at enhancing the survivability of military equipment against infrared (IR) detectors. Recently, two-dimensional (2D) nanomaterials have shown low IR emissivity, widely tunable opto-electronic properties, and compatibility with stealth applications. Among these, graphene and graphene-like materials are the most appealing 2D materials for thermal camouflage applications. In multilayer graphene (MLG), charge density can be effectively tuned through sufficiently intense electric fields or through electrolytic gating. Therefore, MLG's optical properties, like infrared emissivity and absorbance, can be controlled in a wide range by voltage bias. The large emissivity modulation achievable with this material makes it suitable in the design of thermal dynamic camouflage devices. Generally, the emissivity modulation in the multilayered graphene medium is governed by an intercalation process of non-volatile ionic liquids under a voltage bias. The electrically driven reduction of emissivity lowers the apparent temperature of a surface, aligning it with the background temperature to achieve thermal camouflage. This characteristic is shared by other graphene-based materials. In this review, we focus on recent advancements in the thermal camouflage properties of graphene in composite films and aerogel structures. We provide a summary of the current understanding of how thermal camouflage materials work, their present limitations, and future opportunities for development.

Application of High-Surface Tension and Hygroscopic Ionic Liquid-Infused Nanostructured SiO2 Surfaces for Reversible/Repeatable Anti-Fogging Treatment

Anti-fogging coatings/surfaces have attracted much attention lately because of their practical applications in a wide variety of engineering fields. In this study, we successfully developed transparent anti-fogging surfaces using a non-volatile and hygroscopic ionic liquid (IL), bis(hydroxyethyl)dimethylammonium methanesulfonate ([BHEDMA][MeSO3]), with a high surface tension (HST, 66.4 mN/m). To prepare these surfaces, a layer of highly transparent, superhydrophilic silica (SiO2) nano-frameworks (SNFs) was first prepared on a glass slide using candle soot particles and the subsequent chemisorption of tetraethoxysilane (TEOS). This particulate layer of SNFs was then used as the support for the preparation of the [BHEDMA][MeSO3] layer. The resulting IL-infused SNF-covered glass slide was highly transparent, superhydrophilic, hygroscopic, and had self-healing and reasonable reversible/repeatable anti-fogging/frosting properties. This IL-infused sample surface kept its excellent anti-fogging performance in air for more than 8 weeks due to the IL’s non-volatile, HST, and hygroscopic nature. In addition, even if the water absorption limit of [BHEDMA][MeSO3] was reached, the anti-fogging properties could be fully restored reversibly/repeatably by simply leaving the samples in air for several tens of minutes or heating them at 100 °C for a few minutes to remove the absorbed water. Our IL-based anti-fogging surfaces showed substantial improvement in their abilities to prevent fogging when compared to other dry/wet (super)hydrophobic/(super)hydrophilic surfaces having different surface geometries and chemistries.

Role of volatility and thermal properties in droplet spreading: a generalisation to Tanner's law

Droplet spreading is ubiquitous and plays a significant role in liquid-based energy systems, thermal management devices and microfluidics. While the spreading of non-volatile droplets is quantitatively understood, the spreading and flow transition in volatile droplets remains elusive due to the complexity added by interfacial phase change and non-equilibrium thermal transport. Here we show, using both mathematical modelling and experiments, that the wetting dynamics of volatile droplets can be scaled by the spatial–temporal interplay between capillary, evaporation and thermal Marangoni effects. We elucidate and quantify these complex interactions using phase diagrams based on systematic theoretical and experimental investigations. A spreading law of evaporative droplets is derived by extending Tanner's law (valid for non-volatile liquids) to a full range of liquids with saturation vapour pressure spanning from $10^1$ to $10^4$ Pa and on substrates with thermal conductivity from $10^{-1}$ to $10^3\ {\rm W}\ {\rm m}^{-1}\ {\rm K}^{-1}$ . In addition to its importance in fluid-based industries, the conclusions also enable a unifying explanation to a series of individual works including the criterion of flow reversal and the state of dynamic wetting, making it possible to control liquid transport in diverse application scenarios.

Imaging a solvent‐swollen polymer gel network by open liquid transmission electron microscopy

AbstractVisualizing the network of a solvent‐swollen polymer gel remains problematic. To address this challenge, open transmission electron microscopy (TEM) was applied to thin gel films permeated by a nonvolatile ionic liquid. The targeted physical gels were prepared by cooling concentrated solutions of poly(ethylene glycol) in 1‐ethyl‐3‐methyl imidazolium ethyl sulfate [EMIM][EtSO4]. During the cooling, gelation occurred by a frustrated crystallization of the dissolved polymer, leading to a percolated, solvent‐permeated semicrystalline network in which nanoscale polymer crystals acted as crosslinks. Crystalline features ranging from ~5 to ~200 nm were observed, with the visible network strands dominantly consisting of long curvilinear crystallites of ~15–20 nm diameter. Nascent spherulites irregularly decorated the network, creating a complex structural hierarchy that complicated analyses. Lacking diffraction contrast, TEM did not visualize the many disordered, fully solvated PEG chains present in the voids between crystals. Recognizing that a network's three dimensionality is ambiguous when assessed through two‐dimensional microscopy projections, a small gel region was studied by TEM tomography, revealing a nearly isotropic three‐dimensional arrangement of the curvilinear crystallites, which displayed remarkably uniform cylindrical cross sections.

Ionic Liquid-Enhanced Assembly of Nanomaterials for Highly Stable Flexible Transparent Electrodes

HighlightsWe present a method that utilizes ionic liquid-enhanced nanomaterial assembly to fabricate highly stable and large-area MXene-silver nanowire electrodes with ordered layered structures.This approach emphasizes the use of hydrophobic and nonvolatile ionic liquids, which form stable interfaces with water by reducing interface energy, preventing the sedimentation loss of nanomaterials during assembly.The prepared electrodes not only exhibit excellent optoelectronic properties (9.4 Ω sq−1 sheet resistance and 93% transmittance), but also have exceptional antioxidant capacity.

Drops on Polymer Brushes: Advances in Thin-Film Modeling of Adaptive Substrates.

We briefly review recent advances in the hydrodynamic modeling of the dynamics of droplets on adaptive substrates, in particular, solids that are covered by polymer brushes. Thereby, the focus is on long-wave and full-curvature variants of mesoscopic hydrodynamic models in gradient dynamics form. After introducing the approach for films/drops of nonvolatile simple liquids on a rigid smooth solid substrate, it is first expanded to an arbitrary number of coupled degrees of freedom before considering the specific case of drops of volatile liquids on brush-covered solids. After presenting the model, its usage is illustrated by briefly considering the natural and forced spreading of drops of nonvolatile liquids on a horizontal brush-covered substrate, stick-slip motion of advancing contact lines as well as drops sliding down a brush-covered incline. Finally, volatile liquids are also considered.

Heating-induced release of trapped bubbles from dead-end pore throats filled with nonvolatile liquid

The release of trapped bubbles from dead-end pore throats filled with nonvolatile liquid has widespread applications in gas–liquid reactors, radiators, foam flooding, ceramic sintering, and droplet microcarriers. As conventional pressure-driven flow cannot induce the transport of bubbles in dead-end pores, this paper explores the possibility of using heating to control the release of bubbles from dead-end pore throats. Visualization experiments of the microfluidics within a dead-end pore throat structure are conducted to address the release process of bubbles during heating. An increase in temperature causes dissolved gas in the solution to be transferred to the bubble, which enhances the bubble pressure and enables the bubble to pass through the pore throat. We analyze the effects of the initial bubble radius and initial temperature on the critical temperature Tcr at which the bubble passes through the pore throat. A larger initial radius does not necessarily make it more difficult for the bubble to pass through the throat, but there is a critical radius above which any increase in radius produces a lower value of Tcr. A theoretical model considering diffusion mass transfer, capillary forces, and corner film flows is developed, and this model is found to be in good agreement with the experimental results. Finally, we obtain three dimensionless numbers that can be used to predict Tcr. Our work provides guidance for the effective regulation of diffusive growth and the heating-induced release of bubbles from dead-end pore throats.

Capacity of Aqueous Solutions of the Ionic Liquid 1-Ethyl-3-methylimidazolium Acetate to Partially Depolymerize Lignin at Ambient Temperature and Pressure.

Lignin is a very attractive and abundant biopolymer with the potential to be a biorenewable source of a large number of value-added organic chemicals. The current state-of-the-art methods fail to provide efficient valorization of lignin in this regard without the involvement of harsh conditions and auxiliary substances that compromise the overall sustainability of the proposed processes. Making an original approach from the set of mildest temperature and pressure conditions, this work identifies and explores the capacity of an aqueous solution of the nonvolatile ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) to partially depolymerize technical lignin (Indulin AT) by means of a treatment consisting in the simple contact at ambient temperature and pressure. Among a considerable number of valuable phenolic molecules that were identified in the resulting fluid, vanillin (yield of about 3 g/kg) and guaiacol (yield of about 1 g/kg) were the monophenolic compounds obtained in a higher concentration. The properties of the post-treatment solids recovered remain similar to those of the original lignin, although with a relatively lower abundance of guaiacyl units (in agreement with the generation of guaiacyl-derived phenolic molecules, such as vanillin and guaiacol). The assistance of the treatment with UV irradiation in the presence of nanoparticle catalysts does not lead to an improvement in the yields of phenolic compounds.

Detailed discussion on the structure of alloy nanoparticles synthesized via magnetron sputter deposition onto liquid poly(ethylene glycol).

This paper is devoted to reviewing a decade of the development of vacuum sputter deposition onto liquid poly(ethylene glycol) (PEG) to prepare metal and alloy nanoparticles (NPs) with a controlled particle growth, size, structure, and composition. Especially, we have discussed the fine structures of alloy NPs obtained in PEG and compared them with those sputtered onto other non-volatile liquids. Finally, we have shared our prospect of applications for the resulting alloy NPs.

A new method to combine high-pressure vapor–liquid equilibrium and thermophysical property measurements for low-volatility liquids and a gas

Vapor-liquid equilibria measurements involving liquids with low volatility, such as many types of lubricants, ionic liquids, and various solvents are essential for process research and development in a wide variety of fields. State–of–the–art methods to measure these phase equilibria, e.g. thermogravimetric analysis or equilibrium cells, generally cannot be combined with instruments measuring thermophysical properties, e.g. density, transport properties, spectroscopic properties, etc. A novel approach was developed to measure simultaneously vapor–liquid equilibrium and thermophysical properties involving a single gas dissolved in one or more low-volatility liquids. The method is based upon a mass balance measuring liquid phase density, total masses in the system, and volumes. The governing equations of the novel approach are derived, and a detailed uncertainty analysis is presented. As an example, the solubility, density, and viscosity are measured with the new apparatus for a system of a non-volatile ionic liquid solvent saturated with the compressed hydrofluorocarbon gas, pentafluoroethane (R-125), at 25 °C and 75 °C and pressures to ∼ 3.1 MPa. The solubility data are validated by comparison to previously published literature data using a high precision gravimetric microbalance. The combination of vapor–liquid equilibria and thermophysical properties in a single experiment can significantly accelerate scientific and engineering studies.

Quality-by-Design-Based Development of Rivaroxaban-Loaded Liquisolid Compact Tablets with Improved Biopharmaceutical Attributes.

Rivaroxaban (RXN) finds use in the management of pulmonary embolism and deep vein thrombosis. Its poor solubility (5-7µg/mL) and P-gp-mediated efflux from intestinal lining limits the oral application of RXN. This work assessed the impact of liquisolid compact technique in augmenting the solubility and bioavailability of RXN. PEG 400, Avicel PH 200, and Aerosil 200 were used as non-volatile liquid, carrier, and coating material, respectively, to formulate RXN liquid-solid compacts (RXN LSCs). A 32-factor factorial design was used in the optimisation to assess the impacts of factors (load factor and carrier:coating ratio) on the responses (angle of repose and Q30 min). Pre-compression parameters of RXN LSCs suggested adequate flow and compressibility. Optimisation data suggested significant influence of factors on both the responses. Optimised RXN LSC-based tablets showed a significantly higher in vitro dissolution rate than RXN API and Xarelto® tablets due to improved solubility, reduced crystallinity, greater surface area, and enhanced wetting of RXN particles. XRD, DSC, and SEM data supported RXN's amorphization. The cytotoxicity (MTT assay) and permeation studies indicated the nontoxicity of prepared RXN LSC tablets and the role of PEG 400 in inhibiting P-gp. Pharmacokinetic study of RXN LSC-based tablets in Albino Wistar rats exhibited 2.51- and 1.66-times higher AUC in comparison to RXN API and Xarelto® tablets respectively, demonstrating that developed formulation had a greater oral bioavailability. The RXN LSC tablets showed longer bleeding times and higher rates of platelet aggregation than RXN API. Thus, RXN LSC tablets can be considered a facile, scalable technology.

Anomalous near-equilibrium capillary imbibition induced by nanoscale surface topography

This work reports that the nanoscale surface topography induces a crossover from the classical Lucas–Washburn imbibition dynamics to a long-lived anomalously slow regime observed near thermodynamic equilibrium conditions. A compact analytical model considering the interplay between interfacial wetting, thermal motion, and the nanoscale physical topography accounts for experimental observations for the case of capillary rise of different nonvolatile liquids in simple glass tubes. Analytical predictions supported by topographic analysis via atomic force microscopy indicate that topographic features with a specific range of nanoscale dimensions determine the crossover condition and anomalous imbibition rate. Our findings have important implications for the scientific understanding and technical application of capillary imbibition and suggest strategies to control the adsorption of specific liquids in porous materials with complex surface topography.

Study on the ablation of a pulsed plasma thruster with a non-volatile liquid propellant

Perfluoropolyether (PFPE), as a non-volatile liquid propellant for pulsed plasma thrusters (PPTs), has exhibited potential for inhibiting carbon deposition compared with polytetrafluoroethylene (PTFE). However, previous investigations have not focused on the ablation process of PPTs when using PFPE. In this study, ablation and the formation of carbon deposition were assessed based on ablated product analysis, element distributions, long-duration exposure images and emission spectroscopy. The results showed that the ablated products of PTFE were mainly CF and CF2, with a small amount of C, while PFPE was more likely to evaporate or generate molecules with large molecular weights. Carbon deposition on the ablated surface of PTFE was confirmed by the element distribution, while no obvious carbon deposition was found on the ablated surface of the porous ceramic. Carbon deposition was inevitable when using PTFE as a propellant according to the ablated products. The current density near the anode on the ablated surface of the propellant was low, and carbon could not be ablated in a timely manner; thus, carbon deposition easily occurred. For PFPE, the discharge arc was evenly distributed on the ablated surface, which could limit deposition.

Molecular and Supramolecular Designs of Organic/Polymeric Micro-photoemitters for Advanced Optical and Laser Applications.

ConspectusFor optical and electronic applications of supramolecular assemblies, control of the hierarchical structure from nano- to micro- and millimeter scale is crucial. Supramolecular chemistry controls intermolecular interactions to build up molecular components with sizes ranging from several to several hundreds of nanometers using bottom-up self-assembly process. However, extending the supramolecular approach up to a scale of several tens of micrometers to construct objects with precisely controlled size, morphology, and orientation is challenging. Especially for microphotonics applications such as optical resonators and lasers, integrated optical devices, and sensors, a precise design of a micrometer-scale object is required. In this Account, we review the recent progress on precise control of microstructures from π-conjugated organic molecules and polymers, which work as micro-photoemitters and are suitable for optical applications.After the introduction on the importance of the control of the hierarchical structures from molecular assembly, we review supramolecular methodology for assembling molecules and supramolecules to form microstructures such as spheres and polygons with precisely controlled morphology and molecular orientations. The resultant microstructures act as anisotropic emitters of circularly polarized luminescence. We report that synchronous crystallization of π-conjugated chiral cyclophanes forms concave hexagonal pyramidal microcrystals with homogeneous size, morphology, and orientation, which clearly paves the way for the precise control of skeletal crystallization under kinetic control. Furthermore, we show microcavity functions of the self-assembled micro-objects. The self-assembled π-conjugated polymer microspheres work as whispering gallery mode (WGM) optical resonators, where the photoluminescence exhibits sharp and periodic emission lines. The spherical resonators with molecular functions act as long-distance photon energy transporters, convertors, and full-color microlasers. Fabrication of microarrays with photoswitchable WGM microresonators by the surface self-assembly technique realizes optical memory with physically unclonable functions of WGM fingerprints. All-optical logic operations are demonstrated by arranging the WGM microresonators on synthetic and natural optical fibers, where the photoswitchable WGM microresonators act as a gate for light propagation via a cavity-mediated energy transfer cascade. Meanwhile, the sharp WGM emission line is appropriate for utilization as optical sensors for monitoring the mode shift and mode splitting. The resonant peaks sensitively respond to humidity change, absorption of volatile organic compounds, microairflow, and polymer decomposition by utilizing structurally flexible polymers, microporous polymers, nonvolatile liquid droplets, and natural biopolymers as media of the resonators. We further construct microcrystals from π-conjugated molecules with rods and rhombic plates, which act as WGM laser resonators with light-harvesting function. Our developments, precise design and control of organic/polymeric microstructures, form a bridge between nanometer-scale supramolecular chemistry and bulk materials and pave the way toward flexible micro-optics applications.

Ionic liquid functionalized tin halide perovskite investigated by STXM and spectro-ptychography

The structural and compositional properties of tin halide perovskites (CH(NH2)2SnI3, FASnI3) with and without an ionic liquid of 1-Ethyl-3-methylimidazolium bis(trifluormethylsulfonyl) imide (EMITFSI) were investigated using the scanning transmission soft X-ray microscopy (STXM) and spectro-ptychography techniques at the Sn M5,4-edge, I M5,4-edge, O K-edge, C K-edge, and N K-edge. The study offers a comprehensive interpretation of the spectral characteristics of main components (C, N, Sn, and I) in Sn-based perovskites through STXM-based techniques and further reveals differences between the perovskite samples with and without adding EMITFSI ionic liquid. The chemical imaging of Sn and I shows that the perovskite sample without ionic liquid has Sn-rich regions in iodine cavities, while the ionic liquid-treated sample exhibits a more homogeneous perovskite phase. Furthermore, the C and N K-edge XANES resonance features support the interaction between the non-volatile ionic liquid and FA+, thus playing a protective role in the formation and stabilization of perovskite phase.

Design of healable, porous polyurethane with large ionic liquids loading amounts towards ultra-durable pressure sensor

Flexible intelligent sensors have got booming development over the past decades, yet, it is still a huge challenge to construct advanced sensors with long service life and superb durability. Herein, a novel porous capacitance pressure sensor with ultra-durability via sugar template method was prepared successfully by impregnating non-volatile, highly conductive ionic liquids (ILs) into polyurethane (PU-DBTDA5) matrix. As a consequence of the rich hydrogen bonding networks and dynamic hindered urea bond in the polymer chain, the as-prepared PU-DBTDA5 matrix shows excellent self-healing ability (99 %). The ionic liquid-soluble polyethylene glycol (PEG1000) serving as soft segment endows PU-DBTDA5 with ultra-absorption ability of ILs (absorbing ILs over three times to its own weight within 5 min). The pressure sensor with porous structure shows outstanding anti-fatigue ability as well as good sensitivity (S1 = 0.82 kPa−1, S2 = 1.04 kPa−1), and it can even monitor tiny strain as low as 0.5 %. More importantly, due to the well combination of the PU-DBTDA5 with excellent self-healing ability and the non-volatile ionic liquids, not only the healed sensor, but the sensor stored at room environment over 100 days both exhibit stable electronic signals similar to that of freshly-prepared foam sensor in 3000 uninterrupted compression tests, being strong evidence of its ultra-durability.

Pore network modeling of a microporous layer for polymer electrolyte fuel cells under wet conditions

The gas diffusion layers (GDLs) of polymer electrolyte fuel cells have been developed with applying microporous layers (MPLs) in their catalyst layer (CL) side to alleviate the accumulation of liquid water in the CL for oxygen transport to the cathode CL. A three-dimensional porous structure of our in-house hydrophobic MPL is numerically modeled with a pore network model (PNM). The convective air permeability and oxygen diffusivity, which depend on liquid saturation, are evaluated. To construct the PNM, focused ion beam scanning electron microscopy (FIB-SEM) is used to derive the pore size distribution (PSD). The model is ex-situ validated through air permeability and oxygen diffusivity tests with controlled saturation of non-volatile wetting liquid that is stable in the hydrophobic MPL. Oxygen diffusivity of the MPL is obtained by identifying the diffusion resistances of the concentration boundary layers and GDL substrate in the tests. The model predicts the effects of liquid water saturation in the MPL on the air and liquid water permeations, and the oxygen diffusion, and thus can be used to design optimal PSDs for practical cells.

Optimizing interfacial wetting by ionic liquid for high performance solid-state lithium metal batteries operated at ambient temperature

Employing solid electrolytes in lithium metal batteries has been proposed to address the safety issues from the organic liquid electrolyte and Li dendrite growth. However, their practical applications are still plagued by the large interfacial resistance between the electrode and solid-state electrolytes (SSEs). Herein, a small amount of nonflammable and nonvolatile ionic liquids (ILs) are introduced into the poly(ethylene oxide) (PEO)/Li7La3Zr2O12 (LLZO) composite SSEs to simultaneously promote the ionic transport within SSEs bulks and through SSEs-electrode interface. When the 17.5 wt% ILs are added, the ionic conductivity of PEO/LLZO SSEs increases by an order of magnitude, and the interfacial resistance decrease by >5 times at 25 °C. Meanwhile, no leakage of ILs from PEO/LLZO SSEs can be observed under high pressure of 10 MPa. Moreover, it is found that the IL of [Py14]TFSI endows the PEO/LLZO SSEs with better interfacial compatibility with both high voltage cathode and Li metal anode than [BMIM]TFSI and [EMIM]TFSI. Benefiting from these merits of PEO/LLZO@[Py14]TFSI (PLP) SSEs, the pouch-type solid-state LiFePO4||Li cell shows a high average capacity of 124 mAh g−1, average Coulombic efficiency of over 99.5 %, and retains 120 mAh g−1 after 100 cycles at 25 °C.