Excellent Interfacial Compatibility Research Articles

A Rapid Synthesis of Amorphous LiTaOCl4 Solid Electrolytes Through a Two‐Step Reaction Pathway for High‐Rate and Long‐Cycling Lithium Batteries

AbstractA simplified process to prepare solid electrolytes (SEs) that fulfill long cyclability, fast‐charging performance, and wide‐temperature feasibility in all‐solid‐state lithium batteries (ASSLBs) is important. Here, amorphous LiTaOCl4 (aLTOC) SE is synthesized within only four hours via a two‐step reaction by high‐energy ball milling method, which exhibits high ionic conductivity and excellent interfacial compatibility. A bilayer SE based on aLTOC and sulfide along with corresponding ASSLBs, are constructed. Furthermore, slight evolution of the unusual microstructure in the chloride/sulfur interfacial region is observed and analyzed. Density functional theory calculations show that S tends to displace O sites in TaO2Cl4 octahedra instead of Cl sites. As a result of the enhanced interfacial stability and reduced formation of ionically insulating phases, the assembled ASSLBs achieve superior rate performance and cyclability in a wide temperature range. Notably, the ASSLBs show capacity retention of 84.4% and 77.6% after 2000 and 1000 cycles at current density of 10C at 30 and 60 °C, respectively. Importantly, even under −20 °C, the cell works stably over 1600 cycles with capacity retention of 76.3% at 0.5C. The work pave the way for the massive production of high‐performance amorphous chloride electrolytes and the realization of fast‐charging ASSLBs with long cycle life.

Development and Characterization of Ethylene‐Vinyl Acetate‐Graphene Nanocomposites

AbstractThe prospective applications of carbon graphene nanoplatelets (GNPs) reinforced ethylene vinyl acetate (EVA) nanocomposites in flexible electronics, energy storage devices, and thermal management systems have attracted a lot of attention. These nanocomposites offer an effective solution for enhancing the electrical conductivity of interfacing materials in electronic systems and addressing issues related to thermal management. GNPs that possess excellent thermal conductivity of 2000–4000 W m−1 K−1 and an electrical conductivity of 107 S m−1 are utilized in this investigation. The homogeneous dispersion of nanofiller and the effective load transfer between components through strong filler/polymer interfacial interactions are essential for the creation of multifunctional polymer nanocomposites. Particularly, their electrical conductivity and dielectric properties are highlighted in this study, with an emphasis on the synthesis and characterization of nanocomposite materials. This work investigates the utilization of graphene nanocomposites in EVA using a melt‐mixing technique assisted by sonication to fabricate multifunctional composites. Incorporating different weight percentages of GNPs (ranging from 0.1 to 0.4 wt.%) within the polymer matrix is carried out. In the present study, the nanocomposites are characterized by scanning electron microscopy investigation and impedance spectrum analysis. The distinctive characteristics of the AC electrical transport in nanocomposites are investigated between 10 Hz and 1 MHz. Excellent interfacial compatibility has been demonstrated by the homogenous distribution of GNPs within the matrix, confirmed by SEM examination. These EVA nanocomposites demonstrate improved electrical conductivity, thereby rendering them very useful for energy storage applications, such as electronic capacitors, wherein supports with a significant dielectric constant and minimal dielectric loss are required.

Isocyanurate‐Derivative Enables Highly Compatible Poly‐Dioxane Electrolyte for Dendrite‐Free Li Metal Batteries

AbstractThe Li+ transport kinetics and electrochemical stability of advanced solid‐state Li metal batteries (SLMBs) are seriously limited by the actual electrolyte compositions. Here, a novel polyether‐based electrolyte (PTGDOX) is presented through in situ co‐polymerization by integrating 1,3‐dioxane with a multifunctional 1,3,5‐triglycidyl isocyanurate additive. The isocyanurate group in PTGDOX not only provides abundant coordinating sites for Li+ transfer and restricts the movement of anions, but also prompts a beneficial inorganic‐rich solid electrolyte interface on the Li electrode. As a result, PTGDOX exhibits a remarkably increased ionic conductivity of 0.48 mS cm−1 at 30 °C and a reasonable Li‐ion transference number of 0.68, enabling the Li||Li symmetric cells to stably cycle for over 2000 h at 1 mAh cm−2. Meanwhile, the assembled Li||LiFePO4 exhibit a 97.4% capacity retention after 700 cycles at 3 C with excellent thermal stability. Moreover, PTGDOX also demonstrates excellent interfacial compatibility with high‐voltage LiNi0.8Co0.1Mn0.1O2 cathode. As such, this work provides a facile and accessible strategy for designing interface‐stable polymer electrolytes and achieving practical dendrite‐free SLMBs.

Sustainable engineering polymer composites fabricated using delignified bamboo fiber as reinforcement and walnut shell powder as filler

Developing sustainable engineering materials using renewable resources and agro-wastes represents an effective method for reducing carbon emissions and environmental pollution. In this study, a novel approach to fabricating high-performance biomass-based polymer composites was presented. Specifically, partially delignified bamboo fiber (DBF) and walnut shell powder (WSP) were incorporated into the matrix, namely melamine-hexamethylenediamine-urea (MHU) resin which was previously known for its excellent interfacial compatibility. Mechanical property investigations show that the DBF, acting as the reinforcement, provided the hybrid composites with high flexural and tensile strength up to 220 and 120 MPa, respectively, greatly surpassing those of commercial wood-plastic composites, wood-based composites, and natural wood, making them promising structural materials. As the filler, walnut shell powder endowed the composites with high hardness (Shore D > 90) and an appealing mirror-like surface gloss. Owing to the protection provided by the MHU matrix, the composite containing 38 % MHU exhibited outstanding flame retardancy (UL 94-V0 grade), which was further supported by cone calorimeter test (CCT) results. An unexpected and intriguing finding is that the composites exhibited fluorescence under UV irradiation. The rare silvery-grey fluorescence color imparted self-anticounterfeiting property to the composites. This study demonstrated the significant potential of bamboo fiber and walnut shell in the development of sustainable engineering materials.

Solvent-Free Method of Polyacrylonitrile-Coated LLZTO Solid-State Electrolytes for Lithium Batteries.

Solid-state electrolytes (SSEs), particularly garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO), offer high stability and a wide electrochemical window. However, their grain boundaries limit ionic conductivity, necessitating high-temperature sintering for improved performance. Yet, this process results in brittle electrolytes prone to fracture during manufacturing. To address these difficulties, solvent-free solid-state electrolytes with a polyacrylonitrile (PAN) coating on LLZTO particles are reported in this work. Most notably, the PAN-coated LLZTO (PAN@LLZTO) electrolyte demonstrates self-supporting characteristics, eliminating the need for high-temperature sintering. Importantly, the homogeneous polymeric PAN coating, synthesized via the described method, facilitates efficient Li+ transport between LLZTO particles. This electrolyte not only achieves an ionic conductivity of up to 2.11 × 10-3 S cm-1 but also exhibits excellent interfacial compatibility with lithium. Furthermore, a lithium metal battery incorporating 3% PAN@LLZTO-3%PTFE as the solid-state electrolyte and LiFePO4 as the cathode demonstrates a remarkable specific discharge capacity of 169 mAh g-1 at 0.1 °C. The strategy of organic polymer-coated LLZTO provides the possibility of a green manufacturing process for preparing room-temperature sinter-free solid-state electrolytes, which shows significant cost-effectiveness.

Preparation of ZIF-67 composite MBI-modified Co-MOF material and its corrosion resistance to epoxy resin coating

Metal corrosion causes a lot of waste of resources, and the protection of metals from corrosion is becoming increasingly important. In this study, zeolite-imidazole (ZIF-67) was grown on the surface of Co-MOF for the first time by a one-step (complexation) method. 2-Mercaptobenzimidazole (MBI) was then loaded into the inner cavity of ZIF-67, resulting in the formation of a new composite material, Co-MOF@ZIF-67@MBI. The modified Co-MOF exhibits excellent interfacial compatibility with the water-based epoxy resin, and the Co-MOF@ZIF-67@MBI composite coating demonstrates robust anti-corrosion properties. Following a 60-day immersion period, the electrochemical experiment demonstrated that the corrosion resistance modulus of the Co-MOF@ZIF-67@MBI composite coating reached 108 Ω cm², indicating that the coating effectively enhanced the corrosion resistance of the coating and significantly extended the service life of the coating.

Synergistic preparation of a straw fiber/polylactic acid composite with high toughness and strength through interfacial compatibility enhancement and elastomer toughening

Plant fiber-reinforced polylactic acid (PLA) composites are extensively utilized in eco-friendly packaging, sports equipment, and various other applications due to their environmental benefits and cost-effectiveness. However, PLA suffers from brittleness and poor toughness, which restricts its use in scenarios demanding high toughness. To expand the application range of plant fiber-reinforced PLA-based composites and enhance their poor toughness, this study employed a two-step process involving wheat straw fiber (WF) to improve the interfacial compatibility between WF and PLA. Additionally, four elastomeric materials—poly (butylene adipate-co-terephthalate) (PBAT), poly (butylene succinate) (PBS), polycaprolactone (PCL), and polyhydroxyalkanoate (PHA)—were incorporated to achieve a mutual reactive interface enhancement and elastomeric toughening. The results demonstrated that Fe3+/TsWF/PLA/PBS exhibited a tensile strength, elongation at break, and impact strength of 34.01 MPa, 14.23 %, and 16.2 kJ/m2, respectively. These values represented a 2.4 %, 86.7 %, and 119 % increase compared to the unmodified composites. Scanning electron microscopy analysis revealed no fiber exposure in the cross-section, indicating excellent interfacial compatibility. Furthermore, X-ray diffraction and differential scanning calorimetry tests confirmed improvements in the crystalline properties of the composites. This work introduces a novel approach for preparing fiber-reinforced PLA-based composites with exceptional toughness and strength.

Flexible and highly-loaded mixed-matrix membrane with bi-continuous metal–organic frameworks transfer pathway for gas separation

Highly-loaded metal–organic frameworks (MOFs) based mixed matrix membranes (MMMs) are essential for high-efficiency gas separation. However, the continuous distribution of MOFs across the membrane with intensified interface remains challenging. Herein, a flexible and defects-free MMM with a bi-continuous MOFs pathway is constructed by dopamine (DA)-assisted MOFs growth along nanofibers. Nanofibers are used to upload and distribute ZIF-8, which continues to grow via an epitaxial growth strategy to obtain ZIF-8 fibers, achieving ZIF-8 continuous both in long and short range. DA promotes heterogeneous nucleation and growth of ZIF-8 on fiber surface by chelating with Zn2+ through –OH and –NH2 groups. DA also ensures excellent interfacial compatibility by hydrogen bonding interaction between amino groups of DA and ether-oxygen groups of PEO. Finally, the highly-loaded MMM is constructed by in-situ photopolymerization of Poly (ethylene glycol) diacrylate) to embrace ZIF-8 fibers tightly. The resultant MMM presents ZIF-8 loading as high as 72.41 vol% with Young’s modulus of 33.42 MPa, and unchanged morphology and separation performances after bending for 180° over 50 times, revealing outstanding mechanical properties. The CO2 permeability and CO2/N2 selectivity are 280.3 % and 73.0 % higher than the PEO membrane, surpassing the 2019 McKeown upper bound.

Ceria Quantum Dot Filler-Modified Polymer Electrolytes for Three-Dimensional-Printed Sodium Solid-State Batteries.

Solid polymer electrolytes have been considered as promising candidates for solid-state batteries (SSBs), owing to their excellent interfacial compatibility and high mechanical toughness; however, they suffer from intrinsic low ionic conductivity (lower than 10-6 S/cm) and large thickness (usually surpassed over 100 μm or even 500 μm), which has a negative influence on the interface resistance and ionic migration. In this work, ceria quantum dot (CQD)-modified composite polymer electrolyte (CPE) membranes with a thickness of 20 μm were successfully manufactured via 3D printing technology. The CQD fillers can reduce the crystallinity of the polymer, and the oxygen vacancies on CQDs can facilitate the dissociation of ion pairs in the NaTFSI salt to release more free Na+, improving the ionic conductivity. Meanwhile, tailoring the thickness of the CPE-CQDs membrane via 3D printing can further promote the migration and transport of Na+. Furthermore, the printed NNM//CPE-CQDs//Na SSB exhibited outstanding rate capability and cycling stability. The combination of CQD modification and thickness tailoring through 3D printing paves a new avenue for achieving high performance solid electrolyte membranes for practical application in Na SSBs.

Sacrificial NH4HCO3 Inhibits Fluoropolymer/Garnet Interfacial Reactions Toward 1mS cm−1 and 5V‐Level Composite Solid Electrolyte

AbstractComposite solid electrolytes (CSEs) integrate the fast ion conductivity of inorganic electrolytes and the excellent interfacial compatibility of polymer electrolytes. Typically, fluoropolymers and garnets are promising individuals to formulate cutting‐edge CSEs owing to their unique properties. However, the alkaline garnets can induce the dehydrofluorination of fluoropolymers, deteriorating their CSEs performance. Here, for the first time, NH4HCO3 is proposed as a sacrificial inhibitor to effectively prevent the garnet‐induced dehydrofluorination, using Li6.4La3Zr1.4Ta0.6O12 (LLZTO) and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVH) as symbolic garnets and fluoropolymers, respectively. Various findings demonstrate that NH4HCO3 can buffer the alkalinity of LLZTO, thereby inhibiting the dehydrofluorination of PVH. In addition, NH4HCO3 can completely decompose to volatiles upon drying without compromising the properties of LLZTO and PVH. Additionally, a polymer‐in‐salt strategy is further introduced by adding high‐concentration LiTFSI salt to the above system, resulting in the PVH/LiTFSI/LLZTO (PLL) CSEs. Benefiting from the synergetic coupling of the sacrificial inhibitor and polymer‐in‐salt strategies, the PLL exhibits an exceptionally high ionic conductivity of 1.2 mS cm−1 at 25 °C and stable voltage of 5.09 V, outperforming other reported CSEs. Consequently, the PLL delivers impressive high‐rate cyclability in solid‐state lithium‐metal batteries with an outstanding capacity retention of 95.4% after 240 cycles at 1 C (25 °C).

Polycarbonate-based composite polymer electrolytes with Al2O3 enhanced by in situ polymerized electrolyte Interlayers for all-solid-state lithium-metal batteries

Lithium-metal batteries (LMBs) have attracted significant attention as promising energy storage devices due to their high energy density. However, the practical application of LMBs is hindered by issues such as dendrite growth and electrolyte decomposition, which lead to poor cycling stability. To address these challenges, this study focuses on investigating the performance of poly(ethylene carbonate) (PEC)-based composite polymer electrolytes (CPEs) with an in situ polymerized poly(vinyl ethylene carbonate) (PVEC)-based electrolyte interlayer. The electrolytes were optimized by incorporating lithium bis(fluorosulfonyl)imide (LiFSI) salt, lithium bis(oxalato)borate (LiBOB) and lithium nitrate (LiNO3) additives, as well as Al2O3 filler. The objective was to improve the compatibility and cycling stability of LMBs by enhancing the electrolyte/electrode interfacial properties. Remarkably, the Li||Li symmetric cell utilizing the optimized CPE exhibited outstanding stability, operating for 700 h without short-circuiting at 0.1 mA cm−2, indicating excellent interfacial compatibility. Additionally, the Li||LiFePO4(LFP) cells using the same electrolyte demonstrated impressive performance, delivering initial discharge capacity of 159.32 mAh g−1 at 0.1 C with retention and coulombic efficiency close to 100 % after 100 cycles at 60 °C. This paper highlights the effectiveness of utilizing polymer electrolyte interlayers and additives like LiNO3 in CPEs to enhance the interfacial compatibility and cycling stability of LMBs.

Coconstruction of Supramolecular Lithium-Conducting Cross-Linked Networks Based on PVDF and Triblock Polymer Nanomicrosphere Solid-State Polymer Electrolytes for Lithium-Metal Batteries.

Uneven lithium plating and low ionic conductivity currently impede the realization of high-capacity rechargeable lithium metal batteries. And the conventional poly(ethylene oxide) (PEO) solid-state electrolytes are unsuitable for high-energy-density Li anode applications due to their low lithium-ion transference number and high reactivity with Li metal, leading to detrimental dendrite formation and potentially hazardous exothermic reactions with the electrolyte. In this study, we employ a supramolecular approach to develop a novel polymer solid-state electrolyte based on poly(vinylidene fluoride) (PVDF) and a novel triblock polymer nanomicrosphere, (poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone), (PCL-PEG-PCL). The abundance of carbonyl and ether-oxygen functional groups in PCL-PEG-PCL enhances the lithium coordination environment within the polymer solid-state electrolyte. Additionally, the original C-F moieties of PVDF form hydrogen bonds with C-H and terminal hydroxyl groups in PCL-PEG-PCL, collectively creating a multichannel fast Li+-conducting supramolecular cross-linked network. The resulting electrolyte demonstrates a high ionic conductivity of 1.4 × 10-3 S cm-1 and an extended electrochemical window of 5.2 V. Moreover, the electrolyte exhibits a high lithium-ion transference number (tLi+ = 0.63) at room temperature and exhibits excellent interfacial compatibility with the lithium metal anode. For the resulting electrolyte utilized in LiFePO4 batteries, the capacity retention of the cells assembled with this electrolyte exceeds 91.3% after 1000 cycles at 25 °C and 2 C (0.281 mA cm-2).

Energy storage performances of polymer-based composite dielectrics containing an in-situ-grown boron nitride layer

Polymer-based energy storage materials are widely utilized in the fields of electrical and electronics due to their high-power density and excellent charge-discharge efficiency. In this study, polyetherimide (PEI) composite films with outstanding energy storage properties were prepared by growing an inorganic barrier layer of boron nitride (BN) on the surface of PEI films through the in situ chemical vapor deposition (PECVD) method. The effects of BN deposition time on the dielectric properties, leakage current density, and energy storage properties of the composite films were investigated. The results reveal that the BN inorganic barrier layer, prepared by the PECVD method, demonstrates excellent interfacial compatibility with the PEI polymer matrix and forms a densely deposited layer. The BN inorganic barrier layer effectively suppresses carrier injection at the electrode, reduces the current density inside the PEI composite film, and improves the breakdown strength of the composite film. The composite film exhibits optimal performance when BN is deposited for 20 min. At an electric field strength of 660 MV/m, the energy storage density of the composite film reaches 6.08 J/cm3, which is 1.53 J/cm3 higher than that of pure PEI, while maintaining a charge-discharge efficiency of 90.43%. The findings of this study provide valuable theoretical support for the design of polymer-based energy storage materials.

Interfacial compatible PolyMOF membranes as ratiometric fluorescence temperature sensors

Cryogenic temperature sensors play significant roles in manufacturing, metallurgy, and aerospace. Metal-organic frameworks (MOFs) as emerging crystal materials exhibited inherent advantages as fluorescence temperature sensors and researchers have shifted their focus toward incorporating MOFs materials into mixed matrix membranes (MMMs) for broader practical applications. However, the poor interfacial compatibility between MOFs particles and the polymer matrix would cause aggregation-induced fluorescence quenching and reduced energy transfer efficiency, thereby compromising temperature sensing performances. Herein, we adopt a post-synthetic copolymerization strategy to realize an interfacial-compatible membranous ratiometric luminescent thermometer based on the emissions of ligands and lanthanide ions. Benefiting from the controllable covalent cross-linking structures, the designed polyMOF membrane exhibited excellent interfacial compatibility and avoided MOFs irregular morphology agglomeration and phase separation, which contributed to outstanding fluorescence temperature sensing performance with excellent sensitivity ranging from 0.300 to 0.745 %·K−1 within the temperature range of 80–300 K, superior to recent reported MOFs-based thermometers. This research presents a promising approach for the design and fabrication of interfacial compatible MOFs-based membranes with excellent fluorescence temperature sensing properties, advancing the understanding of structure-property relationships and accelerating the practical applications.

Covalently assembling multi-dimensional carbon-based nanoclay composites via ionic liquid linkers into PVA membrane for molecular separation

The application of membrane-based separation technology in purifying azeotropic solutions plays a crucial role in minimizing energy consumption during reactive distillation. The strategic integration of multi-dimensional structural composites within mixed matrix membranes (MMMs), characterized by a robust framework and efficient molecular transport channels, poses challenges but demonstrates significant potential for advancing the development of high-performance membrane fabrication. Herein, we proposed a novel strategy to covalently assemble halloysite nanotubes (HNTs) and graphene oxide (GO) using ionic liquids (ILs) as linkers. When incorporated into the polyvinyl alcohol (PVA) matrix, the ILs@HNTs@GO (IHGO) composites exhibit excellent interfacial compatibility, and ILs also enhanced the composite’s selective transfer ability to water molecules. The optimal separation performance for pervaporation dehydration from a ternary solution was respectively 2.57 (selectivity) and 1.74 (permeability) times higher than those of the pristine PVA membrane. The structural stability of the MMMs and their separation mechanism has been comprehensively validated by adjusting the content of GO in IHGO composites and conducting simulations. This study holds significant theoretical and practical implications for organic compounds purification, while simultaneously paving new avenues for the fabrication of structurally robust and high-performance MMMs with optimal filler effectiveness.

Excellent interfacial compatibility of phase change capsules/polyurethane foam with enhanced mechanical and thermal insulation properties for thermal energy storage

The incorporation of phase change microcapsule (microPCMs) substantially augmented the temperature regulation capacity of foams, endowing it with outstanding application potential in numerous industrial domains. However, interfacial compatibility issues between the capsule and the substrate always exist and affect foam performance. In this study, a milli-meter macrocapsule (macroPCMs) containing microPCMs was prepared using calcium alginate gel as the second layer wall to physically improve the interfacial compatibility. And poly (N-hydroxymethyl acrylamide) was in situ polymerized in the gel layer and provided active alcohol hydroxyl groups to form chemical grafting with the polyurethane raw materials, which further chemically improved the interfacial compatibility. These measures created a significantly improved foam microstructure and a greatly increased foaming capacity, which thus endow the composite foam with excellent thermal insulation performance and mechanical strength. Compared with conventional microPCMs-based foam, the foaming capacity of the macroPCMs-based foam increased by 40 folds, the temperature regulation duration increased by 7 folds, and the mechanical performance increased by 3 folds. Moreover, the insulated incubator fabricated with the macroPCMs-based foam exhibited two-fold greater thermal insulation efficiency than conventional models containing internal ice incubator, which validated the potential of employing macroPCMs-based polyurethane foam in cold chain logistics applications.

Self‐emulsification synthesis of epoxy phosphate ester and its flame‐retardant mechanism in flexible poly(vinyl chloride)/magnesium hydroxide composites

AbstractA trade‐off dilemma exists for simultaneously improving the mechanical properties and flame resistance of flexible polyvinyl chloride (fPVC)/magnesium hydroxide (MH) composites. In this study, epoxy phosphate ester (EPE), a hydrophobic surface modifier of MH, was synthesized using a self‐emulsification method. After modification, EPE was bonded to the surface of MH (MHEPE) without altering its morphology. The results of limiting oxygen index and cone calorimetry tests indicated that fPVC/MHEPE exhibited better flame retardancy and smoke suppression effects than did fPVC/MH. The peak of the heat release rate, total heat release, peak of the smoke production rate, and total smoke production of the fPVC/MHEPE composite were 206.0 kJ m−2, 45.90 MJ m−2, 0.0729 m2 s−1, and 9.88 m2, which were 8.64%, 14.00%, 27.61%, and 9.02% lower than those of the fPVC/MH composite, respectively. For the fPVC/MHEPE composite, a compact and continuous char residue formed, which could inhibit heat and flammable volatile migration between the matrix and burning zones. In the gas phase, the dilution effect of H2O vapor reduced the concentrations of O2 and flammable volatiles. The free‐radical quenching effect of ·PO and ·PO2 also played a vital role in extinguishing flame and terminating combustion. Further, the introduction of EPE improved the tensile and impact strengths of the fPVC/MH composites because of the excellent interfacial compatibility between MHEPE and the fPVC matrix. This study provides a simple and workable solution for the trade‐off dilemma, and the remarkable flame retardancy and mechanical properties of the fPVC/MHEPE composite render it a promising cable material.

Laminated composite fabricated using high-performance polyamine thermoset: Ultra heat resistance and excellent mechanical property

Developing polymer composites that can work in harsh environment are important for advancing materials industry. However, the composites generally based-on epoxy or phenolics resins that can endure both extremely high and low temperature are still rather limited. In this work, melamine-hexamethylenediamine (MH) thermoset which is structurally different from conventional matrices was used as matrix resin for woven glass fiber reinforced MH (GFRMH) laminated composite. Owing to the excellent thermostability (Td ≈ 460 °C) and interfacial compatibility of the MH matrix, the fabricated composites exhibited exceptional resistance to extreme temperature and mechanical performances, which are superior to that of the representative commercial epoxy-based composites. Particularly, the heat deflection temperature (HDT) of GFRMH was above 300 °C which is much higher than that of the representative high-performance commercial composites (220–270 °C). Moreover, GFRMH composite exhibited excellent retainability even at 425 °C while severe carbonization and delamination occurred to all the selected commercial products. Further, the GFRMH laminate exhibited flexural strength of 541 MPa at room temperature, higher than that of the commercial products by 80–160 MPa. Remarkably, the flexural strength increased to 852 MPa at 77 K without declining of toughness, suggesting the excellent resistance to cryogenic temperature. In summary, the results of the study disclosed the suitability of MH resin as a new matrix of glass fiber reinforced engineering materials.

A wrapped and infiltrated ∼20-μm-thick 3D ceramic framework composite enables fast Li+ diffusion and interfacial compatibility for lithium-metal batteries

Composite polymer electrolytes (CPEs) have shown potential for energy-dense Li-metal batteries (LMBs), but CPEs have always encountered poor ionic conductivity, low Li+ transference ability, and dendrite propagation. In our work, a mechanically robust three-dimensional porous framework (3DPF) with a thickness of ∼21 μm was successfully prepared by tape-casting and firing Li6.75La3Zr1.75Ta0.25O12 (LLZTO). After wrapping and infiltrating poly(vinylidene fluoride) (PVDF)−salt (LiTFSI)−LLZTO solution to 3DPF (3DPF-PVDF-LLZTO) for subsequent solidification, the resultant composite electrolyte (∼22 μm) shows an excellent room-temperature ionic conductivity of 1.67 × 10−4 S cm−1 and an extremely high Li+ transference number of 0.82, indicating fast Li+ diffusion. Furthermore, 3DPF-PVDF-LLZTO exhibits a mechanical strength of 37.5 MPa, and the assembled Li|3DPF-PVDF-LLZTO|Li cell ensures stable operation at 1.0 mA cm−2 and presents prolonged cycling stability at 0.2 mA cm−2 over 800 h without exhibiting dendrites, demonstrating excellent interfacial compatibility. A Li|3DPF-PVDF-LLZTO|LiFePO4 battery delivers excellent room-temperature cycle stability and rate capability, with an initial capacity of 160.7 mAh g−1 at 0.2 C and 115.3 mAh g−1 over 450 cycles at 1.0 C. This work provides a practical strategy for constructing highly conductive composite electrolytes with electrode−electrolyte compatibility for LMBs and deepens our understanding of Li+ diffusion pathways.

Zwitterionic Polyurethane Solid Polymer Electrolytes: A Pathway to High-Performance All-Solid-State Lithium-Ion Batteries

Lithium-ion batteries (LIBs) currently dominate the energy storage market for electronic devices, thanks to their high energy density, high operating voltage, and good cycling performance. However, commercial LIBs employing organic liquid electrolyte and lithium (Li) salts pose significant safety concerns, including flammability and the risk of thermal runaway. Consequently, the development of solid electrolytes is of paramount importance. Among several solid ion conductors, solid polymer electrolytes (SPEs) can offer numerous advantages, including excellent flexibility and interfacial compatibility with electrodes, good processibility, low cost, and light weight characteristics. However, current SPEs face challenges such as poor thermal stability, inferior electrochemical stability, and low Li-ion conductivity at room temperature (~ 10-5 S cm-1 at 25 ℃).In this study, we introduce a multifunctional zwitterionic polyurethane-based solid polymer electrolyte (zPU-SPE) for all-solid-state LIBs (SLBs) that addresses the limitations of conventional SPE materials. We synthesized zPU [i.e., poly((diethanolamine ethyl acetate)-co-poly(tetrahydrofuran)-co-(1,6-diisocyanatohexane))] and demonstrated its capability to host high amounts of LiTFSI without phase separation (up to 90 wt% LiTFSI loading). The Li-ion conductivity of zPU-SPE at 25° C is 7.4 × 10-4 S/cm, nearly 14 times greater than that of poly(ethylene oxide) (PEO) SPE (EO/Li+ = 16). Moreover, the high surface energy of zPU-SPE (487.5 J/m2 vs. 1.39 J/m2 of PEO) minimizes interfacial resistance. The zPU-SPE also exhibits outstanding elasticity, with a tensile break of 1700%, attributable to its dense inter- and intra-molecular hydrogen bonding.We evaluated the SLB battery performance of PEO and zPU-SPEs using a solid-state Li/SPE/LiFePO4 cell, which we cycled at a constant current rate of 1 C at 25 °C. The SLB cell with zPU-SPE demonstrates remarkable cycle stability, retaining 86% capacity after 1,000 cycles and 76% capacity after 2,000 cycles at a 1C rate and room temperature, while maintaining nearly 100% coulombic efficiency. In contrast, the capacity of the SLB cell with PEO rapidly decreases to 30% of its initial capacity and fails after 100 cycles. Given that significant capacity loss in LIBs under cold weather conditions poses a challenge for electric vehicles, we also assessed the temperature-dependent battery performance. The SLB with zPU-SPE retains 93.8% capacity at 0 °C, a substantial improvement over state-of-the-art LIBs (< 80% capacity retention). We attribute the high-capacity retention of zPU-SPE at low temperatures to the excellent chain mobility of the soft segment in the zPU matrix, which has a low glass transition temperature (-45 °C) and a high ion transport rate due to the zwitterionic group. We also conducted atomistic molecular modeling to investigate the dissolution and dissociation of Li salts and the Li-ion transport mechanism within the zPU polymer matrix. Furthermore, we employed small-angle X-ray scattering to examine the structural organization of the zPU-SPE matrix and its correlation with ion conductivity. Our work aims to guide the design of novel polymer electrolytes capable of overcoming the trade-offs associated with ion-conducting polymers (i.e., stability and ion conductivity). Figure 1