Polyethylene oxide (PEO) is one of the most widely used polymeric ion conductors which has the potential for a wide range of applications in energy storage. The enhancement of ionic conductivity of ...PEO‐based electrolytes is generally achieved by sacrificing the mechanical properties. Using layer‐by‐layer (LbL) self‐assembly with a nanoscale precision, mechanically strong and self‐healable PEO/polyacrylic acid composite thin films with a high Li+ conductivity of 2.3 ± 0.8 × 10−4 S cm−1 at 30 °C, and a strength of 3.7 MPa is prepared. These values make the LbL composite among the best recorded multifunctional solid electrolytes. The electrolyte thin film withstands at least 1000 cycles of striping/plating of Li at 0.05 mA cm−2. It is further shown that the LbL thin films can be used as separators for Li‐ion batteries to deliver a capacity of 116 mAh g−1 at 0.1 C in an all‐LbL‐assembled lithium iron phosphate/lithium titanate battery. Finally, it is demonstrated that the thin films can be used as ion‐conducting substrates for flexible electrochemical devices, including micro supercapacitors and electrochemical transistors.
Layer‐by‐layer (LbL) self‐assembly with a nanoscale precision enables the preparation of mechanically strong and self‐healable polyethylene oxide/polyacrylic acid composite thin films with a high Li+ conductivity. The LbL assembled thin films as separators for Li‐ion batteries delivers a capacity of 116 mAh g−1 at 0.1 C in an all‐LbL‐assembled lithium iron phosphate/lithium titanate battery.
•Antimicrobial chitosan–polyethylene oxide (CS–PEO) nanofibrous mats were fabricated.•Bioactive Ag NPs were synthesized by reduction with Falcaria vulgaris herbal extract.•The electrospun CS–PEO ...fibers containing 0.25%, 0.50% (w/w) had ∼200nm diameters.•The silver release from nanofibrous mats was sharply increased within first eight hours.•The CS–PEO-0.50% F. vulgaris-Ag NPs mat was preferred for biomedical applications.
The antimicrobial chitosan–polyethylene oxide (CS–PEO) nanofibrous mats were developed by electrospinning technique for wound dressing applications. Indeed, a green route was introduced for fabrication of antibacterial mats loaded with 0.25% and 0.50% (w/w) of bioactive silver nanoparticles (Ag NPs, ∼70nm diameter) reduced by Falcaria vulgaris herbal extract. The mats were characterized by FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. All of the nanofibers had an average ∼200nm diameter. Interestingly, both of the CS–PEO mats containing 0.25% and 0.50% bioactive F. vulgaris-Ag NPs revealed 100% bactericidal activities against both Staphylococcus aureus and Escherichia coli bacteria. The silver release from nanofiber mats was sharply increased within first eight hours for both CS–PEO mats including 0.25% and 0.50% F. vulgaris-Ag NPs but after that the Ag nanoparticles were released very slowly (almost constant). The improved hydrophilicity, higher tensile strength and much greater silver release for CS–PEO-0.50% F. vulgaris-Ag NPs relative to those of the CS–PEO 0.25% F. vulgaris-Ag NPs suggested that the former was superior for biomedical applications.
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Antimicrobial chitosan⿿polyethylene oxide (CS-PEO) nanofibrous mats were fabricated.ZIF-8 NPs (3, 5 and 10%) were incorporated within the CS-PEO mats.The electrospun CS-PEO ...nanocomposite fibers had ⿼70⿿120nm average diameters.The CS-PEO-3% ZIF-8 mat revealed 100% bactericidal activity.CS-PEO-3% ZIF-8 mat was selected as the most appropriate sample for food coating.
Antimicrobial chitosan⿿polyethylene oxide (CS-PEO) nanofiber mats loaded with 3, 5 and 10% (w/w) of zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs, ⿼60nm diameter) were developed by electrospinning technique. The CS-PEO-GA-3% ZIF-8 NPs crosslinked with glutaraldehyde (GA) vapor was also prepared. The electrospun mats were characterized by various analysis including FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. The nanofibers had average diameters within the range ⿼70⿿120nm. Antimicrobial activities of the CS-PEO and CS-PEO-3% ZIF-8 mats were evaluated by the viable cell-counting method for determining their effectiveness in reducing or halting the growth of Staphylococcus aureus and Escherichia coli bacteria so that the CS-PEO mat containing 3% ZIF-8 revealed 100% bactericidal activity against both kinds of bacteria. The crosslinked CS-PEO-GA-3% ZIF-8 NPs sample was less thermally stable but more hydrophilic than its related non-crosslinked mat reflecting there was no need to crosslink the fibers using a chemical crosslinker having adverse effects. The highest hydrophobicity and appropriate thermal and tensile properties of CS-PEO-3% ZIF-8 NPs among those of the mats including 5 and 10% ZIF-8 NPs suggested that the mentioned mat is the most suitable sample for food coating applications.
Schematic illustration for the architecture of SSLMB with a magnification showing CSSE and the structures of LiIL@LiMNT. The EMIM+ and TFSI− in space-filling model are randomly displayed in the layer ...of LiMNT.
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•Li-containing ionic liquid was inserted into a 2D LiMNT structure (LiIL@LiMNT).•LiIL@LiMNT provides a fast 2D Li-ion transport channel in PEO-based Electrolytes.•This CSSE has a high ionic conductivity and Li-ion transference number (0.38).•SSLMBs deliver impressive cycling performance with LFP and NMC111 cathodes.
Polyethylene oxide (PEO)-based solid-state electrolytes (SSEs) typically struggle with poor ionic conductivity, low lithium (Li)-ion transference number, and narrow electrochemical window. For overcoming these drawbacks, we designed a promising composite SSE (CSSE), i.e., a Li-containing ionic liquid (LiIL) was inserted into the Li-montmorillonite (LiMNT) layered structure to form an active filler (LiIL@LiMNT), involving two-dimensional (2D) fast transport channels of Li-ion inside PEO electrolyte. Benefitting from an enhancement of the 2D Li-ion transport channels, the obtained CSSE exhibited an excellent ion conductivity of 1.38 × 10−4 S cm−1 at 30 °C as well as a satisfactory Li-ion transference number (0.38). A Li symmetric battery with the CSSE exhibited a steady cycle for 3000 h with 0.2 mA cm−2 at 60 °C. Under the rate of 0.5C at 60 °C, the solid-state Li-metal batteries (SSLMBs) assembled with LiFePO4 and LiNi0.33Co0.33Mn0.33O2 cathodes maintained a considerable reversible capacity after 400 and 100 cycles, respectively. The assembled SSLMB also achieved a satisfactory performance at 40 °C. The 2D active filler prepared in this work forms efficient 2D Li-ion transport channels inside the CSSE while maintaining a tight interfacial contact with electrodes, which is crucial to achieve a superior performance for CSSEs. This strategy of constructing 2D ion transport channels in polymer electrolytes also provides another way for the design of other CSSEs.
Beyond state-of-the-art lithium-ion battery (LIB) technology with metallic lithium anodes to replace conventional ion intercalation anode materials is highly desirable because of lithium’s highest ...specific capacity (3,860 mA/g) and lowest negative electrochemical potential (∼3.040 V vs. the standard hydrogen electrode). In this work, we report for the first time, to our knowledge, a 3D lithium-ion–conducting ceramic network based on garnet-type Li6.4La₃Zr₂Al0.2O12 (LLZO) lithium-ion conductor to provide continuous Li⁺ transfer channels in a polyethylene oxide (PEO)-based composite. This composite structure further provides structural reinforcement to enhance the mechanical properties of the polymer matrix. The flexible solid-state electrolyte composite membrane exhibited an ionic conductivity of 2.5 × 10−4 S/cm at room temperature. The membrane can effectively block dendrites in a symmetric Li | electrolyte | Li cell during repeated lithium stripping/plating at room temperature, with a current density of 0.2 mA/cm² for around 500 h and a current density of 0.5 mA/cm² for over 300 h. These results provide an all solid ion-conducting membrane that can be applied to flexible LIBs and other electrochemical energy storage systems, such as lithium–sulfur batteries.
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•Doxycycline-loaded membranes are successfully fabricated by electrospinning method.•Hydrophobic and hydrophilic polymers are blended for the fabrication of membranes.•The blending ...polymers provide the adjusting of release profile of doxycycline.•(75:25 w/w) PCL/PEO membrane can be promising as a drug delivery vehicle.
Potential usage of biodegradable and biocompatible polymeric nanofibers is the most attention grabbing topic for the drug delivery system. In order to fabricate ultrafine fibers, electrospinning, one of the well-known techniques, has been extensively studied in the literature. In the present study, the objective is to achieve the optimum blend of hydrophobic and hydrophilic polymers to be used as a drug delivery vehicle and also to obtain the optimum amount of doxycycline (DOXH) to reach the optimum release. In this case, the biodegradable and biocompatible synthetic polymers, poly(ε-caprolactone) (PCL) and poly(ethylene oxide) (PEO), were blended with different ratios for the production of DOXH-loaded electrospun PCL/PEO membranes using electrospinning technique, which is a novel attempt. The fabricated membranes were subsequently characterized to optimize the blending ratio of polymers by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and water contact angle analysis. After the characterization studies, different amounts of DOXH were loaded to the optimized blend of PCL and PEO to investigate the release of DOXH from the membrane used as a drug delivery vehicle. In vitro drug release studies were performed, and in vitro drug release kinetics were assessed to confirm the usage of these nanofiber materials as efficient drug delivery vehicles. The results indicated that 3.5% DOXH-loaded (75:25 w/w) PCL/PEO is the most acceptable membrane to provide prolonged release rather than immediate release of DOXH.
Here we demonstrate that by regulating the mobility of classic -EO- based backbones, an innovative polymer electrolyte system can be architectured. This polymer electrolyte allows the construction of ...all solid lithium-based polymer cells having outstanding cycling behaviour in terms of rate capability and stability over a wide range of operating temperatures. Polymer electrolytes are obtained by UV-induced (co)polymerization, which promotes an effective interlinking between the polyethylene oxide (PEO) chains plasticized by tetraglyme at various lithium salt concentrations. The polymer networks exhibit sterling mechanical robustness, high flexibility, homogeneous and highly amorphous characteristics. Ambient temperature ionic conductivity values exceeding 0.1 mS cm(-1) are obtained, along with a wide electrochemical stability window (>5 V vs. Li/Li(+)), excellent lithium ion transference number (>0.6) as well as interfacial stability. Moreover, the efficacious resistance to lithium dendrite nucleation and growth postulates the implementation of these polymer electrolytes in next generation of all-solid Li-metal batteries working at ambient conditions.
The urgent need for safer batteries is leading research to all-solid-state lithium-based cells. To achieve energy density comparable to liquid electrolyte-based cells, ultrathin and lightweight solid ...electrolytes with high ionic conductivity are desired. However, solid electrolytes with comparable thicknesses to commercial polymer electrolyte separators (~10 μm) used in liquid electrolytes remain challenging to make because of the increased risk of short-circuiting the battery. Here, we report on a polymer-polymer solid-state electrolyte design, demonstrated with an 8.6-μm-thick nanoporous polyimide (PI) film filled with polyethylene oxide/lithium bis(trifluoromethanesulfonyl)imide (PEO/LiTFSI) that can be used as a safe solid polymer electrolyte. The PI film is nonflammable and mechanically strong, preventing batteries from short-circuiting even after more than 1,000 h of cycling, and the vertical channels enhance the ionic conductivity (2.3 × 10
S cm
at 30 °C) of the infused polymer electrolyte. All-solid-state lithium-ion batteries fabricated with PI/PEO/LiTFSI solid electrolyte show good cycling performance (200 cycles at C/2 rate) at 60 °C and withstand abuse tests such as bending, cutting and nail penetration.
Polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs) typically reveal a sudden failure in Li metal cells particularly with high energy density/voltage positive electrodes, e.g. LiNi
Mn
Co
...O
(NMC622), which is visible in an arbitrary, time - and voltage independent, "voltage noise" during charge. A relation with SPE oxidation was evaluated, for validity reasons on different active materials in potentiodynamic and galvanostatic experiments. The results indicate an exponential current increase and a potential plateau at 4.6 V vs. Li|Li
, respectively, demonstrating that the main oxidation onset of the SPE is above the used working potential of NMC622 being < 4.3 V vs. Li|Li
. Obviously, the SPE│NMC622 interface is unlikely to be the primary source of the observed sudden failure indicated by the "voltage noise". Instead, our experiments indicate that the Li | SPE interface, and in particular, Li dendrite formation and penetration through the SPE membrane is the main source. This could be simply proven by increasing the SPE membrane thickness or by exchanging the Li metal negative electrode by graphite, which both revealed "voltage noise"-free operation. The effect of membrane thickness is also valid with LiFePO
electrodes. In summary, it is the cell set-up (PEO thickness, negative electrode), which is crucial for the voltage-noise associated failure, and counterintuitively not a high potential of the positive electrode.
Composite polyethylene-oxide/garnet electrolytes containing LiTFSI as the lithium salt have a Li+ conductivity σLi > 10−4Scm−1 at 55°C and a low plating/stripping impedance of a dendrite-free ...Li-metal anode; they have been developed for a safe solid-state Li-metal rechargeable battery. Composites consisting of “ceramic-in-polymer” to “polymer-in-ceramic” that are flexible and mechanically robust are fabricated by hot-pressing. Safe pouch cells with a remarkable flexibility have been fabricated. Solid-state LiFePO4|Li batteries with electrolytes of “ceramic-in-polymer” and “polymer-in-ceramic” deliver excellent cycling stability with high discharge capacities (139.1mAhg–1 with capacity retention of 93.6% after 100 cycles) and high capacity retention (103.6% with coulombic efficiency of 100% after 50 cycles) at 0.2C and 55°C. Both kinds of electrolytes can be applied to solid-state lithium batteries.
PEO/garnet composite electrolytes from “ceramic-in-polymer” to “polymer-in-ceramic” are prepared by hot-pressing technology without introducing any solvent. The resultant electrolytes exhibit excellent electrochemical properties and the assembled batteries deliver high cycling stability and stable interface with Li anode, demonstrating a promising strategy for a safe, high-performance and solid-state Lithium batteries. Display omitted
•PEO/garnet electrolyte has a Li+ conductivity σLi > 10−4Scm−1 at 55°C.•The electrolytes are flexible and mechanically robust.•The membrane has a low plating/stripping impedance.•All-solid-state LiFePO4/Li cell has a discharge capacities of 148.6mAhg−1.
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