Incorporating multifunctional LiAlSiO_(4) into polyethylene oxide for high-performance solid-state lithium batteries

High ionic conductivity,good electrochemical stability,and satisfactory mechanical property are the crucial factors for polymer solid state electrolytes.Herein,fast ion conductor LiAlSiO_4(LASO) is incorporated into polyethylene oxide(PEO)-based solid-state electrolytes(SSEs).The SSEs containing LASO exhibit enhanced mechanical properties performance compared to pristine PEO-LiTFSI electrolyte.A reduced melting transition temperature of 40.57℃ is enabled by introducing LASO in to PEO-based SSE,which is beneficial to the motion of PEO chain and makes it possible for working at a moderate environment.Coupling with the enhanced motion of PEO,dissociation of the lithium salt,and conducting channel of LASO,the optimized composite polymer SSE exhibits a high ionic conductivity of 4.68×10^(-4),3.16×10^(-4) and 1.62×10^(-4) S cm^(-1) at 60,50 and 40℃,respectively.The corresponding LiFePO_4//Li solid-state battery exhibits high specific capacities of 166,160 and 139 mAh g^(-1) at 0.2 C under 60,40 and 25℃.In addition,it remains 130 mAh g^(-1) at 4.0 C,and maintains 91.74% after 500 cycles at 1.0 C under 60℃.This study provides a simple approach for developing ionic conductor-filled polymer electrolytes in solid-state lithium battery application.

Effects of Polyethylene Oxide Concentration on the Size of Beads in Electrospun Beaded Nanofibers

Embedding particle drugs in beaded nanofibers by electrospinning has been shown a potential approach to control drug release in tissue engineering. The bead size is one of the critical parameters in controlling the drug release rate. In this study,the relationship between polymer concentration and beads size was investigated. Aqueous polyethylene oxide( PEO) solutions with different concentrations were prepared to obtain various beaded nanofibers by electrospnning. Optical microscope and scanning electron microscope( SEM) were used to observe the variation tendency of bead size. With an increase in the polymer concentration,the diameter of fibers between beads became bigger,while the fiber uniformity improved. In addition, the polymer concentration influenced the distribution of bead diameter. Higher polymer concentration would reduce the possibility of small-sized beads formation and improve the uniformity of bead diameter. The study provides a possible way to control the size of beads,which is helpful for further research on the control of particle drug release.

Ionic conductivity study on electron beam irradiated polyacrylonitrile-polyethylene oxide gel

Different mass percent polyacrylonitrile （PAN）-polyethylene oxide （PEO） gels were prepared and irradiated by an electron beam （EB） with energy of 1.0 MeV to the dose ranging from 13 kGy to 260 kGy. The gels were analysed by using Fourier transform infrared spectrum, gel fraction and ionic conductivity （IC） measurement. The results show that the gel is crosslinked by EB irradiation, the crosslinking degree rises with the increasing EB irradiation dose （ID） and the mass percents of both PAN and PEO contribute a lot to the crosslinking; in addition, EB irradiation can promote the IC of PAN-PEO gels. There exists an optimum irradiation dose, at which the IC can increase dramatically. The IC changes of the PAN-PEO gels along with ID are divided into three regions： IC rapidly increasing region, IC decreasing region and IC balanced region. The cause of the change can be ascribed to two aspects, gel capturing electron degree and crosslinking degree. By comparing the IC-ID curves of different mass percents of PAN and PEO in gel, we found that PAN plays a more important role for gel IC promotion than PEO, since addition of PAN in gel causes the IC-ID curve sharper, while addition of PEO in gel causes the curve milder.

Poly(m-phenylene isophthalamide)-reinforced polyethylene oxide composite electrolyte with high mechanical strength and thermostability for all-solid-state lithium metal batteries

Polyethylene oxide(PEO)-based solid polymer electrolytes(SPEs)with flexibility,easy processability,low cost and especially strong ability to dissolve lithium salts have been regarded as promising alternatives to traditional flammable liquid electrolytes in next-generation highsafety and high-energy-density lithium metal batteries.However,the inferior mechanical strength and thermostability of PEO-based SPEs will raise the lithium dendritic penetration issue,further leading to the short circuit in batteries.In this work,aiming at enhancing the interfacial stability against Li dendrites of PEO-based SPEs,poly(mphenylene isophthalamide)(PMIA)is introduced as a reinforcing phase for the rational design of PEO/PMIA composite electrolyte.Impressively,PMIA chain with meta-type benzene-amide linkages significantly improves the mechanical strength(1.60 MPa),thermal stability(260℃)and ability to inhibit the growth of lithium dendrites(>300 h at 0.1 mA·cm^(-2))of SPEs.Meanwhile,allsolid-state LiFePO_(4)‖PEO/PMlA‖Li cell demonstrates superior electrochemical performance in terms of high specific capacity(159.1 mAh·g^(-1)),remarkable capacity retention(82.2%after 200 cycles at 0.5 C)and excellent safety characteristics.No burning or explosion occurs under pressing,bending and cutting conditions.This work opens a new door in developing high-performance PEObased electrolytes for advanced all-solid-state lithium metal batteries.

Polyethylene Oxide-Coated Electrospun Polyimide Fibrous Seperator for High-Performance Lithium-Ion Battery

A polyethylene oxide （PEO）-coated polyimide （PI） membrane was prepared by electrospinning method followed by a dip-coating and drying process for high-performance lithium-ion batteries （LIB）. 8emicrystal PEO was covered on the surface of the fibers and partially enmeshed in PI matrix, which formed unique porous structures. The pores with an average size of 4.1 μm and a porosity of 90% served as ion transport channels. Compared with the cell with Celgard 2400 membrane, the half-cell using PEO-coated P1 membrane as a separator exhibits excellent electrochemical performance both at room temperature and at low temperature. The electrolyte uptaking rate of PEO-coated PI membrane was 170% and the ionic conductivity was 3.83 × 10^-3 S cm^-1. PEO-coated PI membrane possessed 5.3 V electrochemical window. The electrode-electrolyte interfacial resistance was 62.4 Ω. The capacity retention ratios with PEO- coated PI membrane were 86.4% at 5 C and 73.5% at 10 C at 25 ℃ and 75% at 5 C at 0 ℃. Furthermore, the cell using the separator demonstrates excellent capacity retention over cycling. These advanced characteristics would boost the application of the PEO-coated PI membrane for high-power lithium ion battery.

Synthesis and Surface Tension Properties of Polyethyleneimine-Polyethylene Oxide Block Copolymers

This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. These block copolymers were prepared by a three step synthetic sequence. Firstly, PEO glycol was converted to its dimethanesulphonylester (dimesyl) derivative by reacting with methanesulphonyl chloride. Then a tri block polymer was prepared by the ring opening polymerization of 2 methyl 2 oxazoline (MeOZO) with the dimesyl PEO derivative. Lastly, linear PEI blocks were obtained by subsequent hydrolysis and purification. 1H NMR spectra confirmed the structures of the intermediate, final products and their purities (>99%). The utility of these block copolymers is described in terms of their surface tension and clay dispersancy measurements as a function of copolymer chain and block length.

Preparation of polyethylene oxide with 4-amino-N-(2-pyrimidinyl) benzene sulfonamide and diethylenetriaminepentaacetic acid end groups and its enrichment in tumour tissues

Using polyethylene oxide (PEO) with 4 amino N (2 pyrimidinyl) benzene sulfonamide (APBS) and hydroxyl end groups (PEO a h ) as parent compounds, PEO with diethylenetriaminepentaacetic acid (DTPA) and APBS end groups (PEO a d ) was prepared by functionization of PEO a h . After complexation of PEO a d with isotopes of 153 Sm and 99 Tc, and injecting the polymer drug into the Kunming white mouse transplanted with Sarcoma 180, it was confirmed by γ counter that the PEO a d could be concentrated selectively in the tumour tissues, the ratio of concentration of the polymer drug in tumour tissue to that in ordinary organs such as liver, heart, spleen, muscle, blood and bone marrow is about 2.3:1 or even 10:1.

The Structure and Properties of Polyethylene Oxide Reinforced Poly(Metaphenylene Isophthalamide)Fibers

In this paper,the efect of poly(ethylene oxide)(PEO)as an additive on the structure and properties of poly(m-phenylene dimethylene terephthalamide)(PMIA)fbers obtained by wet spinning was investigated.The tensile strength of the composite fbers was substantially enhanced compared to the pure PMIA fber.This was due to the fact that the addition of PEO weakens the hydrogen bonding between PMIA molecular chains resulting in an improved orientation of the composite fbers.It was found that the optimum PEO addition was 2%and the tensile strength of the composite fber was 4.74 cN/dtex,which was 76%higher compared to the pure PMIA fber.However,the heat resistance and fame retardancy of the composite fbers were basically unchanged compared to the pure PMIA fber.The modifcation method is simple,with low raw material cost and good stability,and has not only good academic value but also excellent industrial value.

Studies on the Absorption of NO_2 by Polyethylene Glycol and the Oxidizing Properties of the Resulting Absorbent Product

PEG (Polyethylene glycol average molecular weight 300) is used as absorbent of NO2. The absorption efficiency is found to reach up to 97%. The absorbing product, PEG NO2, can be used to cleave benzyl ethers mildly and selectively to benzaldehyde and corresponding fatty alcohols, showing that PEG is a valuable oxidizing agent of benzyl ethers. As a carrier of NO2.PEG can be recovered and utilized repeatedly after the oxidation.

Improvement of ionic conductivity of solid polymer electrolyte based on Cu-Al bimetallic metal-organic framework fabricated through molecular grafting

A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework(CAB),lithium salt(LiTFSI)and polyethylene oxide(PEO)was fabricated through molecular grafting to enhance the ionic conductivity of the PEO-based electrolytes.Experimental and molecular dynamics simulation results indicated that the electrolyte with 10 wt.%CAB(PL-CAB-10%)exhibits high ionic conductivity(8.42×10~(-4)S/cm at 60℃),high Li+transference number(0.46),wide electrochemical window(4.91 V),good thermal stability,and outstanding mechanical properties.Furthermore,PL-CAB-10%exhibits excellent cycle stability in both Li-Li symmetric battery and Li/PL-CAB-10%/LiFePO4 asymmetric battery setups.These enhanced performances are primarily attributable to the introduction of the versatile CAB.The abundant metal sites in CAB can react with TFSI~-and PEO through Lewis acid-base interactions,promoting LiTFSI dissociation and improving ionic conductivity.Additionally,regular pores in CAB provide uniformly distributed sites for cation plating during cycling.

In-situ polymerized PEO-based solid electrolytes contribute better Li metal batteries:Challenges,strategies,and perspectives

Polyethylene oxide(PEO)-based solid polymer electrolytes(SPEs)with good electrochemical stability and excellent Li salt solubility are considered as one of the most promising SPEs for solid-state lithium metal batteries(SSLMBs).However,PEO-based SPEs suffer from low ionic conductivity at room temperature and high interfacial resistance with the electrodes due to poor interfacial contact,seriously hindering their practical applications.As an emerging technology,in-situ polymerization process has been widely used in PEO-based SPEs because it can effectively increase Li-ion transport at the interface and improve the interfacial contact between the electrolyte and electrodes.Herein,we review recent advances in design and fabrication of in-situ polymerized PEO-based SPEs to realize enhanced performance in LMBs.The merits and current challenges of various SPEs,as well as their stabilizing strategies are presented.Furthermore,various in-situ polymerization methods(such as free radical polymerization,cationic polymerization,anionic polymerization)for the preparation of PEO-based SPEs are summarized.In addition,the application of in-situ polymerization technology in PEO-based SPEs for adjustment of the functional units and addition of different functional filler materials was systematically discussed to explore the design concepts,methods and working mechanisms.Finally,the challenges and future prospects of in-situ polymerized PEO-based SPEs for SSLMBs are also proposed.

Cellulose-Based Nanofibers Electrospun from Cuprammonium Solutions:Preparation,Mechanical and Antibacterial Properties

Nanofibers based on cellulose are highly desired due to their remarkable biocompatibility and attractive physical and biochemical characteristics.The current research describes a simple electrospinning process and the nano-materials therefrom,utilizing the classical cellulose-cuprammonium solution without the more exotic chemical solvent combinations.Furthermore,without the use of organic solvents,a binary polymer system with the addition of polyethylene oxide(PEO)is introduced to improve the robustness of the electrospinning and the properties of the final material.The impacts of the cellulose source,cellulose mass fraction and PEO formulation on spinnability,fiber morphology and mechanical properties are investigated.Nanofibers with diameters ranging from 130 nm to 382 nm are successfully fabricated.The presence of copper in the fabricated material is confirmed by using the X-ray photoelectron spectroscopy(XPS)analysis.The cuprammonium process significantly changes the original crystalline structure of cellulose I into celluloseⅢwithin the nanofiber morphology.The nanofibrous membranes also demonstrate notable antibacterial characteristics for Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).

Chitosan as green kinetic inhibitors for gas hydrate formation

The kinetic inhibiting effect of a number of chitosans on hydrate formation was investigated using methane and methane/ethane gas mixtures.The results indicated that chitosan was a good kinetic inhibitor.The induction time of gas hydrate formation evidently increased with the degree of deacetylation （DD）,however,when DD was higher than 80%,the effect of DD on the induction time was negligible.Moreover,it was found that the molecular weight （MW） of chitosan and the addition of polyethylene oxide （PEO） had little effect on the induction time.The optimal concentration of chitosan was found to be 0.6 wt%.Finally,the mechanisms of the kinetic inhibitor on the hydrate formation were discussed.

3D flame-retardant skeleton reinforced polymer electrolyte for solid-state dendrite-free lithium metal batteries

For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton(3DPA)and adding nano-multifunctional fillers(Li-ILs@ZIF-8).In addition to providing mechanical support for the polyethylene oxide(PEO)matrix,3DPA also has further contributed to the system’s flame retardancy and further improved the safety.Simultaneously,the electrochemical performance is fully guaranteed by rigid Li-ILs@ZIF-8,which provides fast migration channels forLi^(+),reduces the crystallinity of PEO and effectively inhibits lithium dendrites.The limiting oxygen index of the optimal sample(PL3Z/PA)is as high as 20.5%,and the ionic conductivity reaches 2.89×10^(-4) and 0.91×10^(-3) S cm^(-1) at 25 and 55°C,respectively.The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 m A cm^(-2) without short circuit being pierced by lithium dendrites.The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 m Ah g^(-1) under a current density of 0.5 C,and the capacity retention rate was 90.0%after 300 cycles.

Preparation and properties of PEO/LiClO_4/KH560-SiO_2 composite polymer electrolyte by sol-gel composite-in-situ method

Composite polymer electrolytes based on polyethylene oxide(PEO) were prepared by using LiClO4 as doping salt and silane-modified SiO2 as filler. SiO2 was formed in-situ in (PEO)8LiClO4 matrix by the hydrolysis and condensation reaction of Si(OC4H9)4. The crystallinity,morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry,scanning electron microscopy,atom force microscopy and alternating current impedance spectroscopy,respectively. Compared with the crystallinity of the unmodified SiO2 as inert filler,that of composite polymer electrolytes is decreased. The results show that silane-modified SiO2 particles are uniformly dispersed in (PEO)8LiClO4 composite polymer electrolyte film and the addition of silane-modified SiO2 increases the ionic conductivity of the (PEO)8LiClO4 more noticeably. When the mass fraction of SiO2 is about 10%,the conductivity of (PEO)8LiClO4-modified SiO2 attains a maximum value of 4.8×10-5 S·cm-1.

An asymmetric bilayer polymer-ceramic solid electrolyte for highperformance sodium metal batteries

Manufacturing an excellent solid electrolyte compatible with a high-voltage cathode is viewed as a critical tactic for improving the energy density of solid-state sodium-ion batteries(SSIBs).A novel asymmetric bilayer solid electrolyte of the PEO-SN-NaClO_(4)|NZSP-NSO with an anti-reduction PEO-SN-NaClO_(4)layer close to the Na side is constructed by solution casting.The ionic conductivity is enhanced by using succinonitrile(SN)in polyethylene oxide(PEO)polymer electrolyte.The anti-oxidation layer of Na_(3)Zr_(2)Si_(2)PO_(12)with Na_(2)SiO_(3)(NZSP-NSO)is served as the support of the membrane on the cathode,which could improve the interface compatibility and electrochemical performance of SSIBs.The asymmetric bilayer solid electrolyte simultaneously features a wide electrochemical stability window(4.65 V vs.Na+/Na)and a high conductivity(2.68×10^(-4) S cm^(-1)).Furthermore,the solid electrolyte demonstrates stable Na plating/stripping over 700 h and remarkably improves cycling stability in Na/Na_(3) V_(2)(PO_(4))_(3) batteries with an ultra-high capacity retention of 99.6%after 100 cycles at 50℃and 0.5 C.This study provides an effective strategy for designing asymmetric high sodium ion conductivity solid-state electrolytes for high-performance SSIBs.

Effect of catalyst on structure of(PEO)_8LiClO_4-SiO_2 composite polymer electrolyte films

(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra,contact angle method and TEM.The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5and 1.1×10-5S/cm respectively at 30℃.The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2,and influences the surface energy and conductivity of CPE films directly.Meanwhile,the ionic conductivity is related to the surface energy.

Enhancing diamond drilling performance by the addition of non-ionic polymer to the flushing media

Drilling is a most important and crucial operation in the excavation industries.With the objective of looking into the enhancement of diamond drilling performance detailed laboratory investigations were carried out on phosphate rock.The effect of Poly（Ethylene Oxide）（PEO） added to the drilling water was studied by varying machine parameters and PEO concentration.The responses were rate of penetration and torque at the bit rock interface.Slake durability tests were also performed to understand the slaking behavior of phosphate rock in PEO solutions.

Morphology and conductivity of in-situ PEO-LiClO_4-TiO_2 composite polymer electrolyte

PEO-LiClO4-TiO2 composite polymer electrolyte films were prepared. TiO2 was formed directly in matrix by hydrolysis and condensation reaction of tetrabutyl titanate. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. The glass transition temperature and the crystallinity of composite polymer electrolytes are decreased compared with those of PEO-LiClO4 polymer electrolyte film. The results show that TiO2 particles are uniformly dispersed in PEO-LiClO4-5%TiO2 composite polymer electrolyte film. The maximal conductivity of 5.5×10、5 Scm at 20 ℃ of PEO-LiClO4-TiO2 film is obtained at 5% mass fraction of TiO2.

A General Strategy to Electrospin Nanofibers with Ultrahigh Molecular Chain Orientation

The degree of polymer chain orientation is a key structural parameter that determines the mechanical and physical properties of fibers.However,understanding and significantly tuning the orientation of fiber macromolecular chains remain elusive.Herein,we propose a novel electrospinning technique that can efficiently modulate molecular chain orientation by controlling the electric field.In contrast to the typical electrospinning method,this technique can piecewise control the electric field by applying high voltage to the metal ring instead of the needle.Benefiting from this change,a new electric field distribution can be realized,leading to a non-monotonic change in the drafting force.As a result,the macromolecular chain orientation of polyethylene oxide(PEO)nanofibers was significantly improved with a recordhigh infrared dichroic ratio.This was further confirmed by the sharp decrease in the PEO jet fineness of approximately 80%and the nanofiber diameter from 298 to 114 nm.Interestingly,the crystallinity can also be adjusted,with an obvious drop from 74.9%to 31.7%,which is different from the high crystallinity caused by oriented chains in common materials.This work guides a new perspective for the preparation of advanced electrospun nanofibers with optimal orientation–crystallinity properties,a merited feature for various applications.