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NASICON-structured Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) solid electrolyte has low grain boundary conductivity, which impedes its practical application. Herein, W was adopted to partially replace the Al element in LATP to improve its grain boundary conductivity. The W doping reduces the crystal lattice of the electrolyte, which is detrimental to the grain conductivity. But the doping of W can make the grains closely connect and reduce the voids between the grains, which can greatly enhance the grain boundary conductivity. The LATP sample with the W doping content of 0.03 (LATWP003) exhibits the highest total ionic conductivity of 1.186 mS/cm at 30 ℃, which results from the optimum grain boundary conductivity of 2.315 mS/cm. Moreover, the LATWP003 electrolyte displays a negligible electronic conductivity of 2.01×10−9 S/cm. The LiFePO 4 /LATWP003/Li battery with PVDF-HFP polymer protective layer can be charged and discharged. Therefore, the W doped LATP sample is a promising electrolyte for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Summary: Poly(ethylene oxide) (PEO) polymer electrolyte has been regarded as a potential solid electrolyte which can be applied in all‐solid‐state lithium‐ion batteries (ASSLIBs). Nevertheless, low electrochemical properties and poor electrolyte/Li anode interfacial stability hinder its further application. In our work, the Li1.3Al0.3Ti1.7(PO4)3 (LATP) nanomaterials with Nasicon structure have been synthesized using a simple solvent‐thermal method, followed by being embedded into PEO polymer to form LATP filled PEO solid composite electrolytes. Effects of LATP content and particle size on electrochemical performances of solid electrolytes have been studied. By adjusting the calcination temperature, the uniformly distributed Nasicon‐type LATP powders with different sizes can be obtained. The electrochemical properties of PEO polymer electrolyte have been effectively enhanced by filling LATP nanoparticles. The composite electrolyte filled with 5 wt% LATP particles calcined at 850°C exhibits a high ionic conductivity of 5.24×10−4 S cm−1 at 55°C, which has a high electrochemical stability window of over 5 V versus Li/Li+ and a superior interfacial stability with Li metal. A LiFePO4/Li ASSLIB fabricated with the optimum composite electrolyte shows the excellent rate capability, and its discharge capacities at 0.2C, 0.5C, 1C, and 2C are 151.97, 151.56, 145.51, and 128.02 mAh·g−1. Moreover, the discharge capacity of the cell decreases from 151.69 to 130.53 mAh·g−1 after 100 charge‐discharge cycles at 0.5C rate, and the corresponding capacity retention is 86.05%. These results demonstrate that LATP nanoparticles obtained via the solvent‐thermal method are the alternative fillers for PEO polymer electrolyte. [ABSTRACT FROM AUTHOR]

Abstract Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 is regarded as one of the most promising solid electrolytes for all solid state lithium ion batteries (ASSLIBS). However, its grain boundary conductivity is still low, which reduces the total conductivity of electrolyte. In this work, in order to further improve the electrical conductivity of Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 , a series of Y doped Li 1.3 Al 0.3-x Y x Ti 1.7 (PO 4) 3 (x = 0, 0.025, 0.05, 0.075 and 0.15) solid electrolytes were synthesized using a modified solid state method. Effects of Y doping content on morphology, phase and electrical conductivity of Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 electrolyte materials were systematically investigated. All synthetic electrolyte powders show Nasicon-like structure, well-shaped polyhedral morphology as well as good crystallinity. Y dopant content has a great influence on electrochemical properties of electrolytes. The high total conductivity of 7.8 × 10−4 S/cm at room temperature and a low activation energy of 0.17 eV is obtained for the electrolyte with the Y doping content of 0.075 due to the increasing of grain boundary conductivity, and its electrical conductivity is about 2 times larger than that of the undoped electrolyte. The excellent electrochemical performance is mainly attributed to high electrolyte density which results from the good sintering property of electrolyte materials as well as the existence of YPO 4 phase at grain boundaries. Additionally, this electrolyte has a negligible electronic conductivity. These results suggest that Y doped Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 can be used as an alternative solid electrolyte for all solid state lithium ion batteries. Highlights • Nasicon-type Y doped LATP materials were prepared by a modified solid state method. • The optimum conductivity was obtained for the sample with Y doping content of 0.075. • The highest electrical conductivity at room temperature is 7.8 × 10−4 S/cm. • The Y doped LATP electrolyte has a negligible electronic conductivity. [ABSTRACT FROM AUTHOR]

Graphical abstract Hydrophobic fluorinated cross-linked network films were prepared by self-assembling random fluoroacrylate polyol polymer on the HDI modified LB-SiO 2 particulate monolayers. Surface analyses show a low surface segregation degree of fluorinated groups. Highlights • The ester groups stretch towards the inner surface during film forming process. • The surface enrichment of fluorinated groups bonded to ester groups is difficult. • The surface hydrophobicity is attributed to the polymer main chain of -C-C-. Abstract Hydrophobic fluorinated particulate films were fabricated by coupling Langmuir-Blodgett silica (LB-SiO 2) particulate monolayers with fluoroacrylate polymer, and the depth distributions of chemical compositions were studied. The resultant fluorinated particulate films show surface hydrophobic property with water contact angles (WCA) of 123° (300 nm) and 125° (550 nm), which is dominated in Wenzel wetting state. The surface F/C ratio is only 0.09 at 20°, which is slightly higher than 0.07 at 60°. Fitting results of C1s and O1s high-resolution spectra at 20° and 60° indicate the outmost surface is mainly occupied by fluoroacrylate polymer main chains and the ester side chains stretch toward inner surface and thus hydrophobic fluorinated groups in self-assembled fluoroacrylate film cannot efficiently segregate to the outer surface, which results in low surface F/C ratio and surface WCA. [ABSTRACT FROM AUTHOR]

Hydroxyl-containing fluoroacrylate copolymers with different fluorine and hydroxyl concentrations were synthesized via free-radical solution polymerization. Transparent fluorinated polyurethane (FPU) films were prepared by curing the copolymers with HDI (hexamethylene diisocyanate) trimer. The Fourier transform infrared spectroscopy (FT-IR) results revealed introduction of fluorine both into the copolymer and polyurethane. X-ray photoelectron spectroscopy (XPS) analyses indicated that a gradient concentration of fluorine existed in the depth profile of the fluorinated polyurethane films. The highest contact angle (CA) was obtained for the FPU film with fluoroacrylate monomer concentration of 22 wt.% because of fluorine present on the film surface. The surface topographies detected by SEM and AFM indicated that surface roughness contributed little to the film hydrophobicity. By increasing the fluoroacrylate monomer concentration, the decreasing of crosslinking degree of hard segment resulted in lowering the first degradation temperature, while more C-F groups in soft segment led to higher second degradation temperature. UV-Vis spectrophotometer measurements indicated that the FPU film with the fluoroacrylate monomer concentration of 16 wt.% still had a high transmittance of more than 90 % in the whole visible wavelength range. [ABSTRACT FROM AUTHOR]

The dependence of particulate Langmuir-Blodgett (LB) monolayer quality on the surface nature of the substrate was investigated by pretreating the substrates with different methods, and the optimal withdrawal speed was determined by detecting the quality of particulate monolayers deposited at different withdrawal speeds. Furthermore, the effects of stearic acid (SA) concentration on the quality of particulate monolayers were discussed. Results indicated that surface amination would favor the transfer of the floating particulate monolayer from the interface to the substrate, which would be attributed to the formation of chemical bonds between the -2 groups on the substrate surface and the functional groups of - and - groups on surfaces of particles floating at the interface. And the withdrawal speed of 1 mm ⋅ min-1 was appropriate for the fabrication of high-quality particulate LB monolayer because low withdrawal speed can offer sufficient time to form chemical bonds and expel the subphase from the substrate. Additionally, SEM images illustrated that the SA concentration of 0.40 mg ⋅ mL-1 was suitable for the fabrication of well-ordered particulate LB monolayers composed by the particles of 380 nm. [ABSTRACT FROM AUTHOR]

We describe a controllable method to fabricate hexagonally close-packedLangmuir–Blodgett (LB) monolayers with stearic acid (SA) asco-surfactant and methanol as co-solvent. The optimal SA concentrationsand volume ratios of chloroform to methanol are 0.8 mg/mL and 3:1for particles of 140 nm, 0.50 mg/mL and 4:1 for particles of 300 nm,and 0.05 mg/mL and 5:1 for particles of 550 nm, respectively. Additionally,SEM detections of the monolayers transferred at different surfacepressures indicate that the monolayers deposited from the binary systemsare more compressible. The experimental results indicate that theinterparticle repulsions and particle–water interactions canbe enhanced without decreasing the particle hydrophobicity by addingSA and methanol; thus, particulate monolayers with large hexagonallyclose-packed domains composed of small silica particles can be successfullyfabricated using LB technique. We propose that the enhanced interparticlerepulsion is attributed to the Columbic repulsion resulting from theattachment of SA molecules to the CTAB modified particles around thethree phase contact line. [ABSTRACT FROM AUTHOR]

Abstract: The interfacial reaction, metal transformations, and nonmetal bond types of silver ultra-thin film deposited on polyurethane (PU) based interpenetrating polymer networks (IPN) substrate by the liquor-phase reduction at room temperatures were studied by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The IPN substrate was prepared by dip-pulling precursors onto a silicon wafer or a glass plate, followed by solidification at room temperature. The interpenetrate structures of IPN with two crosslinked networks restricted the aggregation of silver during the reduction and deposition. The devised –OH terminal group in PU simplified the determination of reactive site in IPN and reinforced the adhesion between IPN and silver through interfacial reaction. The XPS results, which matched well with the ATR-FTIR results, verified the chemical reactive site of PU in IPN with silver in the oxide state. [Copyright &y& Elsevier]

[Display omitted] • Uniform nanostructured ZIF-67 MOFs with high specific surface area were prepared. • PEO/ZIF-67 solid electrolyte shows a high ionic conductivity of 1.15 × 10−5 S/cm at 25 °C. • PEO/ZIF-67 solid electrolyte displays a good interfacial compatibility with Li. • LiFePO 4 /Li ASSLIB exhibits high rate and cycling performances. Composite polymer electrolyte is a promising solid electrolyte for all solid state lithium ion batteries (ASSLIBs) due to its reliable safety, high ionic conductivity and excellent flexibility. Here, the uniform rhomboid dodecahedron structured zeolitic imidazolate framework-67 (ZIF-67) with high specific surface area and abundant nano-pores have been prepared by adjusting the synthetic solvent, which are subsequently incorporated into poly(ethylene oxide) (PEO) matrixes to form solid composite electrolyte (SCE). ZIF-67 MOFs can reduce the crystallinity of PEO matrixes, coordinate with C-O-C bonds of PEO and improve the mechanical properties of solid electrolyte. Additionally, abundant pore structure of ZIF-67 can endow its ability to absorb anions. The optimized SCE shows high ionic conductivities of 1.51 × 10−5 S/cm at 25 °C, wide electrochemical stable window of around 5.2 V and good interfacial compatibility with lithium. Furthermore, LiFePO 4 /Li ASSLIB exhibits high electrochemical performances. At current rates of 0.2 C, 0.5 C, 1 C and 2 C, the battery has specific discharging capacities of 155.13, 153.77, 148.83 and 139.90 mAh·g−1, respectively, and it demonstrates high capacity retention of 90.17% after 100 cycles at 0.5 C. Therefore, it is concluded that ZIF-67/PEO SCE is a good solid electrolyte candidate for ASSLIB. [ABSTRACT FROM AUTHOR]

The synergistic effects of electric field and polymer structures were innovatively introduced to achieve uniform, beads-free, and robust superhydrophobic electrospun fibers. Aminopropyl triethoxysilane (APTES) terminated block copolymers of APTES-poly (methyl methacrylate)- b -poly (dodecafluoroheptyl methacrylate) (APTES-PMMA- b -PDFMA) and APTES-polystyrene- b -PDFMA (APTES-PS- b -PDFMA) were synthesized via atom transfer radical polymerization (ATRP) and electrospinning in a positive electric field. Uniform, beads-free, and robust superhydrophobic electrospun films were fabricated with APTES-PS- b -PDFMA involving small amount of PDFMA segment. XPS results display that effective surface fluorine enrichment is more easily achieved on APTES-PS- b -PDFMA than on APTES-PMMA-b-PDFMA which involves large amount of DFMA. The mechanism can be summarized as follows: negatively charged block PS in positive electric field migrates towards the core of electrospinning jets, and block PMMA has a better positive charging stability than block DFMA, resulting in preferential surface segregation. This investigation will provide an important instructive value in controllable fabrication of robust superhydrophobic electrospun films applied in the fields of textiles, oil-water separation, membrane distillation, etc. Image 1 • Uniform, beads/particles-free, and robust superhydrophobic APTES-PS- b -PDFMA electrospun fibers have been fabricated. • Electric field promotes selective surface segregation of like-polarity functional groups. • Functional groups having more stable charging ability preferentially migrate to fiber surface. • Polymers containing functional groups of opposite polarity help to achieve efficient surface segregation of block PDFMA. • Block structure helps to achieve surface uniform distributions of fluorinated groups. [ABSTRACT FROM AUTHOR]

Nasicon-type Li 1+x Al x Ge 2-x (PO 4) 3 (x = 0–0.5) electrolytes have been prepared via a facile and economic method. All synthetic electrolyte samples show Nasicon structure and good crystallinity. The Al doping content has a great influence on the electrical conductivity of electrolyte. The electrolyte with the composition of Li 1.4 Al 0.4 Ge 1.6 (PO 4) 3 exhibits a highest electrical conductivity of 2.72 × 10−4 S/cm at room temperature, which is mainly attributable to fewer impurity and dense electrolyte structure. The LiFePO 4 /Li cell assembled with this electrolyte delivers an initial specific discharge capacity of 127.86 mAh g−1 at a charge/discharge current density of 0.5C at 60 °C, which shows an excellent cycling performance with high discharge capacity of 131.2 mAhg−1 after 150 cycles. These results suggest that the Li 1.4 Al 0.4 Ge 1.6 (PO 4) 3 electrolyte is a potential electrolyte for all solid state lithium-ion battery. • Nasicon-type LAGP electrolytes were successfully synthesized via a facile route. • The room temperature highest electrical conductivity is 2.72 × 10−4 S/cm. • An ASSLIB with LiFePO 4 /LAGP/Li structure was successfully assembled. • The cell showed a stable cycling performance. [ABSTRACT FROM AUTHOR]

The observation facts of trend and variability are estimated for a century‐long timescale, as well as some possible attributions affecting temperature extremes over Beijing‐Tianjin‐Hebei region. In this paper, the new constructed daily maximum and minimum temperature series during the last 100 years in situ stations of Beijing, Tianjin and Baoding city are used, and two 30‐year baseline climatology of 1961–1990 and 1980–2010 are both used in calculating extreme temperature events. The results indicate that there are long‐lasting, frequent and serious extreme warming over Beijing‐Tianjin‐Hebei region, especially for extreme low temperature, with larger declining trends (at 5% significance) from 1981 to 2010 baseline than those from 1961 to 1990 baseline. And from a statistical perspective, El Niño decay years and surface sea temperature (SST) anomalies at some typical ocean regions of the Arabian Sea and the Bengal Bay on the northern Indian Ocean, the Western Pacific and the Mid Atlantic, Southern Indian Ocean and around 45°–85°E, 68°–82°N on the southwest Arctic Ocean can be used as the warning signals denoting extreme warming over Beijing‐Tianjin‐Hebei region. Additionally, urbanization has a significant (at 5% significance) effect on extreme warming over Beijing‐Tianjin‐Hebei region since 1979, with 24.3% warming contribution for annual minimum temperature. [ABSTRACT FROM AUTHOR]

High voltage spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) cathode materials with well-developed polyhedral-shape structure have been successfully synthesized via a rapid hydrothermal process followed by high-temperature calcination with Li source. The as-synthesized samples were characterized by powder X-ray diffraction, Raman spectroscopy, Scanning electron microscopy and electrochemical test. All samples show polyhedral-shape morphologies as well as cubic spinel structure with Fd3m space group. Electrochemical analysis verifies that the spinel LNMO cathode prepared with sulfate at hydrothermal temperature of 200 °C exhibits the better electrochemical properties in terms of discharge capacity, cycling stability and rate performance. This sample delivers an initial discharge capacity of 131.1 mAh g −1 at 0.5 C rate at 25 °C, with the capacity retention of 85.2% after 100 charge-discharge cycles. Additionally, it still shows high rate performance with a discharge capacity of 110.9 mAh g −1 even at 20 C rate. The excellent electrochemical properties are mainly attributed to its high crystallinity, appropriate particle size and uniform particle size distribution. These results suggest that the rapid hydrothermal and post-calcination method is an effective way for preparing high voltage LNMO cathode materials which can be applied to lithium ion batteries. [ABSTRACT FROM AUTHOR]

It is well documented that the East Asian summer monsoon has been experiencing a steady weakening trend in recent decades. Because the Asian summer monsoon (including both East Asian monsoon and South Asian monsoon) is the largest and most pronounced monsoonal system in the world, its change in strength may exert a profound impact on global weather and climate systems, especially on the rainfall pattern in South and East Asia. On the other hand, as a vast elevated landmass, the Tibetan Plateau forms a huge heat source protruding into the free atmosphere. Setting against the backdrop of global climate change, whether or not does the change of this heating affect the change of Asian summer monsoon and thus rainfall distribution? Here we show that the apparent heat source over the Tibetan Plateau is closely correlated with the East Asian summer monsoonal circulation, and that the weakening of the East Asian summer monsoon is closely associated with the decreasing trend of the Tibetan Plateau apparent heat source. Further analysis indicates that the change of rainfall pattern in China in recent decades is consistent with the decreasing of the East Asian summer monsoon. [ABSTRACT FROM AUTHOR]