Highly reinforce the interface stability using 2-Phenyl-1H-imidazole-1-sulfonate electrolyte additive to enhance the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries

This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries.After 450 cycles at room temperature(25℃),the discharge capacity retentions of batteries with blank and PHIS-containing electrolyte are 56.03%and 94.92%respectively.After 230 cycles at high temperatures(45℃),their values are 75.30%and 88.38%respectively.The enhanced electrochemical performance of the batteries with PHIS-containing electrolyte is supported by the spectroscopic characterization and theoretical calculations.It is demonstrated that this PHIS electrolyte additive can facilitate the construction of the electrode interface films,remove the H2O/HF in the electrolyte,and improve the electrochemical performance of the batteries.This work not only develops a sulfonate-based electrolyte but also can stimulate new ideas of functional additives to improve the battery performance.

Shrinkage Behavior of High Performance Concrete at Different Elevated Temperatures under Different Sealing Conditions

The shrinkage behavior of high performance cement concrete made from Portland cement, ultra fine granulated blast furnace slag and pulverized fly ash with addition of superplasticizer at different temperatures from ambient temperature to 120 ℃ under different seuliug conditions was investigated by means of length change measurement on cylindrical concrete specimens along with curing age. Results show that drying shrinkage deformations of titled concrete specimens increased rapidly as the curing temperature rose. The development of dryiing shrinkage deformatian can be efficiently controlled with the aid of aluminum tape sealing as compared with the unsealed specimens, especially when the curing temperature is below 60℃ , although it will increase dramatically when the curing temperature is elevated to above 90%＂ . Polymer coating on concrete specimens showed a similar effect on the control of drying shrinkage as the sealing operation with aluminum tape.

Effects of flaky rare earth oxide additives on the high temperature performance of nickel electrodes

Effects of flaky rare earth oxide additives including Er2O3,Tm2O3,and Yb2O3,Lu2O3 on high temperature and high rate discharge performance of nickel electrodes were investigated.The discharge efficiency at 0.2C reached 96% at 60 oC for electrodes with 1 at.% flaky rare earth oxides.The high rate discharge performance for electrodes with flaky rare earth oxides were improved significantly,for example,discharge efficiency at 5C improved from 50% to 70%.The results showed that the end charging potential of the ...

High Temperature Performances of Spherical Nickel Hydroxide with Additive Y_2O_3

The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.

HETEROAROMATIC POLYMERS—HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3',4'-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

A new type of aromatic tetraarnine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin＇s reaction. 3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis（3＇,4＇-diaminophenyl）-4-biphenyl pyridine （DPPA）. A series of polypyrrolones （PPys） were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure. All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen. The polymers exhibit no apparent glass transition temperatures （Tgs） except PPy-1 （Tg= 327℃）, which is derived from tetraamine DPPA and 2,2-bis[4-（3＇,4＇-dicarboxyphenoxy）-phenyl]propane dianhydride （BPADA）. In addition, the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa. The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.

Comprehensive Analysis of High Temperature Performance of SBS-modified Asphalt Mixture

Evaluation of high temperature performance of SBS-modified asphalt mixture was presented.Both wheel loaded method and creep method were adopted for two different mixtures and two kinds of specimens with different height,and corresponding indicators were measured.Meanwhile,the correlation between these indicators was thoroughly analyzed and two kinds of mixtures were compared.The experimental results show that there is a good linear relationship between LWT indicators and CT indicators for M-13,while a relatively poor relationship for M-25,especially that between dynamic stiffness and static stiffness and that between dynamic stability and static creep stiffness.Besides,logarithmic relationship between DS and RD has a higher determination coefficient than that for linear relationship.Thus,multi-index evaluation should be taken for synthetically assessing high temperature performance of asphalt mixture.

Functional copolymer binder for nickel-rich cathode with exceptional cycling stability at high temperature through coordination interaction

Nickel-rich layered oxide LiNi_(1-x-y)Co_(x)Al_yO_(2)(NCA) with high theoretical capacity is a promising cathode material for the next-generation high-energy batteries.However,it undergoes a rapid capacity fading when operating at high temperature due to the accelerated cathode/electrolyte interfacial reactions and adhesive efficacy loss of conventional polyvinylideneffuoride(PVdF) binder.Herein,poly(acrylonitrile-co-methyl acrylate) copolymer is designed with electron-rich-C≡N groups as a novel binder for LiNi_(0.8)Co_(0.1)Al_(0.1)O_(2) cathode at high temperature.The electron-rich-C≡N groups are able to coordinate with the active Ni^(3+) on the surface of NCA,alleviating electrolyte decomposition and cathode structure degradation.Moreover,the strong adhesive ability is conducive to maintain integrity of electrodes upon cycling at 55℃.In consequence,the NCA electrodes with this functional binder display improved cycling stability(81.5% capacity retention after 100 cycles) and rate performance at 55℃.

Advancements in the preparation of high-performance liquid chromatographic organic polymer monoliths for the separation of small-molecule drugs

The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency.

Highly Thermally Conductive Polymer/Graphene Composites with Rapid Room‑Temperature Self‑Healing Capacity

Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects.However,in view of the complexity of composite structure and composition,its self-heal is facing challenges.In this article,supramolecular effect is proposed to repair the multistage structure,mechanical and thermal properties of composite materials.A stiff and tough supramolecular frameworks of 2-[[(butylamino)carbonyl]oxy]ethyl ester(PBA)–polydimethylsiloxane(PDMS)were established using a chain extender with double amide bonds in a side chain to extend prepolymers through copolymerization.Then,by introducing the copolymer into a folded graphene film(FGf),a highly thermally conductive composite of PBA–PDMS/FGf with self-healing capacity was fabricated.The ratio of crosslinking and hydrogen bonding was optimized to ensure that PBA–PDMS could completely self-heal at room temperature in 10 min.Additionally,PBA–PDMS/FGf exhibits a high tensile strength of 2.23±0.15 MPa at break and high thermal conductivity of 13±0.2 W m^(−1)K^(−1);of which the self-healing efficiencies were 100%and 98.65%at room temperature for tensile strength and thermal conductivity,respectively.The excellent self-healing performance comes from the efficient supramolecular interaction between polymer molecules,as well as polymer molecule and graphene.This kind of thermal conductive self-healing composite has important application prospects in the heat dissipation field of next generation electronic devices in the future.

High-temperature electrochemical performance and phase composition of Ti_(0.7) Zr_(0.5) V_(0.2) Mn_(1.8-x)Ni_x hydrogen storage electrode alloys

The rapid development of electric vehicles demands the development of high performance nickel metal hydride battery that is able to endure high temperature. The discharge properties of Ti 0.7 Zr 0.5 V 0.2 Mn 1.8- x Ni x ( x =0.4, 0.8, 1.1, 1.4, 1.7)hydrogen storage alloys was investigated and its phase composition was analyzed using X ray diffraction. The results show that the cycling life was improved as the content of nickel increases. When x =0.4, 0.8, 1.1 and 1.4, the main phase is MgZn 2 type C14 Laves phase and the second one is cubic TiNi phase. When x =1.7, the Laves phase structure disappears. EDAS analysis shows that the increase of nickel content is effective in suppressing the dissolution of vanadium component in alloys. [

Influence of the Steel-making Dust on High Temperature and Fatigue Performance of Asphalt Mortars

To research the possibility of steel-making dust as a kind of mineral filler in asphalt mixture, two steel-making dusts and one ordinary mineral filler were adopted. The specific density, specific surface area, fineness modulus and mineralogy component of the dusts were tested. Scanning electron microscopy(SEM) was carried out to research the microstructure of the dusts; dynamic shear rheological(DSR) test and time sweep test were used to research the high temperature and fatigue performance of asphalt mortars containing steel-making dust. The experimental results indicate that, compared with ordinary mineral filler, steel-making dusts have more active ingredients, difference surface characteristics and micro-structure. Furthermore, the high temperature and fatigue performance of steel-making dusts corresponding asphalt mortars are superior to those of reference group. Therefore, the steel-making dust would be an alternative to the ordinary mineral filler to improve the performance of asphalt mortars and reduce the harm of the dusts to the environment at the same time.

FAILURE MODE AND CONSTITUTIVE MODEL OF PLAIN HIGH-STRENGTH HIGH-PERFORMANCE CONCRETE UNDER BIAXIAL COMPRESSION AFTER EXPOSURE TO HIGH TEMPERATURES

An orthotropic constitutive relationship with temperature parameters for plain highstrength high-performance concrete （HSHPC） under biaxial compression is developed. It is based on the experiments performed for characterizing the strength and deformation behavior at two strength levels of HSHPC at 7 different stress ratios including a=σs ： σ3=0.00：-1,-0.20：-1,-0.30 ： -1,-0.40：-1,-0.50：-1,-0.75：-1,-1.00：-1, after the exposure to normal and high temperatures of 20, 200, 300, 400, 500 and 600℃, and using a large static-dynamic true triaxial machine. The biaxial tests were performed on 100 mm×100 mm×100 mm cubic specimens, and friction-reducing pads were used consisting of three layers of plastic membrane with glycerine in-between for the compressive loading plane. Based on the experimental results, failure modes of HSHPC specimens were described. The principal static compressive strengths, strains at the peak stress and stress-strain curves were measured; and the influence of the temperature and stress ratios on them was also analyzed. The experimental results showed that the uniaxial compressive strength of plain HSHPC after exposure to high temperatures does not decrease dramatically with the increase of temperature. The ratio of the biaxial to its uniaxial compressive strength depends on the stress ratios and brittleness-stiffness of HSHPC after exposure to different temperature levels. Comparison of the stress-strain results obtained from the theoretical model and the experimental data indicates good agreement.

High temperature polymer electrolyte membrane fuel cell

One of the majorissuesli mitingtheintroduction of polymer electrolyte membranefuel cells(PEMFCs) is thelowtemperature ofoperation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO,inevitably present in reformedfuel.In order to alleviate the problemof COpoisoning andi mprove the power density of the cell,operating at temperature above 100 ℃ispreferred.Nafion-type perfluorosulfonated polymers have been typically used for PEMFC.However,the conductivity of Nafion-typepolymers is not high enoughto be usedfor fuel cell operations at higher temperature(>90 ℃) and atmospheric pressure because they dehy-drate under these condition.An additional problem which faces the introduction of PEMFCtechnology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications.Consequently the use of alternative fuels such as methanol and ethanol is of interest,especially if thiscan be used directlyinthe fuel cell,without reformationto hydrogen.Ali mitation of the direct use of alcohol is thelower activity of oxida-tionin comparison to hydrogen,which means that power densities are considerably lower.Hence to i mprove activity and power outputhigher temperatures of operation are preferable.To achieve this goal,requires a newpolymer electrolyte membrane which exhibits stabilityand high conductivityin the absence of liquid water.Experi mental data on a polybenzi midazole based PEMFC were presented.Asi mple steady-stateisothermal model of the fuel cell is alsoused to aidin fuel cell performance opti misation.The governing equations involve the coupling of kinetic,ohmic and mass transport.Thispaper also considers the advances madeinthe performance of direct methanol and solid polymer electrolyte fuel cells and considers theirli mi-tations in relation to the source and type of fuels to be used.

Experimental Performance of Moderate and High Temperature Heat Pump Charged with Refrigerant Mixture BY-3

Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water when the low temperature was 20 ℃. The following results were obtained: the highest temperature at the condenser outlet reached about 85 ℃; when the difference between the water temperatures at the condenser outlet and the evaporator inlet was less than 40 ℃, the coefficient of performance (COP) was larger than 4; when the difference reached 55 ℃, the COP still kept 3; the discharge temperature of BY-3 was lower than 100 ℃, and the refrigerant vapor pressure kept lower than 1.8 MPa. When the water temperature at the condenser outlet reached over 85 ℃, nearly a 5 ℃ superheating temperature was maintained.

Design of the material performance test apparatus for high temperature gas-cooled reactor

Most materials can be easily corroded or ineffective in carbonaceous atmospheres at high temperatures in the reactor core of the high temperature gas-cooled reactor(HTGR).To solve the problem,a material performance test apparatus was built to provide reliable materials and technical support for relevant experiments of the HTGR.The apparatus uses a center high-purity graphite heater and surrounding thermal insulating layers made of carbon fiber felt to form a strong carbon reducing atmosphere inside the apparatus.Specially designed tungsten rhenium thermocouples which can endure high temperatures in carbonaceous atmospheres are used to control the temperature field.A typical experimental process was analyzed in the paper,which lasted 76 hours including seven stages.Experimental results showed the test apparatus could completely simulate the carbon reduction atmosphere and high temperature environment the same as that confronted in the real reactor and the performance of screened materials had been successfully tested and verified.Test temperature in the apparatus could be elevated up to 1600oC,which covered the whole temperature range of the normal operation and accident condition of HTGR and could fully meet the test requirements of materials used in the reactor.

Optimization of technical measures for improving high-temperature performance of asphalt-rubber mixture

Asphalt-rubber pavements often become dam-aged in high-temperature regions and appear rutted or wavy, and experience slippage. To improve the high-temperature performance of the asphalt-rubber mixture, technical measurements, such as, the optimal adjustment of gradation, technique of composite modification, and control of compaction were investigated. An optimal adjustment of aggregate gradation based on stone matrix asphalt improves the high-temperature stability of the asphaltrubber mixture significantly. Through composite modifi- cation, the effect of asphalt-rubber modification was enhanced, and the dynamic stability and relative defor- mation indices of the asphalt-rubber mixture were improved significantly. Furthermore, compaction parame- ters had a significant influence on the high-temperature stability of the asphalt-rubber mixture. The rolling times for compacting the asphalt-rubber mixture should be controlled to within 18-20 round-trips at a molding temperature at 180℃; if the rolling time is a 12 round-trip, the compaction temperature of the asphalt-rubber mixture should be controlled between 180 and 190℃.

Synthesis and high-temperature performance of Ti substituted α-Ni(OH)_2

Ti substituted α-Ni（OH）2（c=2.121nm, a =0.307nm） with perfect high-temperature performance was prepared by the co-precipitation method. The effects of Ti addition on the structure and the electrochemical properties were investigated. The results indicate that the substitution of Ti for Ni leads to the conversion of β-Ni（OH）2 to α-Ni（OH）2 and the increase of the inter layer distance along c-axis from 0.464nm to 0.707nm. Infrared study reveals that more anions（SO2-4 and CO2-3 ions） and H2O exist in the Ti substituted α-Ni（OH）2. The discharge capacity of the Ti substituted α-Ni（OH）2 is 210mA·h/g at 20℃ and reaches up to 270mA·h/g at 80℃ owing to the inhibition of the oxygen evolution at high temperature.

High pressure and high temperature induced polymerization of C60 quantum dots

We synthesized C60 quantum dots(QDs) with a uniform size by a modified ultrasonic process and studied its polymerization under high pressure and high temperature(HPHT).Raman spectra showed that a phase assemblage of a dimer(D) phase(62 vol%) and a one-dimensional chain orthorhombic(O) phase(38 vol%) was obtained at 1.5 GPa and 300℃.At 2.0 GPa and 430℃,the proportion of the O phase increased to 46 vol%,while the corresponding D phase decreased to 54 vol%.Compared with bulk and nanosized C60,C60 QDs cannot easily form a high-dimensional polymeric structure.This fact is probably caused by the small particle size,orientation of the disordered structure of C60 QDs,and the barrier of oxide function groups between C60 molecules.Our studies enhance the understanding of the polymerization behavior of low-dimension C60 nanomaterials under HPHT conditions.

Evaluation on High-temperature Adhesion Performance of Hot-applied Sealant for Asphalt Pavement

In order to investigate the high-temperature performances of the asphalt pavement hot-applied sealant, as well as to reduce failures of the sealant pullout, the softening point test and the flow test（two existing methods for evaluating high-temperature performances） were conducted. It was found that both tests could not accurately reflect the adhesion performances of the sealant at high temperatures. For this purpose, the adhesion test for PSAT（pressure sensitive adhesive tape） has been taken as a reference to develop a device that is suitable for evaluating the adhesion performances, by modifying relevant test parameters according to the road conditions at high temperatures. Thirteen common sealants were tested in the modified adhesion test, softening point test and f low test. The experimental results show that no significant correlation（p〉0.05） exists between the adhesion value, softening point, adhesion value and flow value; while a significant correlation（p〈0.05） exists between the softening point and flow value. The modified adhesion test is efficient in distinguishing the hightemperature adhesion performances of different sealants, and can be used as a standard method for evaluating such performances.