Low-temperature Performance Research Articles

RESIDUAL BINDER OF ROAD BITUMINOUS EMULSIONS INVESTIGATED USING THE SUPERPAVE SYSTEM. REVIEW

The article reviews the features of the study of residual binder obtained from bituminous emulsions using the SUPERPAVE system. The need to add improving additives to bituminous emulsions, namely modifiers (polymeric and adhesive additives) and special additives of different effects (solvents, stabilizers, thickeners, defoamers) is characterized. It is determined that the effect of special additives with different effects on the properties of the residual binder of the emulsion is not fully investigated. It is shown that the method of obtaining residual binder from bitumen emulsions in the laboratory is especially important. Today, all methods of obtaining residual binder from an emulsion can be divided into high-temperature distillation methods and low-temperature evaporation. The literature review confirmed that the high-temperature and low-temperature performance characteristics of the residual binder of emulsions primarily depend on the amount and type of modifier and emulsifier used.

Design and Corrosion Resistance Performance of Nano-Multilayer Coatings for the Protection of Breathing Gas Cylinders Used in Diving

Seamless gas cylinders for diving exhibit excellent low-temperature impact performance, lightweight characteristics, and good corrosion resistance, making them widely applicable in underwater activities. However, during use, the peeling of paint or corrosion on the surface of these cylinders poses a significant threat to their safety. In this study, environmentally friendly arc ion plating technology was used to deposit TiBN, CrAlN, and nano-multilayer coatings of CrAlN/TiBN. The surface morphology, tribological properties, and corrosion resistance of these coatings were investigated. The results indicated that both CrAlN and CrAlN/TiBN coatings possess fewer droplets, pinholes, and pits, and the cross-section of the CrAlN/TiBN coating exhibits a denser structure. The preferred orientation for TiBN was identified as TiB2 (101), while that for CrAlN was Cr(Al)N (200), with the preferred orientation for CrAlN/TiBN being TiB2 (101). The friction measurements revealed that the lowest coefficient was observed in the CrAlN/TiBN coating (0.489), followed by CrAlN (0.491) and then TiBN (0.642). Electrochemical tests conducted in artificial seawater demonstrated that the self-corrosion potential was highest for the CrAlN/TiBN coating, followed by CrAlN and lastly TiBN. The developed TiBN-based nano-multilayer coatings hold substantial application value in protecting seamless gas cylinders used in diving.

Synthesis and Evaluation of Polyurethane as Waterproof Adhesion Layer for Steel Bridge Deck

Service life of traditional steel bridge deck pavement is significantly shortened due to the failure of waterproof adhesion. To improve the interlayer bonding performance and extend its service life, polyurethane is proposed as a waterproof adhesion layer (WAL) for a steel bridge deck. This study aims to synthesize polyurethane WAL by free radical solution polymerization under different types and dosages of crosslinking agents as well as the mixing ratio of an acrylic co-blend. Tensile properties, water resistance, glass transition temperatures, thermal stability, and adhesive strength of the polyurethane binder are evaluated. The results demonstrate that polyurethane WAL yields desirable performance by using a hydroxyl molar ratio of 1/3 and an acrylic co-blend of 65%. Specifically, the tensile strength and breaking elongation of polyurethane WAL reach the maximum values of 6.466 MPa and 268.4%, respectively. The water absorption rate of polyurethane WAL is less than 4%. Glass transition temperatures of polyurethane WAL are between −80 °C and 60 °C, respectively. Polyurethane WAL features remarkable high- and low-temperature performance and thermal stability. Finally, adhesion strength between polyurethane WAL and the steel plate reaches up to 5.21 MPa. The outcome of this study facilitates the design and application of polyurethane waterproofing adhesion layers for steel bridge decks.

Antifreezing functionalized-alginate-based electrolytes for zinc-ion batteries

Flexible zinc-ion batteries (ZIBs) assembled with hydrogel electrolyte are considered as promising flexible energy storage devices because of their inherent safety and versatility. However, the ionic conductivity and mechanical properties of most hydrogel electrolytes are not satisfactory, Furthermore, they will freeze at subzero temperature due to existing water. In this work, a freezing resistant polycarboxylic double network gel electrolyte (SIP-CS) with high ionic conductivity (14.36 mS cm⁻1 at −20 °C) and excellent mechanical property (fracture stress of 241.5 kPa and fracture strain of 1011 %) is prepared. Iminodiacetic acid (IDA) is applied to modify the alginate mainchains with many -COOH groups, which could provide channels for ion migration and endow hydrogel with high ionic conductivity. Additionally, sorbitol, containing lots of hydroxyl groups, is applied as a cryoprotectant to enhance the subzero performance of the electrolyte, because sorbitol could break the hydrogen bonds between water molecules, inhibit the formation of ice crystals, and reduce the freezing point of the gel electrolyte. The freezing point of SIP-CS is −37.0 °C, enabling the electrolyte to perform well at low temperatures. The flexible quasi solid Zn-MnO2 battery is assembled to evaluate the low-temperature electrochemical performance of SIP-CS. The assembled Zn-MnO2 battery shows good cycling and stable electrochemical performance, which proves the excellent antifreezing property of SIP-CS. This work provides a new strategy for preparing an electrolyte with good withstand low-temperature capability.

Comparative investigation of nanomaterial-enhanced asphalt binders in the UAE: a multifaceted study

ABSTRACT This study explores the impact of incorporating six distinct nanomaterials into asphalt binders to determine their effectiveness in resisting permanent deformation, fatigue and thermal cracking. Additionally, the study aimed to establish the Optimum Nano Content (ONC) for each nanomaterial to achieve the best performance against these distresses. The key findings revealed that asphalt binders with 2% Carbon Nanotubes (CNT) or Nano CuO (NCO) demonstrated the best rheological properties, partially in enhancing Elastic Recovery (ER) and rutting resistance, making them ideal for use in hot climate regions. In terms of fatigue performance, all nanomodified asphalt binders, except 2% NAT, exhibited higher fatigue life (Nf) than the control, with the NCO-nanomodified asphalt binder exhibiting the highest Nf, achieving values six to seven times greater than the control. Most nanomaterials showed no noticeable improvement in low-temperature performance, where the best performance was observed for 2% CNT and 6% Nano Iron Trioxide (NIT). For rutting resistance, the ONC for most nanomaterials was approximately 2%, whereas the ONC for fatigue resistance was typically 6%. A proposed ranking system revealed that sixteen of the nanomodified asphalt binders outperformed the control, with the 2% CNT providing the best-balanced performance, while 2% NAT was the least effective.

Evaluation of SMA-13 Asphalt Mixture Reinforced by Different Types of Fiber Additives

This research aims at systematically evaluating the properties of SMA-13 asphalt mixture reinforced by several fiber additives including flocculent lignin fiber (FLF), granular lignin fiber (GLF), chopped basalt fiber (CBF), and flocculent basalt fiber (FBF). Firstly, the thermal stability, moisture absorption, and oil absorption property of these fiber additives were analyzed. Secondly, the property of SMA-13 reinforced using four types of single fibers and two kinds of composite fibers (FLF + CBF and FLF + FBF) was comprehensively analyzed. Specifically, the high-temperature performance was evaluated using the uniaxial penetration test and the rutting test, the medium-temperature anticracking property was evaluated using the IDEAL-CT test, the low-temperature property was analyzed using the beam bending test, and the water stability was studied by the freeze–thaw splitting test. Thirdly, the dynamic mechanical response of different-fibers-modified SMA-13 was evaluated using the uniaxial compression dynamic modulus test. Finally, correlation analysis between the results of dynamic modulus and the high-, medium-, and low-temperature mechanical performance was carried out. The research results reveal that the stability of CBF and FBF under thermal action is better than that of GLF and FLF, and FBF shows the best thermal stability. The oil absorption property of FLF is better than that of GLF, followed by FBF and CBF. The comprehensive mechanical properties of CBF- and FBF-reinforced SMA-13 are better than those of FLF- and GLF-modified SMA-13. CBF can better reinforce the mechanical property of SMA-13 under low and medium temperature, while FBF can better reinforce the performance of SMA-13 at high temperature. FLF/CBF- and FLF/FBF-composite-modified SMA-13 show better high-temperature mechanical performance than that of the single-fiber-reinforced mixture, and FLF has some negative impact on the properties of FLF/FBF-composite-modified SMA-13 at low temperature. Fibers have no significant influence on the water stability of the mixtures. Meanwhile, the linear correlation between the mechanical performance of all the fiber-reinforced SMA-13 and the dynamic modulus result is good.

Rechargeable Hydrogen Gas Batteries: Fundamentals, Principles, Materials, and Applications.

The growing demand for renewable energy sources has accelerated a boom in research on new battery chemistries. Despite decades of development for various battery types, including lithium-ion batteries, their suitability for grid-scale energy storage applications remains imperfect. In recent years, rechargeable hydrogen gas batteries (HGBs), utilizing hydrogen catalytic electrode as anode, have attracted extensive academic and industrial attention. HGBs, facilitated by appropriate catalysts, demonstrate notable attributes such as high power density, high capacity, excellent low-temperature performance, and ultralong cycle life. This review presents a comprehensive overview of four key aspects pertaining to HGBs: fundamentals, principles, materials, and applications. First, detailed insights are provided into hydrogen electrodes, encompassing electrochemical principles, hydrogen catalytic mechanisms, advancements in hydrogen catalytic materials, and structural considerations in hydrogen electrode design. Second, an examination and future prospects of cathode material compatibility, encompassing both current and potential materials, are summarized. Third, other components and engineering considerations of HGBs are elaborated, including cell stack design and pressure vessel design. Finally, a techno-economic analysis and outlook offers an overview of the current status and future prospects of HGBs, indicating their orientation for further research and application advancements.

Optimizing the low-temperature performance of high-wax-content crude oil with emulsion-based wax inhibitors: Mechanisms and efficacy.

Wax deposition in constant-temperature transportation of waxy oil with high pour points poses a significant challenge for the oil industry. The demand for efficient methods to solve wax deposition has gained attention. To elucidate the impact of emulsion-based wax inhibitors on the performance of crude oils with varying wax content at low temperatures, experiments, rheological analyses, and microscopic analyses were conducted to study their pour point regulation, low-temperature flow improvement, wax prevention effectiveness, and wax crystallization behavior. The results indicate that emulsion-based wax inhibitors significantly reduce the pour point of crude oil, especially for high-wax-content oil, while for low-wax-content oil, the pour point only decreased by 3°C. By penetrating and dispersing wax crystals, the inhibitor reduced the viscosity of crude oil at low temperatures, enhancing its flowability. At 28°C, crude oil transitioned from a shear-thinning non-Newtonian fluid to a Newtonian fluid at wax inhibitor dosages of 500-750ppm. At 1000ppm, the wax prevention rate for high-wax-content oil reached 87.5%, but the effect plateaued beyond this concentration. Additionally, the wax prevention and removal mechanism of the emulsion-based wax inhibitors is discussed. This study confirms that emulsion-based wax inhibitors significantly enhance the low-temperature processability of crude oil, offering a viable strategy for the conveyance and refinement in cold climates.

Evaluation of pine needle oil recycled asphalt: Rheological characterization and molecular dynamics simulation

The regenerant based on bio-oil has the potential to lower carbon emissions, conserve natural resources, and shows promising prospects for application. In this paper, pine needle oil (PNO) and dioctyl phthalate (DOP) were utilized as base materials for asphalt rejuvenator. The primary aim of this research was investigate the impact of the rejuvenator on the rheological characteristics of asphalt and the compatibility between the rejuvenator and aged asphalt. The rheological properties of the asphalt were evaluated by the bending beam rheometer (BBR) and the dynamic shear rheometer (DSR). The glass transition temperature of the asphalt was tested by differential scanning calorimetry (DSC). Finally, the glass transition temperature (Tg), mean square displacement (MSD), cohesive energy density (CED), and solubility parameter (δ) were calculated and analyzed through molecular dynamics simulation to clarify the mechanism of PNO and DOP on asphalt. In the tested temperature range, the creep stiffness modulus of the PNO compound DOP recycled asphalt had decreased by 43.7∼68.4 % compared with the aged asphalt, and the rutting factor had decreased by 59.6∼75.3 %, but it was still better than the original asphalt. This showed that the regenerant had significantly restored the rheological properties of the asphalt. At 413.15 K, the difference of solubility parameters between PNO and DOP was the lowest, which was 1.37 and 0.17 (J/cm3)0.5, respectively. At this time, the compatibility between the PNO regenerant and aged asphalt was the best. The addition of the PNO softened the aged asphalt, reduced the rutting factor, adjusted the composition of the aged asphalt, improved its colloidal structure, and thereby enhanced its low temperature performance. The PNO regenerant also improved the diffusion of the four components of the aged asphalt and positively influenced the diffusion and fusion process of the system. DOP molecules lowered the asphalt's glass transition temperature, increased the amount of free space available for the thermal motion of asphalt molecules, and improved the compatibility of the asphalt with the regenerant.

Rheological Properties and Modification Mechanism of Emulsified Asphalt Modified with Waterborne Epoxy/Polyurethan Composite.

In research aimed at improving the brittleness of WER (waterborne epoxy)-modified emulsified asphalt, commonly encountered issues are that the low-temperature performance of this type of asphalt becomes insufficient and the long curing time leads to low early strength. Matrix-emulsified asphalt was modified with WPU (waterborne polyurethane), WER, and DMP-30 (accelerator). Firstly, the performance changes of modified emulsified asphalt at different single-factor dosages were explored through conventional performance tests and assessments of its adhesion, tensile properties, and curing time. Secondly, based on a response surface methodology test design, the material composition of the composite-modified emulsified asphalt was optimized, and its rheological properties were analyzed by a DSR test and a force-ductility test. Finally, the modification mechanism was explored by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that WER can improve the adhesion strength of modified emulsified asphalt and greatly reduce elongation at break. WPU can effectively improve the elongation at break of composite-modified emulsified asphalt, but it has a negative impact on adhesion strength. DMP-30 mainly affects the curing time of modified emulsified asphalt; EPD (composite modification) can effectively improve the high-temperature rutting resistance of matrix-emulsified asphalt, and its low-temperature performance is significantly improved compared with WER-modified emulsified asphalt. The EPD modification process mainly consists of physical blending. In the case of increasing the curing rate, it is recommended that the contents of WER and WPU be lower than 10% and 6%, respectively, to achieve excellent comprehensive performance of the composite modification.

Morphological characteristics of low-asphalt RAP and influence of its reaction product during combustion heating on regenerated asphalt

To provide reference for regeneration of the finely separated low-asphalt reclaimed asphalt pavement (RAP), the macroscopic and microscopic laboratory testing and quantum chemical simulation were combined. The morphological characteristics of the basalt and limestone low-asphalt RAP were analyzed. The low-asphalt RAP needs to be dried before regeneration, so the reaction mechanism and product of the asphalt film on its surface during drying were clarified. The product influence on the temperature resistance and fatigue performance of the virgin asphalt was studied, so as to consider their mixing during the subsequent regeneration process. Result shows that the gradation of limestone low-asphalt RAP is coarser and particles are slenderer than basalt with the same particle size grade. The 5–10 mm low-asphalt RAP particles are slenderer than those in the 10–20 mm grade. In the drying cylinder, asphalt basically generate no new functional groups below 200℃, while the asphalt film on the low-asphalt RAP surface undergoes pyrolysis to produce carbon black with the particle size around 100μm in the combustion heating area. The most easily oxidation or pyrolysis site in asphalt molecule is the carbon atom connected to the benzene ring. The pyrolysis of asphalt molecules to generate free radicals in the local oxygen deficient environment is the prerequisite for the carbon black formation, and pyrolysis requires higher temperature than oxidation because of its higher energy barrier. As the carbon black content increases, the penetration and ductility of asphalt decrease, the softening point increases, the high-temperature performance is enhanced, the low-temperature performance is weakened, and the fatigue performance is not significantly affected. As the particle size of carbon black increases, the decrease range in penetration, ductility and low-temperature performance of asphalt declines, the increase or improvement range of softening point and high-temperature performance enhanced, while the fatigue performance still shows no significant and regular change.

Influence of flue gas components on SO2 adsorption by activated carbon at low temperature

Activated carbon can adsorb SO2 in flue gas, whose performance is significantly enhanced when lowering the adsorption temperature; however, the characteristics and mechanism of SO2 adsorption under the action of complex flue gas components at low temperatures remain unclear. In this study, adsorption experiments were conducted to investigate the characteristics of SO2 adsorption on activated carbon and the impact of O2, H2O, and NO within −20 to 20 °C. The saturated adsorption of SO2 showed a 2.21-fold increase when the temperature was lowered from 20 °C to −20 °C. Within this temperature range, physical adsorption was dominant, accounting for 73.7–91.0 %. O2 and H2O inhibited the physical adsorption of SO2 and promoted its chemical adsorption. As the temperature was lowered, the promoting effect of O2 increased, while the influence of H2O shifted from promotion to inhibition. NO affects SO2 adsorption only when co-existing with O2. As the temperature decreased, the promoting effect of NO on both physical and chemical adsorption strengthened and was significantly higher than that of O2 and H2O. Based on desorption experiments and quantum chemical calculations, the mechanisms by which H2O and NO affect SO2 adsorption were proposed·H2O and SO2 share the same physical adsorption sites, with H2O being more strongly adsorbed, thus significantly inhibiting the SO2 physical adsorption. When NO coexists with O2, gaseous SO2 reacts with the NOx adsorption configurations to form C-SO3 and C-HSO3. Active atoms near C-SO3 and C-HSO3 can adsorb NO2, forming a co-adsorption configuration, which in turn enhances the nearby physical adsorption of SO2. Enhancing the catalytic oxidation and adsorption of NO through surface modification of activated carbon can improve the low-temperature adsorption performance of SO2.

Ideal Co-NiO solid solution with excellent low-temperature propene catalytic combustion performance

Doping engineering of transitional metal oxides offers a great opportunity to further optimize the performance of corresponding catalysts. Here, we presented a solid-state co-precipitation routine to synthesize the Co-NiO ideal solid solution, where Co atoms achieved nearly atomically isolation in the NiO lattice matrix. Remarkably a clear correlation was established between the reactivity for propene combustion and the Co dopant amounts, with the propene combustion rate increasing proportionally to the Co dopant amounts. The homogeneously dispersed Co single atoms or tiny CoOx nanoclusters ensure this linear relationship. More importantly, due to the emergence of Co single atoms and CoOx nanoclusters with a lower coordination number, significant propene adsorption and subsequent C = C bond dissociation were observed in this Co-doped NiO, which improved the propene combustion reaction rate. Therefore, this solid-state co-precipitation strategy provides an effective doping route for building an ideal doped solid solution.

Stable heterometallic metal-organic frameworks and pellet composites for low-temperature natural gas storage

Liquefied natural gas coupled with adsorbed natural gas charging (LNG-ANG) offers an efficient solution for recycling boil-off gas, providing a promising strategy for the competent storage and transportation of natural gas. The key challenge in LNG-ANG coupling systems is identifying adsorbents that exhibit superior methane adsorption performance and excellent stability under cryogenic conditions (∼159 K). In this work, we systematically investigated the methane adsorption performance of a stable metal–organic framework, PCN-250-Fe2Ni, under LNG-ANG related conditions. The results demonstrated that PCN-250-Fe2Ni exhibited a high methane capacity of 286 cm3 (standard temperature and pressure, STP) cm−3 (0.227 g g−1) at 6 bar/159 K. Furthermore, the pellet composite of PCN-250-Fe2Ni and polyvinyl butyral also displayed a high methane adsorption capacity with excellent cycling stability. Combined with grand canonical Monte Carlo simulations, our findings revealed that the cage-type pores serve as initial methane adsorption sites, followed by the channel-type pores, both of which contribute to the framework’s high low-temperature methane storage performance at saturation.

An anti-freezing hydrogel electrolyte based on hydroxyethyl urea for dendrite-free Zn ion batteries

Aqueous zinc ion batteries are considered as a promising energy storage resource due to their high security, abundant resources and low price. However, the development of aqueous zinc ion batteries has been severely hindered by compulsive dendrite generation, serious side reactions and poor temperature adaptability. Herein, we used hydroxyethyl urea as a hydrogel electrolyte additive to address above-mentioned challenges. Hydroxyethyl urea can break the hydrogen bonds (HBs) of water and enhancing the freezing-tolerance ability of the electrolyte. Meanwhile, hydroxyethyl urea can prevent the corrosion issue and inhibition of Zn dendrites. Consequently, the Zn//Zn symmetric battery can sustain stable cycling for over 3000 h at 1 mA cm−2, and it achieves a high coulombic efficiency of 99.6 %. Even at −40 ℃ the batteries show excellent cycling stability, the Zn//Zn symmetry battery can achieve steadily cycles over 3000 h. The Zn//NVO battery equipped with the altered electrolyte exhibits enhanced capacity retention compared to the one without additives.It demonstrates not only robust stability at room temperature but also maintains commendable functionality down to −40 ℃, validating the method’s efficacy. This work provides a simple strategy for enhancing low temperature performance of zinc ion batteries.

Pivotal copper bimetallic oxide in hierarchical Calcium magnesium materials for low-temperature carbon capture and utilization

Carbon removal from anthropogenic greenhouse gas emissions is essential to achieve net-zero emissions and mitigate climate change, and integrated carbon capture and utilisation (ICCU) has been studied for subsequent in-situ chemical production. However, high temperature and CaO sintering remain critical issues, highlighting the need for improved, low-cost CO2 adsorbents that can be regenerated at lower temperatures. Herin, we innovatively introduce the low-temperature ICCU coupled with reverse water gas shift reactions (RWGS) using dual functional materials (DFMs), exemplifying a range of potential transition metals doped over CaO with or without the MgO support. Among all the prepared DFMs, D-Cu showed desirable enhanced catalytic activity at a comparatively low-temperature performance (550°C) and still maintained a stable CO2 capture capacity (7.0mmol g−1) and CO yield (8.0mmol g−1) with an exceptional CO2 conversion (94.4 %) and CO selectivity (97.6 %) after cyclic hydrogenation. The mechanism study revealed that Ca2CuO3 bimetalliccatalyst in the hierarchical porous 2CaO/MgO matrix of D-Cu plays a crucial role in retaining its cyclic stability, surpassing that of noble D-Pt. Given the ICCU-RWGS performance and cyclic stability of cost-effective D-Cu at reduced operating temperatures, the findings would minimise energy and cost consumption.

Breaking boundaries in O3-type NaNi1/3Fe1/3Mn1/3O2 cathode materials for sodium-ion batteries: An industrially scalable reheating strategy for superior electrochemical performance

To address the challenges of air stability and slurry processability in layered transition metal oxide O3-type NaNi1/3Fe1/3Mn1/3O2 (NFM) for sodium-ion batteries (SIBs), we have designed an innovative 500 °C reheating strategy. This method improves the surface properties of NFM without the need for additional coating layers, making it more efficient and suitable for large-scale applications. Pristine NFM (NFM-P) was first synthesized through a high-temperature solid-state method and then modified using this reheating approach (NFM-HT). This strategy significantly enhances air stability and electrochemical performance, yielding an initial discharge specific capacity of 151.46 mAh/g at 0.1 C, with a remarkable capacity retention of 95.04% after 100 cycles at 0.5 C. Additionally, a 1.7 Ah NFM||HC (hard carbon) pouch cell demonstrates excellent long-term cycling stability (94.64% retention after 500 cycles at 1 C), superior rate capability (86.48% retention at 9 C), and strong low-temperature performance (77% retention at −25 °C, continuing power supply at −40 °C). Notably, even when overcharged to 8.29 V, the pouch cell remained safe without combustion or explosion. This reheating strategy, which eliminates the need for a coating layer, offers a simpler, more scalable solution for industrial production while maintaining outstanding electrochemical performance. These results pave the way for broader commercial adoption of NFM materials.

Electronic effect tuned ion-dipole interactions for low-temperature electrolyte design of LiFePO4-based lithium-ion batteries

Poor low-temperature performance is one of the major challenges hindering the widespread use of lithium-ion batteries. Modulation of Li+ solvation structure to facilitate desolvation process is an important strategy in electrolyte engineering under low temperature. Herein, different electronic effect groups including electron-withdrawing groups (CH2Cl) and electron-donating groups (CH3), are introduced in the weakly solvated solvent tetrahydrofuran (THF), respectively, to compare their effects on the ion-dipole interaction in the electrolyte and thus the regulation of Li+ solvation structure. Theoretical calculations combined with characterization demonstrates that the introduction of electron-withdrawing groups CH2Cl in the solvent can reduce the electron cloud density of oxygen in the THF solvent molecule, weaken the binding energy between Li+ and the solvent, and lead to more anions participating in solvation shell of Li+ and coordinating with Li+, thus accelerating the desolvation kinetics of Li+. This electrolyte-design strategy based on electronic effect tuned ion-dipole interactions has notably increased the cycling stability of the LiFePO4||Li half-cell at −20 °C, that is, it not only increases the capacity by about 10 mAh g−1 at the rate of 0.2 C, but also maintains the capacity retention rate at 97.4 % after 100 cycles. This study reveals an important electrolyte design strategy at the molecular level.

Effects of ultraviolet and thermal oxygen ageing on the rheological properties of SEBS/MWCNTs composite-modified asphalt

To enhance the anti-ageing properties of asphalt binder, multiwalled carbon nanotubes (MWCNTs) and styrene-ethylene-butylene-styrene (SEBS) were used to create a composite-modified asphalt (CMA). The ageing resistance was assessed through rheological property changes, using a dynamic shear rheometer (DSR) for various tests. FTIR spectroscopy analyzed the ageing mechanism. The results showed that CMA exhibited significantly better rutting resistance than matrix and SBS asphalt. Although the fatigue life of CMA was lower than SBS asphalt, ist was still dramatically higher than matrix asphalt. MWCNTs reduced the low-temperature relaxation performance of unaged asphalt. Notably, CMA showed superior ageing resistance against both thermal oxygen and UV ageing, with decreases of about 30% and 28% in the UV ageing index and long-term ageing index, respectively, compared to matrix asphalt. The carbonyl and sulfoxide indices increased after ageing, with the composite containing 3% SEBS demonstrating optimal ageing resistance and road performance.

LiF-enriched interphase promotes Li+ desolvation and transportation enabling high-performance carbon anode under wide-range temperature

Li-ion batteries (LIBs) have made inroads into the electric vehicle area with high energy densities, but they still suffer from slow kinetics of Li+ limited by the graphite anode especially at high current density and low-temperature conditions. Sluggish de-solvation of Li+ at the electrode surface and slow Li+ transfer in solid electrolyte interphase (SEI) are main determining factors that restrict the fast-charging and low-temperature performance of graphite-based LIBs. Here, we construct the sodium lignosulfonate layer with abundant polar functional groups on the lithium-montmorillonite surface, which can make it simple for electrons transfer to promote in-situ formation of LiF-based SEI with high ionic conductivity. The thin and robust LiF-based SEI promotes the de-solvation of Li salts and Li+ transfer as proved by the comprehensive electrochemical studies and density functional theory (DFT) calculations. Consequently, a combination of excellent stability and fast-charging ability for LIBs at room and low temperatures is achieved. The designed anode shows the remarkable capacity of 1500 mAh/g at 0.1 A/g, which was 3–4 times better than the commercial graphite. At the high current density of 5 A/g, it can still keep stable with the capacity retention of 70 % after 7000 cycles. Besides, an impressive 70 % of their room-temperature capacity is attained at −10 °C and 150 mAh/g is achieved under the extremely low temperature of −40 °C. This study establishes the effective strategy to construct the LiF-rich interface on the surface of anode to improve the Li+ kinetics and stability of the battery.