The ever‐increasing demands for batteries with high energy densities to power the portable electronics with increased power consumption and to advance vehicle electrification and grid energy storage ...have propelled lithium battery technology to a position of tremendous importance. Carbon nanotubes (CNTs) and graphene, known with many appealing properties, are investigated intensely for improving the performance of lithium‐ion (Li‐ion) and lithium–sulfur (Li–S) batteries. However, a general and objective understanding of their actual role in Li‐ion and Li–S batteries is lacking. It is recognized that CNTs and graphene are not appropriate active lithium storage materials, but are more like a regulator: they do not electrochemically react with lithium ions and electrons, but serve to regulate the lithium storage behavior of a specific electroactive material and increase the range of applications of a lithium battery. First, metrics for the evaluation of lithium batteries are discussed, based on which the regulating role of CNTs and graphene in Li‐ion and Li–S batteries is comprehensively considered from fundamental electrochemical reactions to electrode structure and integral cell design. Finally, perspectives on how CNTs and graphene can further contribute to the development of lithium batteries are presented.
The regulating role of carbon nanotubes (CNTs) and graphene in Li‐ion and Li–S batteries is comprehensively discussed from the viewpoints of fundamental electrochemical reactions to electroactive materials, electrode structure, and integral cell design. Perspectives on how CNTs and graphene can further contribute to the development of lithium batteries are presented.
Although the rechargeable lithium-sulfur battery is an advanced energy storage system, its practical implementation has been impeded by many issues, in particular the shuttle effect causing rapid ...capacity fade and low Coulombic efficiency. Herein, we report a conductive porous vanadium nitride nanoribbon/graphene composite accommodating the catholyte as the cathode of a lithium-sulfur battery. The vanadium nitride/graphene composite provides strong anchoring for polysulfides and fast polysulfide conversion. The anchoring effect of vanadium nitride is confirmed by experimental and theoretical results. Owing to the high conductivity of vanadium nitride, the composite cathode exhibits lower polarization and faster redox reaction kinetics than a reduced graphene oxide cathode, showing good rate and cycling performances. The initial capacity reaches 1,471 mAh g
and the capacity after 100 cycles is 1,252 mAh g
at 0.2 C, a loss of only 15%, offering a potential for use in high energy lithium-sulfur batteries.
Rechargeable batteries are considered promising replacements for environmentally hazardous fossil fuel‐based energy technologies. High‐energy lithium‐metal batteries have received tremendous ...attention for use in portable electronic devices and electric vehicles. However, the low Coulombic efficiency, short life cycle, huge volume expansion, uncontrolled dendrite growth, and endless interfacial reactions of the metallic lithium anode are major obstacles in their commercialization. Extensive research efforts have been devoted to address these issues and significant progress has been made by tuning electrolyte chemistry, designing electrode frameworks, discovering nanotechnology‐based solutions, etc. This Review aims to provide a conceptual understanding of the current issues involved in using a lithium metal anode and to unveil its electrochemistry. The most recent advancements in lithium metal battery technology are outlined and suggestions for future research to develop a safe and stable lithium anode are presented.
Lithium (Li) metal anode is broadly recognized as an excellent candidate for nextgeneration energy storage devices owing to its high specific energy density. In this Review, a conceptual understanding about the key aspects of Li metal anode is provided, the most recent advancements in Li metal battery technology are outlined and suggestions for future research on Li anodes are presented.
Aluminum battery systems are considered as a system that could supplement current lithium batteries due to the low cost and high volumetric capacity of aluminum metal, and the high safety of the ...whole battery system. However, first the use of ionic liquid electrolytes leading to AlCl4− instead of Al3+, the different intercalation reagents, the sluggish solid diffusion process and the fast capacity fading during cycling in aluminum batteries all need to be thoroughly explored. To provide a good understanding of the opportunities and challenges of the newly emerging aluminum batteries, this Review discusses the reaction mechanisms and the difficulties caused by the trivalent reaction medium in electrolytes, electrodes, and electrode–electrolyte interfaces. It is hoped that the Review will stimulate scientists and engineers to develop more reliable aluminum batteries.
Al instead of Li: The recent developments of rechargeable aluminum battery systems and their limitations are discussed in this Review. It gives guidelines for better aluminum battery system design in terms of electrodes, electrolytes and electrodes/electrolyte interface.
Lithium‐sulfur (Li‐S) batteries have attracted tremendous interest because of their high theoretical energy density and cost effectiveness. The target of Li‐S battery research is to produce batteries ...with a high useful energy density that at least outperforms state‐of‐the‐art lithium‐ion batteries. However, due to an intrinsic gap between fundamental research and practical applications, the outstanding electrochemical results obtained in most Li‐S battery studies indeed correspond to low useful energy densities and are not really suitable for practical requirements. The Li‐S battery is a complex device and its useful energy density is determined by a number of design parameters, most of which are often ignored, leading to the failure to meet commercial requirements. The purpose of this review is to discuss how to pave the way for reliable Li‐S batteries. First, the current research status of Li‐S batteries is briefly reviewed based on statistical information obtained from literature. This includes an analysis of how the various parameters influence the useful energy density and a summary of existing problems in the current Li‐S battery research. Possible solutions and some concerns regarding the construction of reliable Li‐S batteries are comprehensively discussed. Finally, insights are offered on the future directions and prospects in Li‐S battery field.
The research status of Li‐S batteries is briefly reviewed based on statistical analysis results. A summary of existing problems in the current Li‐S battery research is concluded with possible solutions and some concerns comprehensively discussed. Perspectives are proposed with respect to more reliable lithium‐sulfur batteries with rationally improved performance.
By combining calorimetric measurements with dilatometry, it has been possible to calculate the contributions of thermal expansion, pore pressure, and crystallization pressure of ice to the strain ...observed in a mortar during freezing/thawing cycles. Air-entrained mortars contract upon freezing, while non-air-entrained mortars expand. The expansion of the latter is attributed primarily to hydraulic pressure, owing to the rapid growth of ice, which nucleates at low temperatures in laboratory samples. Poromechanical calculations account quantitatively for the contraction of samples with air entrainment, assuming that ice crystals form in the air voids. As originally proposed by Powers and Helmuth, those crystals create suction in the pore liquid that offsets the crystallization pressure of ice in the mesopores of the paste, resulting in a net contraction. Ice in the matrix also contributes significantly to the increase in the thermal expansion coefficient of the mortar.
The magnitude of the contraction in air-entrained mortar is shown to account for a reduction of salt scaling damage. According to the glue-spall theory, the damage results from cracking of the ice on the surface of concrete, when the thermal expansion mismatch stress exceeds the strength of the ice. The contraction of the mortar caused by air entrainment offsets the thermal expansion mismatch sufficiently to prevent cracking.
Based on observations of the nucleation temperature of ice in laboratory samples of various sizes, it is estimated that there is one site capable of nucleating ice at −
1
°C in a cube of mortar roughly 34
cm on an edge (or, one per square meter in a slab 3
cm thick). This suggests that ice nucleates in the field at high temperatures, compared to what is typically seen in the laboratory, and propagates slowly through the pores as the temperature drops. This mode of growth may lead to fatigue damage over many cycles, owing to local stresses from crystallization pressure, where the contribution of hydraulic pressure is insignificant.
Plasmon‐based photothermal therapy is one of the most intriguing applications of noble metal nanostructures. The photothermal conversion efficiency is an essential parameter in practically realizing ...this application. The effects of the plasmon resonance wavelength, particle volume, shell coating, and assembly on the photothermal conversion efficiencies of Au nanocrystals are systematically studied by directly measuring the temperature of Au nanocrystal solutions with a thermocouple and analyzed on the basis of energy balance. The temperature of Au nanocrystal solutions reaches the maximum at ∼75°C when the plasmon resonance wavelength of Au nanocrystals is equal to the illumination laser wavelength. For Au nanocrystals with similar shapes, the larger the nanocrystal, the smaller the photothermal conversion efficiency becomes. The photothermal conversion can also be controlled by shell coating and assembly through the change in the plasmon resonance energy of Au nanocrystals. Moreover, coating Au nanocrystals with semiconductor materials that have band gap energies smaller than the illumination laser energy can improve the photothermal conversion efficiency owing to the presence of an additional light absorption channel.
The effects of the plasmon wavelength, particle volume, shell coating, and assembly states of Au nanocrystals are systematically investigated by directly measuring the temperature of Au nanocrystal solutions with a thermocouple and analyzed on the basis of energy balance.
Truck rollover is a problem that seriously endangers the safety of human life. Under special conditions, when the driver takes a sharp turn, the truck is most prone to rollover. Speed seriously ...affects the driving stability of the truck in a sharp turn, but the calculation of the safe speed is not accurate enough at present. The aim of this paper is to develop a more accurate safe speed calculation method to avoid the truck rollover in a sharp turn. Firstly, the calculation formula of the rollover threshold was derived based on a theoretical model, then, the simulation tests were carried out. We selected a 4-axle truck with a total weight of 30t as the subject, simulated the dynamic process of the truck rollover in a sharp turn with TruckSim, evaluated the dynamic rollover risk levels of the truck during this process, and verified the accuracy of the simulation results by results of the theoretical model. Finally, by analyzing the steering principle of the vehicle, the safe speed threshold and the limit speed threshold of the truck in a sharp turn were calculated according to the lateral acceleration corresponding to the rollover risk levels. The results show that no matter what the loading condition of the truck is, when the rollover margin is reduced to about 0.15g, the truck just reaches the risk level of critical rollover; the result provides an accurate algorithm for speed thresholds of the truck when turning radius is less than 250 m. The research provides a calculation method for safe speed of trucks from a dynamic perspective. The research results can be applied to the speed warning system of trucks, which can make drivers better control the rollover risk of trucks in the process of driving and improve driving safety.
The pore structure of mortar (w/c
=
0.55) was examined using thermoporometry (TPM), nitrogen adsorption/desorption (NAD), and mercury intrusion porosimetry (MIP). The TPM measurements were calibrated ...by comparison to NAD and MIP measurements on porous glass; similar comparisons were made on dried and resaturated mortars. For undried mortars, TPM provides the size of pore entries (from the freezing cycle) and interiors (from the melting cycle). In keeping with previous studies, we find that there is an unfrozen layer of water between the ice and the pore wall in porous glass that is about 0.8
nm thick; when lime-saturated water is used, the thickness of that layer increases by about 10%. In mortar, the unfrozen layer is about 1.0–1.2
nm thick, so no freezing occurs in pores with diameters ≤
4.5
nm, at least down to −
40
°C (where the radius of the crystal/liquid interface is ∼
1.5
nm). Based on the hysteresis in the freezing and melting curves, the larger mesopores in mortar were found to be rather spheroidal, while the smaller ones were more cylindrical.
The majority of patients with thyroid cancer can attain a favorable prognosis with a comprehensive treatment program based on surgical treatment. However, the current treatment options for advanced ...thyroid cancer are still limited. In recent years, chimeric antigen receptor-modified T-cell (CAR-T) therapy has received widespread attention in the field of oncology treatment. It has achieved remarkable results in the treatment of hematologic tumors. However, due to the constraints of multiple factors, the therapeutic efficacy of CAR-T therapy for solid tumors, including thyroid cancer, has not yet met expectations. This review outlines the fundamental structure and treatment strategies of CAR-T cells, provides an overview of the advancements in both preclinical investigations and clinical trials focusing on targets associated with CAR-T cell therapy in treating thyroid cancer, and discusses the challenges and solutions to CAR-T cell therapy for thyroid cancer. In conclusion, CAR-T cell therapy is a promising therapeutic approach for thyroid cancer, and we hope that our review will provide a timely and updated study of CAR-T cell therapy for thyroid cancer to advance the field.
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