The use of silicon (Si) as a lithium-ion battery's (LIBs) anode active material has been a popular subject of research, due to its high theoretical specific capacity (4200 mAh g
). However, the ...volume of Si undergoes a huge expansion (300%) during the charging and discharging process of the battery, resulting in the destruction of the anode's structure and the rapid decay of the battery's energy density, which limits the practical application of Si as the anode active material. Lithium-ion batteries' capacity, lifespan, and safety can be increased through the efficient mitigation of Si volume expansion and the maintenance of the stability of the electrode's structure with the employment of polymer binders. The main degradation mechanism of Si-based anodes and the methods that have been reported to effectively solve the Si volume expansion problem firstly are introduced. Then, the review demonstrates the representative research work on the design and development of new Si-based anode binders to improve the cycling stability of Si-based anode structure from the perspective of binders, and finally concludes by summarizing and outlining the progress of this research direction.
Phenazine-based redox-active centers are capable of averting chemical bond rearrangements by coupling during the reaction process, leading to enhanced stabilization of the material. When introduced ...into a high-performance polymer with excellent physicochemical properties, they can be endowed with electrochemical properties and related prospective applications while maintaining the capabilities of the materials. In this study, a facile C-N coupling method was chosen for the synthesis of serial poly(aryl ether sulfone) materials containing phenazine-based redox-active centers and to explore their electrochemical properties. As expected, the cyclic voltammetry curves of PAS-DPPZ-60, which basically overlap after thousands of cycles, indicate the stability of the electrochemical properties. As an electrochromic material, the transmittance change in PAS-DPPZ-60 exhibits only a slight attenuation after as long as 600 cycles. Meanwhile, as an organic battery cathode material, PAS-DPPZ has a theoretical specific capacity of 126 mAh g
, and the capacity retention rate is 82.6% after 100 cycles at a 0.1 C current density. The perfect combination of advantageous features between phenazine and poly(aryl ether sulfone) is considered to be the reason for the favorable electrochemical performance of the material series.
As a popular energy storage equipment, lithium-ion batteries (LIBs) have many advantages, such as high energy density and long cycle life. At this stage, with the increasing demand for energy storage ...materials, the industrialization of batteries is facing new challenges such as enhancing efficiency, reducing energy consumption, and improving battery performance. In particular, the challenges mentioned above are particularly critical in advanced next-generation battery manufacturing. For batteries, the electrode processing process plays a crucial role in advancing lithium-ion battery technology and has a significant impact on battery energy density, manufacturing cost, and yield. Dry electrode technology is an emerging technology that has attracted extensive attention from both academia and the manufacturing industry due to its unique advantages and compatibility. This paper provides a detailed introduction to the development status and application examples of various dry electrode technologies. It discusses the latest advancements in commonly used binders for different dry processes and offers insights into future electrode manufacturing.
Lithium-ion batteries (LIBs) have recently become popular for energy storage due to their high energy density, storage capacity, and long-term cycle life. Although binders make up only a small ...proportion of LIBs, they have become the key to promoting the transformation of the battery preparation process. Along with the development of binders, the battery manufacturing process has evolved from the conventional slurry-casting (SC) process to a more attractive solvent-free (SF) method. Compared with traditional LIBs manufacturing method, the SF method could dramatically reduce and increase the energy density due to the reduced preparation steps and enhanced electrode loading. Polytetrafluoroethylene (PTFE), as a typical binder, has played an important role in fabricating high-performance LIBs, particularly in regards to the SF technique. In this paper, the development history and application status of PTFE binder was introduced, and then its contributions and the inherent problems involved in the SF process were described and analyzed. Finally, the viewpoints concerning the future trends for PTFE-based SF manufacturing methods were also discussed. We hope this work can inspire future research concerning high-quality SF binders and assist in promoting the evolution of the SF manufacturing technology in regards to LIBs.
A series of aminoalkyl-substituted polyfluorene copolymers with benzothiadiazole (BTDZ) of different content were synthesized by Suzuki coupling reaction, and their quaternized ammonium ...polyelectrolyte derivatives were obtained through a postpolymerization treatment on the terminal amino groups. Copolymers are soluble in environmentally friendlier solvents, such as alcohols. It was found that the efficient energy transfer occurs by exciton trapping on the narrow band gap BTDZ site under UV illumination. Only 1% of BTDZ content is needed to completely quench a fluorene emission for both the neutral and the quaternized copolymers in the neat film. Absolute PL efficiencies of copolymer films were greatly enhanced as a result of the suppression of excimer formation. Light-emitting devices fabricated from these copolymers show high external quantum efficiencies over 3% and 1% for the neutral precursor and the quaternized copolymers, respectively, with high work function metals such as Al as a cathode. To the best of our knowledge, this is the first report on an electroluminescent polymer which bears the high EL efficiency, the electron-injection ability from high work function metals, and the solubility in environment-friendly solvents at the same time. These features make them a promising candidate for the next generation of light-emitting copolymers in PLED flat panel display application.
Apoptosis is a common pathway that finally mediated the killing functions of anticancer drugs, which is an important cause of multidrug resistance (MDR). The aim of this study was to investigate the ...potential benefit of combination therapy with magnetic nanoparticle of Fe(3)O(4) (MNP(Fe(3)O(4))) and 5-bromotetrandrin (BrTet). Analysis of the apoptosis percentage showed that combination of daunorubicin (DNR) with either MNP(Fe(3)O(4)) or BrTet exerted a potent cytotoxic effect on K562/A02 cells, while MNP(Fe(3)O(4)) and BrTet cotreatment can synergistically enhance DNR-induced apoptosis. Importantly, we confirmed that the distinct synergism effect of that composite on reverse multidrug resistance may owe to the regulation of various proliferative and antiapoptotic gene products, including P53 and caspase-3. Thus our in vitro data strongly suggests a potential clinical application of MNP(Fe(3)O(4)) and BrTet combination on CML.
Natural gas hydrate (NGH) has the advantages of wide distribution and large reserves, and has attracted extensive attention from the international community. Researchers have conducted quantitative ...microscopic pore-scale simulations, exploitation surveys, laboratory tests, and numerical simulations, but commercial development is still a long way off. In view of the existing problem of insufficient productivity, enlarged permeable well wall technology is studied in this paper, which is a method to improve reservoir productivity by changing well conditions. There is a free gas zone in the Class 1 reservoir and no free gas zone in the Class 3 reservoir; the structural differences lead to different multiphase seepage processes, and the mechanisms of stimulation are also different. In order to further improve productivity and understand the production difference between the two reservoirs, this paper selects Class 1 and Class 3 reservoirs, establishes the numerical simulation model of NGH extraction by the depressurization method, analyzes the influence of well radius and permeability on productivity, and compares the influence of this technology on the two reservoirs. The results show that (1) the productivity of Class 1 and Class 3 reservoirs is significantly increased under this technology. The same well adjustment has a better effect on Class 3 reservoirs. (2) When the radius is 1 m, the best stimulation effect is shown; the radius enlarges from 0.1 to 1 m, and the V P of Class 1 and Class 3 reservoirs is increased by 19.70 and 17.06%, respectively. (3) When permeability is 1 × 10–7 m2, the best stimulation effect is shown; the permeability is increased from 1 × 10–9 to 1 × 10–7 m2, and V P is increased by 35.50 and 115.35%, respectively. (4) Changing the radius and permeability at the same time can better improve the productivity of the two reservoirs, and has a synergistic effect on Class 3 reservoirs.
A series of ammonium-ended alkyl-substituted polyfluorene copolymer with narrow band-gap comonomer benzothiadiazole (BTDZ) and 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DBT) were synthesized of by ...Suzuki polycondensation. The resulting polymers can be processed as an RGB active layer in polymer light emitting devices from environment friendly solvents such as alcohols. It is found out that devices from such polymers show equal or higher external quantum efficiencies (QE) with the high work-function metal cathode such as Al than by using the low work-function (Ca or Ba) cathode. The added BTDZ and DBT units not only change the polymers’ emission color, but also greatly improved the device performances of the polymers, as a result of the suppression of excimer formation which is common to rigid polyelectrolyte chains.
Traditional web services transaction processing mechanism handle exception by forward recovery and backward recovery. These compensation mechanisms often lead to waste of resources and time. In this ...paper, we propose a framework for predicting outcomes of service executions as part of service compositions which allows to choose service instances that are likely to lead to a successful result in the first instance and thus reduces the need for invoking costly recovery mechanisms. The framework makes use of watchdogs to maintain an awareness of service availability and a pre-coordinator which has oversight of the whole composite Web service and acts as a control center. An analysis of a scenario shows that we cannot only provide users with a more satisfactory result, but also can reduce the overhead costs of resources and waste.
PDF
