The low-tortuosity microchannels of wood-based carbon matrix in free-standing cathodes for lithium sulfur batteries (LSBs) were a double-edged sword, which brought in both a high energy density due to a high sulfur loading and severe shuttle effect for poor cycling stability. Herein, a layer of cellulose aerogel extracted from the wood wall was coated on the inner surface of the low-tortuosity microchannels of the wood plate, which was further transformed into a hierarchical carbon matrix using in free-standing cathode for LSBs. The decorated cathode exhibited a maximal specific capacity of 1377.2 mAh g−1 due to the enhanced utilizing ratio of active materials and exceptional cycling stability even under a high current density (1 C) for more than 500 cycles. Furthermore, the decorated cathode maintained good cycling stability with a higher sulfur areal loading (6.3 mg cm−2). The cellulose-based carbon aerogel coated on the inner surface of low-tortuosity microchannels provided a large specific surface area. This decoration strategy not only provided physical restriction on polysulfides but also increased conversion sites for polysulfides, improving the cycling performance of the wood-based free-standing cathode of LSBs. This work provided a potential structural design strategy for the advanced free-standing cathode of LSBs.

Lithium-sulfur (Li-S) batteries have high theoretical capacity and high energy density, and their practical application is difficult because of the “shuttle effect” induced by lithium polysulfides (LiPSs) and the difficulty of insoluble Li2S decomposition. Functionalized graphene quantum dots (GQDs) can anchor LiPSs and suppress the “shuttle effect” because of the various polar functional groups. This work investigates the effect of the size of GQDs and the N/O functional groups on the anchoring performance by first-principles calculations. In addition, the influence on the decomposition of Li2S, the diffusion of Li+, and the Gibbs free energy needed for the sulfur reduction reaction was also studied. The results show that the GQDs can effectively anchor LiPSs when the size is larger than 1.44 nm, and all the N/O-functionalized GQDs can also effectively anchor LiPSs. Among these N/O-functionalized GQDs, GQDs-COOH has the smallest Li+ diffusion energy barrier (0.52 eV) and low Li2S decomposition energy barrier (1.12 eV). It indicates that GQDs-COOH enables the rapid diffusion of Li+, ensures the smooth decomposition of Li2S, and catalyzes the effective conversion of LiPSs. Moreover, this work will promote the application of GQDs in Li-S batteries.

Polymer-based composite electrolytes composed of three-dimensional Li6.4La3Zr2Al0.2O12 (3D-LLZAO) have attracted increasing attention due to their continuous ion conduction and satisfactory mechanical properties. However, the organic/inorganic interface is incompatible, resulting in slow lithiumion transport at the interface. Therefore, the compatibility of organic/inorganic interface is an urgent problem to be solved. Inspired by the concept of "gecko eaves", polymer-based composite solid electrolytes with dense interface structures were designed. The bridging of organic/inorganic interfaces was established by introducing silane coupling agent (3-chloropropyl)trimethoxysilane (CTMS) into the PEO-3D-LLZAO (PL) electrolyte. The in-situ coupling reaction improves the interface affinity, strengthens the organic/ inorganic interaction, reduces the interface resistance, and thus achieves an efficient interface ion transport network. The prepared PEO-3D-LLZAO-CTMS (PLC) electrolyte exhibits enhanced ionic conductivity of 6.04 x 10-4 S cm-1 and high ion migration number (0.61) at 60 degrees C and broadens the electrochemical window (5.1 V). At the same time, the PLC electrolyte has good thermal stability and high mechanical properties. Moreover, the LiFePO4|PLC|Li battery has excellent rate performance and cycling stability with a capacity decay rate of 2.2% after 100 cycles at 60 degrees C and 0.1 C. These advantages of PLC membranes indicate that this design approach is indeed practical, and the in-situ coupling method provides a new approach to address interface compatibility issues.(c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Lithium sulfur batteries are listed among the most prospective energy storage devices because of its theoretical specific capacity as high as 1675 mA h/g. However, the actual practice of lithium sulfur batteries meets two major challenges of low utilization of sulfur along with polysulfides shuttling. In this work, a hierarchical porous structure carbon (ECKCa-11) from Eucommia leaf residue-derived as raw materials is manufactured by the coauxiliary activation of KCl and CaCl2 with a low dosage of KOH. ECKCa-11 possesses reasonable channel distribution with 1724.38 m2/g as specific surface area and nitrogen-containing functional groups, which can chemically "anchor" the lithium polysulfides by Li-N interplay. Furthermore, a possible co-auxiliary activation mechanism is proposed by analyzing the surface morphology and the information of specific surface and aperture size distribution of the ECKCa-11 at different temperatures from 500 degrees C to 900 degrees C. The ECKCa-11/S cathode offers excellent electrochemical performances, delivering an initial discharge specific capacity of 1336.0 mA h/g at 0.1C in lithium sulfur batteries. This work prepares hierarchical porous carbon from invalid biomass by coauxiliary activation, reducing the amount of KOH used, preventing equipment corrosion, and mitigating environmental pollution.

Background:: Astragalus, as a common traditional Chinese medicine (TCM), has many pharmacological effects, such as protection of nerves, heart, blood vessels, kidneys, etc. It can also be used to treat colds, numbness, diarrhea, indigestion, and anemia. Because of the current market, there are a large number of synonyms, synonyms, and multiple sources of one medicine. The use of near-edge plants in medicine and other fake, substandard as a good phenomenon also prevails. Methods:: In this study, a method combining electrochemical fingerprinting with SPSS software was developed to identify the origin of Astragalus membranaceus. The electrochemical fingerprints of Astragalus membranaceus with different accessions and different origins were examined using an electrochemical workstation. Then the characteristic parameters were selected to achieve the origin identification of Astragalus with SPSS software using cluster analysis and discriminant analysis. Results:: The results of this method divided the origin of Astragalus into the Qinling production area and other production areas. Conclusion:: This method can be used to identify the origin of Astragalus membranaceus, which provides a new method to identify Astragalus membranaceus and other TCM without extracting the active ingredients of Chinese medicines, in line with the traditional "holistic" treatment concept of TCM.

Rechargeable aqueous zinc batteries (RAZBs) represent a sustainable, environmentally benign, cost-efficient energy storage solution for the scaled renewable power system. However, the cycling endurance and temperature adaptability of RAZBs are hindered by practical technological barriers such as the subzero freezing point of aqueous electrolyte, severe cation dissolution of the cathode, and dendrite growth on the Zn anode. Herein, we optimize the hybrid electrolyte formulation of 8 M ZnCl2 in the ethylene glycol-water mixed solvent to reconfigure the hydrogen bonding and [Zn(H2O)1.80(EG)0.23]2+ solvation sheath, which well balances the ionic conductivity and the antifreezing property until -125 °C. As monitored by operando X-ray diffraction, meanwhile, the structural dissolution of the V2O5 cathode upon the dynamic cycling and static idling storage at elevated temperature are effectively restrained. At the anode side, the thermally induced substitution between the Ag2Se overcoating and Zn foil in situ constructs the site-selective, mosaic interface layer, in which the solvophilic ZnSe facilitates the desolvation, while the Ag species provide zincophilic nucleation sites for high-throughput Zn deposition. The synergistic coupling of the antifreezing electrolyte and anode interfacial design enables the wide-temperature-range adaptability of the RAZB prototype (10 μm Zn foil and 1 mAh cm-2 V2O5 cathode), which balances the cycling endurance (92.5% capacity retention rate for 1000 cycles), 84.7% mitigation of the self-discharge rate at 55 °C, as well as the secured cyclability even at -40 °C.

Coating conductive polymers on carbon/sulfur (C/S) cathode is an effective strategy for improving electrochemical performances of lithium-sulfur (Li–S) batteries. Furthermore, the heteroatoms in conductive polymer coating exhibit positive effects on electrochemical property. Herein, the C/S cathode was coated by polypyrrole (PPy) and polythiophene (PTh) which were fabricated and systematically investigated to reveal the effect of nitrogen (N) and S heteroatoms on the electrochemical property. As expected, both experimental identification and theoretical calculation verified that the PPy containing N heteroatom-coated C/S cathode possessed strong chemical adsorption capability for soluble polysulfides, which suppressed shuttle effect more effectively and displayed a more stable cycling life, while the PTh@C/S cathode containing S atom presented less Li + diffusion energy barrier, which exhibited reduced polarization and superior rate performance. This work demonstrated the specific functions of N and S heteroatoms in conductive polymer coating on C/S cathode materials, indicating their promising application for advanced Li–S batteries.

Lithium-sulfur batteries are considered an extremely promising new generation of energy storage systems due to their extremely high energy density. However, the practical application of lithium-sulfur batteries is greatly hindered by the poor conductivity of the cathode, the effect of volume expansion, and the "shuttle effect" of the lithium polysulfides (LiPSs). With the development of computer science, the theoretical approach, such as first-principles computation has also gradually emerged. Therefore, this paper reviews the relevant applications of DFT calculation, starting from the research hotspots of lithium-sulfur battery cathode materials (carbon materials, metal compounds, MXenes, polymers, etc.). Specifically, the microscopic level analysis provides insights into the adsorption and catalytic properties of materials for LiPSs and provides theoretical guidance for the practical development of lithium-sulfur battery cathode materials. Finally, an outlook on the development of simulation calculations for lithium-sulfur batteries is provided.

在"四新"建设背景下,物理化学教学秉承"以学生为中心,以目标为导向"的教学理念,采用雨课堂与三课融合的线上线下混合式教学模式;以学生的"知识、能力、素质"协同发展为目标,把教学内容整合成基础知识、实际应用、内容拓展三大模块;针对不同的教学内容采用适用的教学方法,并通过绘制思维导图、撰写小组报告、课程论文、文献研读报告等形式对教学评价形式进行改革,构建系统的知识体系,培养学生的自学能力、创新意识、科学思维方法和团队协作精神.

The development of lithium-sulfur（Li-S） battery as one of the most attractive energy storage systems among lithium metal batteries is seriously hindered by low sulfur utilization, poor cycle stability and uneven redeposition of Li anode. It is necessary to propose strategies to address the problems as well as improve the electrochemical performance. One of the effective solutions is to improve the sulfiphilicity of sulfur cathode and the lithiophilicity of the Li anode. Herein, we reported that a synergistic functional separator（graphene quantum dots（GQDs）-polyacrylonitrile（PAN） @polypropylene（PP） separator）improved the electrochemical activity of sulfur cathode as well as the stability of Li anode. GQDs induced uniform Li + nucleation and deposition, which slowed down the passivation of Li anode and avoided shortcircuit. Further, three-dimensional network constructed by electrospinning nanofibers and the polar functional groups of GQDs could both effectively inhibit the shuttle of LiPSs and improve the sulfur utilization. The stability of Li-S battery was improved by the synergistic effect. In addition, GQDs and electrospinning nanofibers protector increased lifetime of separators. Benefiting from the unique design strategy, Li//Li symmetric battery with GQDs-PAN@PP separators exhibited stably cycling for over 600 h. More importantly, the Li-S full batteries based GQDs-PAN@PP separators enabled high stability and desirable sulfur electrochemistry, including high reversibility of 558.09 mA h g -1 for 200 cycles and durable life with a low fading rate of 0.075% per cycle after 500 cycles at 0.5 C. Moreover, an impressive areal capacity of 3.23 mA h cm -2 was maintained under high sulfur loading of 5.10 mg cm -2 . This work provides a new insight for modification separator to improve the electrochemical performance of Li-S/Li metal batteries.

The capacity attenuation caused by the serious "shuttle effect" of soluble lithium polysulfides (LiPSs) and the growth of lithium dendrites resulting in the short life restricting the development of high-performance lithiumsulfur (Li-S) batteries. Herein, based upon the structural engineering, a multifunctional Li-S batteries separator (NC-Co3O4/PANF) with adsorption and catalytic effect on LiPSs was synthesized by introducing zeolitic imidazolate frameworks (ZIFs) derived polyhedron (NC-Co3O4) to the electrospinning polyacrylonitrile (PAN) nanofibers. Benefiting from unparalleled design, the compounded of fibers and particles, the NC-Co3O4/PANF separators not only guarantee high electrolyte absorption/retention of 335.13%, significant thermal stability (no change even at 200 degrees C) and improved mechanical properties (tensile strength of 8 MPa), but also provides more adsorption and catalytic sites for LiPSs, and effectively inhibiting the "shuttle effect" and improving the electrochemical kinetics. As a result, the Li-S batteries with NC-Co3O4/PANF separators enabled modified stability and electrochemical activity, including improved reversibility of 400.23 mA center dot h g-1 for 100 cycles and rate performance with the discharge capacity of 384.60 mA center dot h g-1 at 1 C. It is worth noting that the Li//Li symmetric cell with NC-Co3O4/PANF separator exhibits persistent cycling over 800 h, highlighting the promising prospect of notable stability and long lifespan energy storage devices.

21 世纪以来,全球国际化趋势愈加明显,世界各国在科技、经济、制造业、农业等各方面的国际合作越来越多,因此对当前高等院校大学生的国际视野和国际交流能力的要求也逐年提高.在以培养具备国际化视野的卓越工程师为目标的工科高等教育行业,与所学专业密切相关的专业英语教学将发挥比以往更加重要的作用.文章以西安理工大学理学院应用化学专业的专业英语课程教学为例,分析总结当前专业英语教学的问题与困境,并从培养方案改革、丰富课程内容、授课方式多元化及考核方式扩展等方面探索专业英语教学模式的改革方向和创新方法,增强专业英语课程在专业人才培养过程中的正面作用与价值引导.

Abstract Lithium-sulfur batteries, as a promising electrochemical energy storage device, are impeded by sluggish reaction kinetics and poor cycle life under high sulfur loading. Herein, a natural wood disc derived carbon matrix with anisotropic and aligned microchannels decorated with carbonized cellulose aerogel was proposed to serve as a host for self-supporting sulfur/carbon composite cathodes (S/DBWC/CCA) in Li-S batteries. The obtained cathodes were capable of high sulfur areal loading (3.1 and 6.3 mg cm-2). Furthermore, exceptional cycling stabilities were achieved not only under a high current density (1 C) but also under a high sulfur areal loading of 6.3 mg cm-2. The improved performance is attributed to the synergistic effect of the ordered microchannels with low tortuosity and 3D conductive network of carbonized cellulose aerogel. This work provides an ideal host derived from natural resources for viable Li-S batteries with excellent cycling stability, which is a potential strategy for structural design of advanced energy storage devices.

The seriously dissolution of the intermediate into the organic electrolyte has been the key limitation for metal-organic compounds in K-ion batteries. Here, we initially inhibit the dissolution of intermediate products (TCNQ0) with a highly conducting polymer (polypyrrole, PPy) coated on the CuTCNQ. And the adsorption energy between the conductive polymer PPy and the intermediate product TCNQ can be significantly enhanced (-0.55 eV) as compared to the TCNQ molecules (0.21 eV), which can restrain the free intermediate product dissolved in the organic electrolyte, resulting in an enhanced cyclic stability as well as rate performance. Additionally, the highly conductive PPy exhibits flexible structure, which can weaken the interface effect between the electrode and the coating layer. This work provides further understanding on surface coating on metal-organic compounds and has significant basic scientific sense for the in-depth research of K-ion batteries.

A coaxial anode with a carbon fiber core encapsulated in nanocrystalline FeNiMnO4 with a nitrogen-doped carbon sheath was prepared using carbon fiber cloth as the core, FeNiMnO4 nanocrystallite arrays as the first coating layer and nitrogen-doped carbon derived from F127 (a kind of triblock copolymer)-resorcinol-melamine gel as the outer layer. After annealing at 600 °C it was used as the anode material of an all solid flexible lithium ion battery using LiFePO4 as the cathode material and boron nitride modified polyethylene oxide as the electrolyte. The battery had a large areal capacity of ∼1.40 mAh cm−2 and satisfactory cycling stability under different bending and strain states. Annealing below 600 °C leads to incomplete carbonization of the nitrogen-doped carbon and thus a low electrical conductivity while above 600 °C aggregation of FeNiMnO4 nanocrystallites and their detachment during cycling are observed under bending and strain.

A temperature-controlled electrochemical sensor was constructed based on a composite membrane composed of temperature-sensitive polymer poly (N-isopropylacrylamide) (PNIPAM) and carboxylated multi-walled carbon nanotubes (MWCNTs-COOH). The sensor has good temperature sensitivity and reversibility in detecting Dopamine (DA). At low temperatures, the polymer is stretched to bury the electrically active sites of carbon nanocomposites. Dopamine cannot exchange electrons through the polymer, representing an “OFF” state. On the contrary, in a high-temperature environment, the polymer shrinks to expose electrically active sites and increases the background current. Dopamine can normally carry out redox reactions and generate response currents, indicating the “ON” state. In addition, the sensor has a wide detection range (from 0.5 μM to 150 μM) and low LOD (193 nM). This switch-type sensor provides new avenues for the application of thermosensitive polymers.

The alarming resource shortage of the lithium battery supply chain has triggered new vitality to the close-loop recycling of retired batteries. As compared to hydrometallurgy or pyrometallurgy strategies for the cathode recovery, the proper use of degraded graphite anodes, featuring with the solvated Li+ intercalation and in-plane defect formation, is hitherto neglected. In this work, we propose a facile "green route" to extract values from spent graphite anode. Through elucidating the dynamic Li occupancy in graphite lattice, an up-scaling delamination protocol is developed with the aid of in-situ generated H-2 bubbles in the protic mixed solvent, to weaken van der Waals (vdW) bonding of the graphite interlayers and generate few-layer graphene flakes (similar to 2 nm); meanwhile high-purity Li salt could be simultaneously extracted from the residue solvent (similar to 98% Li leaching efficiency). Upon exquisite interfacial modification, the as-exfoliated graphene flakes tend to assemble with the Na2Ti6O13 (NTO) nanosheets as a layer-stacked, mechanical-flexible anode, which further demonstrates a robust cycling at various flexing states and extreme power output of 1142 Wkg(-1) as paired with the LiFePO4 cathode (5.3 mg cm(-2)) in the integrated, thin-film battery. This work vividly demonstrates potential add-value market of spent anodes in the flexible power sources.

Shuttling of soluble polysulfides (Li2Sn, 4 <= n <= 8) results in a low discharge capacity and unstable cycling performance of lithium-sulfur (Li-S) batteries. Furthermore, the formation of insoluble sulfides (Li2S2/Li2S) can retard the reaction kinetics, resulting in poor rate capability and short cycle life. In this study, a novel structural configuration, including a honeycomb-like porous carbon (HPC) as the sulfur host and gel polymer electrolyte (GPE), is proposed. HPC derived from waste coffee grounds possesses a tri-modal pore system. The micropore, as the main reactor, undergoes a "solid-solid" reaction mechanism in carbonate -based electrolyte, effectively preventing the generation of polysulfides. The macro-and mesopores can improve the accessibility of the electrolyte, accelerating ion transfer in the cell. Density functional theory calculations reveal that the functional groups on the HPC show strong interactions with polysulfides. These data in combination with X-ray photoelectron spectroscopy measurements indicate the presence of ef-fective and stable mediator groups without the formation of polysulfides. The GPE provides adequate electrolyte infiltration and minimizes the leakage of flammable liquid, affording excellent cycling stability. As a result, the cell with this novel configurational shows only 0.03% capacity fading per cycle over 1500 cycles at 0.5 C-rate, providing excellent long-term cycle durability up to 10 C-rate. The excellent cycling stability and rate performance demonstrate that the novel structural configuration is effective in improving the electrochemical performance and prolonging the cycle life of Li-S batteries.(c) 2022 Elsevier B.V. All rights reserved.

Many kinds of nanostructured metal oxides were introduced in cathodes of Li-S batteries for high sulfur utilization and effective confinement for polysulfides. Herein, Gd2O3 nanoparticles modified wave-like carbon host, which are derived from soybean residue by activation and pyrolysis processes. After the activated soybean residue derived carbon (ASC) host modified by Gd2O3 nanoparticles, the ASC-Gd was integrated with sulfur by melting method and then used as cathode in lithium-sulfur (Li-S) batteries. According to the electrochemical results of ASC-Gd/S cathode, a high initial discharge capacity (1343 mAh g(-1) at 0.1 C) and improved cycling stability were exhibited, which was attributed to the strong adsorption ability for polysulfides and ultrahigh specific surface area of the ASC. As a result, the Gd2O3 nanoparticles modified wave-like biomass carbon was a promising host material of Li-S batteries with high performances.

The insulation of sulfur and Li2S/Li2S2 (discharge products) and the "shuttle" of soluble lithium polysulfides (LiPSs) seriously limit the research of high specific capacity lithium-sulfur (Li-S) batteries with high sulfur loading. Inspired by the natural architecture of pomelo peels, we report a self-supporting carbon framework (SCF) modified by reduced graphene oxide (rGO) as conductive skeleton and sulfur carrier for the cathode of rechargeable Li-S batteries. The high initial capacity (1489.65 mA h g(-1)) of SCF@rGO/S binder-free cathode with the high sulfur areal loading (similar to 5.50 mg cm(-2)) arise from the improved batteries conductivity by the interconnecting conductive skeleton. The SCF@rGO with hierarchical porous structure, abundant microchannels and oxygenic functional groups can effectively physical limit/intercept and chemical adsorption/anchor LiPSs, thereby improving the utilization of active sulfur and promoting the reuse. Sufficient active sites in SCF@rGO/S provide close electrical contact to accelerate electrons and ions transfer, resulting in high electrochemical activity and redox kinetics. Consequently, the SCF@rGO/S cathode exhibits an outstanding capacity retention (569.66 mA h g(-1)) and cycle stability at 1 C for over 200 long-term cycles with a decline of only 0.13% per cycle. Even at 2 C, the capacity is still up to 645.59 mA h g(-1). The SCF@rGO/S cathode provide a feasible approach and strategy to develop high performance Li-S batteries.