Constructing Donor–Acceptor‑Linked COFs Electrolytes to Regulate Electron Density and Accelerate the Li^(+)Migration in Quasi‑Solid‑State Battery

Regulation the electronic density of solid-state electrolyte by donor–acceptor(D–A)system can achieve highly-selective Li^(+)transportation and conduction in solid-state Li metal batteries.This study reports a high-performance solid-state electrolyte thorough D–A-linked covalent organic frameworks(COFs)based on intramolecular charge transfer interactions.Unlike other reported COFbased solid-state electrolyte,the developed concept with D–A-linked COFs not only achieves electronic modulation to promote highly-selective Li^(+)migration and inhibit Li dendrite,but also offers a crucial opportunity to understand the role of electronic density in solid-state Li metal batteries.The introduced strong electronegativity F-based ligand in COF electrolyte results in highlyselective Li^(+)(transference number 0.83),high ionic conductivity(6.7×10^(-4)S cm^(−1)),excellent cyclic ability(1000 h)in Li metal symmetric cell and high-capacity retention in Li/LiFePO_(4)cell(90.8%for 300 cycles at 5C)than substituted C-and N-based ligands.This is ascribed to outstanding D–A interaction between donor porphyrin and acceptor F atoms,which effectively expedites electron transferring from porphyrin to F-based ligand and enhances Li^(+)kinetics.Consequently,we anticipate that this work creates insight into the strategy for accelerating Li^(+)conduction in high-performance solid-state Li metal batteries through D–A system.

Tuning Li/Ni mixing by reactive coating to boost the stability of cobalt-free Ni-rich cathode

Cobalt-free cathode materials are attractive for their high capacity and low cost,yet they still encounter issues with structural and surface instability.AlPO_(4),in particular,has garnered attention as an effective stabilizer for bulk and surface.However,the impact of interfacial reactions and elemental interdiffusion between AlPO_(4) and LiNi_(0.95)Mn_(0.05)O_(2) upon sintering on the bulk and surface remains elusive.In this study,we demonstrate that during the heat treatment process,AlPO_(4) decomposes,resulting in Al doping into the bulk of the cathode through elemental interdiffusion.Simultaneously,PO_(4)^(3-)reacts with the surface Li of material to form a Li_3PO_(4) coating,inducing lithium deficiency,thereby increasing Li/Ni mixing.The suitable Li/Ni mixing,previously overlooked in AlPO_(4) modification,plays a pivotal role in stabilizing the bulk and surface,exceeding the synergy of Al doping and Li_3PO_(4) coating.The presence of Ni^(2+)ions in the lithium layers contributes to the stabilization of the delithiated structure via a structural pillar effect.Moreover,suitable Li/Ni mixing can stabilize the lattice oxygen and electrode-electrolyte interface by increasing oxygen removal energy and reducing the overlap between the Ni^(3+/4+)e_g and O^(2-)2p orbitals.These findings offer new perspectives for the design of stable cobalt-free cathode materials.

Li掺杂对4H-SiC光电性质影响的理论研究

采用基于密度泛函理论的第一性原理方法,计算了Li掺杂4H-SiC体系的电子结构及光学性质.结果表明,掺杂前后的4H-SiC均为间接带隙半导体,Li原子间隙掺杂后形成n型半导体,Li原子替位式掺杂体系的禁带中出现了杂质能级,降低了电子跃迁时所需的能量;对电荷差分密度图的分析表明,Li原子失去电子,导致Li-C键和Li-Si键的共价性降低,以离子性为主;在可见光区域,相比于4H-SiC体系,掺杂体系的吸收率峰值均有所提高,其中Li间隙掺杂体系吸收带边最小,吸收率峰值最大,掺杂后的4H-SiC体系对红外、可见光、紫外均能够有所吸收,说明Li掺杂能够有效拓宽4H-SiC对光的响应范围.

Boosting High-Voltage Practical Lithium Metal Batteries with Tailored Additives

The lithium(Li)metal anode is widely regarded as an ideal anode material for high-energy-density batteries.However,uncontrolled Li dendrite growth often leads to unfavorable interfaces and low Coulombic efficiency(CE),limiting its broader application.Herein,an ether-based electrolyte(termed FGN-182)is formulated,exhibiting ultra-stable Li metal anodes through the incorporation of LiFSI and LiNO3 as dual salts.The synergistic effect of the dual salts facilitates the formation of a highly robust SEI film with fast Li+transport kinetics.Notably,Li||Cu half cells exhibit an average CE reaching up to 99.56%.In particular,pouch cells equipped with high-loading lithium cobalt oxide(LCO,3 mAh cm^(-2))cathodes,ultrathin Li chips(25μm),and lean electrolytes(5 g Ah-1)demonstrate outstanding cycling performance,retaining 80%capacity after 125 cycles.To address the gas issue in the cathode under high voltage,cathode additives 1,3,6-tricyanohexane is incorporated with FGN-182;the resulting high-voltage LCO||Li(4.4 V)pouch cells can cycle steadily over 93 cycles.This study demonstrates that,even with the use of ether-based electrolytes,it is possible to simultaneously achieve significant improvements in both high Li utilization and electrolyte tolerance to high voltage by exploring appropriate functional additives for both the cathode and anode.

Boosting the cycling stability of all-solid-state lithium metal batteries through MOF-based polymeric protective layers

Solid-state electrolytes(SSEs)play a pivotal role in advancing next-generation lithium metal battery technology.However,they commonly encounter substantial interfacial resistance and poor stability when interfacing with lithium metal,hindering practical applications.Herein,we introduce a flexible metal-organic framework(MOF:NUS-6)-incorporated polymeric layer,denoted as NP,designed to protect the sodium superionic conductor(NASICON)-type Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)electrolyte from Li metal anodes.The NP matrix establishes a soft interface with the LATP surface,effectively reducing voids and gaps that may arise between the LATP electrolyte and Li metal.Moreover,the MOF component in NP enhances ionic conductivity,offers abundant Li^(+)transport sites,and provides hierarchical ion channels,ensuring a homogeneous Li^(+)flow and thus effectively inhibiting Li dendrite formation.Utilizing NP,we fabricate Li symmetrical cells cycled for over 1600 h at 0.2 mA cm^(-2)and all-solid-state LiINP-LATPI LiFePO_(4)batteries,achieving a remarkable 99.3%capacity retention after 200 cycles at 0.2 C.This work outlines a general strategy for designing long-lasting and stable solid-state Li metal batteries.

Improvement of microstructure and mechanical properties of Al−Cu−Li−Mg−Zn alloys through water-cooling centrifugal casting technique

The microstructure and mechanical properties of as-cast Al−Cu−Li−Mg−Zn alloys fabricated by conventional gravity casting and centrifugal casting techniques combined with rapid solidification were investigated.Experimental results demonstrated that compared with the gravity casting technique,the water-cooling centrifugal casting technique significantly reduces porosity,refinesα(Al)grains and secondary phases,modifies the morphology of secondary phases,and mitigates both macro-and micro-segregation.These improvements arise from the synergistic effects of the vigorous backflow,centrifugal field,vibration and rapid solidification.Porosity and coarse plate-like Al13Fe4/Al7Cu2Fe phase result in the fracture before the gravity-cast alloy reaches the yield point.The centrifugal-cast alloy,however,exhibits an ultra-high yield strength of 292.0 MPa and a moderate elongation of 6.1%.This high yield strength is attributed to solid solution strengthening(SSS)of 225.3 MPa,and grain boundary strengthening(GBS)of 35.7 MPa.Li contributes the most to SSS with a scaling factor of 7.9 MPa·wt.%^(-1).The elongation of the centrifugal-cast alloy can be effectively enhanced by reducing the porosity and segregation behavior,refining the microstructure and changing the morphology of secondary phases.

Constructing lithiophilic sites-rich artificial solid electrolyte interphase to enable dendrite-free and corrosion-free lithium-sulfur batteries

An artificial solid electrolyte interphase(SEI)with lithiophilic sites and chemical bonds anchoring lithium polysulfides(LiPSs)has been developed as a potential solution to protect the lithium(Li)metal anode of Lithium-sulfur(Li-S)batteries.This strategy aims to guide consistent Li deposition and relieve lithium corrosion.Herein,the evolution process of lithiophilic sites based on aluminum fluoride(AlF_(3))in an artificial SEI is disclosed in Li-S batteries with metal-based lithiophilic sites.The polyester polymer(PMMA and PPC)/AlF_(3) artificial SEI(MPAF-SEI)was homogeneously anchored on Li anode by in-situ polymerization.The conversion of AlF_(3) into Li-Al and LiF lithiophilic sites effectively reduce the Li nucleation overpotential and prevents the formation of Li dendrites.At the same time,the polymer can anchor LiPSs by chemical bonds and prevents Li corrosion.The optimized MPAF-SEI protected Li demonstrates excellent stability for over 3000 h at a capacity of 1 mAh cm^(-2) in Li||Li symmetric cells.The Li-S battery with low N/P(4)exhibits a capacity of 532.6 mAh g^(-1) over 300 cycles lifespan at 0.5 C.

Constructing a stable interface on Ni-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode via lactic acid-assisted engineering strategy

Ni-rich layered oxides are potential cathode materials for next-generation high energy density Li-ion batteries due to their high capacity and low cost.However,the inherently unstable surface properties,including high levels of residual Li compounds,dissolution of transition metal cations,and parasitic side reactions,have not been effectively addressed,leading to significant degradation in their electrochemical performance.In this study,we propose a simple and effective lactic acid-assisted interface engineering strategy to regulate the surface chemistry and properties of Ni-rich LiNi_(0.8)Co_(0.1)Mr_(0.1)O_(2) cathode.This novel surface treatment method successfully eliminates surface residual Li compounds,inhibits structural collapse,and mitigates cathode-electrolyte interface film growth.As a result,the lactic acidtreated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) achieved a remarkable capacity retention of 91.7% after 100 cycles at 0.5 C(25℃) and outstanding rate capability of 149.5 mA h g^(-1) at 10 C,significantly outperforming the pristine material.Furthermore,a pouch-type full cell incorporating the modified LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode demonstrates impressive long-term cycle life,retaining 81.5% of its capacity after 500 cycles at 1 C.More importantly,the thermal stability of the modified cathode is also dramatically improved.This study offers a valuable surface modification strategy for enhancing the overall performance of Ni-rich cathode materials.

Molecule‑Level Multiscale Design of Nonflammable Gel Polymer Electrolyte to Build Stable SEI/CEI for Lithium Metal Battery

The risk of flammability is an unavoidable issue for gel polymer electrolytes(GPEs).Usually,flameretardant solvents are necessary to be used,but most of them would react with anode/cathode easily and cause serious interfacial instability,which is a big challenge for design and application of nonflammable GPEs.Here,a nonflammable GPE(SGPE)is developed by in situ polymerizing trifluoroethyl methacrylate(TFMA)monomers with flame-retardant triethyl phosphate(TEP)solvents and LiTFSI–LiDFOB dual lithium salts.TEP is strongly anchored to PTFMA matrix via polarity interaction between-P=O and-CH_(2)CF_(3).It reduces free TEP molecules,which obviously mitigates interfacial reactions,and enhances flame-retardant performance of TEP surprisingly.Anchored TEP molecules are also inhibited in solvation of Li^(+),leading to anion-dominated solvation sheath,which creates inorganic-rich solid electrolyte interface/cathode electrolyte interface layers.Such coordination structure changes Li^(+)transport from sluggish vehicular to fast structural transport,raising ionic conductivity to 1.03 mS cm^(-1) and transfer number to 0.41 at 30℃.The Li|SGPE|Li cell presents highly reversible Li stripping/plating performance for over 1000 h at 0.1 mA cm^(−2),and 4.2 V LiCoO_(2)|SGPE|Li battery delivers high average specific capacity>120 mAh g^(−1) over 200 cycles.This study paves a new way to make nonflammable GPE that is compatible with Li metal anode.

Simulating the Dynamics of Bimetallic Clusters Deposited onto a Surface Using Molecular Dynamics

This paper examines the interface development between a single crystalline Ag matrix and core-shell AgnCom nanoclusters that have been deposited with energies varying between 0.25 eV and 1.5 eV per atom using computer modeling techniques. Clusters undergo deformation as a result of the slowing down;they may also become epitaxial with the substrate and maintain their core-shell structure. A detailed analysis of the effects of the cluster-surface interaction is conducted over a realistic size and energy range, and a model is created to show how clusters accumulate. It is discovered that both the silver shells and the cobalt cluster cores exhibit limited epitaxy with the substrate, and that the contact produced is only a few atomic layers thick. The effect is higher for Ag shells than for Co cores, and it is not very energy dependent.

Influence of pH value and chelating reagent on performance of Li_3V_2(PO_4)3/C cathode material

The Li3V2（PO4）3/C composite cathode material was synthesized via sol-gel method using three different chelating agents （citric acid, salicylic acid and polyacrylic acid） at pH value of 3 or 7. The crystal structure, morphology, specific surface area and electrochemical performance of the prepared samples were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS） and galvanostatic charge/discharge test. The results show that the effects of pH value on the performance of the prepared materials are greatly related to the chelating agents. With salicylic acid or polyacrylic acid as the chelating reagent, the structure, morphology and electrochemical performance of the samples are greatly influenced by the pH values. However, the structure of the materials with citric acid as the chelating agent does not change as pH value changes, and the materials own uniform particle size distribution and good electrochemical performance. It delivers an initial discharge capacity of 113.58 mA·h/g at 10C, remaining as high as 108.48 mA·h/g after 900 cycles, with a capacity retention of 95.51%.

2023年LIS期刊论文研究方法应用态势

研究方法的选择和运用影响研究的深度和可靠性,对科学研究发展十分重要。文章在总结LIS领域方法论研究的基础上,将LIS领域常用的研究方法整理、汇总、编码,以LIS领域11种TOP期刊2023年收录的论文为数据源,统计分析LIS期刊论文的研究方法应用态势,探讨LIS学科性质、研究对象、作者学科背景等因素对研究方法的影响。研究发现:LIS领域论文使用的研究方法内容不断演进,跨学科和新兴理论方法以及多元研究方法的应用促进了研究的深入和丰富。

有界Heyting代数的模糊LI-理想

理想是研究逻辑代数结构特征的重要工具性概念之一.本文综合运用代数学与模糊集的方法和原理,在有界Heyting代数中引入模糊LI-理想概念并研究其性质.进而讨论了模糊LI-理想与模糊格理想之间的关系,并给出了由一个模糊集生成的模糊LI-理想的表示定理,最后证明了一个给定有界Heyting代数的全体模糊LI-理想之集在模糊集合包含序下构成一个完备Heyting代数.

锂玻璃探测器^(6)Li原子数标定

在聚变包层中子学性能的实验检验中,造氚率是重要的测量参数之一,探测器中^(6)Li原子数目作为计算造氚率的归一化因子,是决定测量结果精度的关键因素,必须进行精确标定。对^(6)Li原子数标定原理、实验配置及过程、不确定度量化方法进行具体介绍,并首次在中国绵阳研究堆(CMRR)的M5水平孔道以锗单晶单色器获得32.36 meV中子对小型锂玻璃探测器中^(6)Li原子数进行了标定,不确定度为2.62%。

热处理对Mg-3Sn-2Al-1Zn-5Li合金耐蚀性能的影响

对Mg-3Sn-2Al-1Zn-5Li合金进行了不同方式的热处理。利用电化学测试研究了不同热处理状态合金在3.5%NaCl溶液中的腐蚀电化学行为,并通过扫描电镜、能谱以及X射线衍射分析了合金腐蚀形貌及腐蚀产物的成分。结果表明:经固溶处理和时效处理后,合金的耐蚀性能有所提高,并且固溶态的Mg-3Sn-2Al-1Zn-5Li合金有着最佳的耐蚀性能;合金的腐蚀特征为丝状腐蚀,腐蚀产物主要为Mg(OH)_(2)。

电流密度、温度、阴极孔隙率和N_(2)溶解度因子对Li-N_(2)电池放电性能的影响

Li-N_(2)电池是一种具有电化学固氮功能的新型储能系统,文章利用有限元软件COMSOL耦合多物理场建立的电化学模型能揭示各因素对其放电性能的影响。模拟结果表明:放电电流密度、温度、阴极孔隙率和电解液中的N_(2)溶解度因子对Li-N_(2)电池的放电性能均有影响;较大的放电电流密度会降低该电池的电压和容量;阴极孔隙率和电解液中的N_(2)溶解度因子是影响该电池电压和容量的关键性因素,提高阴极孔隙率和电解液中的N_(2)溶解度因子均能增加该电池的电压和容量;电池放电的平台电压随温度升高而升高,但放电容量几乎不受温度影响。

基于铁锈红和废锂箔制备LiFePO_(4)/C正极材料的储锂性能

磷酸铁锂电池的需求大、市场垄断而导致原材料价格日益高涨。以铁锈红和废锂箔为原材料,采用磷酸铁工艺制备了LiFePO_(4)/C粉末,并测试其电化学储锂性能。结果表明:LiFePO_(4)/C粉末由粒径尺寸为110~400nm的颗粒组成,在1.0C循环350圈后的可逆比容量和容量保持率分别为129.7mAh/g和98.0%,与商业LiFePO_(4)正极材料性能相当。可见,该结果降低了LiFePO 4的制备成本,有利于循环经济和可持续发展。

Estimating light interception using the color attributes of digital images of cotton canopies

Crop growth and yield depend on canopy light interception （LI）. To identify a low-cost and relatively efficient index for measuring LI, several color attributes of red-green-blue （RGB）, hue-saturation-intensity （HSI）, hue-saturation-value （HSV） color models and the component values of color attributes in the RGB color model were investigated using digital images at six cotton plant population densities in 2012-2014. The results showed that the LI values followed downward quadratic curves after planting. The red （R）, green （G） and blue （B） values varied greatly over the years, in accordance with Cai＇s research demonstrating that the RGB model is affected by outside light. Quadratic curves were fit to these color attributes at six plant population densities. Additionally, linear regressions of LI on every color attribute revealed that the hue （H） values in HSI and HSV were significantly linearly correlated with LI with a determination coefficient （R2）〉0.89 and a root mean square error （RMSE）=0.05. Thus, the H values in the HSI and HSV models could be used to measure LI, and this hypothesis was validated. The H values are new indexes for quantitatively estimating the LI of heterogeneous crop cano- pies, which will provide a theoretical basis for optimizing the crop canopy structure. However, further research should be conducted in other crops and under other growing and environmental conditions to verify this finding.

有源层厚度对Li-ZTO TFT电学性能的影响

本研究旨在制备Li-ZTO单有源层薄膜晶体管,并研究有源层厚度对其性能的影响。该研究采用磁控溅射方法,使用Li-ZTO靶材制备出了有源层厚度分别为70 nm,90 nm,110 nm的器件。采用了X射线光电子能谱(XPS)、原子粒显微镜(AFM)、X射线衍射仪(XRD)等设备对制备出的Li-ZTO薄膜进行测试分析。通过对不同有源层厚度的薄膜物质组成、表面形貌、晶粒生长情况的测试分析,进一步研究了有源层厚度对Li-ZTO薄膜性能的影响。除此之外,我们还利用半导体参数仪对Li-ZTO的电学性能进行了测试。结果表明,过厚的有源层将影响电荷传输,增加散射中心,影响器件性能。因此,有源层厚度为70 nm的Li-ZTO具有最好的性能,包括12.33 cm^(2)/vs的饱和迁移率、0.66 V的阈值电压、2.12 V/dec的亚阈值摆幅以及>10~8的开关比。

化浊解毒活血方对慢性萎缩性胃炎伴随肠上皮化生患者PG、PGR、LI-CD的影响

目的探讨化浊解毒活血方对慢性萎缩性胃炎(CAG)伴肠上皮化生患者血清胃蛋白酶原(PG)、胃蛋白酶原比值(PGR)及胃黏膜中肝肠钙黏连蛋白(LI-CD)表达的影响。方法采用随机数字表法,将2016年1月—2017年12月在河北省中医院脾胃病科诊治的120例CAG伴肠上皮化生患者分为中药组和中成药组,每组60例。中药组口服化浊解毒活血方(1剂/d,分2次温服),中成药组口服摩罗丹(每次8丸,3次/d),2组疗程均为6个月。比较2组患者治疗前后胃镜像病情程度、病理(炎症、腺体萎缩、肠上皮化生)变化程度、血清PG水平、PGR和胃黏膜肠化生组织中LI-CD阳性表达情况。结果治疗后,2组胃镜像和炎症、腺体萎缩、肠上皮化生程度均较治疗前明显改善(P均<0.05),且中药组的改善情况均明显优于中成药组(P均<0.05)。治疗后,2组血清PGⅠ水平和中药组PGR均较治疗前明显升高(P均<0.05),2组血清PGⅡ水平和中成药组PGR与治疗前比较差异均无统计学意义(P均>0.05);治疗后中药组血清PGⅠ和PGⅡ水平均明显高于中成药组(P均<0.05)。治疗后,2组胃黏膜肠化生组织中LI-CD阳性表达平均光密度值均较治疗前明显降低(P均<0.05),且中药组明显低于中成药组(P<0.05)。结论化浊解毒活血方能有效改善CAG伴肠上皮化生患者的病理表现,可能与其提升血清PGI水平,下调LI-CD在胃黏膜的表达有关。