Fast capture and stabilization of Li‐ions via physicochemical dual effects for an ultra‐stable self‐supporting Li metal anode

Lithium(Li)metal is regarded as one of the most promising anode candidates for next-generation batteries due to its extremely high specific capacity and low redox potential.However,its application is still hindered by the uncontrolled growth of dendritic Li and huge volume fluctuation during cycles.To address these issues,flexible and self-supporting three-dimensional(3D)interlaced Ndoped carbon nanofibers(NCNFs)coated with uniformly distributed 2D ultrathin NiCo_(2)S_(4)nanosheets(denoted CNCS)were designed to eliminate the intrinsic hotspots for Li deposition.Physicochemical dual effects of CNCS arise from limited surface Li diffusivity with a higher Li affinity,leading to uniform Li nucleation and less random accumulation of Li,as confirmed by ab initio molecular dynamics simulations.Due to the unique structure,exchange current density is reduced significantly and metallic Li is further contained within the interspace between the NCNF and NiCo_(2)S_(4)nanosheets,preventing the formation of dendritic Li.The symmetric cell with a Li/CNCS composite anode shows a long-running lifespan for almost 1200 h,with an exceptionally low and stable overpotential under 1mA cm^(-2)/1 mAh cm^(-2).A full cell coupled with a LiFePO4 cathode at a low N/P ratio of 2.45 shows typical voltage profiles but more significantly enhanced performance than that of a LiFePO4 cathode coupled with a bare Li anode.

A 10-μm Ultrathin Lithium Metal Composite Anodes with Superior Electrochemical Kinetics and Cycling Stability

Lithium metal is a promising candidate for the promotion of the next generation high energy density batteries.The employment of ultrathin Li metal anode with controllable thickness could enable a higher efficiency of Li utilization.Herein,a simple method to fabricate free-standing 10μm ultrathin Li metal anode is developed in this work.A three-dimensional MnO_(x)-coated CNT framework is constructed through a facile hydrothermal process,utilizing as a host for molten Li infusion,which could not only put forward a simple strategy to modulate the thickness of Li metal film but also restricts the volume expansion.The abundant MnO_(x)nanoparticles acting as lithiophilic sites reduce the Li nucleation barrier and optimize the electrochemical kinetics at the anode/electrolyte interface.As a result,the ultrathin Li composite anode exhibits a superior lifespan expanded to 2000 cycles in a symmetric cell,as well as a better capacity and rate capability than that of bare Li anode in full cell,fulfilling the requirements of high energy density and stable cycling life.Furthermore,a wave-shaped Li metal pouch cell based on the ultrathin Li composite anode is assembled that exhibits remarkable mechanical bending toleration and cyclic stability,demonstrating large potential application in the field of flexible wearable devices.

地黄梓醇调控ATDC5软骨细胞的衰老

背景:课题组前期体内、体外研究结果表明地黄梓醇能够显著降低膝骨关节炎大鼠滑膜组织中炎症指标水平,同时能够延缓膝骨关节炎进展,但是否通过影响软骨细胞衰老进而延缓膝骨关节炎的进展尚未明确。目的:探讨地黄梓醇能否调控ATDC5软骨细胞衰老及可能的机制。方法:将ATDC5软骨细胞分为空白组(0.1%牛血清白蛋白)、模型组(0.1%牛血清白蛋白+1μmol/L阿霉素)、地黄梓醇低剂量组(0.1%牛血清白蛋白+1μmol/L阿霉素+20μmol/L地黄梓醇)及地黄梓醇高剂量组(0.1%牛血清白蛋白+1μmol/L阿霉素+80μmol/L地黄梓醇)。应用阿霉素诱导构建ATDC5软骨细胞衰老模型,按上述分组予以对应的处理。CCK-8法检测地黄梓醇对ATDC5软骨细胞活力的影响,筛选地黄梓醇最佳给药浓度。相应处理后应用β-半乳糖苷酶染色法检测各组ATDC5软骨细胞衰老情况;实时荧光定量PCR法检测相关基因表达(P21、P53、Ⅱ型胶原、基质金属蛋白酶13、白细胞介素6);Western blot检测P21、P53、Ⅱ型胶原、基质金属蛋白酶13、白细胞介素6的表达水平;免疫荧光法检测P21、P53和Ⅱ型胶原表达情况;流式细胞仪检测各组细胞凋亡情况。结果与结论:(1)经鉴定成功诱导ATDC5软骨细胞并诱导衰老模型;(2)地黄梓醇浓度在0,20,40,80μmol/L时对细胞活力均无明显影响,提示地黄梓醇对细胞无毒性,可安全使用(P> 0.05);当浓度≥100μmol/L时,细胞活力降低,提示可能存在毒性,故选择80μmol/L作为高剂量进行后续实验;(3)与空白组β-半乳糖苷酶阳性细胞百分率(17.32±0.72)%比较,模型组(86.93±2.18)%显著升高(P <0.05);与模型组比较,地黄梓醇低、高剂量组(57.28±1.73)%、(27.18±0.97)%均显著降低(P <0.05);(4)与模型组比较,地黄梓醇低、高剂量组的P21、P53、基质金属蛋白酶13、白细胞介素6 mRNA和蛋白相对表达量均显著下调,而Ⅱ型胶原的mRNA和蛋白相对表达量显著上调(P <0.05),高剂量组更为明显(P <0.05);(5)与模型组比较,地黄梓醇低、高剂量组的P21、P53荧光信号均显著减弱,而Ⅱ型胶原的荧光信号显著增强(P <0.05),高剂量组更为明显(P <0.05);(6)经Annexin V/PI法检测各组细胞凋亡情况,与空白组比较,模型组的凋亡情况无明显变化(P> 0.05);与模型组比较,地黄梓醇低、高剂量组的凋亡指标均显著升高,且以高剂量组更为明显(P <0.05);(7)提示地黄梓醇能够通过促进衰老的ATDC5软骨细胞凋亡,进一步清除衰老的ATDC5软骨细胞,降低衰老相关表型进而延缓骨关节炎的进展。

Cyclin D_1蛋白在碳酸锂对抗黄曲霉素B1诱导大鼠肝癌过程中的表达及意义

目的与方法 :应用免疫组化法检测碳酸锂 (Li2 CO3)对抗黄曲霉素B1(AFB1)诱导大鼠肝癌过程中癌基因蛋白cyclinD1的表达及意义。结果 :cyclinD1在诱癌早期 (实验第 6周 )即有表达 ,第 10周显著增高 ,差异均有显著性 (P <0 .0 1)。阳性对照组 (B)组cyclinD1蛋白阳性率最高 ,碳酸锂同时给药组 (C组 )及先期给药组 (D组 )阳性率显著降低 ,C组阳性率略高于D组。结论 :Li2 CO3 可明显对抗AFB1诱导肝癌过程中cyclinD1的表达 ,通过抑制细胞的持续性增殖从而起到抗癌作用。

洁净核能源技术和D-Li强中子源的应用设想

在讨论国际科学界普遍关注的加速器驱动核动力装置技术，及其在未来洁净核能源开发和利用核嬗变方法处理核废料等方面的应用意义和可行性的同时，从我国的实际出发，提出了立足国内，利用中能（４０ＭｅＶ）、强流（２×１２５ｍＡ）质子加速器作Ｄ－Ｌｉ超强中子源，开展零功率加速器驱动核裂变装置技术的原理性研究和核嬗变、聚变材料、抗核加固及核物理研究。

大爆炸核合成相关的^8Li（d，p）^9Li反应截面测量

利用8Li次级束测量了质心系能量 7. 8MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.

采用量子含时波包方法研究H/D+Li_2→LiH/LiD+Li反应

采用量子波包方法和二阶分裂算符方法对H/D+Li_2→LiH/LiD+Li反应在0.01到0.4 eV的碰撞能范围内进行了动力学计算.在态分辨的理论水平上计算了反应概率、积分截面、微分截面等动力学性质并与之前的理论结果进行了比较.结果表明:由于本文的计算中包含了总角动量J在体固定坐标轴上的所有投影所得,结果更加精确;此外,当H原子被重的同位素原子D取代,反应概率、积分截面增大,然而这并没有对反应机理产生大的影响.前后对称的微分截面表明插入反应机理在反应过程中占据主导地位.

Three dimensional porous frameworks for lithium dendrite suppression

Lithium metal is a promising anode material owing to its very low electrochemical potential and ultrahigh specific capacity.However,the growth of lithium dendrites could result in a short lifespan,low coulombic efficiency,and potential safety hazards during the progress of lithium plating/stripping.These factors drastically hinder its application in lithium metal batteries.This review focuses on the use of three dimensional(3D)porous host frameworks to improve Li plating/stripping behaviors,accommodate the change in volume,and suppress or block lithium dendrite growth.Various 3D porous frameworks,including the conductive carbon-based,metal-based,and lithiophilic inorganic-compound frameworks are introduced and summarized in detail.The particular functions,relative developments,and optimized strategies of various 3D porous frameworks for lithium deposition/dissolution behaviors are discussed.Moreover,the challenges and promising developments in the field of Li metal anodes will be discussed at the end of this review.

A novel design of 3D carbon host for stable lithium metal anode

Rational design of porous conductive hosts with high electrical conductivity,large surface area,and adequate interior space is desirable to suppressing dendritic lithium growth and accommodating large volume change of lithium metal anode during the Li plating/stripping process.However,due to the conductive nature of the conductive hosts,Li is easily deposited directly on the top of the hosts,which hinders it from fully functioning.To circumvent the issue,in this study,we designed a novel porous carbon host with a gradient-pore-size structure based on one-dimensional(1D)carbon with different diameters.With this kind of host,stable cycling with high and stable Coulombic efficiency of~98%is achieved at 0.5 mA cm^(−2) with an areal capacity of 1 mAh cm^(−2) over 320 cycles.In contrast,the normal three-dimensional(3D)carbon nanotube host presents a moss-like Li morphology with wildly fluctuating Coulombic efficiency after 100 cycles.The results reveal that the unique gradient-pore-size structure of the 3D conductive host greatly improves the performance of lithium metal batteries.

Vesicle-shaped ZIF-8 shell shielded in 3D carbon cloth for uniform nucleation and growth towards long-life lithium metal anode

Lithium metal has aroused extensive research interests as the anode for next-generation rechargeable batteries.However,the well-known dendritic Li growth and consequent safety issues still impair the long-term cycling performance.Herein,a hybrid structure composed of 3 D carbon cloth and vesicleshaped hollow ZIF-8 modification shell(HZS@CC)was prepared as a smart host for guiding uniform Li deposition.The long-range interconnected 3 D carbon fiber network enables the reduced local current density with homogeneous electrons distribution.Synergistically,abundant surface polar groups and the ultrastructure on ZIF-8 particles effectively guide a well-distributed Li-ions flow to promote the uniform Li nucleation and growth.As a result,stable Li plating/stripping for 2000 h with a low overpotential(≈15 mV)at 1 mA cm^(-2) were achieved in symmetric cells.Coupling with LiFePO_(4) cathode,the full cell delivered long life over 1200 cycles at 6 C.This research demonstrated that a homogenization guiding of Li-ions is of great importance to better make use of the structural advantage of 3 D hosts and achieve improved electrochemical performance.

Designer uniform Li plating/stripping through lithium–cobalt alloying hierarchical scaffolds for scalable high-performance lithium-metal anodes

Lithium metal anodes are of great interest for advanced high-energy density batteries such as lithiumair, lithium-sulfur and solid-state batteries, due to their low electrode potential and ultra-high theoretical capacity. There are, however, several challenges limiting their practical applications, which include low coulombic efficiency, the uncontrollable growth of dendrites and poor rate capability. Here, a rational design of 3D structured lithium metal anodes comprising of in-situ growth of cobalt-decorated nitrogen-doped carbon nanotubes on continuous carbon nanofibers is demonstrated via electrospinning.The porous and free-standing scaffold can enhance the tolerance to stresses resulting from the intrinsic volume change during Li plating/stripping, delivering a significant boost in both charge/discharge rates and stable cycling performance. A binary Co-Li alloying phase was generated at the initial discharge process, creating more active sites for the Li nucleation and uniform deposition. Characterization and density functional theory calculations show that the conductive and uniformly distributed cobalt-decorated carbon nanotubes with hierarchical structure can effectively reduce the local current density and more easily absorb Li atoms, leading to more uniform Li nucleation during plating. The current work presents an advance on scalable and cost-effective strategies for novel electrode materials with 3D hierarchical microstructures and mechanical flexibility for lithium metal anodes.

Revisiting the Role of Physical Confinement and Chemical Regulation of 3D Hosts for Dendrite-Free Li Metal Anode

Lithium metal anode has been demonstrated as the most promising anode for lithium batteries because of its high theoretical capacity,but infinite volume change and dendritic growth during Li electrodeposition have prevented its practical applications.Both physical morphology confinement and chemical adsorption/diffusion regulation are two crucial approaches to designing lithiophilic materials to alleviate dendrite of Li metal anode.However,their roles in suppressing dendrite growth for long-life Li anode are not fully understood yet.Herein,three different Ni-based nanosheet arrays(NiO-NS,Ni_(3)N-NS,and Ni_(5)P_(4)-NS)on carbon cloth as proof-of-concept lithiophilic frame-works are proposed for Li metal anodes.The two-dimensional nanoarray is more promising to facilitate uniform Li^(+)flow and electric field.Compared with the NiO-NS and the Ni_(5)P_(4)-NS,the Ni_(3)N-NS on carbon cloth after reacting with molten Li(Li-Ni/Li_(3)N-NS@CC)can afford the strongest adsorption to Li+and the most rapid Li+diffusion path.Therefore,the Li-Ni/Li_(3)N-NS@CC electrode realizes the lowest overpotential and the most excellent electrochemical performance(60 mA cm^(−2)and 60 mAh cm^(−2)for 1000 h).Furthermore,a remarkable full battery(LiFePO_(4)||Li-Ni/Li_(3)N-NS@CC)reaches 300 cycles at 2C.This research provides valuable insight into designing dendrite-free alkali metal batteries.

A 3D conducting scaffold with in-situ grown lithiophilic Ni_(2)P nanoarrays for high stability lithium metal anodes

Lithium(Li)metal is the most potential anode material for the next-generation high-energy rechargeable batteries.However,intrinsic surface unevenness and‘hostless’nature of Li metal induces infinite volume effect and uncontrollable dendrite growth.Herein,we design the in-situ grown lithiophilic Ni_(2)P nanoarrays inside nickel foam(PNF).Uniform Ni_(2)P nanoarrays coating presents a very low nucleation overpotential,which induces the homogeneous Li deposition in the entire spaces of three-dimensional(3D)metal framework.Specifically,the lithiophilic Ni_(2)P nanoarrays possess characteristics of electrical conductivity and structural stability,which have almost no expansion and damage during repeating Li plating/stripping.Therefore,they chronically inhibit the growth of Li dendrites.This results in an outstanding Coulombic efficiency(CE)of 98% at 3 mA cm^(-2) and an ultra long cycling life over 2000 cycles with a low overpotential.Consequently,the PNF-Li||LiFePO_(4) battery maintains a capacity retention of 95.3% with a stable CE of 99.9% over 500 cycles at 2 C.

“All‐In‐One” integrated ultrathin SnS2@3D multichannel carbon matrix power high‐areal–capacity lithium battery anode

Construction of a thickness‐independent electrode with high active material mass loading is crucial for the development of high energy rechargeable lithium battery.Herein,we fabricate an all‐in‐one integrated SnS2@3D multichannel carbon matrix(SnS2@3DMCM)electrode with in‐situ growth of ultrathin SnS2 nanosheets inside the inner walls of three dimensional(3D)multichannels.The interconnected conductive carbon matrix derived from natural wood acts as an integrated porous current collector to avail the electrons transport and accommodate massive SnS2 nanosheets,while plenty of 3D aligned multichannels facilitate fast ions transport with electrode thickness‐independent even under high mass loading.As expected,the integrated SnS2@3DMCM electrode exhibits remarkable electrochemical lithium storage performance,such as exceptional high‐areal‐capacity of 6.4 mAh cm−2,high rate capability of 3 mAh cm−2 under current of 6.8 mAcm−2(10 C),and stable cycling performance of 6.8 mAcm−2 with a high mass loading of 7mg cm−2.The 3D integrated porous electrode constructing conveniently with the natural source paves new avenues towards future high‐performance lithium batteries.

Scalable Synthesis of LiF-rich 3D Architected Li Metal Anode via Direct Lithium-Fluoropolymer Pyrolysis to Enable Fast Li Cycling

Lithium metal anode holds an important position in fast-charging batteries.But lithium dendrite issues tend to exacerbate at high currents.Li F can be considered as an effective way to improve the Li metal surface electrochemical stability to achieve high power and high energy.However,most of reported work are relying on in situ formation of a 2D Li F on Li metal in liquid electrolyte,which limits the scalability and plated Li quantity.Here,we address this challenge and report a scalable synthesis of Li F-rich 3D architected Li metal anode via a direct pyrolysis of molten lithium and fluoropolymer to enable fast Li charging with high current density(20 mA cm-2)and high areal capacity(20 m Ah cm-2).The 3D structure is synthesized by the pyrolysis of fluoropolymer with Li metal and results show high similarity to the pristine electrolyte-derived solid-electrolyte-interphase(SEI).This concept using pyrolysis of fluoropolymer with Li-containing active materials could be also extended to modify Li metal oxide cathode(e.g.,Li Ni0.5Mn1.5O4)for mixed conductive interphase and engineer Li solid ion conductors(e.g.,Li garnet-type oxides)for interface stabilization andframework design.

Quasiclassical-Trajectory Investigation on the Isotopic Effect of H(D)+LiF→H(D)F+Li(v=0-4,j=0) Reaction

A quasi-classical trajectory （QCT） method is employed to investigate the scalar properties and vector correlations of H＋LiF→HF＋Li and D＋LiF→DF＋Li reactions. The collision energy （Ecol = 4-25 kcal//mol） and vibrational excitation effects （v = 0-4） are studied by using the Aguado-Paniagua2-potential energy surface （AP2-PES） [J. Chem. Phys. 107（1997） 10085]. The reaction probability, cross section and rate constant are calculated, which demonstrate obvious energy and vibrational excitation dependences in the probability, cross section, and a high-temperature region of the rate constant. In addition, two product angular distributions P（Or） and P（φr） are calculated to facilitate a deeper insight into vector correlations. The H＋LiF→HF＋Li and D＋LiF→DF＋Li reactions reveal strong isotopic effects. Moreover, these scalar and vector results of both the reactions show sensitive behaviors to the changes of vibrational levels and the collision energy.

机载LiDAR点云和倾斜摄影影像数据融合处理技术流程

机载LiDAR点云和倾斜摄影影像是两种新型测绘地理信息数据,可以用来制作DEM、DOM和建筑三维模型。在分析点云数据和倾斜数据基础上,阐述点云和影像数据融合处理的关键步骤和方法。对点云配准、航带裁切、三维建模以及正射影像制作流程进行了详细阐述,开创了两种数据源融合处理的新模式。

Li-KCl熔融界面上离子扩散的分子动力学研究

采用分子动力学(MD)方法研究了熔融Li(电极)-KCl(电解质)界面上离子的扩散行为。熔融界面上离子的扩散动力学通过离子质心的均方位移(MSD)和速度自相关函数(VACF)进行研究,扩散系数由MSD(t)函数线性区间的斜率和VACF(t)函数积分得到。模拟结果表明,在熔融的Li-KCl界面上,Li+离子在浓度梯度的驱动下穿过界面发生定向迁移,导致双电层的形成和外电路上电流的输出。Li+离子的扩散系数比K+和Cl-离子的大7～8倍,说明在界面上Li+离子是主要的载荷子,热电池的电荷传输机制主要与Li+离子的扩散运动有关。由Nernst-Einstein公式对电导率进行估算,由扩散到KCl层中的Li+离子产生的电导率约为0.4 S.cm-2,对应的电流密度估算值为3.27×105A.cm-2。

HPLC法测定烟台柴胡中柴胡皂苷a和d的含量

[目的]建立烟台柴胡中柴胡皂苷a、d含量的HPLC测定方法,研究烟台柴胡中柴胡皂苷a、d的含量,为评价烟台柴胡品质提供科学方法。[方法]采用Thermo ODS-2 HYPERIL(250 mm×4.6 mm,5μm)色谱柱;流动相为乙腈和水,梯度洗脱;流速1 m L/min;柱温25℃;检测波长210 nm。[结果]方法学考察表明柴胡皂苷a、d的峰面积积分值和进样量的线性关系良好,精密度试验的RSD分别为0.67%和0.75%;加样回收率分别为99.4%和98.7%,RSD分别为1.53%和1.76%。不同来源的烟台柴胡中柴胡皂苷a、d的含量相当,总量在0.772%~1.079%。[结论]该方法稳定、重现性好、操作简单,可用于烟台柴胡的质量控制。烟台柴胡中柴胡皂苷a、d含量高于药典规定的柴胡标准,可以作为柴胡的药材新资源。