Unlock the full potential of carbon cloth-based scaffolds towards magnesium metal storage via regulation on magnesiophilicity and surface geometric structure

The development of rechargeable magnesium(Mg) batteries is of practical significance to upgrade the electric energy storage devices due to exceptional capacity and abundant resources of Mg-metal anode.However,the reversible Mg electrochemistry suffers from unsatisfied rate capability and lifespan,mainly caused by non-uniform distribution of electrodeposits.In this work,a fresh design concept of threedimensional carbon cloths scaffolds is proposed to overcome the uncontrollable Mg growth via homogenizing electric field and improving magnesiophilicity.A microscopic smooth and nitrogen-containing defective carbonaceous layer is constructed through a facile pyrolysis of ZIF8 on carbon cloths.As revealed by finite element simulation and DFT calculation results,the smooth surface endows with uniform electric field distribution and simultaneously the nitrogen-doping species enable good magnesiophilicity of scaffolds.The fine and uniform Mg nucleus as well as the inner electrodeposit behavior are also disclosed.As a result,an exceptional cycle life of 500 cycles at 4.0 mA cm^(-2) and 4.0 mA h cm^(-2) is firstly realized to our best knowledge.Besides,the functional scaffolds can be cycled for over 2200 h at 2.0 mA cm^(-2) under a normalized capacity of 5.0 mA h cm^(-2),far exceeding previous results.This work offers an effective approach to enable the full potential of carbon cloths-based scaffolds towards metal storage for next generation battery applications.

Hybrid solid electrolyte interphases formed in conventional carbonate electrolyte enable high-voltage and ultra-stable magnesium metal batteries

Magnesium metal batteries are considered as viable alternatives of lithium-ion batteries for their low cost and high capacity of magnesium.Nevertheless,the practical application of magnesium metal batteries is extremely challenging due to a lack of suitable electrolyte that can stabilize magnesium metal anode and high-voltage cathode simultaneously.Herein,we found that in-situ formed lithium/magnesium hybrid electrolyte interphases in conventional LiPF6-containing carbonate-based electrolyte can not only prevent the production of passivation layer on the magnesium metal anode,but also inhibit the oxidation of the electrolyte under high voltage.The symmetric magnesium‖magnesium battery can achieve reversible stripping/plating for 1600 and 600 h at 0.02 and 0.1 mA cm^(-2),respectively.In addition,when coupled with a carbon fiber cathode,the magnesium metal battery exhibited a capacity retention rate of 96.3% for 1000 cycles at a current density of 500 mA g^(-1)and presented a working voltage of ~3.1 V.This research paves a new and promising path to the commercialization process of rechargeable magnesium metal batteries.

Transient liquid phase bonding of TiC particulate reinforced magnesium metal matrix composite (TiC_p/AZ91D)

Microstructures and mechanical properties of transient liquid phase （TLP） bonded magnesium metal matrix composite （ MMC） joints using copper interlayer have been investigated. With an increase of bonding times from 5 min to 50 min at bonding temperature of 510 ℃ , the average concentration of copper in the bonded zone decreased, the microstructure in the zone changed from Cu, α-Mg and CuMg2 to α-Mg, CuMg2 and TiC, and mechanical properties of the joint increased. The shear strength of the joint bonded at 510 ℃ for 50 min reached 64 MPa due to the metallurgical bonding of the joint and improving its homogeneity of composition and microstructure. It is favorable to increase the bonding time for improving mechanical properties of TLP bonded magnesium MMC joint.

Synthesis and Crystal Structure of a Magnesium Metal-organic Framework

A magnesium metal organic framework, [N-H2（CH3）2][-N（CH3）4][Mgs（bpdc）3（O2CH）6]· 3H2O （1, bpdcH2 = 4,4＇-biphenyldicarboxylic acid）, has been solvothermally synthesized and structurally characterized. 1 crystallizes in the trigonal system, space group R-3, with a = 11.3427（3）, c = 41.5662（18） A, V = 4631.3（3） A^3, Z = 3 and the final R = 0.0457. Its structure features a pillared-layered three-dimensional network with 8.21 A cavities, in which cationic [NH2（CH3）2]^＋ or [N（CH3）4]^＋ and lattice water molecules are located. Thermal stability of the title compound has also been investigated.

Tailoring Electrode–Electrolyte Interface Using an Electron-Deficient Borate-Based Additive in MgTFSI_(2)-MgCl_(2)/DME Electrolyte for Rechargeable Magnesium Batteries

Rechargeable magnesium metal batteries need an electrolyte that forms a stable and ionically conductive solid electrolyte interphase(SEI)on the anodes.Here,we used molecular dynamic simulation,density functional theory calculation,and X-ray photoelectron spectroscopy analysis to investigate the solvation structures and SEI compositions in electrolytes consisting of dual-salts,magnesium bis(trifluoromethanesulfonyl)imide(MgTFSI_(2)),and MgCl_(2),with different additives in 1,2-dimethoxyethane(DME)solvent.We found that the formed[Mg_(3)(μ-Cl)_(4)(DME)mTFSI_(2)](m=3,5)inner-shell solvation clusters in MgTFSI_(2)-MgCl_(2)/DME electrolyte could easily decompose and form a MgO-and MgF_(2)-rich SEI.Such electron-rich inorganic species in the SEI,especially MgF_(2),turned out to be detrimental for Mg plating/stripping.To reduce the MgF_(2)and MgO contents in SEI,we introduce an electron-deficient tri(2,2,2-trifluoroethyl)borate(TFEB)additive in the electrolyte.Mg//Mg cells using the MgTFSI_(2)-MgCl_(2)/DME-TFEB electrolyte could cycle stably for over 400 h with a small polarization voltage of~150 mV.Even with the presence of 800 ppm H_(2)O,the electrolyte with TFEB additive could still preserve its good electrochemical performance.The optimized electrolyte also enabled stable cycling and high-rate capability for Mg//Mo6S8 and Mg//CuS full cells,showing great potential for future applications.

Uniform nanoplating of metallic magnesium film on titanium dioxide nanotubes as a skeleton for reversible Na metal anode

To meet the low-cost concept advocated by the sodium metal anode,this paper reports the use of a pulsed electrodeposition technology with ionic liquids as electrolytes to achieve uniform nanoplating of metallic magnesium films at around 20 nm on spaced titanium dioxide(TiO_(2))nanotubes(STNA-Mg).First,the sodiophilic magnesium metal coating can effectively reduce the nucleation overpotential of sodium metal.Moreover,three-dimensional STNA can limit the volume expansion during sodium metal plating and stripping to achieve the ultrastable deposition and stripping of sodium metals with a high Coulombic efficiency of up to 99.5%and a small voltage polarization of 5 mV in symmetric Na||Na batteries.In addition,the comparative study of sodium metal deposition behavior of STNA-Mg and STNA-Cu prepared by the same route further confirmed the advantage of magnesium metal to guide sodium metal growth.Finally,the prepared STNA-Mg-Na metal anode and commercial sodium vanadium phosphate cathode were assembled into a full cell,delivering a discharge capacity of 110.2 mAh·g^(-1)with a retention rate of 95.6%after 110 cycles at 1C rate.

Micro or nano:Evaluation of biosafety and biopotency of magnesium metal organic framework-74 with different particle sizes

In recent years,various particulate materials have played important roles in medical applications.However,nano-and micron-sized particles of the same material could exhibit distinct properties due to different particle sizes.This finding provided a simple and effective way to improve the biological applications of particulate materials.Therefore,as a highly promising member,the effect of the particle size change of the magnesium metal organic framework-74(Mg-MOF74)was well worth evaluating.Here we firsth assessed the in vitro and in vivo toxicity of micron/nanoscale Mg-MOF74(m-Mg-MOF74/n-Mg-MOF74)in detail.Our in vitro study revealed that compared to micron-sized subjects,n-Mg-MOF74 provided a wider range of safe concentrations.Furthermore,both micron/nanoscale Mg-MOF74 showed good biocompatibility and allowed all the rats under the treatment to survive through the expected experimental periods,with n-Mg-MOF74 still showing lower cardiotoxicity.These advantages of nanoscale Mg-MOF74might benefit from its sustainable and balanced release of Ma^2+both inside and outside the cells.Based on the biosafety evaluation,advanced bio-functional assessments of m/n-Mg-MOF74 including early osteogenesis and angiogenesis were alsoperformed.Similarly,the suitable dose groups of n-Mg-MOF74 achieved optimal early osteogenic promotion and angiogenic stimulation effects.Overall,our combined data delineated the toxicity and biological behaviors of Ma-MOF74 of different scales,and sugqested nanoscale Mg-MOF74 as a better choice for future applications.This result revealed that particle size reductior might be a viable strategy to improve and expand medical applications of MOFs or other particulate materials.

Statistical model for combustion of high-metal magnesium-based hydro-reactive fuel

We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.

金属颗粒增强镁基复合材料制备技术及性能的研究进展

镁基复合材料具有低的密度、优异的力学性能等特点,在汽车、电子、航空航天等领域有广阔的应用前景。本文综述了国内外金属颗粒增强镁基复合材料的研究进展,详细介绍了金属颗粒增强镁基复合材料常见制备方法的特点,分析了金属颗粒增强镁基复合材料的界面结构和主要强韧化机理。最后,对金属颗粒增强镁基复合材料制备材料及工艺的发展进行了展望。

Kinetic Factors for Intensive Reaction of Magnesium-Based Spheroidiser in Hot Metal

The spheroidiser is a necessary additive to manufacture ductile iron.Sometimes with the same hot metal,spheroidisers and treated technology,reactions differ greatly from each other.The reaction may be quite normal in one case,but very intensive for another one.The effects of kinetic factors such as size,surface area and morphology o f spheroidiser on the reaction of spheoidization are studied.

镁合金尾翼类构件径向同步加载工艺研究

目的针对常规挤压工艺成形尾翼类构件飞行时翼片径向产生挠曲变形的问题,提出了一种可调控金属流动的径向同步加载成形方法。方法结合ANSYS、Deform-3D有限元模拟和物理实验,分析径向同步加载的金属流动行为、等效应变和金属流线分布,通过拉伸实验测试成形翼片挤压方向(Extrusion Direction,ED)和横截面方向(Transverse Direction,TD)的力学性能,并通过观察显微组织揭示径向强化机理。结果径向同步加载通过对坯料施加周向压应力促进了金属径向流动,形成了沿径向分布良好的金属流线,有利于提升径向力学性能;采用该工艺试制构件表面质量良好,无宏观缺陷,且形成沿径向分布的宏观流线;翼片径向力学性能显著提升,屈服强度提升了57.8 MPa,抗拉强度提升了80.1 MPa,延伸率提升了1.4%,其强塑性的提升与纤维组织和块状LPSO相的纤维强化密切相关。结论实现了尾翼类构件的径向同步加载整体成形,通过调控金属流动形成径向分布良好的金属流线,提升了成形翼片径向强度,为高性能镁合金尾翼类构件的整体成形提供了理论基础和技术支撑。

可降解镁基金属引导骨再生膜的研究现状与展望

可降解镁基金属引导骨再生(GBR)膜具有良好的机械性能、生物降解性和生物促成骨性能,是治疗颌面部骨缺损的理想植入物。本文对镁基金属引导骨再生膜的现状和未来的研究趋势进行阐述。首先介绍了镁基金属的研究历史及应用领域,随后从镁基金属GBR膜的机械性能、生物相容性和促成骨性能及其机制方面介绍了镁基金属制备GBR膜的应用优势,最后对当前镁基金属GBR膜的局限性及在口腔医学中的应用和展望进行介绍。镁基金属GBR膜在基础和转化研究方面都取得了重要的进展,为治疗口腔颌面部的骨缺损奠定了重要的基础。

荷正电膜的制备及研究进展

随着分离体系复杂程度的增加及对膜分离性能要求的提高,荷正电膜分离技术发挥着越来越重要的作用。介绍了荷正电膜的制备方法,综述了荷正电膜在纺织印染废水、镁/锂分离、去除重金属和生物医药等方面的应用进展,探讨了荷正电膜存在的主要问题,展望了未来荷正电膜分离技术的发展方向。随着研究的深入及市场需求的增加,荷正电膜将迎来更大的发展空间,在解决水资源短缺、水环境污染方面发挥更加重要的作用。

半封闭空间内氢化镁粉尘爆炸火焰的传播特性

在自行搭建的5 L粉尘爆炸火焰传播特性实验装置中,实验研究了半封闭空间内氢化镁(MgH_(2))粉尘爆炸火焰的传播特性。实验结果表明:随MgH_(2)粉尘浓度的提高,MgH_(2)粉尘爆炸火焰由点火至稳定传播所用时间先缩短后延长以及预热区宽度先减小后增大,火焰亮度、锋面平滑度、及火焰传播速度呈先提高后降低的趋势,并在质量浓度为800 g/m^(3)时呈最佳燃烧状态。不同浓度的MgH_(2)粉尘爆炸火焰传播瞬时速度整体呈波动趋势,波动幅度随浓度的提高而先减小后增大,800 g/m^(3)时波动幅度最小,瞬时传播速度变化趋势随浓度的变化呈现不同的变化趋势。最后,根据MgH_(2)爆炸产物的XRD测试结果,分析MgH_(2)粉尘爆炸反应机理,发现MgH_(2)粉尘爆炸是以MgH_(2)燃烧反应为主并伴随有MgH_(2)和Mg(OH)2分解以及Mg和H_(2)氧化等多个总包反应的复杂过程,爆炸反应的最终产物为MgO。

钙锶镁锌交联藻酸盐水凝胶的制备及其细胞相容性研究

目的:制备4组含不同种类二价金属离子Ca^(2+)、Sr^(2+)、Mg^(2+)、Zn^(2+)交联的藻酸盐凝胶支架,检测其理化性能,观察MC3T3-E1细胞在各组凝胶表面的黏附、增殖及成骨分化情况。方法:配制4组离子总浓度为6.5g/L且含不同种类Ca^(2+)、Sr^(2+)、Mg^(2+)、Zn^(2+)的混合溶液作为交联剂,与海藻酸钠溶液发生螯合反应制备多离子交联水凝胶,依据所含离子种类分为Ca组、Ca-Sr组、Ca-Sr-Mg组、Ca-Sr-Mg-Zn组,Ca组为对照组。使用扫描电镜观察凝胶冻干后的表面形态,检测其降解、溶胀性能及Sr^(2+)、Mg^(2+)、Zn^(2+)析出浓度。将MC3T3-E1细胞接种在水凝胶表面,观察细胞黏附形态,采用CCK-8法和活死染色法评价其生物安全性和细胞增殖能力。诱导MC3T3-E1细胞成骨分化,检测ALP活性,茜素红染色观察钙盐沉积情况,RT-qPCR检测成骨基因的表达。结果:与Ca组相比,Ca-Sr组、Ca-Sr-Mg组、Ca-Sr-Mg-Zn组水凝胶的孔隙更均匀致密,凝胶的降解速度与溶胀率均减小(P<0.05),细胞在凝胶表面的黏附形态由球形变为多角形;与Ca组比较,Ca-Sr组、Ca-Sr-Mg组、Ca-Sr-Mg-Zn组水凝胶表面的细胞增殖活性、细胞内ALP活性、钙结节生成面积及I型胶原、骨形态发生蛋白2、Runt相关转录因子2等成骨基因的表达量升高(P<0.05),且Ca-Sr组、Ca-Sr-Mg组、Ca-Sr-Mg-Zn组水凝胶表面的细胞增殖活力及成骨分化效果依次提高(P<0.05)。结论:较Ca^(2+)交联的海藻酸钙水凝胶相比,使用Ca^(2+)、Sr^(2+)、Mg^(2+)、Zn^(2+)混合金属阳离子作为交联剂,能改善藻酸盐水凝胶的理化性能,促进MC3T3-E1细胞在凝胶表面的黏附及成骨分化。

生物活性离子改性透钙磷石骨水泥的生物和理化性能

背景:透钙磷石骨水泥作为一种骨替代和骨填充材料,因其具有良好的生物相容性、骨传导性等优点,尤其是相比于其他磷酸钙类骨水泥具有更好的生物降解能力,在骨修复方面有重要应用价值,但也因其存在机械性能不足、固化反应快及注射性能差等问题的限制,目前一般只能用于非负重区骨的修复。目的:探讨生物活性离子(金属离子和非金属离子)改性透钙磷石骨水泥,以期拓展使用范围。方法:利用Pub Med、Science Direct和中国知网、万方数据库检索2018-2023年发表的文献,中文检索词为“金属离子,铁,铜,锶,镁,锌,非金属离子,改性,骨,透钙磷石骨水泥”;英文检索词为“metal ion,iron,Fe,copper,Cu,strontium,Sr,magnesium,Mg,zinc,Zn,non-metal ion,modification,bone,Brushite Cements”。通过阅读标题、摘要对所得文献进行初筛,排除重复及内容不相关文献,最终纳入64篇文献进行综述。结果与结论:(1)生物活性离子影响透钙磷石骨水泥水化反应过程,不同离子以离子取代的方式掺入透钙磷石骨水泥晶体结构中,改变了骨水泥晶体形态,引起凝固时间、注射性、抗压强度等理化性能改变。(2)离子改性的透钙磷石骨水泥因不同的晶体结构而产生不同的离子释放效应,不同类型离子具有如促血管生成/成骨、抗菌及抗肿瘤等特性而发挥作用,此外,透钙磷石骨水泥具有良好的生物降解性,这对于各离子性能的发挥具有极大优势。(3)不同离子改性透钙磷石骨水泥理化性能影响如下:铁、铜、锶、镁、锌、银、钴可延长凝固时间;锶、镁可提高注射性能;铜、锶、镁、银、硅可增强抗压强度;能同时改善透钙磷石骨水泥以上3种理化性能的离子有锶、镁;良好的理化性能是临床应用的前提,故离子改善透钙磷石骨水泥的凝固时间、注射性及抗压强度等性能对骨水泥的研究应用具有重要意义。(4)不同离子改性透钙磷石骨水泥生物性能影响如下:铜、锶、镁、锌、钴、锂、硅、硒具有促血管生成/成骨效应;铁、铜、镁、锌、银具有抗菌特性;镁离子具有抗炎特性;铜、硒具有抗肿瘤性。(5)综上所述,镁离子能改善透钙磷石骨水泥凝固时间、注射性和抗压强度,同时具有促新生血管生成/成骨及抗菌性,对合并感染的骨缺损治疗具有良好应用前景;此外,铜还具有抗肿瘤特性,因此铜离子在感染、肿瘤引起的骨缺损治疗方面有巨大潜力;只是目前相关研究仍处于基础研究阶段,不同离子掺杂浓度和合成条件等对透钙磷石骨水泥理化性能的影响需进一步探索,同时对于生物性能影响也需更长期的研究观察。

An Insight on Future Development Approaches of Salt Lake Magnesium Resources:from the Current Situation of China's Magnesium Industry

Magnesium-bearing minerals discovered on the earth so far occur mainly as solid or liquid.The former include magnesite(Mg CO3),dolomite(Mg CO3·Ca CO3),carnallite(Mg Cl2·KCl·6H2O),bischofite(Mg Cl2·6H2O)and

金属镁冶炼技术现状及经济性分析

金属镁是极具开发和应用潜力的绿色工程材料。介绍了镁冶炼技术及发展现状,在分析技术发展趋势和新技术应用基础上,重点对两种煅烧工艺进行了技术经济分析。得出结论:原镁的生产工艺主要有两种,国内以硅热法(皮江法)为主流;与此同时,国内正在研究传统皮江法的替代工艺,竖罐法是目前皮江法的改良方向;通过对比回转窑煅烧工艺和悬浮焙烧煅烧工艺,前者投资强度低、应用成熟,但后者在生产成本和能耗方面具有明显优势。

基于内非金属元素掺杂的外微波电场协同增强镁储氢机理研究

在众多的固态储氢材料中,镁基材料已被公认为极具应用前景,但镁在储氢过程中需要克服动力学性能差(氢解离扩散难)、反应能耗高等难题,因而阻碍了其大规模商业化应用。微波外场可高效加速化学反应并降低反应温度和能耗,已逐渐应用于改善储氢过程,但目前针对内非金属元素掺杂外微波电场协同增强镁储氢的研究鲜有报道。为此,基于第一性原理计算探究了内掺杂非金属元素外微波电场协同改善镁储氢的作用机制,分析了有无非金属元素掺杂下镁—氢气体系在微波电场作用前后的吸附能、电子特性、过渡态等热动力学性能变化机理。研究结果表明:①微波电场改变了氢气分子和镁表面的电荷分布,使得氢气分子出现电荷分离(发生极化);②态密度计算结果也表明微波电场改变了H-s轨道的电子态分布,使得H-s电子向高能量区域移动,从而增强H-s与Mg-sp轨道杂化,导致镁与氢气之间的相互作用增强;③内非金属元素掺杂外微波电场协同改性使吸氢过程的反应能垒从0.94 eV大幅降至0.77 eV。结论认为:①微波电场有助于氢气发生极化,激活了氢气的反应活性,降低反应能耗;②内非金属元素掺杂外微波电场协同改性促进了氢气在镁表面的反应进程,有效提高了镁吸氢过程的动力学性能。

TiO_(2)直接还原制备超低氧钛

提出在MgCl_(2)−KCl−YCl_(3)熔盐中,通过熔盐电解产生Mg直接还原TiO_(2)制备低氧钛。绘制Mg−Ti−O三元相图和电位−氧势(φ−pO^(2)−)图,表明镁还原TiO_(2)制备低氧钛是可行的。在MgCl_(2)−YCl_(3)和MgCl_(2)−YCl_(3)−KCl熔盐中,不同温度和施加电压条件下,开展熔盐电解−镁热还原TiO_(2)实验研究,结果表明:借助YOCl沉淀及CO_(x)同步生成,将还原和脱氧产物O^(2)−快速脱除,在1073~1173 K、施加电压2.5~3.1 V的条件下,通过电化学还原可以将TiO_(2)还原为高氧钛(Ti6O)。在温度为1173 K的MgCl_(2)−YCl_(3)熔盐中,开展不同施加电压下的高氧钛电化学脱氧实验。此外,还观察到有可能将高氧钛的氧含量可从1200×10^(−6)降至100×10^(−6)以下。