Enhanced reversible hydrogen storage properties of wrinkled graphene microflowers confined LiBH_(4) system with high volumetric hydrogen storage capacity

LiBH_(4)with high hydrogen storage density,is regarded as one of the most promising hydrogen storage materials.Nevertheless,it suffers from high dehydrogenation temperature and poor reversibility for practical use.Nanoconfinement is effective in achieving low dehydrogenation temperature and favorable reversibility.Besides,graphene can serve as supporting materials for LiBH_(4)catalysts and also destabilize LiBH_(4)via interfacial reaction.However,graphene has never been used alone as a frame material for nanoconfining LiBH_(4).In this study,graphene microflowers with large pore volumes were prepared and used as nanoconfinement framework material for LiBH_(4),and the nanoconfinement effect of graphene was revealed.After loading 70 wt%of LiBH_(4) and mechanically compressed at 350 MPa,8.0 wt% of H2 can be released within 100 min at 320C,corresponding to the highest volumetric hydrogen storage density of 94.9 g H2 L^(-1)ever reported.Thanks to the nanoconfinement of graphene,the rate-limiting step of dehydrogenation of nanoconfined LiBH_(4) was changed and its apparent activation energy of the dehydrogenation(107.3 kJ mol^(-1))was 42%lower than that of pure LiBH_(4).Moreover,the formation of the intermediate Li_(2)B_(12)H_(12) was effectively inhibited,and the stable nanoconfined structure enhanced the reversibility of LiBH_(4).This work widens the understanding of graphene's nanoconfinement effect and provides new insights for developing high-density hydrogen storage materials.

M_(4)X_(3) MXenes:Application in Energy Storage Devices

MXene has garnered widespread recognition in the scientific com-munity due to its remarkable properties,including excellent thermal stability,high conductivity,good hydrophilicity and dispersibility,easy processability,tunable surface properties,and admirable flexibility.MXenes have been categorized into different families based on the number of M and X layers in M_(n+1)X_(n),such as M_(2)X,M_(3)X_(2),M_(4)X_(3),and,recently,M_(5)X_(4).Among these families,M_(2)X and M_(3)X_(2),par-ticularly Ti_(3)C_(2),have been greatly explored while limited studies have been given to M_(5)X_(4)MXene synthesis.Meanwhile,studies on the M_(4)X_(3)MXene family have developed recently,hence,demanding a compilation of evaluated studies.Herein,this review provides a systematic overview of the latest advancements in M_(4)X_(3)MXenes,focusing on their properties and applications in energy storage devices.The objective of this review is to provide guidance to researchers on fostering M_(4)X_(3)MXene-based nanomaterials,not only for energy storage devices but also for broader applications.

Formation mechanism of MgB_2 in 2LiBH_4+MgH_2 system for reversible hydrogen storage

The formation conditions of MgB2 in 2LiBH4 ＋ MgH2 system during dehydrogenation were investigated and its mechanism was discussed. The results show that direct decomposition of LiBH4 is suppressed under relative higher initial dehydrogenation pressure of 4.0×10^5 Pa, wherein LiBH4 reacts with Mg to yield MgB2, and 9.16% （mass fraction） hydrogen is released within 9.6 h at 450 ℃. However, under relatively lower initial dehydrogenation pressure of 1.0×10^2 Pa, LiBH4 decomposes independently instead of reacting with Mg, resulting in no formation of MgB2, and 7.91% hydrogen is desorbed within 5.2 h at 450 ℃. It is found that the dehydrogenation of 2LiBH4 ＋ MgH2 system proceeds more completely and more hydrogen desorption amount can be obtained within a definite time by forming MgB2. Furthermore, it is proposed that the formation process of MgB2 includes incubation period and nucleus growth process. Experimental results show that the formation process of MgB2, especially the incubation period, is promoted by increasing initial dehydrogenation pressure at constant temperature, and the incubation period is also influenced greatly by dehydrogenation temperature.

Preparation of LaMgNi_(4-x)Co_x alloys and hydrogen storage properties

The LaMgNi4xCox （x=0, 0.3, 0.5） compounds were prepared by the method of levitation melting and a subsequent heat treatment at 1073 K for 10 h. XRD analysis shows that the obtained LaMgNia-xCox alloys consist of a single phase with the structure of cubic SnMgCu4 （AuBe5 type）. The hydrogen absorption/desorption properties of LaMgNi4 were investigated by PCI measurement at various temperatures （T=373, 398, 423 K） and the results show that the maximum absorbed hydrogen capacity reaches 1.45% （5.79H/M） under a hydrogen pressure of 4.3 MPa at 373 K. The XRD patterns during absorbing procedure at 373 K indicate the phase structure changing from cubic （a-LaMgNi4） to orthorhombic （fl-LaMgNiaH3.41） and after hydrogenation finally back to cubic （y-LaMgNiaH4.87）, and a partial desorption was also observed under this condition. With increasing temperature, a slight decrease of the absorbed hydrogen content was observed and the number of plateaus reduces from two to one, but the hydrogen absorption kinetics improves. The electrochemical properties of the LaMgNiaxCox were measured by simulated battery test, which shows that the discharge capacity of the alloys significantly improves with the increase of Co content.

Electrochemical performances of AB_5-type hydrogen storage alloy modified with Co_3O_4

Anodic electrodes with the mixture of hydrogen storage alloys and different contents of Co3O4（2%,4%,6% and 8%,mass fraction） powders were made.The effects of Co3O4 on the electrochemical performance of the alloy electrodes were studied.The constant charge-discharge tests show that the discharge capacity of alloy electrodes with Co3O4 significantly increases,and the maximum discharge capacities of electrodes with 2%,4%,6% and 8% Co3O4 are higher than the electrode with no Co3O4 by 0.83%,4.86%,7.18% and 9.21%,accordingly.Linear polarization（LP） and electrochemical impedance spectroscopy（EIS） tests suggest that charge-transfer resistance decreases by the addition of Co3O4.Cyclic voltammogram（CV）,scanning electron microscopy（SEM） and energy dispersive spectrum（EDS） tests indicate that Co3O4 can partly dissolve and experience a reversible oxidation-reduction process of Co to Co（OH）2,leading to the improvement in the electrochemical performance of hydrogen storage alloy.

4℃冷藏保存血小板输注对大鼠失血性休克/复苏致急性肾损伤的影响研究

目的研究4℃冷藏保存血小板(cold storage platelets,CSP)对大鼠失血性休克/复苏(HS/R)导致急性肾损伤的影响。方法健康雄性SD大鼠40只,随机选取20只用以制备血小板制剂,剩余大鼠随机分为4组:假手术组(空白组)、HS/R模型组(模型组)、CSP输注组、22℃±2℃振荡保存血小板输注组(RTP输注组)。容量复苏后24 h处死动物,采集血和肾组织标本。检测各组血清中血肌酐(Scr)、尿素氮(BUN)、血清胱抑素C(CysC)及肾组织中白细胞介素1β(IL-1β)、白细胞介素18(IL-18)含量。Western Blot法检测各组大鼠肾组织中性粒细胞明胶酶相关脂质运载蛋白(NGAL)、肾损伤因分子1(KIM-1)表达量,HE染色观察肾组织病理学改变。结果①四组大鼠基线状态体质量、MAP、SCr、BUN等指标无明显差异(P>0.05)。②复苏后24 h,模型组大鼠SCr(P<0.05)、BUN(P<0.01)、CysC(P<0.01)水平均高于其他三组;CSP输注组BUN(P<0.01)、SCr(P=0.037)、CysC(P=0.020)水平低于RTP输注组。③与模型组比较,CSP输注组和RTP输注组血清IL-1β和IL-18水平均显著降低。较于RTP输注组,CSP输注组血清IL-1β水平有所降低(P=0.041)。④与模型组相比,CSP输注组NGAL蛋白表达明显下降(P<0.01),CSP输注组和RTP输注组KIM-1蛋白表达均显著下降(P<0.01)。肾组织病理学结果示,CSP输注可减轻肾细胞变性、坏死及炎性细胞浸润程度。结论较于RTP,CSP输注可减轻SD大鼠HS/R急性肾损伤。

Dual-ion carrier storage through Mg^(2+) addition for high-energy and long-life zinc-ion hybrid capacitor

Cation additives can efficiently enhance the total electrochemical capabilities of zinc-ion hybrid capacitors (ZHCs).However their energy storage mechanisms in zinc-based systems are still under debate.Herein,we modulate the electrolyte and achieve dual-ion storage by adding magnesium ions.And we assemble several Zn//activated carbon devices with different electrolyte concentrations and investigate their electrochemical reaction dynamic behaviors.The zinc-ion capacitor with Mg^(2+)mixed solution delivers 82 mAh·g^(-1)capacity at 1 A·g^(-1) and maintains 91%of the original capacitance after 10000 cycling.It is superior to the other assembled zinc-ion devices in single-component electrolytes.The finding demonstrates that the double-ion storage mechanism enables the superior rate performance and long cycle lifetime of ZHCs.

Dynamic tracking and mobility analysis of single GLUT4 storage vesicle in live 3T3-L1 cells

Glucose transporter 4 (GLUT4) is responsible for insulin-stimulated glucose transporting into the insulin-sensitive fat and muscle cells. The dynamics of GLUT4 storage vesicles (GSVs) remains to be explored and it is unclear how GSVs are arranged based on their mobility. We examined this issue in 3T3-L1 cells via investigating the three-dimensional mobility of single GSV labeled with EGFP-fused GLUT4. A thin layer of cytosol right adjacent to the plasma membrane was illuminated and successively imaged at 5 Hz under a total internal reflection fluorescence microscope with a penetration depth of 136 nm. Employing single particle tracking, the three-dimensional subpixel displacement of single GSV was tracked at a spatial precision of 22 nm. Both the mean square displacement and the diffusion coefficient were calculated for each vesicle. Tracking results revealed that vesicles moved as if restricted within a cage that has a mean radius of 160 nm, suggesting the presence of some intracellular tethering matrix. By constructing the histogram of the diffusion coefficients of GSVs, we observed a smooth distribution instead of the existence of distinct groups. The result indicates that GSVs are dynamically retained in a continuous and wide range of mobility rather than into separate classes.

Effect of ternary transition metal sulfide FeNi_(2)S_(4)on hydrogen storage performance of MgH_(2)

Hydrogen storage is a key link in hydrogen economy,where solid-state hydrogen storage is considered as the most promising approach because it can meet the requirement of high density and safety.Thereinto,magnesium-based materials(MgH_(2))are currently deemed as an attractive candidate due to the potentially high hydrogen storage density(7.6 wt%),however,the stable thermodynamics and slow kinetics limit the practical application.In this study,we design a ternary transition metal sulfide FeNi_(2)S_(4)with a hollow balloon structure as a catalyst of MgH_(2)to address the above issues by constructing a MgH_(2)/Mg_(2)NiH_(4)-MgS/Fe system.Notably,the dehydrogenation/hydrogenation of MgH_(2)has been significantly improved due to the synergistic catalysis of active species of Mg_(2)Ni/Mg_(2)NiH_(4),MgS and Fe originated from the MgH_(2)-FeNi_(2)S_(4)composite.The hydrogen absorption capacity of the MgH_(2)-FeNi_(2)S_(4)composite reaches to 4.02 wt%at 373 K for 1 h,a sharp contrast to the milled-MgH_(2)(0.67 wt%).In terms of dehydrogenation process,the initial dehydrogenation temperature of the composite is 80 K lower than that of the milled-MgH_(2),and the dehydrogenation activation energy decreases by 95.7 kJ·mol-1 compared with the milled-MgH_(2)(161.2 kJ·mol^(-1)).This method provides a new strategy for improving the dehydrogenation/hydrogenation performance of the MgH_(2)material.

Progress and prospect for NASICON-type Na3V2(PO4)3 forelectrochemical energy storage

Sodium-ion batteries （SIBs） have attracted increasing attention in the past decades, because of high over-all abundance of precursors, their even geographical distribution, and low cost. Na3V2（PO4）3 （NVP）, atypical sodium super ion conductor （NASlCON）-based electrode material, exhibits pronounced structuralstability, exceptionally high ion conductivity, rendering it a most promising electrode for sodium storage.However. the comparatively low electronic conductivity makes the theoretical capacity of NVP cannot befully accessible even at comparatively low rates, presenting a major drawback for further practical ap-plications, especially when high rate capability is especially important. Thus, many endeavors have beenconformed to increase the surface and intrinsic electrical conductivity of NVP by coating the active mate-rials with a conductive carbon layer, downsizing the NVP particles, combining the NVP particle with vari-ous carbon materials and ion doping strategy. In this review, to get a better understanding on the sodiumstorage in NVP, we firstly present 4 distinct crystal structures in the temperature range of-30℃-225℃ namely α-NVP, β-NVP, β′-NVP and γ-NVP. Moreover, we give an overview of recent approaches to en-hance the surface electrical conductivity and intrinsic electrical conductivity of NVP. Finally, some poten-tial applications of NVP such as in all-climate environment and PHEV, EV fields have been prospected.

The electrochemical characteristics of AB_(4)-type rare earth-Mg-Ni-based superlattice structure hydrogen storage alloys for nickel metal hydride battery

Rare earth-Mg-Ni-based alloys with superlattice structures are new generation negative electrode materials for the nickel metal hydride batteries.Among them,the novel AB_(4)-type superlattice structure alloy is supposed to have superior cycling stability and rate capability.Yet its preparation is hindered by the crucial requirement of temperature and the special composition which is close to the other superlattice structure.Here,we prepare rare earth-Mg-Ni-based alloy and study the phase transformation of alloys to make clear the formation of AB_(4)-type phase.It is found Pr_(5)Co_(19)-type phase is converted from Ce_(5)Co_(19)-type phase and shows good stability at higher temperature compared to the Ce_(5)Co_(19)-type phase in the range of 930-970℃.Afterwards,with further 5℃increasing,AB_(4)-type superlattice structure forms at a temperature of 975℃by consuming Pr_(5)Co_(19)-type phase.In contrast with A_(5)B_(19)-type alloy,AB_(4)-type alloy has superior rate capability owing to the dominant advantages of charge transfer and hydrogen diffusion.Besides,AB_(4)-type alloy shows long lifespan whose capacity retention rates are 89.2%at the 100;cycle and 82.8%at the 200;cycle,respectively.AB_(4)-type alloy delivers 1.53 wt.%hydrogen storage capacity at room temperature and exhibits higher plateau pressure than Pr_(5)Co_(19)-type alloy.The work provides novel AB_(4)-type alloy with preferable electrochemical performance as negative electrode material to inspire the development of nickel metal hydride batteries.

The Popularization and Application of Cold Storage Red Blood Cells or Whole Blood at -80 ℃ of the Rh(D) Negative Patients in Surgical Operation

Summary: The efficiency of cold storage red blood cells (CSRBC) or whole blood at -80 ℃ used in 27 Rh(D) negative patients during surgical operation was reported. The Rh(D) negative patients received the transfusion of CSRBC or whole blood stored at -80 ℃ for 180 to 360 days. The changes in the indexes, such as blood TB, DB, K +, Na +, BUN, Cr, urine protein (URPO), UOB, Hb, HCT, serum total protein, relative to hemolytic reaction and blood volume before and after transfusion were observed. The results showed that after transfusion of CSRBC or whole blood 27 cases were negative for urine protein and UOB, and the levels of BUN and Cr were normal (P>0.05). Blood TB, DB, Hb, and HCT were increased, while pH, blood K + and blood Na + was normal with the difference being not significant before and after operation (P>0.05). Plasma protein was decreased, but there was no significant difference before and after operation (P>0.05). It was suggested that CSRBC or whole blood at -80 ℃ could be safely infused to the Rh(D) negative patients without side effects during the surgical operation.

Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming decades.Exploring an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short term.In this study,we attempted to construct sediment samples with different residual CH_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced CH_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,respectively.The results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage efficiency.Affected by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 times.Additionally,we noticed two other advantages of this method.One is that CO_(2) injection can enhance CH_(4) recovery rate and increases CH_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious shrinkage.Obviously,this is crucial for protecting the goaf stability.In summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

Changes of Terrestrial Water Storage in River Basins of China Projected by RegCM4

In this study, a historic simulation covering the period from 1951 to 2000 and three projected scenario simulations covering 2001-2050 were conducted em- ploying the regional climate model RegCM4 to detect the changes of terrestrial water storage （TWS） in major river basins of China, using the Intergovernmental Panel on Climate Change （IPCC） Special Report on Emissions Scenarios （SRES）： A1B, A2, and B1. The historic simula- tion revealed that the variations of TWS, which are dominated by precipitation in the basins, rely highly on their climatic features. Compared with the historic simu- lation, the changes of TWS in the scenario simulations showed strong regional differences. However, for all sce- narios, TWS was found to increase most in Northeast China and surrounding mountains around the Tibetan Plateau, and decrease most in eastern regions of China. Unlike the low seasonal variations of TWS in arid areas, the TWS showed strong seasonal variations in eastern monsoon areas, with the maximum changes usually oc- curring in summer, when TWS increases most in a year. Among the three scenario simulations, TWS increased most in Songhua River Basin of B1 scenario, and de- creased most in Pearl River Basin of A2 scenario and Hal River Basin of A1B scenario, accompanied by different annual trends and seasonal variations.

Preparation and phase change performance of Na_2HPO_4·12H_2O@poly(lactic acid) capsules for thermal energy storage

Micro-encapsulated phase-change materials(micro PCMs) with Na_2 HPO_4·12 H_2 O encapsulated in poly(lactic acid)(PLA) shell were prepared by a solvent evaporation–precipitation method that involves the use of a coaxial needle. The effects of PLA concentration, stirring speed, injection rate of core and shell solutions, and polyvinyl alcohol(PVA) concentration on phase change properties were investigated. The thermal properties of microP CMs were characterized by differential scanning calorimetry(DSC). The capsules prepared under the optimal conditions are about 2 mm in diameter and show a latent heat of up to 122.2 J·g^(-1).

Effects of Fe Modified Na2WO4 Additive on the Hydrogen Storage Properties of MgH2

A Fe modified Na2WO4 compound was synthesized by a solution impregnation method and was ball-milled with MgH2 to constitute a novel MgH2-Fe2O3/Na2WO4 composite. The effects of the Fe2O3/Na2WO4 additive on the hydrogen storage properties of MgH2 together with the corresponding mechanism were investigated. At 423 K, within the first 200 seconds, the hydrogen absorption amount of MgH2+20 wt% Fe2O3/Na2WO4 was almost 5 times that of pure MgH2. And at 573 K, its total hydrogen desorption amount was 7 times that for pure MgH2. Meanwhile, its onset dehydrogenation temperature was 110 K lower than that of pure MgH2. It was worth noting that the MgH2+20 wt% Fe/Na2WO4 presented the lower dehydrogenation reaction activation energy(Ea) of 35.9 kJ·mol^-1 compared to that of pure MgH2. The active MgWO4, Mg2 FeH6 and MgO formed during the milling process were responsible for the improvement of the hydrogen storage properties for MgH2.

Ti-6Al-4V ELI钛合金的宽温域(-253~350℃)力学性能研究

钛及钛合金是一种重要的太空金属材料,在航空航天领域发挥重要的作用。研究了Ti-6Al-4V ELI钛合金在室温(20℃)、高温(350℃)以及超低温(-253℃)环境下的拉伸力学性能,比较了Ti-6Al-4V ELI钛合金在不同温度下的力学性能指标,分析了其断口形貌特征。结果表明,Ti-6Al-4V ELI钛合金在超低温下表现出较高的力学性能,抗拉强度可达1900 MPa以上,其断口形貌呈现脆性断裂特点。在室温和高温下,Ti-6Al-4V ELI钛合金表现出良好的塑性和韧性,具有较为明显的韧性断裂特点。因其良好的宽温域力学性能,Ti-6Al-4V ELI钛合金是未来发展航天航空领域必不可少的重要金属材料。

LiBH4 for hydrogen storage-New perspectives

Hydrogen energy has been recognized as“Ultimate Power Source”in the 21st century.It is a boon in these days of energy crunches and concerns about climate change because of the characterized advantages,such as high energy density,large calorific value,abundant resource,zero pollution,zero carbon emission,storable and renewable.State-of-the-art perspectives on tuning the stable thermodynamics and sluggish kinetics of dehydrogenation and re-hydrogenation of LiBH4,which has been regarded as a promising hydrogen storage alternative for onboard energy carrier applications have been discussed.Five major technological approaches are involved,including nanoengineering,catalyst modification,ions substitution,reactant destabilization and a novel process termed as high-energy ball milling with in-situ aerosol spraying(BMAS).It is worth noting that BMAS has the potential to help overcome the kinetic barriers for thermodynamically favorable systems like LiBH4 t MgH2 mixture and provide thermodynamic driving force to enhance hydrogen release at a lower temperature.

Impact of preparation conditions on hydrogen storage performance of metallic Ti-doped NaAlH_4

Contrary to the popular opinion, it has been found that metallic Ti powder can be directly utilized as dopant precursor to prepare catalytically enhanced NaAlH4 through mechanical milling. As a novel method for preparation of catalytically enhanced NaAlH4, direct metallic Ti-doping possesses practical advantage over the state-of-the-art doping technology: elimination of the inactive by-products and the gas impurities that are highly detrimental to fuel cell operation. A systematic investigation along this new approach was performed under various preparation conditions, including different starting materials, milling atmosphere and milling time. The materials thus prepared under different conditions were found to share some common features, while at the meantime, differ significantly from each other on hydrogen storage performance. A comprehensive understanding of these results provides valuable insight into a series of fundamental questions in catalytically enhanced Ti-NaAlH4 system.

High-capacity Hydrogen Storage on Novel Sandwich-like Binuclear Compounds: N_4-M_2-N_4 (M = Sc and Ti)

With respect to the first principle calculations, we predicted that two pairs of transition metals （e.g., Sc2 and Ti2） can be interbedded between two tetranitrogen rings to form two sandwich-like binuclear complexes respectively （e.g. N4Sc2N4 and NaTi2N4）. These two complexes can adsorb up to eight and ten hydrogen molecules, corresponding to a gravimetric storage capacity of 7.7 and 9.9 wt%, respectively. These sandwich-type complexes proposed in this work are favorable for reversible adsorption and desorption of hydrogen at ambient conditions. The results are helpful for the development of a new class of high-capacity hydrogen-storage media.