Hydrogen Storage Properties of Ti_(1.2)Fe+xCa Hydrogen Storage Alloys

The hydrogen storage properties of Ti1,2Fe+xCa （x=1%, 3% and 5% in mass fraction） alloys was Investl- gated. Results show that the modified alloys can be activated without any thermal treatment at room temperatrLre due to the addition of Ca and excess Ti in the alloys. Hydrogen storage properties of these modified alloys vary with Ca amount and reaction temperature. In addition, the influence mechanism of the addition of Ca and excessive Ti on the activation behavior and hydrogen storage capacity of the alloys was discussed.

Effect of Glutathione and Storage Time on Rheological Properties of Per-proofed Frozen Dough

The effect of reduced glutathione (GSH) on fresh and pre-proofed frozen dough rheological properties were investigated using dynamic stress rheometry and small scale extensibility with the addition of three levels (80×10-6, 160× 10-6 and 240×10-6 GSH) and six storage times (0 and 1 day, 2, 4, 6 and 8 weeks). Three relaxation times (1, 13 and 26min) after loading the dough in the rheometer were used to determine storage (G’) and loss (G”) moduli. Correlations for G’ (r=0.678 and 0.622 at 0.05, and 10Hz, respectively) and G” (r=0.699, and 0.690 at 0.05, and 10Hz, respectively) were observed with the area under the extension curve at 26 min relaxation time. The addition of GSH to fresh dough reduced G’ (16.4% to 55.9%) and G” (13.7% to 52.2%). Freezing and frozen storage caused increase in G’ and G”. The addition of GSH reduced dough strength indicated by the reduction in maximum resistance to extension (Rmax) and the ratio of maximum resistance to extensibility (Rmax/E). The reduction in Rmax across all relaxation times ranged from 16.2% to 59.4%. An increase in dough extension (E) was observed with 240×10-6 GSH at all frozen storage and rest period times. Addition of GSH caused an increase of liquid phase (30.6% to 35.3%) in fresh dough and frozen dough (10.3% to 20.7%) after one day frozen storage. Negative correlations of water content in the solid phase with dough extensibility and area under the extensibility curve were found (r=-0.594 and-0.563, respectively, p<0.001). This suggests a loss of dough extensibility and strength as the water holding capacity of the dough components changes during frozen storage.

Evaluation of myocardial viability during cold storage by measurement of myocardual dielectric properties tanδm in radio frequency

Objective To study the mechanism of myocardial dielectric property changes in radio frequency during hypothermic preservation and explore myocardial viability evaluative method. Methods Hybrid young pigs ( 20 - 30 kg) were used in the experiment. Heart arrest was in-

Accurate quantification of TiO_(2)(B)'s phase purity via Raman spectroscopy

Bronze phase titanium dioxide(TiO_(2)(B))could be a promising high-power anode for lithium ion battery.However,TiO_(2)(B)is a metastable material,so the as-synthesized samples are inevitably accompanied by the existence of anatase phases.It has been found that the TiO_(2)(B)'s purity is positively correlated with its electrochemical performance.Herein,we have established an accurate quantification of the TiO_(2)(B)/anatase ratio,by figuring out the function between the purity of TiO_(2)(B)phase in the high purity range and its Raman spectra features in combination of the calibration by the synchrotron radiation X-ray diffraction(XRD).Compared with the time-consuming electrochemical method,the rapid,sensitive and non-destructive features of Raman spectroscopy have made it a promising candidate for determining the purity of TiO_(2)(B).Further,the correlations developed in this work should be instructive in synthesizing pure TiO_(2)(B)and furthermore optimizing its electrochemical charge storage properties.

Novel lead-free NaNbO_(3) -based relaxor antiferroelectric ceramics with ultrahigh energy storage density and high efficiency

The development of environmentally friendly ceramics for electrostatic energy storage has drawn growing interest due to the wide application in high power and/or pulsed power electronic systems.However,it is difficult to simultaneously achieve ultrahigh recoverable energy storage density(W rec>8 J/cm^(3))and high efficiency(η>80%),which restricts their application in the miniaturized,light weight and easy integrated electronic devices.Herein,the novel NaNbO_(3)-(Bi_(0.8)Sr_(0.2))(Fe_(0.9) Nb_(0.1))O_(3) relaxor antiferro-electric ceramics,which integrates the merits of antiferroelectrics and relaxors,are demonstrated to exhibit stabilized antiferroelectric phase and enhanced dielectric relaxor behavior.Of particular impor-tance is that the 0.88NN-0.12BSFN ceramic achieves giant electric breakdown strength E_(b)=98.3 kV/mm,ultrahigh W _(rec)=16.5 J/cm^(3) and high h=83.3%,as well as excellent frequency,cycling and thermal reliability simultaneously.The comprehensive energy storage performance of NN-BSFN not only out-performs state-of-the-art dielectric ceramics by comparison,but also displays outstanding potential for next-generation energy storage capacitors.

Optimizing the grain size and grain boundary morphology of (K,Na) NbO_(3)-based ceramics: Paving the way for ultrahigh energy storage capacitors

Relaxor dielectric ceramic capacitors are very attractive for high-power energy storage.However,the low breakdown strength severely restricts improvements to the energy storage density and practical application.Here,a strategy of designing small grain sizes and abundant amorphous grain boundaries is proposed to improve the energy storage properties under the guidance of phase field theory.0.925(K_(0.5)Na_(0.5))NbO_(3)-e0.075Bi(Zn_(2/3)(Ta_(0.5)Nb_(0.5))1/3)O_(3)(KNNe-BZTN)relaxor ferroelectric ceramic is taken as an example to verify our strategy.The grain sizes and grain boundaries of the KNNeBZTN ceramics are carefully controlled by the high-energy ball milling method and twoestep sintering strategy.Impedance analysis and diffusion reflectance spectra demonstrate that KNNeBZTN ceramics with a small grain size and abundant amorphous grain boundary exhibit a lower charge carrier concentration and higher band gap.As a consequence,the breakdown electric field of KNNeBZTN ceramics increases from 222 kV/cm to 317 kV/cm when the grain size is decreased from 410 nm to 200 nm,accompanied by a slightly degraded maximum polarization.KNNeBZTN ceramics with an average grain size of~250 nm and abundant amorphous grain boundaries exhibit optimum energy storage properties with a high recoverable energy density of 4.02 J/cm^(3) and a high energy efficiency of 87.4%.This successful local structural design opens up a new paradigm to improve the energy storage performance of other dielectric ceramic capacitors for electrical energy storage.

Effects of Crystallinity and Defects of Layered Carbon Materials on Potassium Storage:A Review and Prediction

Layered carbon materials(LCMs)are composed of basic carbon layer units,such as graphite,soft carbon,hard carbon,and graphene.While they have been widely applied in the anode of potassium-ion batteries,the potassium storage mechanisms and performances of various LCMs are isolated and difficult to relate to each other.More importantly,there is a lack of a systematic understanding of the correlation between the basic microstructural unit(crystallinity and defects)and the potas-sium storage behavior.In this review,we explored the key structural factors affecting the potassium storage in LCMs,namely,the crystallinity and defects of carbon layers,and the key parameters(L_(a),L_(c),d_(002),I_(D)/I_(G))that characterize the crystallinity and defects of different carbon materials were extracted from various databases and literature sources.A structure–property database of LCMs was thus built,and the effects of these key structural parameters on the potassium storage properties,including the capacity,the rate and the working voltage plateau,were systematically analyzed.Based on the structure–prop-erty database analysis and the guidance of thermodynamics and kinetics,a relationship between various LCMs and potas-sium storage properties was established.Finally,with the help of machine learning,the key structural parameters of layered carbon anodes were used for the first time to predict the potassium storage performance so that the large amount of research data in the database could more effectively guide the scientific research and engineering application of LCMs in the future.

Mechanochemistry and hydrogen storage properties of 2Li_(3)N+Mg mixture

The Li-Mg-N-H hydrogen storage system is a promising hydrogen storage material due to its moderate operation temperature,good reversibility,and relatively high capacity.In this work,the Li-Mg-N-H composite was directly synthesized by reactive ball milling(RBM) of Li3N and Mg powder mixture with a molar ratio of 2:1 under hydrogen pressure of 9 MPa.More than 8.8 wt%hydrogen was absorbed during the RBM process.The phases and structural evolution during the in situ hydrogenation process were analyzed by means of in situ solidgas absorption and ex situ X-ray diffraction(XRD) measurements.It is determined that the hydrogenation can be divided into two steps,leading to mainly the formation of a lithium magnesium imide phase and a poorly crystallized amide phase,respectively.The H-cycling properties of the as-milled composite were determined by temperature-programmed dehydrogenation(TPD) method in a closed system.The onset dehydrogenation temperature was detected at 125℃,and it can reversibly desorb 3.1 wt% hydrogen under a hydrogen back pressure of 0.2 MPa.The structural evolution during dehydrogenation was further investigated by in situ XRD measurement.It is found that Mg(NH_(2))_(2)phase disappears at about 200 ℃,and Li_(2)Mg_(2)N_(3)H_(3),LiNH_(2),and Li_(2)MgN_(2)H_(2)phases coexist at even 300 ℃,revealing that the dehydrogenation process is step-wised and only partial hydrogen can be desorbed.

Enhanced energy-storage performance in BNT-based lead-free dielectric ceramics via introducing SrTi_(0.875)Nb_(0.1)O_(3)

Environmentally friendly lead-free ceramics capacitors,with outstanding power density,rapid charging/discharging rate,and superior stability,have been receiving increasing attention of late for their ability to meet the critical requirements of pulsed power devices in low-consumption systems.However,the relatively low energy storage capability must be urgently overcome.Herein,this work reports on leadfree SrTi_(0.875)Nb_(0.1)O_(3)(STN)replacement of(Bi_(0.47)La_(0.03)Na_(0.5))_(0.94)Ba_(0.06)TiO_(3)(BLNBT)ferroelectric ceramics with excellent energy storage performance.Improving relaxor behaviour and breakdown strength(Eb),decreasing grain size,and mitigating large polarization difference are conductive to the enhancement of comprehensive energy storage performances.The phase-field simulation methods are further analysized evolution process of electrical tree in the experimental breakdown.In particular,the 0.70BLNBT-0.30STN ceramic exhibit a large discharged energy density of 4.2 J/cm^(3) with an efficiency of 89.3%at room temperature under electric field of 380 kV/cm.Additionally,for practical applications,the BLNBT-based ceramics achieve a high power density(~62.3 MW/cm^(3))and fast discharged time(~148.8 ns)over broad temperature range(20-200℃).Therefore,this work can provide a simple and effective guideline paradigm for acquiring high-performance dielectric materials in low-consumption systems operating in a wide range of temperatures and long-term operations.

Structure,dielectric properties of low-temperature-sintering BaTiO3-based glass–ceramics for energy storage

The 0.85BaTiO3–0.15Bi(Mg_(2/3)Nb_(1/3))O_(3)(BTBMN)ceramics with low-melting-temperature B_(2)O_(3)–Na_(2)B_(4)O_(7)–Na_(2)SiO_(3)(BNN)glass addition were prepared by the solid state method.The composition of the glass–ceramics was BTBMN–x wt.%BNN(x=0,1,3,5,7,9,12,15;abbreviated as BG).The sintering characteristics,phase structure,microstructure,dielectric properties and energy storage properties were systematically investigated.The sintering temperature of BTBMN ceramics was greatly reduced by the addition of BNN glass.The second-phase BaTi(BO_(3)T_(2)was observed in the BG system until the glass content reached 15 wt.%.The addition of BNN glass significantly reduces the grain size of BTBMN ceramics.With the increase of BNN glass content,dielectric constant of BG glass–ceramics at 1 kHz gradually decreased,the maximum dielectric constant("mT of BG glass–ceramics gradually decreased,while the temperature corresponding to the maximum dielectric constant(T_(m)T increased,the ferroelectric relaxation behavior decreased and the temperature stability of the dielectric constant gradually improved.As the BNN glass content increased,the breakdown electric field strength(BDS)of BG glass–ceramics increased first and then decreased,and the polarization values reduced gradually,while the trend of energy storage performance is similar to BDS.When the BNN glass content was 3 wt.%,the energy storage properties of the BG glass–ceramics were optimal,and a recoverable energy storage density(Wrec)of 1.26 J/cm^(3)and an energy storage efficiency(η)of 80.9%were obtained at the electric field strength of 220 kV/cm.The results showed that BG glass–ceramics were promising for energy storage capacitors.

Preparation and Li-storage properties of SnSb/graphene hybrid nanostructure by a facile one-step solvothermal route

A SnSb nanocrystal/graphene hybrid nanocomposite was synthesized by a facile one-step solvothermal route using graphite oxide,SnCl_(2).2H_(2)O and SbCl_(3) as the starting materials,absolute ethanol as the solvent,and NaBH4 as the reductant.The formation of SnSb alloy and the reduction of the graphene oxide occur simultaneously.SnSb nanoparticles with a size of 30–40 nm were uniformly anchored and confined by the graphene sheets,forming a unique SnSb/graphene hybrid nanostructure.The electrostatic attraction between the positively charged ions(Sn^(2+) and Sb^(3+))and the negatively charged graphene oxide plays an important role in the uniform distribution of the SnSb particles on the graphene sheets.The electrochemical Li-storage properties of the nanocomposite were investigated as a potential high-capacity anode material for Li-ion batteries.The results show that the nanocomposite exhibits an obvious enhanced Li-storage performance compared with bare SnSb.The improvement of the electrochemical performance could be attributed to the formation of two-dimensional conductive networks,homogeneous dispersion and confinement of SnSb nanoparticles and the enhanced wetting of active material with the electrolyte for increased specific surface area by the introduction of graphene into SnSb nanoparticles.Li-ion chemical diffusion coefficient and ac impedance were measured to understand the underlying mechanism for the improved electrochemical performance.

Excellent thermal stability and high energy storage performances of BNT-based ceramics via phase-structure engineering

Herein,a novel strategy for regulating the phase structure was used to significantly enhance the recoverable energy storage density(Wrec)and the thermal stability via designing the(1-x)[(Bi_(0.5)Na_(0.5))_(0.7)Sr_(0.3)TiO_(3)]-xBiScO_(3)((1-x)BNST-xBS)relaxor ferroelectric ceramics.The incorporation of BS into BNST ceramics markedly increases the local micro-structure disorder,causing a high polarization and inhibiting polarization hysteresis for 0.95BNST-0.05BS ceramics,leading to a large Wrec of 5.41 J/cm^(3)with an ideal efficiency(h)of 78.5%.Meanwhile,transmission electron microscope(TEM)results further proved that the nano-domain structure and the tetragonal(P4bm)phase superlattice structure of 0.95BNST-0.05BS ceramics possess an excellent thermal stability(20-200℃).An outstanding Wrec value of 3.18×(1.00±0.03)J/cm^(3)and an h value of 74.500±0.025 are achieved under a temperature range from 20℃to 200℃.This work provides a promising method for phase-structure design that can make it possible to apply temperature-insensitive ceramic dielectrics with a high energy storage density in harsh environments.

Enhancing lithium-sulfur battery performance with In_(2)O_(3)-In_(2)S_(3)@NSC heterostructures:Synergistic effects of double barrier and catalytic transformation

The sluggish redox reaction kinetics of lithium polysulfides(LiPSs)are considered the main obstacle to the commercial application of lithium-sulfur(Li-S)batteries.To accelerate the conversion by catalysis and inhibit the shuttling of soluble LiPSs in Li-S batteries,a solution is proposed in this study.The solution involves fabrication of N,S co-doped carbon coated In_(2)O_(3)/In_(2)S_(3)heterostructure(In_(2)O_(3)-In_(2)S_(3)@NSC)as a multifunctional host material for the cathode.The In_(2)O_(3)-In_(2)S_(3)@NSC composite can reduce the Gibbs free energy for the conversion reactions of LiPSs,which results in superior performance.The synergy between different components in In_(2)O_(3)-In_(2)S_(3)@NSC and the unique 3D structure facilitate ion and electron transport in Li-S batteries.The In_(2)O_(3)-In_(2)S_(3)@NSC/Li 2 S 6 cathode exhibits excellent rate capacity,with a capacity of 599 mAh g−1 at 5.5 C,and good cycle stability,with a capacity of 436 mAh g^(−1)after 1000 cycles at 1 C.Overall,this study proposes a promising solution to improve the energy storage properties of Li-S batteries,which could potentially facilitate the commercialization of Li-S batteries.