Electrochemical Discharge Capacity Research Articles

Nickel-rich layered cathode LiNi0.8Co0.1Mn0.1O2 mediated by a selective lattice doping towards high-performance lithium ion battery

Rapid capacity loss and voltage fading pose a significant barrier to the commercialization of nickel-rich materials with layered structures due to particle cracking and structure degradation. Double element selective lattice modification strategy that can balance multiple performance requirements is gaining attention. Here, we proposed a selective lattice doping strategy to enhance the lattice stability of LiNi0.8Co0.1Mn0.1O2 via a double element co-doping of Mg and W. Impressively, the Mg/W co-doping improved electrochemical reaction kinetics and discharge capacity, and largely suppressed structure degradation simultaneously. In situ X-ray diffraction (XRD) results demonstrated that W/Mg co-doping can tune H2−H3 phase transition, relieving the lattice stress and mechanical degradation. These improvements can be attributed to a synergistic effect of W and Mg, in which high valence state W6+ induced the formation of Ni2+ and strong W−O bonds increased layer structure stability, meanwhile Mg2+ as a pillar inhibited Li+/Ni2+ mixing and maintained structural stability. This work provides selective lattice dual-doping strategic guidelines for the use of high energy efficiency and robust stability high-nickel low-cobalt cathodes in lithium-ion batteries.

Studies of the effect of Hf doping on the electrochemical performance of C15 Laves type metal hydride battery anode alloys

This paper focuses on the studies of the electrochemical performance of arc-melted Hf-modified Ti-Zr based AB2 Laves type metal hydride battery anode alloys with composition HfxZr24-xTi6.5V3.9Mn22.2Fe3.8Ni38La0.3Sn0.3 (x = 1–4). The phase composition and the morphology of the alloys were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Metal-gas interactions and electrochemical performances were studied by building PCT diagrams and by electrochemical tests performed in a 9 N KOH electrolyte solution at ambient temperature when using the half-cells in a three-electrode assembly.All studied alloys were two-phase and contained the Laves phase intermetallics of C15 (major constituent) and C14 (minor constituent) types. An increase in Hf content caused a growth of the abundance of the C14 phase and was accompanied by a decrease in the electrochemical discharge capacities, exchange current densities, and H diffusion rates as compared to the Hf-free alloy. Among the Hf-containing alloys, an introduction of 2 wt% Hf into the alloy's composition resulted in a higher H diffusion rate, while the highest H storage capacity has been reached for the alloy with the lowest, 1 wt%, content of Hf. The surface of the alloys contained catalysing hydrogen exchange metallic nickel clusters with the highest enrichment observed for the 2 wt% Hf alloy. An influence of Hf on the hydrogen storage and electrochemical performance can be understood in terms of the modification of the intrinsic properties of the alloys following a substitution (Zr/Ti) → Hf as C15 type alloys show the fastest hydrogen diffusion rates while a gradually increasing content of the hexagonal C14 type in the Hf-containing alloys slows down the H diffusion process.

Structure and electrochemical hydrogen storage properties of spinel ferritesSmxZn1−xFe2O4alloys (x = 0,x = 0.2,x = 0.4, andx = 0.6) forNi‐MHaccumulator applications

AbstractIn this article, we examine the effects of Sm substitution by Zn on the structures and electrochemical characteristics of SmxZn1−xFe2O4alloys prepared by sol–gel technique. The structural properties of the electrodes are studied by X‐ray diffraction and scanning electron microscope (SEM). The structural properties of these alloy are well influenced by the substitution rate. The SEM images of the powder of all samples (x = 0, 0.2, 0.4, and 0.6) shows the presence of agglomerates in the powder particles. Moreover, EDX investigation demonstrates that the chemical and theoretical compositions of all the prepared alloys are almost the same. The electrochemical performance of the oxide electrodes was analyzed at temperature 298 K using chronopotentiometry, chronoamperometry, and cyclic voltammetry techniques. During the first cycles, the electrochemical discharge capacity increases for all alloys. Obviously, this evolution is rapid for the unsubstituted alloy, but it becomes slower by increasing the substitution rate. The highest discharge capacity value was obtained for the ZnFe2O4electrode of the order of 180 mAh/g while the highest retained capacity was observed for the Sm0.6Zn0.4Fe2O4electrode. The kinetic results showed that the exchange current densityI0and the hydrogen diffusion coefficientDHof the anodes increased with increasing substitution rate and the best values were obtained for the Sm0.6Zn0.4Fe2O4anode.

Effect of Three-in-One Surface Modification of Spherical, Co-Free Li-Rich Cathode Material for Li-Ion Batteries (Li1.2Mn0.6Ni0.2O2) with Citric Acid

The electrochemical activation of Li2MnO3 domains in Li- and Mn-rich layered oxides (LRLO) is highly important, and can be tuned by surface modification of the active materials to improve their cycling performance. In this study, citric acid was employed as a combined organic acid, reducing agent, and carbon precursor in order to remove surface residues from the calcination process, implement an oxygen deficient layer on the surface of the primary LRLO particles, and cover their surface with a carbon-containing coating after a final annealing step. A broad selection of bulk and surface sensitive characterization methods was used to characterize the post-treated spherical particles, providing the evidence for successful creation of an oxygen deficient near-surface region, covered by carbon-containing deposits. Post-treated materials show enhanced electrochemical discharge capacities after progressive Li2MnO3 activation, reaching maximum capacities of 247 mAh g−1. Gassing measurements reveal the suppression of oxygen release during the first cycle, concomitant with an increased CO2 formation for the carbon-coated materials. The voltage profile analysis in combination with post-mortem characterization after 300 cycles provide insights into the aging of the treated materials, which underlines the importance of the relationship between structural changes during scalable post-treatment and the electrochemical performance of the powders.

Nafion/Aquivion‐Based Composite Lithium Ion Exchange Membranes for High Capacity Li‐S Batteries

AbstractLithiated Nafion (Li‐Naf) and lithiated Aquivion (Li‐Aqu) ion exchange membranes are applied as electrolyte and separator to prevent the polysulfide shuttle effect in Li−S batteries. The production and characterization of Li‐Naf, Li‐Aqu, and their composites (2 : 1, 1 : 1, and 1 : 2; w/w) are carried out. The ion exchange capacity and polysulfide transition of the produced membranes are examined and structural characterizations are conducted via Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). CR2032 half cells are assembled in order to perform electrochemical analysis. The electrochemical performances of the membranes are investigated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge‐discharge tests. Due to the low equivalent weight of Aquivion, the ion exchange capacity and ionic conductivity of the membrane enhance with the increasing amount of Li‐Aqu in the composite membrane. Because of the synergistic effect of Nafion and Aquivion, Li‐Naf : Li‐Aqu/1 : 2 composite offers 61.2 % capacity retention and the best electrochemical discharge capacity of 826 mAhg−1 after 100 charge‐discharge cycles. As a result, Nafion and Aquivion composite membranes can successfully inhibit the shuttle movement of negatively charged polysulfide species while allowing the transition of positively charged lithium ions for high performed Li−S batteries.

Thermal, Microstructural and Electrochemical Hydriding Performance of a Mg65Ni20Cu5Y10 Metallic Glass Catalyzed by CNT and Processed by High-Pressure Torsion

A Mg65Ni20Cu5Y10 metallic glass was produced by melt spinning and was mixed with a 5 wt.% multiwall carbon nanotube additive in a high-energy ball mill. Subsequently, the composite mixture was exposed to high-pressure torsion deformation with different torsion numbers. Complimentary XRD and DSC experiments confirmed the exceptional structural and thermal stability of the amorphous phase against severe plastic deformation. Combined high-resolution transmission electron microscopy observations and fast Fourier transform analysis revealed deformation-induced Mg2Ni nanocrystals, together with the structural and morphological stability of the nanotubes. The electrochemical hydrogen discharge capacity of the severely deformed pure metallic glass was substantially lower than that of samples with the nanotube additive for several cycles. It was also established that the most deformed sample containing nanotubes exhibited a drastic breakdown in the electrochemical capacity after eight cycles.

Novel Cathode Electrode with Superior Rate Capability Using Perforated Aluminum Current Collector for Lithium-Ion Batteries

Electrodes were fabricated using a perforated aluminum current collector and a standard aluminum foil, and the relationship between the electrochemical performance of the battery and the current collector was investigated. The perforated aluminum foil improved the contact characteristics between the cathode materials particles and the current collector. Also, electrochemical performance indicators such discharge capacity and rate characteristics were improved due to the increased adhesion of the electrode using the perforated current collector.

TEMPO‐Contained Polymer Grafted onto Graphene Oxide via Click Chemistry as Cathode Materials for Organic Battery

AbstractPoly(2,2,6,6‐tetramethylpiperidin‐1‐oxyl‐4‐yl methacrylate) (PTMA) is a typical organic battery material containing nitrogen and oxygen radicals. The grafting of PTMA onto graphene oxide to obtain composite cathode material poly(2,2,6,6‐tetramethylpiperidin‐1‐oxyl‐4‐yl methacrylate)‐Graphene Oxide (PTMA‐GO) via click chemistry is reported. The method of preparing PTMA‐GO is completed at room temperature, which can retain the oxygen‐containing functional groups on the surface of graphene oxide, and the process is simple and easy to conduct. The composite materials are characterized by infrared, X‐ray diffraction, thermogravimetry, and electron paramagnetic resonance. The cathode material is assembled in a button battery to measure its cyclic voltammogram, electrochemical impedance spectroscopy, and charge and discharge capacity cycles. It is found that the PTMA‐GO electrode is twice as conductive as the PTMA electrode alone. The specific capacity of the PTMA‐GO electrode is nearly 2.3 times higher than that of the PTMA electrode after 300 charge–discharge cycles. This represents an important reference value for the development of organic batteries, especially for the research of nitroxide radical polymer electrode materials.

Effect of Substitutional Elements on the Thermodynamic and Electrochemical Properties of Mechanically Alloyed La1.5Mg0.5Ni7−xMx alloys (M = Al, Mn)

The A2B7-type La-Mg-Ni-M-based (M = Al, Mn) intermetallic compounds were produced by mechanical alloying and annealing. The thermodynamic and electrochemical properties of these materials were studied. The nickel substitution by aluminum and manganese in the La-Mg-Ni system improves the kinetics of hydrogen absorption. The hydrogen desorption capacity of Mn substituted compounds is improved significantly, and it reaches the value of 1.79 wt.% at 303 K when the composition is La1.5Mg0.5Ni6.80Mn0.20. On the other hand, the La1.5Mg0.5Ni6.85Al0.15 shows a much higher reversible electrochemical capacity than the La1.5Mg0.5Ni7 materials at the 50th cycle. The electrochemical discharge capacity stability increases with the increasing value of Al and Mn up to x = 0.2 and 0.3, respectively. Additionally, a reduction in the discharge capacity was measured for the Al and Mn content above x = 0.25 and 0.5, respectively. From the practical aspect, only La1.5Mg0.5Ni6.80Mn0.20 has a potential in the application as a hydrogen storage material.

Investigation of the microstructure and the thermodynamic and kinetic properties of ball-milled CeMg12-type composite materials as hydrogen storage materials

In order to improve the electrochemical discharge and kinetics of CeMg12-type hydrogen storage materials, ball-milling was used and Ni was added to fabricate alloying materials with a nanocrystalline and amorphous structure. The phase composition and crystalline structure were characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The electrochemical discharge performances were characterized by determining the discharge capacity and electrochemical cycling stability. High-rate dischargeability (HRD), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization were utilized to investigate the changes in electrochemical kinetics. The results indicate that the addition of Ni significantly enhances the glass-forming ability of the alloy samples during ball milling, which significantly improves the electrochemical cycling stability of the alloy samples. The maximum discharge capacity of the ball-milled composites monotonously increases from 41.7mAh/g to 485.5 mAh/g with an increment in the Ni content from 50 wt>% to 200 wt%. An increase in the Ni content results in a considerable reduction in the enthalpy (ΔH) from −106.2 kJ/molto −43.1 kJ/mol and in the entropy (ΔS) from −350.73 kJ/mol/K to −22.49 kJ/mol/K. The addition of Ni reduces the stability of the hydride and improves the electrochemical discharge capacity. With regard to the electrochemical kinetics, the addition of Ni can diminish the activation energy of the alloy samples from74.02 kJ/mol to 33.28 kJ/mol with an increase in the Ni content from 50 wt% to 200 wt%, which speeds up the charge-transfer reaction on the surface. The addition of Ni accelerates the hydrogen diffusion rate(which is related to the limiting current density IL) inside the alloy particles. These effects improve the electrochemical kinetics.

Studies of Zr-based C15 type metal hydride battery anode alloys prepared by rapid solidification

The objective of the present work was to study an interrelation between the conditions of the rapid solidification casting and electrochemical properties of a C15 Laves-type Zr-based metal hydride battery anode alloy. A 7-component overstoichiometric with B/A>2 alloy (Ni + Mn + V + Fe/Zr + Ti + La = 2.078) was Zr- and Ni-rich. Melt spinning was performed using as cast mother ingot at different rotation speeds of 5, 16.5, and 33 Hz with a 20-cm diameter Cu cooling wheel. The phase composition and morphology of the ribbons were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) along with X-ray energy dispersive spectroscopy (EDS). Partial Mn vaporization took place during the melt spinning and became more pronounced with the increase in the quenching rate at higher wheel rotation speeds. The SEM study showed a successful refinement and a more homogeneous distribution of La in the melt-spun alloys. However, the alloys demonstrated a more difficult activation performance as compared to the as-cast sample which was associated with introduction of Zr into the composition of the secondary La-and Ni-rich phase when quenching the melt. Presence of Zr in the secondary phase results in inferior rate of its hydrogenation. The formed during the rapid solidification (La,Zr) (Ni,Mn) secondary phase also contained a significant amount of oxygen additionally worsening the activation performance. The grain size gradually decreased from 3.5 μm in the as-cast alloy to approximately 250 nm for the melt spun sample obtained at the highest cooling rate. The two-phase alloys contained a mixture of two Laves type intermetallics, C15 and C14 ones. The abundance of the secondary C14 phase decreased with increase of the cooling rate as compared to the as-cast sample. The electrochemical performance was significantly affected by the compositional and microstructural changes associated with the variation in the cooling rate. The highest electrochemical discharge capacity of 414 mAh/g was obtained for the 16.5 Hz melt spun rate because of an optimized composition of the Laves phase. Furthermore, the diffusion coefficient of hydrogen in this alloy was the highest in a full state of charge, which indicates that faster hydrogen diffusion and shorter hydrogen diffusion paths were achieved via an application of the rapid solidification process. An optimization of the rapid solidification conditions is required to improve an activation behavior of the studied Laves types metal hydride anode alloys.

Study on the gaseous and electrochemical hydrogen storage properties of as-milled Ce[sbnd]Mg[sbnd]Ni-based alloys

For gaining further insight into the involvement of the gaseous and electrochemical hydrogen storage properties of CeMg12-type alloys, partial substitution and ball milling were both used to synthesize the nanocrystalline and amorphous CeMg11Ni + x wt.% Ni (x = 100, 200) samples. This research aims at elucidating the functional roles of Ni content and milling time on samples' structure and hydrogen storage performance. X-Ray diffraction and high-resolution transmission electron microscope were used to reveal the micro constructions of alloys. To determine the gaseous hydrogen storage property, Sievert's apparatus and a thermal gravity analysis bonded with a H2 probe were adopted. The dehydrogenation activation energy was computed in the Kissinger method. The electrochemical performances of the as-milled samples were measured through a constant current system. Further researches showed that the electrochemical performance of as-milled samples had been dramatically improved by increasing Ni content. With milling duration lengthens, the gaseous hydrogen absorption capacity, gaseous hydriding rate and high rate discharge capability of samples reached the maximal values, but electrochemical discharge capacity and gaseous dehydriding rate always increased. The dehydrogenation activation energy decrease resulted by improving Ni percent and milling duration was deemed as the cause of the excellent gaseous kinetics of samples.

Hydrogenation and crystallization of amorphous phase: A new mechanism for the electrochemical capacity and its decay in milled Mg[sbnd]Ni alloys

MgNi-based alloys have been regarded as very promising anode material for nickel-metal hydride battery owing to their electrochemcial capacity much higher than that of AB5 alloys. However, MgNi alloy anodes generally suffer very serious capacity decay in cycling, which is previously ascribed to the corrosion of Mg in alkali electrolyte in the past decades. To further reveal the capacity fading mechanism of MgNi-based alloys, the electrochemcial hydrogen storage properties of Mg2Ni and amorphous Mg50Ni50 alloys and their microstructural evolution during cycling were comparatively studied. It has been firstly demonstrated that it is the amorphous MgNi phase instead of Mg2Ni phase contributes to electrochemical discharge capacity, because the Mg2NiH4 hardly released hydrogen under electrochemcial conditions. Then, it has been found that the charge input level has significant effect on the cyclic performance of amorphous Mg50Ni50 alloy anode. At full charge of 500 mAh g−1, the amorphous MgNi phase easily crystallized to the nanocrystalline Mg2NiH4, which leaded to the capacity decay immediately. Comparatively, with the low charge input of 100 mAh g−1, the discharge capacity of amorphous Mg50Ni50 alloy remained almost unchanged for 425 cycles. The excellent cyclability is attributed to the less hydrogenation-induced crystallization at low charge input. This work clearly demonstrates that the hydrogenation-induced crystallization is a dominating reason for the electrochemical capacity decay in the milled amorphous MgNi anode. It provides a new approach to improve the electrochemcial properties of MgNi alloy electrode by inhibiting the hydrogenation-induced crystallization.

Magnesium Composite Materials for Nickel–Metal Hydride Batteries

Amorphous MgNi and MgNi0.5Co0.5 composites were prepared by mechanical ball grinding in an argon atmosphere. The electrodes made of these composites are characterized by high electrochemical discharge capacity: 872 mA · h/g for MgNi and 309 mA · h/g for MgNi0.5Co0.5. The cyclic stability (S30) of the MgNi0.5Co0.5 electrode (42%) is somewhat higher compared to MgNi (26%). Reduction in the capacity of electrodes is associated with bulk and corrosion processes. The MgNi0.5Co0.5 electrode increases its capacity to a greater extent than MgNi after deep discharge.

Highly ameliorated gaseous and electrochemical hydrogen storage kinetics of nanocrystalline and amorphous CeMg12-type alloys by mechanical milling

An attempt that effectively advances the quantity of hydrogen storage for CeMg12-type alloys was adopting a method of partial substitution of Mg in alloy by Ni. It is also employing mechanical ball-milling technology to prepare the nanocrystalline and amorphous CeMg11Ni + x wt.% Ni (x = 100, 200) alloys. And these two factors, Ni content after replacement as well as ball grinding time, affecting the structures and hydrogen storage dynamics belonging experimental alloys were studied systematically. Thereinto, characterization analysis on structures was using XRD, SEM and HRTEM. Then, the test of gaseous hydrogen storage performance was carried out through Sievert device as well as differential scanning calorimeter (DSC) that connected with H2 detector. Besides, Arrhenius and Kissinger equations were served as a convenient method for calculating the hydrogen desorption activation energy of alloys. Finally, it can adopt the automatic galvanostatic system to measure the electrochemical hydrogen storage performance. It is shown that, for experimental alloys, the more Ni content shows beneficial on the formation of glass, meanwhile, it also strikingly ameliorates both gaseous and electrochemical hydrogen storage dynamics properties. In addition, milling time varying brings a very large impact upon hydrogen storage properties of alloys. When the ball-grinding time is constantly changing, the gaseous hydrogen absorption capacity, gaseous hydriding rate as well as high-rate discharge ability (HRD) of alloys are able to appear the maximum values respectively. However, following the prolongation of milling time, both electrochemical discharge capacity and gaseous dehydrogenating rate raise all the time. The increase in Ni content and the prolongation of milling time can both enhance the gaseous hydrogen storage dynamics of alloys, inferring that their essence all can be attributed to the reduction of the activation energy of hydrogen desorption.

In Situ Studies of 30% Li-Doped Bi25FeO40 Conversion Type Lithium Battery Electrodes.

One of the important discharge mechanisms for lithium batteries is the conversion reaction mechanism, where a metal oxide (fluoride) can decompose into metallic nanoparticles embedded in a Li2O (LiF) matrix. Here, 30% Li-doped Bi25FeO40 is successfully synthesized and displays an electrochemical discharge capacity of ∼300 mAh/g above 1.5 V (vs Li/Li+). During the electrochemical cycling process, 30% Li-doped Bi25FeO40 is decomposed into metallic Bi. During the subsequent charging process, the metallic bismuth can be first converted into an amorphous bismuth oxide phase, which contributed to the electrochemical discharge activities observed between 2 and 2.5 V. At a higher charging voltage between 3.5 and 5 V, metallic Bi can be oxidized to BiOx2–O3–2x–, which contributes to the discharge activities observed above 2.5 V. Using graphite as current collectors can prevent the corrosion from O– species and the discharge capacity is greatly enhanced at the voltage region between 1.5 and 2.5 V. This work provides a deeper understanding over the role of oxygen ions during the conversion reaction process and is beneficial for the future design of battery systems based on the conversion reaction.

All solid state sodium-sulfur cells using composite sulfur cathode at room temperature conditions

Sulfur based cathodes have recently attracted global attention as suitable cathode materials forlithium-sulfur and sodium-sulfur cells. We report the electrochemical studies on sodium-sulfur cells using composite sulfur cathode and three different sodium ion containing gel electrolytes. The electrolytes are tested in the following cell configuration:SS/electrolyte/SS for investigating the electrochemical impedance behavior. The cell performance studies on sodium-sulfur cells with configuration Na anode/electrolyte/sulfur-cathode have been carried out using charge-discharge unit at room temperature in open atmosphere. The electrochemical studies such as open circuit voltage and electrochemical discharge capacity are reported and discussed

New nanoparticles of (Sm,Zn)-codoped spinel ferrite as negative electrode in Ni/MH batteries with long-term and enhanced electrochemical performance

In this investigation, the longevity performance of the electrochemical hydrogen storage characteristics, the kinetic properties and the structural characterization of the Sm0.6Zn0.4Fe2O4 compound were all studied.The Sm0.6Zn0.4Fe2O4 nanomaterial was prepared using sol-gel process. The structural study of the alloy through X-ray diffraction proved the good crystallization of this compound. The electrochemical performance of the Sm0.6Zn0.4Fe2O4 electrode at C/10 rate and at ambient temperature was studied by various electrochemical techniques, such as chronopotentiometry, chronoamperometry and cyclic voltammetry. This compound showed a good electrochemical behaviour with a high capacity (142 mA h.g-1) as well as a good discharge capacity preservation of 64.7% over 100 cycles.There was adequate agreement between the evolution of the different electrochemical parameters (exchange current density, Nernst potential, DH/a2 ratio and the electrochemical discharge capacity) versus cycle number.

The Influence of Pr and Nd Substitution on Hydrogen Storage Properties of Mechanically Alloyed (La,Mg)2Ni7-Type Alloys

The (La,Mg)2Ni7-type alloys are candidates for hydrogen storage materials. In this study, mechanical alloying with subsequent annealing under the argon atmosphere at 1123 K for 0.5 h is applied to produce La1.5−xPrxMg0.5Ni7 and La1.5−xNdxMg0.5Ni7 alloys (x = 0, 0.25, 0.5, 1). A shaker-type ball mill is used in the study. The objective of the present study is to investigate the influence of the amount of Pr or Nd in the La-Mg-Ni alloy on the electrochemical, hydrogenation and dehydrogenation properties of (La,Mg)2Ni7-type materials. The x-ray diffraction analysis reveals the formation of multi-phase structure materials. The obtained alloys were studied by a conventional Sievert’s type apparatus at 303 K. It has been observed that a chemical modification by Pr and Nd can affect the kinetics of the hydrogen absorption process and the maximum hydrogen storage capacity. Moreover, the stability of the electrochemical discharge capacity during cyclic work of the (La,Mg)2Ni7-type alloys is improved by a substitution with the La by Pr or Nd atoms.

Hydrogen storage properties of amorphous and nanocrystalline (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys

The as-cast and spun (Mg24Ni10Cu2)100-xNdx (x = 0–20) alloys were prepared in this experiment to study their hydrogen storage performances. The alloys were tested on composition, structure, de-/hydriding kinetics and electrochemical property in many ways including XRD, SEM, TEM, Sieverts apparatus and automatic galvanostatic system. It was found that each as-cast alloy is multi-phased, including Mg2Ni-type major phase and some second phases of Mg6Ni, Nd5Mg41 and NdNi, the proportion of which obviously increases with Nd content rising. After being melt spinning, the structure of no-Nd-added alloy is nanocrystalline, while the Nd-added alloy holds an amorphous and nanocrystalline structure, whose amorphization degree rises significantly with Nd content increasing. The hydrogen storage kinetics of alloys can be improved by the addition of Nd significantly. Besides, adding Nd results in the electrochemical discharge capacity of the as-spun alloy augments at first and declines later as well as cycle stability.