Magnesium Storage Research Articles

Water-Pillared Sodium Vanadium Bronze Nanowires for Enhanced Rechargeable Magnesium Ion Storage.

Owing to the advantages of high safety, low cost, high theoretical volumetric capacities, and environmental friendliness, magnesium-ion batteries (MIBs) have more feasibility for large-scale energy storage compared to lithium-ion batteries. However, lack of suitable cathode materials due to sluggish kinetics of magnesium ion is one of the biggest challenges. Herein, water-pillared sodium vanadium bronze nanowires (Na2 V6 O16 ·1.63H2 O) are reported as cathode material for MIBs, which display high performance in magnesium storage. The hydrated sodium ions provide excellent structural stability. The charge shielding effect of lattice water enables fast Mg2+ diffusion. It exhibits high specific capacity of 175 mAh g-1 , long cycle life (450 cycles), and high coulombic efficiency (≈100%). At high current density of 200 mA g-1 , the capacity retention is up to 71% even after 450 cycles (compared to the highest capacity), demonstrating excellent long-term cycling performance. The nature of charge storage kinetics is explored. Furthermore, a highly reversible structure change during the electrochemical process is proved by comprehensive electrochemical analysis. The remarkable electrochemical performance makes Na2 V6 O16 ·1.63H2 O a promising cathode material for low-cost and safe MIBs.

Effect of Magnesium Supply and Storage Time on Anti-Nutritive Compounds in Potato Tubers

The nutritional quality of potato tubers is cultivar-specific and depends on climate-soil conditions and agrotechnical practices, as well as the conditions during long-term storage. Studies were performed from 2009–2011 to determine the effects of magnesium fertilisation and storage duration on the contents of the anti-nutritive compound nitrates, nitrites and total glycoalkaloids (TGA) in potato tubers of mid-early cultivar “Bila” (Solanum tuberosum L.). Magnesium (Mg) was applied in doses of 0, 20, 40, 60, 80 and 100 kg MgO ha−1, respectively, in the form of kieserite–magnesium sulphate (26% MgO). Potato quality after harvest and after three and six months of storage was determined. The content of nitrates in tubers after harvest ranged from 303 to 356 mg kg−1 FW and nitrites from 1.59 to 1.67 mg kg−1 FW. Increasing magnesium fertilisation reduced the nitrate and nitrite content of tubers but increased TGA content. Possible explanations for the TGA increase after Mg supply are discussed. Tubers that contained less TGA after harvest also had less glycoalkaloids after storage. However, physical damage during harvest or transportation, exposure to light and bad storage conditions increase the concentrations of glycoalkaloids in tubers. The consumption of cultivar “Bila” would not exceed the acceptable daily intake of harmful substances.

Graphene Supported Boron Nitride Nanosheets as Advanced Electroanalytical Performance for Rechargeable Magnesium Storage System

Graphene Supported Boron Nitride Nanosheets as Advanced Electroanalytical Performance for Rechargeable Magnesium Storage System

Hierarchical Copper Sulfide Porous Nanocages for Rechargeable Multivalent-Ion Batteries.

Copper sulfide (CuS) has been identified as a promising positive electrode material for some multivalent-ion batteries (such as the magnesium-ion battery) because of its high theoretical capacity, environmental friendliness, and wide availability. However, the clumsy multivalent-ion with high polarity inclines toward sluggish ion insertion/de-insertion, leading to inadequate electrochemical performance. In this work, the hierarchical CuS porous nanocages are successfully fabricated via a facile one-step room-temperature liquid-phase process and evaluated as positive electrode materials for rechargeable magnesium batteries. Owing to the structural advantages, a high reversible magnesium storage capacity of 228 mA h g-1 is attained, which is superior to the previously reported results under similar conditions. Besides, the application of CuS as positive electrode materials for calcium-ion, zinc-ion, iron-ion, and aluminum-ion batteries is investigated. The hierarchical CuS porous nanocages display promising electrochemical performance in those multivalent-ion battery systems. Our work proves the superiority of the nanostructure design in improving the electrochemical performance of positive electrode materials for multivalent-ion batteries.

Atomic-scale investigation of enhanced lithium, sodium and magnesium storage performance from defects in MoS2/graphene heterostructures.

MoS2 is of great interest as an anode material of batteries due to its high theoretical reversible capacity; in particular, a defective MoS2/graphene heterostructure exhibits excellent cycling stability. However, very little is known about the diffusion and ion storage mechanism at the atomistic level. To provide insights into the issue, we have developed and used first principles calculations and an atom intercalation/deintercalation algorithm to model the adsorption, diffusion, insertion and removal of Li, Na and Mg in pristine and defective MoS2/graphene systems. First, the adsorption of Li, Na and Mg is generally more stable in the defective MoS2/graphene structure. Mg and Li prefer to diffuse in the structure with disulfide defects, while Na prefers to diffuse in the molybdenum defective structure. Next, we found that the atomic configurations of both pristine and defective MoS2/graphene are not restored to their original states after the insertion and removal of Li, Na and Mg, which is related to the irreversible capacity loss of the system. Furthermore, by excluding the amount of lithium atoms related to the unrestored sulfur atoms, an algorithm was proposed to calculate the reversible capacity and it was verified by experimental results. We have also demonstrated that the introduction of defects leads to significant increase in the theoretical capacities of the Na and Mg systems, however, decreasing the capacity retention rate of Mg.

Silver chalcogenides (Ag2X, X=S, Se) nanoparticles embedded in carbon matrix for facile magnesium storage via conversion chemistry

Despite intensive studies for the last several decades, the progress in the development of efficient cathode materials for rechargeable magnesium batteries is slow. In particular, most intercalation-based materials demonstrate lethargic reaction kinetics owing to a large activation barrier for Mg2+ migration. Here, for the first time, we evaluate silver chalcogenides as efficient cathode materials based on a conversion reaction mechanism. Simple one-pot ball milling is employed to produce silver chalcogenide nanoparticles embedded in a carbon matrix, which exhibits excellent electrochemical activity with Mg2+ at room temperature. Particularly, the Ag2Se composite delivers a theoretical magnesium storage capacity of 182 ​mA ​h g−1 at a 0.1-C rate and 79 ​mA ​h g−1 at a 1-C with an adequate stability up to 500 cycles. Structural analyses during cycling confirm that silver chalcogenides operate via a conversion reaction route. This investigation provides an opportunity to develop a new class of viable cathode materials utilizing conversion chemistry.

Atomic-scale observation of phase transition of MgMn2O4 cubic spinel upon the charging in Mg-ion battery

Direct observation of demagnesiated structure of MgMn2O4 spinel oxides at atomic scale has been achieved using spherical aberration-corrected scanning transmission electron microscopy (STEM) with high-angle annular-dark-field (HAADF) and annular-bright-field (ABF) techniques. Upon the Mg ions extraction from MgMn2O4 spinel oxides, structural transition from cubic to tetragonal phases was observed. The phase transition is a result of Mn octahedral distortion due to cooperative Jahn–Teller distortion of six-coordinate MnIII (t2g3–eg1). On the basis of HAADF/ABF micrographs and electron energy-loss spectrometer (EELS), it is suggested that Mn3+/Mn4+ and/or Mn3+/Mn5+ redox couples play a crucial role in the first electrochemical Mg deintercalation. This is the first report on observation of cubic-tetragonal phase transition in charged spinel MgMn2O4 which shed new insight into the magnesium storage mechanism in this important cathode material for Mg-ion batteries.

Constructing a disorder/order structure for enhanced magnesium storage

Rechargeable magnesium-ion batteries (MIBs) are a potential alternative to lithium-ion batteries (LIBs). However, the strong interaction between the divalent Mg2+ and the host lattice leads to the destruction of electrode materials structure. In this work, we have presented electrochemically induced formation of disorder/order structure to improve the structural stability of electrode material during magnesium storage. FeVO4 cathode displays a high Mg storage capacity (~300 mAh g−1) and excellent cycling stability (capacity retention of 85% after 1000 cycles at 1 A g−1). Additionally, the Mg storage mechanism of FeVO4 cathode is demonstrated as the irreversible transformation at first discharge process and the reversible intercalation-type reaction at subsequent cycling. This work demonstrates that disorder/order engineering is a new way to achieve excellent magnesium storage performance.

How Do Actinyls Interact with Hyperphosphorylated Yolk Protein Phosvitin?

The development of the nuclear industry has raised multiple questions about its impact on the biotope and humans. Proteins are key biomolecules in cell machinery and essential in deciphering toxicological processes. Phosvitin was chosen as a relevant model for phosphorylated proteins because of its important role as an iron, calcium, and magnesium storage protein in egg yolk. A multitechnique spectroscopic investigation was performed to reveal the coordination geometry of two oxocations of the actinide family (actinyl UVI , NpV ) in speciation with phosvitin. IR spectroscopy revealed phosphoryl groups as the main functional groups interacting with UVI . This was confirmed through laser luminescence spectroscopy (U) and UV/Vis absorption spectroscopy (Np). For UVI , X-ray absorption spectroscopy at the LIII edge revealed a small contribution of bidentate binding present, along with predominantly monodentate binding of phosphoryl groups; for NpV , uniquely bidentate binding was revealed. As a perspective to this work, X-ray absorption spectroscopy speciation of UVI and NpV in the extracted yolk of living eggs of the dogfish Scyliorhinus canicula was determined; this corroborated the binding of phosphorous together with a reduction of the actinyl moiety. Such data are essential to pinpoint the mechanisms of heavy metals (actinyls) accumulation and toxicity in oviparous organisms, and therefore, contribute to a shift from descriptive approaches to predictive toxicology.

One‐Step Synthesis of 2‐Ethylhexylamine Pillared Vanadium Disulfide Nanoflowers with Ultralarge Interlayer Spacing for High‐Performance Magnesium Storage

AbstractRechargeable magnesium batteries (RMBs) are attractive candidates for large‐scale energy storage owing to the high theoretical specific capacity, rich earth abundance, and good safety characteristics. However, the development of desirable cathode materials for RMBs is constrained by the high polarity and slow intercalation kinetics of Mg2+ ions. Herein, it is demonstrated that 2‐ethylhexylamine pillared vanadium disulfide nanoflowers (expanded VS2) with enlarged interlayer distances exhibit greatly boosted electrochemical performance as a cathode material in RMBs. Through a one‐step solution‐phase synthesis and in situ 2‐ethylhexylamine intercalation process, VS2 nanoflowers with ultralarge interlayer spacing are prepared. A series of ex situ characterizations verify that the cathode of expanded VS2 nanoflowers undergoes a reversible intercalation reaction mechanism, followed by a conversion reaction mechanism. Electrochemical kinetics analysis reveal a relatively fast Mg‐ion diffusivity of expanded VS2 nanoflowers in the order of 10−11–10−12 cm2 s−1, and the pseudocapacitive contribution is up to 64% for the total capacity at 1 mV s−1. The expanded VS2 nanoflowers show highly reversible discharge capacity (245 mAh g−1 at 100 mA g−1), good rate capability (103 mAh g−1 at 2000 mA g−1), and stable cycling performance (90 mAh g−1 after 600 cycles at 1000 mA g−1).

Self-supporting, eutectic-like, nanoporous biphase bismuth-tin film for high-performance magnesium storage

Magnesium ion batteries are emerging as promising alternatives to lithium ion batteries because of their advantages including high energy density, dendrite-free features and low cost. Nevertheless, one of the major challenges for magnesium ion batteries is the kinetically sluggish magnesium insertion/extraction and diffusion in electrode materials. Aiming at this issue, biphase eutectic-like bismuth-tin film is designed herein to construct a self-supporting anode with interdigitated phase distribution and hierarchically porous structure, and further fabricated by a facile one-step magnetron cosputtering route. As benchmarked with single-phase bismuth or tin film, the biphase bismuth-tin film delivers high specific capacity (538 mAh/g at 50 mA/g), excellent rate performance (417 mAh/g at 1,000 mA/g) and good cycling stability (233 mAh/g at the 200th cycle). The superior magnesium storage performance of the sputtered bismuth-tin film could be attributed to the synergetic effect of the interdigitated bismuth/tin phase distribution, hierarchically porous structure and biphase buffering matrices, which could increase ionic transport channels, shorten diffusion lengths and reduce total volume changes.

2D Layered Dichalcogenides As Active Cathode Materials for Magnesium-Ion Batteries

Rechargeable battery chemistries that can circumvent some of the issues associated with modern lithium-ion technologies are in great demand for specialized application, where safety is more important than raw power density. Magnesium has been the focus of many alternative approaches, due to its high volumetric density, high abundance and its homogeneous electrochemical plating characteristics. In the past, a lack of suitable electrolytes with high oxidative stability and good conductivity as well as a paucity of viable cathode materials limited research to only a few standard materials, such as the Chevrel-phase Mo6S8. While providing a good benchmark system for comparison of different battery chemistries, such materials will not lead to a commercial success of the magnesium-ion technology. On the basis of our recently developed halide free electrolytes, we are able to investigate a wide range of new cathode materials for high voltage Magnesium-ion batteries. In this presentation we are focusing on 2D-layered metal-dichalcogenides and their capability to reversibly store magnesium. We investigate their electrochemical performance using a coin-cell platform. Ex-situ XRD, SEM and XPS experiments are performed to monitor changes in crystal structure or surface morphology and identify side reactions as well as the mechanism of magnesium storage.

On the Mechanism of Magnesium Storage in Micro- and Nano-Particulate Tin Battery Electrodes.

This study reports on the electrochemical alloying-dealloying properties of Mg2Sn intermetallic compounds. 119Sn Mössbauer spectra of β-Sn powder, thermally alloyed cubic-Mg2Sn, and an intermediate MgSn nominal composition are used as references. The discharge of a Mg/micro-Sn half-cell led to significant changes in the spectra line shape, which is explained by a multiphase mechanism involving the coexistence of c-Mg2Sn, distorted Mg2−δSn, and Mg-doped β-Sn. Capacities and capacity retention were improved by using nanoparticulate tin electrodes. This material reduces significantly the diffusion lengths for magnesium and contains surface SnO and SnO2, which are partially electroactive. The half-cell potentials were suitable to be combined versus the MgMn2O4 cathodes. Energy density and cycling properties of the resulting full Mg-ion cells are also scrutinized.

Opening Magnesium Storage Capability of Two-Dimensional MXene by Intercalation of Cationic Surfactant.

Two-dimensional (2D) Ti3C2 MXene has attracted great attention in electrochemical energy storage devices (supercapacitors and lithium-ion and sodium-ion batteries) due to its excellent electrical conductivity as well as high volumetric capacity. Nevertheless, a previous study showed that multivalent Mg2+ ions cannot reversibly insert into MXene, resulting in a negligible capacity. Here, we demonstrate a simple strategy to achieve high magnesium storage capability for Ti3C2 MXene by preintercalating a cationic surfactant, cetyltrimethylammonium bromide (CTAB). Density functional theory simulations verify that intercalated CTA+ cations reduce the diffusion barrier of Mg2+ on the MXene surface, resulting in the significant improvement of the reversible insertion/deinsertion of Mg2+ ions between MXene layers. Consequently, the MXene electrode exhibits a desirable volumetric specific capacity of 300 mAh cm-3 at 50 mA g-1 as well as outstanding rate performance. This work endows MXene material with an application in electrochemical energy storage and, simultaneously, introduces magnesium battery materials as a member.

Magnesium storage performance and mechanism of CuS cathode

The exploration of cathode materials with high energy density has been considered as one key for the development of magnesium batteries. The high magnesium storage capacity of CuS has been demonstrated at high temperature (over 100 °C), but its electrochemical performance at lower temperature still needed to be improved largely. Herein, we realize the high magnesium storage activity (over 300 mAh g−1) of CuS cathode at room temperature via adjusting electrode-electrolyte interface. In the full magnesium battery, CuS cathode achieves a high capacity of 119 mAh g−1 after 30 cycles at 50 mA g−1. Besides, the conversion-type storage mechanism has been certified via ex-situ XRD and so on. This work demonstrated CuS is a promising cathode material for magnesium battery.

A novel bismuth-based anode material with a stable alloying process by the space confinement of an in situ conversion reaction for a rechargeable magnesium ion battery.

A novel Bi-based anode material with a stable alloy reaction is prepared by a solvothermal method. The Mg storage mechanism is elucidated for the first time. Owing to the space confinement of in situ conversion, the anode material shows superior magnesium storage performance, especially the cycling stability (capacity retention >96% after 100 cycles).

H2V3O8 Nanowires as High-Capacity Cathode Materials for Magnesium-Based Battery.

Magnesium-based batteries have received much attention as promising candidates to next-generation batteries because of high volumetric capacity, low price, and dendrite-free property of Mg metal. Herein, we reported H2V3O8 nanowire cathode with excellent electrochemical property in magnesium-based batteries. First, it shows a satisfactory magnesium storage ability with 304.2 mA h g-1 capacity at 50 mA g-1. Second, it possesses a high-voltage platform of ∼2.0 V vs Mg/Mg2+. Furthermore, when evaluated as a cathode material for magnesium-based hybrid Mg2+/Li+ battery, it exhibits a high specific capacity of 305.4 mA h g-1 at 25 mA g-1 and can be performed in a wide working temperature range (-20 to 55 °C). Notably, the insertion-type ion storage mechanism of H2V3O8 nanowires in hybrid Mg2+/Li+ batteries are investigated by ex situ X-ray diffraction and Fourier transform infrared. This research demonstrates that the H2V3O8 nanowire cathode is a potential candidate for high-performance magnesium-based batteries.

A first-principles comparative study of lithium, sodium, and magnesium storage in pure and gallium-doped germanium: Competition between interstitial and substitutional sites.

Thermodynamics and kinetics of Li, Na, and Mg storage in Ge are studied ab initio. The most stable configurations can consist of tetrahedral, substitutional, or a combination of the two types of sites. In the dilute limit, Li and Na prefer interstitial, while Mg prefers substitutional sites. At higher concentrations of Li, Na, and Mg, there is a combination of interstitial and substitutional sites. This is an important finding, as most previous ab initio studies of alloying type electrode materials ignored substitutional sites. Insertion energies computed at dilute concentration (x = 1/64) show that Na and Mg insertion are not thermodynamically favored in Ge vs. the formation of bulk Na and Mg, as opposed to Li insertion which is favored. We investigate the effect of p-doping of Ge (with Ga) on the thermodynamics and find that it considerably lowers the defect formation energies associated with the insertion of Li/Na/Mg at tetrahedral sites. On the other hand, the energetics associated with Li/Na/Mg insertion at substitutional sites are not significantly affected. In addition, we compute the migration energy barriers for Li/Na/Mg diffusion between two tetrahedral sites (0.38/0.79/0.66 eV), between two substitutional sites (0.77/0.93/1.83 eV), and between two sites of different types (2.15/1.75/0.85 eV).

Synthesis of Sn Nanoparticles/Graphene Nanosheet Hybrid Electrode Material with Three-Dimensional Conducting Network for Magnesium Storage

Synthesis of Sn Nanoparticles/Graphene Nanosheet Hybrid Electrode Material with Three-Dimensional Conducting Network for Magnesium Storage

Magnesium Storage Performance and Surface Film Formation Behavior of Tin Anode Material

AbstractElectrochemical cycling performance of microsize bulk and thin film Sn electrodes up to 50 cycles in Mg half‐cell configuration, as well as Mg diffusivity and interfacial reaction behavior in a phenylmagnesium chloride (PhMgCl)/THF electrolyte are studied. The bulk Sn electrode delivers capacities of 321–289 mAh g−1 with capacity retention of 90 % and coulombic efficiencies higher than 99 % over 30 cycles, and thus demonstrates the potential of Sn anodes. The Sn film electrode shows good cycling ability. Surface analysis by XPS reveals that the surface of cycled electrodes is composed of a mixture of various inorganic salts of Sn and Mg formed by interfacial reactions between Sn and PhMgCl, and organic functionality produced by decomposition of THF, indicating surface film formation. The Mg2+ diffusivity of Sn is on the order of 10−11 cm2 s−1, which is four orders of magnitude lower than the Li+ diffusivity of Sn in Li‐ion batteries. Advanced material design for enhanced electronic conductivity and control of the interfacial chemistry for formation of a surface protective film are believed to be the keys to overcome such sluggish kinetics, increase the capacity, and improve the cycling performance.