Cathode Material For Magnesium Batteries Research Articles

Re-evaluating the Magnesium-ion Storage Capability of Vanadium Dioxide, VO2 (B): Uncovering the Influence of Water Content on the Previously Overestimated High Capacity.

Magnesium batteries have emerged as a promising alternative to lithium-ion batteries due to their theoretical high energy density and abundant magnesium resources. Vanadium dioxide, VO2 (B), has been reported as a high-capacity cathode material for magnesium batteries. However, the electrochemical intercalation mechanism requires further elucidation due to a limited understanding of the structure-property relationship. In this study, we re-evaluated the magnesium storage capability of the material, with a particular focus on the influence of water content in nonaqueous electrolytes. The higher discharge capacity of 250 mAh g-1 is achieved exclusively in the wet electrolyte with 650 ppm water content. A significantly lower capacity of 51 mAh g-1 was observed in the dry electrolyte solution containing 40 ppm water content. Through X-ray structural and elemental analyses, as well as magnesium-ion diffusion pathway analysis using bond-valence-energy-landscape calculations, the restricted capacity was clarified by examining the reaction mechanism. According to this study, the impressive capacity of magnesium-ion battery cathodes may be exaggerated due to the involvement of non-magnesium-ion insertion unless the electrolytes' water content is appropriately regulated.

Copper Doping of CoSe2 Nanoparticles Encapsulated into Carbon Nanotubes with Enhanced Electron Conductance as Cathode for Rechargeable Magnesium Batteries

AbstractRechargeable magnesium batteries (RMBs) have been considered a promising alternative to lithium‐ion batteries (LIBs) due to the high energy density and abundance of magnesium resources. However, the development of high‐performance cathode materials for magnesium batteries has been a significant challenge. Herein, through comprehensive and simple hydrothermal, selenization and impregnation methods, Cu‐doped CoSe2 nanoparticles encapsulated into carbon nanotubes (Cu‐CoSe2@NC) was fabricated. CoSe2 nanoparticles confined in carbon nanotubes (CNTs) growing in three dimensions on the surface of nanofibers have abundant active sites and high doping degree. Cu doping further improves the electron conductance of the Cu‐CoSe2@NC for RMBs. As cathode, Cu‐CoSe2@NC delivers a reversible capacity of 294 mAh g−1 at 20 mA g−1 and 104 mAg g−1 at 500 mA g−1, which exhibits a reasonable specific capacity and rate capability. The characterization of the Cu‐CoSe2@NC by ex‐situ transmission electron microscopy (TEM) after cycles shows that it can be well adapted to the (de)intercalation of magnesium ions. Density Functional Theory (DFT) calculation shows that CoSe2 band gap decreases obviously after Cu doping, favoring the electron and ion transport. This work provides a reference for the design of cathode materials based on transition metal selenide for RMBs.

CoS2 as Cathode Material for Magnesium Batteries with Dual-salt Electrolytes

CoS₂ as Cathode Material for Magnesium Batteries with Dual-salt Electrolytes

Phase Transition Behavior of MgMn2O4 Spinel Oxide Cathode during Magnesium Ion Insertion

The 3d transition metal oxides with a spinel structure are among the most promising cathode materials for magnesium batteries. In this study, we investigated the reaction mechanism of magnesium ion...

Study on MXene-supported Layered TiS2 as Cathode Materials for Magnesium Batteries

Study on MXene-supported Layered TiS2 as Cathode Materials for Magnesium Batteries

Polyaniline-coated VS4@rGO nanocomposite as high-performance cathode material for magnesium batteries based on Mg2+/Li+ dual ion electrolytes

Magnesium batteries based on Mg2+/Li+ dual ion electrolytes (MLIBs) have attracted increasing attention due to fast Li+ or Mg2+/Li+ insertion kinetics, abundant Mg resources, and high volumetric capacity of dendrite-free Mg anodes. Herein, we report polyaniline (PANI)–coated VS4@reduced graphene oxide (rGO) with nanostructures synthesized via hydrothermal synthesis and subsequent PANI polymerization as the cathode material for MLIBs. The PANI layer serves as a conductive medium to enhance electron transfer and Mg2+/Li+ transportation as well as to mitigate the structure changes of VS4 during the cycling process. Indeed, this material demonstrates enhanced electrochemical performance with a high discharge capacity of 200.7 mAh g−1 after 20 cycles and 91.2% retention after 50 cycles. Mechanism analysis reveals that Li+ insertion into VS4 produced an amorphous VS4 host in the first discharge, which inclined to store Mg2+ rather than Li+ in the subsequent cycles. Our study provides new insights into the development of amorphous electrode materials for magnesium batteries.

Salt-controlled dissolution in pigment cathode for high-capacity and long-life magnesium organic batteries

Benefiting from high volumetric energy density and generally dendrite-free growth of Mg metal, rechargeable magnesium batteries (MBs) become a promising next-generation energy storage system. Organic electrode materials, with characteristic of sustainable resource and flexible structure, have been widely studied in alkali metal ion batteries, but are rarely reported in MBs. Herein, we demonstrate that 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) serves as a cathode material for MBs in non-aqueous system, which realizes a fast diffusion kinetics and remarkable Mg-storage performance through a salt-dissolution inhibition approach for the electrolyte. The PTCDA exhibits a reversible capacity of 126 mAh g−1 (at 200 mA g−1), excellent rate performance, and good cycling stability (100 mAh g−1 even after 150 cycles). Furthermore, the evolution mechanism of the PTCDA electrode based on the transformation between carbonyl groups (CO) and enolate groups (C–O) is revealed by ex-situ phase characterization and functional group analysis. Besides, the dissolution inhibition of the PTCDA could also be realized through the incorporation of other soluble salt (KCl or NaCl) into all phenyl complex (APC) electrolyte, resulting in an enhanced cycling capacity. Considering the designable configuration of the organic materials, this work would pave way for their utilization on multi-valent ion batteries and provide efficient strategy to realize high voltage and satisfied cycle life.

An effective performance of F-Doped hexagonal boron nitride nanosheets as cathode material in magnesium battery

Abstract A facile method was developed to prepare fluorinated hexagonal boron nitride nanosheets (F-h-BNNSs) through F-doping into the nanosheets of boron nitride via chemical solution process with fluoroboric acid. Prepared F-h-BNNSs were analyzed by using different analytical instruments such as X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and Xray diffraction. The electrochemical analysis was conducted by using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge. It was observed that the effective performance of F-doped BN nanosheets as cathode material for magnesium batteries, which exhibit a reversible capacity of 50 mAh.g-1 and good capacity retention over the first 80 cycles. The effective performance of F-doped BN nanosheets are attributed to the unique structure and synergetic effects between layered BN.

Green synthesis of Co3O4/graphene nanocomposite as cathode for magnesium batteries

AbstractUltrafine Co3O4nanoparticles homogeneously attached to graphene sheets by sonochemical method have been demonstrated as a promising cathode material for magnesium batteries. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) have been employed to characterize the structural properties of this material. SEM analyses clearly confirmed that the Co3O4nanoparticles have been uniformly coated on the entire surface of graphene sheets to form a compact composite. The Co3O4-graphene nanocomposite was employed as a cathode electrode in magnesium-ion batteries, and their electrochemical properties were briefly investigated. The graphene sheets can also effectively buffer the volume change in Co3O4upon magnesium insertion/extraction, thus improving the cycling preformance of the composite electrode. It was revealed that the Co3O4-graphene composite can provide a small capacity of 16 mAh·g-1using a new nonaqueous electrolyte that is tetrahydrofuran-free, which provides a new direction to explore cathode materials for Mg batteries.

MgFeSiO4 as a potential cathode material for magnesium batteries: ion diffusion rates and voltage trends

Developing rechargeable magnesium batteries has become an area of growing interest as an alternative to lithium-ion batteries largely due to their potential to offer increased energy density from the divalent charge of the Mg ion.

Graphite fluoride as a cathode material for primary magnesium batteries with high energy density

Graphite fluorides have become promising electrode materials for lithium batteries while their applications in magnesium batteries are rarely reported. Here we demonstrate for the first time CF0.8 as a cathode material for magnesium batteries with a high discharge capacity of more than 800mAhg−1. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and the charge/discharge measurements are used to characterize its structure and electrochemical performance. SEM indicates that CF0.8 sample is a layered structure with the thickness of approximately 300∼400nm. The CF0.8 cathode exhibits a high discharge capacity of 813.4mAhg−1 after discharging to 0.5V at 20mAg−1 in 0.4M (PhMgCl)2-AlCl3/THF electrolyte (named as APC/THF). Discharge product MgF2 is confirmed by EDX and XPS measurements. Addition of LiCl to APC/THF solution can not only enhance the gravimetric energy densities but also greatly improve the rate performance. The possible function mechanism is proposed and discussed.

Co-intercalation of Mg(2+) and Na(+) in Na(0.69)Fe2(CN)6 as a High-Voltage Cathode for Magnesium Batteries.

Thanks to the advantages of low cost and good safety, magnesium metal batteries get the limelight as substituent for lithium ion batteries. However, the energy density of state-of-the-art magnesium batteries is not high enough because of their low operating potential; thus, it is necessary to improve the energy density by developing new high-voltage cathode materials. In this study, nanosized Berlin green Fe2(CN)6 and Prussian blue Na(0.69)Fe2(CN)6 are compared as high-voltage cathode materials for magnesium batteries. Interestingly, while Mg(2+) ions cannot be intercalated in Fe2(CN)6, Na(0.69)Fe2(CN)6 shows reversible intercalation and deintercalation of Mg(2+) ions, although they have the same crystal structure except for the presence of Na(+) ions. This phenomenon is attributed to the fact that Mg(2+) ions are more stable in Na(+)-containing Na(0.69)Fe2(CN)6 than in Na(+)-free Fe2(CN)6, indicating Na(+) ions in Na(0.69)Fe2(CN)6 plays a crucial role in stabilizing Mg(2+) ions. Na(0.69)Fe2(CN)6 delivers reversible capacity of approximately 70 mA h g(-1) at 3.0 V vs Mg/Mg(2+) and shows stable cycle performance over 35 cycles. Therefore, Prussian blue analogues are promising structures for high-voltage cathode materials in Mg batteries. Furthermore, this co-intercalation effect suggests new avenues for the development of cathode materials in hybrid magnesium batteries that use both Mg(2+) and Na(+) ions as charge carriers.

Synthesis of MgMnSiO4 and Its Application as Cathode Material for Magnesium Battery

Orthosilicate MgMnSiO4 was prepared by sol-gel route and a subsequent heating procedure as a cathode material for rechargeable magnesium batteries. XRD patterns showed that MgMnSiO4 has a orthorhombic system with space group Pbnm(62). MgMnSiO4 presents good electrochemical behaviors at 10 mAg-1 discharge current density with specific capacity 130.1 mAhg-1 after 20 cycles. The results show that MgMnSiO4 could be a potential cathode material for high-energy magnesium secondary battery.

MgFePO4F as a feasible cathode material for magnesium batteries

Novel MgFePO4F exhibits a promising feasibility as a cathode material for Mg batteries in spite of its cationic-disordered crystal structure.

A new class of cathode materials for rechargeable magnesium batteries: Organosulfur compounds based on sulfur–sulfur bonds

A class of energy storage materials, organosulfur compounds with S–S bonds, has been proposed as novel cathode materials for rechargeable magnesium batteries. The cleavage and recombination of S–S bonds formed during discharge and charge process are the key components for the capacity. The cathode performance of three organosulfur materials, i.e. 2,5-dimercapto-1,3,4-thiadiazole (DMcT), poly-2,2′dithiodianiline (PDTDA) and a conductive sulfur-containing material (CMS) were characterized here. Among them, DMcT compounded with polyaniline (PAn) can provide a relatively flat discharge potential at about 1.4 V vs. Mg/Mg 2+. PDTDA exhibits better kinetics and electrical conductivity based on the intramolecular electrocatalytic effect of the aniline moiety on thiolate anions. CMS compounded with PAn produces stable backbones to provide electrically conducting channels and higher disulfide bond content; it exhibits nearly 120 mAh/g initial discharge capacity and good capacity retention. We expect that further improvements to the capacity and cyclability will make organosulfur compounds potential cathode materials for magnesium batteries.