Magnesium Ethylenediamine Borohydride as Solid-State Electrolyte for Magnesium Batteries.
Ontology highlight
ABSTRACT:
SUBMITTER: Roedern E
PROVIDER: S-EPMC5384009 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Rechargeable solid-state magnesium batteries are considered for high energy density storage and usage in mobile applications as well as to store energy from intermittent energy sources, triggering intense research for suitable electrode and electrolyte materials. Recently, magnesium borohydride, Mg(BH4)2, was found to be an effective precursor for solid-state Mg-ion conductors. During the mechanochemical synthesis of these Mg-ion conductors, amorphous Mg(BH4)2 is typically formed and it was postulated that this amorphous phase promotes the conductivity. Here, electrochemical impedance spectroscopy of as-received ?-Mg(BH4)2 and ball milled, amorphous Mg(BH4)2 confirmed that the conductivity of the latter is ~2 orders of magnitude higher than in as-received ?-Mg(BH4)2 at 353?K. Pair distribution function (PDF) analysis of the local structure shows striking similarities up to a length scale of 5.1?Å, suggesting similar conduction pathways in both the crystalline and amorphous sample. Up to 12.27?Å the PDF indicates that a 3D net of interpenetrating channels might still be present in the amorphous phase although less ordered compared to the as-received ?-phase. However, quasi elastic neutron scattering experiments (QENS) were used to study the rotational mobility of the [BH4] units, revealing a much larger fraction of activated [BH4] rotations in amorphous Mg(BH4)2. These findings suggest that the conduction process in amorphous Mg(BH4)2 is supported by stronger rotational mobility, which is proposed to be the so-called "paddle-wheel" mechanism.
| S-EPMC7270138 | biostudies-literature
Project description:Using a new class of (BH4)- substituted argyrodite Li6PS5Z0.83(BH4)0.17, (Z = Cl, I) solid electrolyte, Li-metal solid-state batteries operating at room temperature have been developed. The cells were made by combining the modified argyrodite with an In-Li anode and two types of cathode: an oxide, LixMO2 (M = ? Ni, ? Mn, ? Co; so called NMC) and a titanium disulfide, TiS2. The performance of the cells was evaluated through galvanostatic cycling and Alternating Current AC electrochemical impedance measurements. Reversible capacities were observed for both cathodes for at least tens of cycles. However, the high-voltage oxide cathode cell shows lower reversible capacity and larger fading upon cycling than the sulfide one. The AC impedance measurements revealed an increasing interfacial resistance at the cathode side for the oxide cathode inducing the capacity fading. This resistance was attributed to the intrinsic poor conductivity of NMC and interfacial reactions between the oxide material and the argyrodite electrolyte. On the contrary, the low interfacial resistance of the TiS2 cell during cycling evidences a better chemical compatibility between this active material and substituted argyrodites, allowing full cycling of the cathode material, 240 mAhg-1, for at least 35 cycles with a coulombic efficiency above 97%.
| S-EPMC7558157 | biostudies-literature
Project description:Rational structure design is a successful approach to develop high-performance composite solid electrolytes (CSEs) for solid-state Li metal batteries. Herein, a novel CSE membrane is proposed, that consists of interwoven garnet/polyethylene oxide-Li bis(trifluoromethylsulphonyl)imide (LLZO/PEO-LiTFSI) microfibers. This CSE exhibits high Li-ion conductivity and exceptional Li dendrite suppression capability, which can be attributed to the uniform LLZO dispersion in PEO-LiTFSI and the vertical/horizontal anisotropic Li-ion conduction in the CSE. The uniform LLZO particles can generate large interaction regions between LLZO and PEO-LiTFSI, which thus form continuous Li-ion transfer pathways, retard the interfacial side reactions and strengthen the deformation resistance. More importantly, the anisotropic Li-ion conduction, that is, Li-ion transfers much faster along the microfibers than across the microfibers, can effectively homogenize the electric field distribution in the CSE during cycling, which thus prevents the excessive concentration of Li-ion flux. Finally, solid-state Li||LiFePO4 cells based on this CSE show excellent electrochemical performances. This work enriches the structure design strategy of high-performance CSEs and may be helpful for further pushing the solid-state Li metal batteries towards practical applications.
| S-EPMC8373100 | biostudies-literature
Project description:Solid-state reaction was used for Li7La3Zr2O12 material synthesis from Li2CO3, La2O3 and ZrO2 powders. Phase investigation of Li7La3Zr2O12 was carried out by x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) methods. The thermodynamic characteristics were investigated by calorimetry measurements. The molar heat capacity (Cp,m), the standard enthalpy of formation from binary compounds (ΔoxHLLZO) and from elements (ΔfHLLZO), entropy (S0298), the Gibbs free energy of the Li7La3Zr2O12 formation (∆f G0298) and the Gibbs free energy of the LLZO reaction with metallic Li (∆rGLLZO/Li) were determined. The corresponding values are Cp,m = 518.135 + 0.599 × T - 8.339 × T-2, (temperature range is 298-800 K), ΔoxHLLZO = -186.4 kJ·mol-1, ΔfHLLZO = -9327.65 ± 7.9 kJ·mol-1, S0298 = 362.3 J·mol-1·K-1, ∆f G0298 = -9435.6 kJ·mol-1, and ∆rGLLZO/Li = 8.2 kJ·mol-1, respectively. Thermodynamic performance shows the possibility of Li7La3Zr2O12 usage in lithium-ion batteries.
| S-EPMC8746261 | biostudies-literature
Project description:Solid-state batteries are a promising option toward high energy and power densities due to the use of lithium (Li) metal as an anode. Among all solid electrolyte materials ranging from sulfides to oxides and oxynitrides, cubic garnet-type Li7La3Zr2O12 (LLZO) ceramic electrolytes are superior candidates because of their high ionic conductivity (10-3 to 10-4 S/cm) and good stability against Li metal. However, garnet solid electrolytes generally have poor contact with Li metal, which causes high resistance and uneven current distribution at the interface. To address this challenge, we demonstrate a strategy to engineer the garnet solid electrolyte and the Li metal interface by forming an intermediary Li-metal alloy, which changes the wettability of the garnet surface (lithiophobic to lithiophilic) and reduces the interface resistance by more than an order of magnitude: 950 ohm·cm2 for the pristine garnet/Li and 75 ohm·cm2 for the surface-engineered garnet/Li. Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN) was selected as the solid-state electrolyte (SSE) in this work because of its low sintering temperature, stabilized cubic garnet phase, and high ionic conductivity. This low area-specific resistance enables a solid-state garnet SSE/Li metal configuration and promotes the development of a hybrid electrolyte system. The hybrid system uses the improved solid-state garnet SSE Li metal anode and a thin liquid electrolyte cathode interfacial layer. This work provides new ways to address the garnet SSE wetting issue against Li and get more stable cell performances based on the hybrid electrolyte system for Li-ion, Li-sulfur, and Li-oxygen batteries toward the next generation of Li metal batteries.
| S-EPMC5384807 | biostudies-literature
Project description:Sulfide solid electrolytes (SEs) with high Li-ion conductivities (σion) and soft mechanical properties have limited applications in wet casting processes for commercial all-solid-state batteries (ASSBs) because of their inherent atmospheric and chemical instabilities. In this study, we fabricated sulfide SEs with a novel core-shell structure via environmental mechanical alloying, while providing sufficient control of the partial pressure of oxygen. This powder possesses notable atmospheric stability and chemical resistance because it is covered with a stable oxysulfide nanolayer that prevents deterioration of the bulk region. The core-shell SEs showed a σion of more than 2.50 mS cm-1 after air exposure (for 30 min) and reaction with slurry chemicals (mixing and drying for 31 min), which was approximately 82.8% of the initial σion. The ASSB cell fabricated through wet casting provided an initial discharge capacity of 125.6 mAh g-1. The core-shell SEs thus exhibited improved powder stability and reliability in the presence of chemicals used in various wet casting processes for commercial ASSBs.
| S-EPMC7558032 | biostudies-literature
Project description:Rechargeable solid-state sodium-ion batteries (SSSBs) hold great promise for safer and more energy-dense energy storage. However, the poor electrochemical stability between current sulfide-based solid electrolytes and high-voltage oxide cathodes has limited their long-term cycling performance and practicality. Here, we report the discovery of the ion conductor Na3-xY1-xZrxCl6 (NYZC) that is both electrochemically stable (up to 3.8 V vs. Na/Na+) and chemically compatible with oxide cathodes. Its high ionic conductivity of 6.6 × 10-5 S cm-1 at ambient temperature, several orders of magnitude higher than oxide coatings, is attributed to abundant Na vacancies and cooperative MCl6 rotation, resulting in an extremely low interfacial impedance. A SSSB comprising a NaCrO2 + NYZC composite cathode, Na3PS4 electrolyte, and Na-Sn anode exhibits an exceptional first-cycle Coulombic efficiency of 97.1% at room temperature and can cycle over 1000 cycles with 89.3% capacity retention at 40 °C. These findings highlight the immense potential of halides for SSSB applications.
| S-EPMC7902639 | biostudies-literature
Project description:Solid electrolytes with high Li-ion conductivity and electrochemical stability are very important for developing high-performance all-solid-state batteries. In this work, Li2(BH4)(NH2) is nanoconfined in the mesoporous silica molecule sieve (SBA-15) using a melting-infiltration approach. This electrolyte exhibits excellent Li-ion conduction properties, achieving a Li-ion conductivity of 5.0 × 10-3 S cm-1 at 55 °C, an electrochemical stability window of 0 to 3.2 V and a Li-ion transference number of 0.97. In addition, this electrolyte can enable the stable cycling of Li|Li2(BH4)(NH2)@SBA-15|TiS2 cells, which exhibit a reversible specific capacity of 150 mAh g-1 with a Coulombic efficiency of 96% after 55 cycles.
| S-EPMC8068180 | biostudies-literature
Project description:Replacement of Li-ion liquid-state electrolytes by solid-state counterparts in a Li-ion battery (LIB) is a major research objective as well as an urgent priority for the industry, as it enables the use of a Li metal anode and provides new opportunities to realize safe, non-flammable, and temperature-resilient batteries. Among the plethora of solid-state electrolytes (SSEs) investigated, garnet-type Li-ion electrolytes based on cubic Li7La3Zr2O12 (LLZO) are considered the most appealing candidates for the development of future solid-state batteries because of their low electronic conductivity of ca. 10-8 S cm-1 (RT) and a wide electrochemical operation window of 0-6 V vs. Li+/Li. However, high LLZO density (5.1 g cm-3) and its lower level of Li-ion conductivity (up to 1 mS cm-1 at RT) compared to liquid electrolytes (1.28 g cm-3; ca. 10 mS cm-1 at RT) still raise the question as to the feasibility of using solely LLZO as an electrolyte for achieving competitive energy and power densities. In this work, we analyzed the energy densities of Li-garnet all-solid-state batteries based solely on LLZO SSE by modeling their Ragone plots using LiCoO2 as the model cathode material. This assessment allowed us to identify values of the LLZO thickness, cathode areal capacity, and LLZO content in the solid-state cathode required to match the energy density of conventional lithium-ion batteries (ca. 180 Wh kg-1 and 497 Wh L-1) at the power densities of 200 W kg-1 and 600 W L-1, corresponding to ca. 1 h of battery discharge time (1C). We then discuss key challenges in the practical deployment of LLZO SSE in the fabrication of Li-garnet all-solid-state batteries.
| S-EPMC8782839 | biostudies-literature
Project description:The high anodic stability of electrolytes for rechargeable magnesium batteries enables the use of new positive electrodes, which can contribute to an increase in energy density. In this study, novel Ph3COMgCl-, Ph3SiOMgCl-, and B(OMgCl)3-based electrolytes were prepared with AlCl3 in triglyme. The Ph3COMgCl-based electrolyte showed anodic stability over 3.0?V vs. Mg but was chemically unstable, whereas the Ph3SiOMgCl-based electrolyte was chemically stable but featured lower anodic stability than the Ph3COMgCl-based electrolyte. Advantageously, the B(OMgCl)3-based electrolyte showed both anodic stability over 3.0?V vs. Mg (possibly due to the Lewis acidic nature of B in B(OMgCl)3) and chemical stability (possibly due to the hard acid character of B(OMgCl)3). B(OMgCl)3, which was prepared by reacting boric acid with a Grignard reagent, was characterized by nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and X-ray absorption spectroscopy (XAS). The above analyses showed that B(OMgCl)3 has a complex structure featuring coordinated tetrahydrofuran molecules. 27Al NMR spectroscopy and Al K-edge XAS showed that when B(OMgCl)3 was present in the electrolyte, AlCl3 and AlCl2+ species were converted to AlCl4-. Mg K-edge XAS showed that the Mg species in B(OMgCl)3-based electrolytes are electrochemically positive. As a rechargeable magnesium battery, the full cell using the B(OMgCl)3-based electrolyte and a Mo6S8 Chevrel phase cathode showed stable charge-discharge cycles. Thus, B(OMgCl)3-based electrolytes, the anodic stability of which can be increased to ~3?V by the use of appropriate battery materials, are well suited for the development of practical Mg battery cathodes.
| S-EPMC7193642 | biostudies-literature