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To compare the cumulative impact of sequential wear on mechanical properties and appearance of a composite resin (CR), Filtek Z250®, a glass ionomer GI, Fuji IX GP®, and a glass hybrid (GH), Equia Forte®. Six equally sized specimens of each material were subjected to wear tests, i.e., simulation of brushing, chewing and acidic liquid exposure, mimicking at least 6 months of clinical exposure. Surface roughness, hardness, substance loss and degree of shade lightness were determined. Following wear tests, significant increase in surface roughness and decrease in hardness values were observed for all materials (p <.05). Significantly larger substance loss was found in Equia Forte® specimens compared to Filtek Z250® (p <.05), while that of Fuji IX® exceeded the measurement capacity of the instrument. Opposite to the two other materials, the shade of Filtek Z250® became darker. Sequential wear exposure mimicking abrasion, erosion and attrition to products representing CR, GI and GH, caused weakening and change in appearance of the materials. The composite resin was the most mechanically resistant to the sequential wear. [ABSTRACT FROM AUTHOR]

We have used operando 5D synchrotron total scattering computed tomography (TSCT) to understand the cycling and possible long term deactivation mechanisms of the lithium-ion battery anode bismuth vanadate. This anode material functions via a combined conversion/alloying mechanism in which nanocrystals of lithium–bismuth alloy are protected by an amorphous matrix of lithium vanadate. This composite is formed in situ during the first lithiation of the anode. The operando TSCT data were analyzed and mapped using both pair distribution function and Rietveld methods. We can follow the lithium–bismuth alloying reaction at all stages, gaining real structural insight including variations in nanoparticle sizes, lattice parameters and bond lengths, even when the material is completely amorphous. We also observe for the first time structural changes related to the cycling of lithium ions in the lithium vanadate matrix, which displays no interactions beyond the first shell of V–O bonds. The first 3D operando mapping of the distribution of different materials in an amorphous anode reveals a decline in coverage caused by either agglomeration or partial dissolution of the active material, hinting at the mechanism of long term deactivation. The observations from the operando experiment are backed up by post mortem transmission electron microscope (TEM) studies and theoretical calculations to provide a complete picture of an exceptionally complex cycling mechanism across a range of length scales. [ABSTRACT FROM AUTHOR]

The properties of the mixed system LiBH4–LiCl–P2S5 are studied with respect to all-solid-state batteries. The studied material undergoes an amorphization upon heating above 60 °C, accompanied with increased Li+ conductivity beneficial for battery electrolyte applications. The measured ionic conductivity is ∼10−3 S cm−1 at room temperature with an activation energy of 0.40(2) eV after amorphization. Structural analysis and characterization of the material suggest that BH4 groups and PS4 may belong to the same molecular structure, where Cl ions interplay to accommodate the structural unit. Thanks to its conductivity, ductility and electrochemical stability (up to 5 V, Au vs. Li+/Li), this new electrolyte is successfully tested in battery cells operated with a cathode material (layered TiS2, theo. capacity 239 mA h g−1) and Li anode resulting in 93% capacity retention (10 cycles) and notable cycling stability under the current density ∼12 mA g−1 (0.05C-rate) at 50 °C. Further advanced characterisation by means of operando synchrotron X-ray diffraction in transmission mode contributes explicitly to a better understanding of the (de)lithiation processes of solid-state battery electrodes operated at moderate temperatures. [ABSTRACT FROM AUTHOR]

Bi2(MoO4)3 has been evaluated as an interesting anode material for application in lithium-ion batteries (LIBs). When cycled in the voltage window of 0.01–2.50 V a specific charge capacity of more than 800 mA h g−1 is retained after 50 cycles. According to operando synchrotron X-ray diffraction (XRD) the long-range order is lost during the initial lithiation. Direct insight into the electronic changes during cycling is obtained from operando Bi L3- and Mo K-edge X-ray absorption near edge spectroscopy (XANES) data collected during the first 1.5 cycles. A redox pair with anodic reactions at 0.97 V and cathodic reactions at 0.59 V is ascribed to alloying of bismuth: 3Li + Bi ↑ 2Li + LiBi ↑ Li3Bi. Likewise, reactions are ascribed to redox processes of Mo. Notably, the use of a cycling range limited to 2.00 V does not allow for a complete reoxidation of Mo, which in turn limits the reversibility of the Mo redox reactions. [ABSTRACT FROM AUTHOR]

BiVO4 undergoes a series of conversion and alloying reactions as an anode material in lithium ion batteries. The current work demonstrates a charge capacity of 485 mA h g−1 after 50 cycles in a voltage range of 0–2.00 V (graphite has a capacity of 372 mA h g−1 theoretically). An exceptionally high volumetric capacity makes BiVO4 suitable for compact applications (volumetric capacity of 3984 mA h cm−3 for BiVO4 in comparison to 756 mA h cm−3 for graphite theoretically). Reaction steps and electronic transformations have been identified by operando quasi simultaneous synchrotron X-ray diffraction and absorption spectroscopy studies. An irreversible reaction step occurs for the Bi3+/Bi0 redox pair, whereas reversible mechanisms are found for the V5+/V3+ and Bi0/Bi3− redox pairs. The proposed mechanisms are supported by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

γ-MoO3 nanobelts prepared by hydrothermal synthesis were studied by synchrotron radiation powder diffraction, scanning electron microscopy, transmission electron microscopy and selected area electron diffraction. Their nm dimensions, in particular in two crystallographic directions, have a profound influence on electrochemical properties during cycling as the cathode material in lithium-ion batteries (LIBs). The diffraction analysis shows clearly that the crystal structure for the γ-MoO3 nanobelts differs significantly from that of bulk α-MoO3. The observed powder diffraction pattern, with asymmetric peaks, extremely broad peaks, as well as additional or absent diffraction peaks, is fully described by means of a model based on stacking disorder of MoO3 slabs. [ABSTRACT FROM AUTHOR]

The lithium ion battery concept is a promising energy storage system, both for larger automotive systems and smaller mobile devices. The smallest of these, the microbatteries, are commonly based on the all-solid state concept consisting of thin layers of electroactive materials separated by a solid state electrolyte. The fact that solid state electrolytes are required puts rather severe constraints on the materials in terms of electronic and ionic conductivity, as well as lack of pinholes otherwise leading to self-discharge. The atomic layer deposition (ALD) technology is especially suitable for realization of such microbatteries for the Li-ion technology. ALD has an inherent nature to deposit conformal and pinhole free layers on complex geometrical shapes, an architecture most commonly adopted for microbattery designs. The current paper gives an overview of ALD-type deposition processes of functional battery materials, including cathodes, electrolytes, and anodes with the aim of developing all-solid-state batteries. Deposition of Li-containing materials by the ALD technique appears challenging and the status of current efforts is discussed. [ABSTRACT FROM AUTHOR]

The properties of the mixed system LiBH 4 -LiCl-P 2 S 5 are studied with respect to all-solid-state batteries. The studied material undergoes an amorphization upon heating above 60 °C, accompanied with increased Li + conductivity beneficial for battery electrolyte applications. The measured ionic conductivity is ∼10 -3 S cm -1 at room temperature with an activation energy of 0.40(2) eV after amorphization. Structural analysis and characterization of the material suggest that BH 4 groups and PS 4 may belong to the same molecular structure, where Cl ions interplay to accommodate the structural unit. Thanks to its conductivity, ductility and electrochemical stability (up to 5 V, Au vs. Li + /Li), this new electrolyte is successfully tested in battery cells operated with a cathode material (layered TiS 2 , theo. capacity 239 mA h g -1 ) and Li anode resulting in 93% capacity retention (10 cycles) and notable cycling stability under the current density ∼12 mA g -1 (0.05C-rate) at 50 °C. Further advanced characterisation by means of operando synchrotron X-ray diffraction in transmission mode contributes explicitly to a better understanding of the (de)lithiation processes of solid-state battery electrodes operated at moderate temperatures.

BiVO4 undergoes a series of conversion and alloying reactions as an anode material in lithium ion batteries. The current work demonstrates a charge capacity of 485 mA h g-1 after 50 cycles in a voltage range of 0-2.00 V (graphite has a capacity of 372 mA h g-1 theoretically). An exceptionally high volumetric capacity makes BiVO4 suitable for compact applications (volumetric capacity of 3984 mA h cm-3 for BiVO4 in comparison to 756 mA h cm-3 for graphite theoretically). Reaction steps and electronic transformations have been identified by operando quasi simultaneous synchrotron X-ray diffraction and absorption spectroscopy studies. An irreversible reaction step occurs for the Bi3+/Bi0 redox pair, whereas reversible mechanisms are found for the V5+/V3+ and Bi0/Bi3- redox pairs. The proposed mechanisms are supported by density functional theory (DFT) calculations.