A5088173404- Advanced Battery Materials and Technologies
- Advancements in Battery Materials
- Hydrogen Storage and Materials
- Chemical Synthesis and Characterization
- Thermal Expansion and Ionic Conductivity
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Boron and Carbon Nanomaterials Research
- Advanced battery technologies research
- Perovskite Materials and Applications
- Inorganic Chemistry and Materials
- Rare-earth and actinide compounds
- Solid-state spectroscopy and crystallography
- Quantum Dots Synthesis And Properties
- Boron Compounds in Chemistry
- Photonic and Optical Devices
- High-pressure geophysics and materials
- Polyoxometalates: Synthesis and Applications
- Advanced NMR Techniques and Applications
- Optical properties and cooling technologies in crystalline materials
- ZnO doping and properties
- Organic Electronics and Photovoltaics
- Organic Light-Emitting Diodes Research
- Nanowire Synthesis and Applications
- Conducting polymers and applications
Swiss Federal Laboratories for Materials Science and Technology
2016-2023
University of Geneva
2017-2022
École Polytechnique Fédérale de Lausanne
2015
We reveal an iodine vapor-induced degradation mechanism in formamidinium–lead-iodide-based perovskite solar cells stressed under combined heat and light illumination.
Na<sub>2</sub>(B<sub>12</sub>H<sub>12</sub>)<sub>0.5</sub>(B<sub>10</sub>H<sub>10</sub>)<sub>0.5</sub>, a new solid-state sodium electrolyte is shown to offer high Na<sup>+</sup> conductivity of 0.9 mS cm<sup>−1</sup> at 20 °C.
We report on a particularly stable 3 V all-solid-state sodium–ion battery built using <italic>closo</italic>-borate based electrolyte, namely Na<sub>2</sub>(B<sub>12</sub>H<sub>12</sub>)<sub>0.5</sub>(B<sub>10</sub>H<sub>10</sub>)<sub>0.5</sub>.
Abstract High ionic conductivity of up to 6.4 × 10 −3 S cm −1 near room temperature (40 °C) in lithium amide‐borohydrides is reported, comparable values liquid organic electrolytes commonly employed lithium‐ion batteries. Density functional theory applied coupled with X‐ray diffraction, calorimetry, and nuclear magnetic resonance experiments shed light on the conduction mechanism. A Li 4 Ti 5 O 12 half‐cell battery incorporating amide‐borohydride electrolyte exhibits good rate performance...
A self-passivating cathode/electrolyte interface achieves stable, room-temperature long-term cycling of 4 V-class Na<sub>3</sub>(VOPO<sub>4</sub>)<sub>2</sub>F|Na<sub>4</sub>(CB<sub>11</sub>H<sub>12</sub>)<sub>2</sub>(B<sub>12</sub>H<sub>12</sub>)|Na all-solid-state sodium batteries with the highest reported discharge cell voltage and cathode-based specific energy.
We report a robust methodology based on linear sweep voltammetry to determine experimentally the electrochemical oxidative stability of hydroborate-based solid-state electrolytes for all-solid-state batteries. To accelerate kinetics and improve sensitivity decomposition, we explore different electrolyte/carbon composites employ low scan rate 10 μV s–1. Using LiBH4 as model system, show that proper selection conductive carbon its ratio in composite are important an accurate determination...
The conduction mechanism of Na2(B12H12)0.5(B10H10)0.5, a particularly promising solid-state electrolyte for sodium-ion batteries, is elucidated. We find from electrochemical impedance spectroscopy that the temperature-dependent conductivity characterized by three distinct regimes conductivity. In first regime, at temperatures below −50 °C, remains low before glasslike transition identified X-ray diffraction and calorimetry causes faster increase sodium through site disordering. second regime...
Abstract All‐solid‐state batteries (ASSBs) promise higher power and energy density than based on liquid electrolytes. Recently, a stable 3 V ASSB the super ionic conductor (1 mS cm −1 near room temperature) Na 4 (B 12 H )(B 10 ) has demonstrated excellent cycling stability. This study concerns development of five‐step, scalable, solution‐based synthesis ). The use wet chemistry approach allows solution processing with high throughput addresses main drawbacks for this technology,...
An elastic electrolyte with a <italic>T</italic><sub>g</sub> = −51 °C, an ionic conductivity of 4.8 × 10<sup>−5</sup> S cm<sup>−1</sup>, and transference number 0.53 showed high initial capacity 134 mA h g<sup>−1</sup> 75% retention after 150 cycles at 0.1 cm<sup>−2</sup> 60 °C in full cell.
Vapor-based processes are promising options to deposit metal halide perovskite solar cells in an industrial environment due their ability uniform layers over large areas a controlled without resorting the use of (possibly toxic) solvents. In addition, they yield conformal on rough substrates, important aspect view producing perovskite/crystalline silicon tandem featuring textured wafer for light management. While inorganic precursors well suited thermal evaporation high vacuum, sublimation...
closo -Borates, such as Na 2 B 12 H , are an emerging class of ionic conductors that show promising chemical, electrochemical and mechanical properties electrolytes in all-solid-state batteries. Motivated by theoretical predictions, high-pressure situ powder X-ray diffraction on was performed two phases discovered. The first phase transition occurs at 0.5 GPa it is persistent to ambient pressure, whereas the second takes place between 5.7 8.1 fully reversible. mechanisms transitions means...
Quantum dots (QDs) embedded in nanowires represent one of the most promising technologies for applications quantum photonics. Self-assembled bottom-up fabrication is attractive to overcome technological challenges involved a top-down approach, but it needs post-growth investigations order understand self-organization process. We investigate QD formation by self-segregation AlxGa1−xAs shells as function thickness and cross-section morphology. By analysing light emission from several hundreds...
Lithium amide–borohydrides Li[BH4]1–x[NH2]x possess liquid-like Li superionic conductivity at nearly ambient temperature. The fast Li+ diffusion facilitated by the localized motions of anions is proposed to occur through a network vacant tetrahedral sites, acting as conduction channels. To study reorientational dynamics anions, we have performed quasielastic neutron scattering experiments on samples with different compositions (x = 2/3, 0.722, 0.737, 3/4) over broad temperature and time...
In this work, we report on the structural properties of alkali hydrido-closo-(car)borates, a promising class solid-state electrolyte materials, using high-pressure and temperature-dependent X-ray diffraction experiments combined with density functional theory (DFT) calculations. The mechanical are determined via pressure-dependent studies DFT calculations; shear moduli appear to be very low for all studied compounds, revealing their high malleability (that can beneficial manufacturing stable...
A volatile high molecular weight organic salt semiconductor is presented, allowing the introduction of physical vapour deposition techniques in cyanine dye semiconductors.
Thermal stability of solid electrolytes and their compatibility with battery electrodes are key factors to ensure stable cycling high operational safety all-solid-state batteries. Here, we study the a hydroborate electrolyte Na4(B12H12)(B10H10) 3 V-class cathode active materials: NaCrO2, NaMnO2, NaFeO2. Among these layered sodium transition metal oxide cathodes, NaCrO2 shows highest thermal in contact up 525 °C discharged state. Furthermore, remains intact upon internal decomposition...
We report on a particularly stable 3 V all-solid-state sodium–ion battery built using closo-borate based electrolyte, namely Na 4 (B 12 H )(B 10 ). The employs sodium metal anode and NaCrO 2 cathode. Battery performance is enhanced through the creation of an intimate cathode–electrolyte interface resulting in reversible cycling with capacity 85 mAh/g at C/20 80 C/5 more than 90% retention after 20 cycles 85% 250 C/5. also discuss effect outside electrochemical stability window show that...
While the size of electronic components has shrunk dramatically over last few decades, footprint autonomous devices is today often limited by battery. Miniaturization batteries challenging in particular when using liquid electrolytes based on organic solvents. All-solid-state employing solid-state promise to facilitate miniaturization and integration. Current developments for lithium ion focus mainly oxide- thiophosphate-based compounds, but have not yet enabled fabrication a competitive...
All-solid-state lithium-ion batteries employing solid-state electrolytes promise higher operational safety, enhanced temperature stability, potentially cell voltages, and consequently energy density compared to traditional with liquid based on flammable organic solvents. So far, only a few oxide- thiophosphate-based exhibit lithium ion conductivities near room comparable electrolytes. However, none of these has enabled the fabrication competitive all-solid-state battery yet. Here we report...
The identification of a solid-state electrolyte that fulfills all the requirements to enable competitive bulk-type all-solid-state battery remains challenging task. should display high ionic conductivity, thermal stability, good processability and importantly large electrochemical stability window ideally spans redox potential conducted metal ion. Several electrolytes within class complex hydrides such favorable combination relevant properties. Here, we will discuss our recent results for...