| 1. |
- Ahmed, Istaq, 1972, et al.
(author)
-
Crystal structure and proton conductivity of BaZr0.9Sc0
- 2008
-
In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:9, s. 3039-3044
-
Journal article (peer-reviewed)abstract
- Solid-state sintering has been used to prepare the perovskite BaZr0.9Sc0.1O3-delta. Analysis of X-ray powder diffraction data shows that an increase of the unit cell parameter, a, was observed after deuteration. Rietveld analysis of room-temperature neutron powder diffraction data confirmed cubic symmetry (space group Pm-3m). Dynamic thermogravimetric analysis indicates that the hydration process occurs below 335 degrees C and approximately 58% of the theoretical number of protonic defects can be filled. The presence of protons/deutrons is seen from the strong O-H/O-D stretch band in the infrared spectrum of the hydrated/deuterated samples. The proton conductivity of a prehydrated sample was investigated under dry and wet Ar atmospheres
|
|
| 2. |
- Ahmed, Istaq, 1972, et al.
(author)
-
Location of deuteron sites in the proton conducting perovskite BaZr0.50In0.50O3-y
- 2008
-
In: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388. ; 450:1-2, s. 103-110
-
Journal article (peer-reviewed)abstract
- High-resolution neutron powder diffraction data have been collected on deuterated and dried samples of the perovskite BaZr0.5In0.5O2.75 at 5 K and room temperature, respectively. Inspection of Fourier nuclear density maps for the deuterated phase have allowed the deuteron position to be refined on a 12h (1/2, y, 0) crystallographic site, with y = 0.217(4) yielding a chemically reasonable O-D distance of 0.92(2) angstrom. Evidence for anisotropy of the deuteron position is also found consistent with a 24k crystallographic site (0.56, 0.21, 0) indicative of displacements of the ion towards neighbouring oxygen ions. The presence of static oxygen disorder in both the dried and deuterated samples is apparent from the structural analyses. Raman spectra confirm short range deviations from cubic symmetry for both dried and hydrated samples.
|
|
| 3. |
- Atkins, Duncan, et al.
(author)
-
Accelerating Battery Characterization Using Neutron and Synchrotron Techniques: Toward a Multi-Modal and Multi-Scale Standardized Experimental Workflow
- 2022
-
In: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 12:17
-
Journal article (peer-reviewed)abstract
- Li-ion batteries are the essential energy-storage building blocks of modern society. However, producing ultra-high electrochemical performance in safe and sustainable batteries for example, e-mobility, and portable and stationary applications, demands overcoming major technological challenges. Materials engineering and new chemistries are key aspects to achieving this objective, intimately linked to the use of advanced characterization techniques. In particular, operando investigations are currently attracting enormous interest. Synchrotron- and neutron-based bulk techniques are increasingly employed as they provide unique insights into the chemical, morphological, and structural changes inside electrodes and electrolytes across multiple length scales with high time/spatial resolutions. However, data acquisition, data analysis, and scientific outcomes must be accelerated to increase the overall benefits to the academic and industrial communities, requiring a paradigm shift beyond traditional single-shot, sophisticated experiments. Here a multi-scale and multi-technique integrated workflow is presented to enhance bulk characterization, based on standardized and automated data acquisition and analysis for high-throughput and high-fidelity experiments, the optimization of versatile and tunable cells, as well as multi-modal correlative characterization. Furthermore, new mechanisms, methods and organizations such as artificial intelligence-aided modeling-driven strategies, coordinated beamtime allocations, and community-unified infrastructures are discussed in order to highlight perspectives in battery research at large scale facilities.
|
|
| 4. |
- Karlsson, Maths, et al.
(author)
-
Short-range structure of proton-conducting perovskite BaInxZr1-xO3-x/2 (x=0-0
- 2009
-
In: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 20:10, s. 3480-3486
-
Journal article (peer-reviewed)abstract
- In a systematic study, we investigate the effect of dopant level and hydration on the short-range structure of the proton-conducting perovskite-type oxide BaInxZr1-xO3-x/2 (x = 0 - 0.75), using infrared and Raman spectroscopy. The results show that the doping leads to significant local distortions of the average cubic structure of these materials. By increasing the In concentration from x = 0 to x = 0.75, new bands appear and grow in intensity in both the IR and the Raman spectra, showing that the local distortions become successively more and more pronounced. The structural distortions are largely uncorrelated to the presence of oxygen vacancies, but instead are mainly driven by the size and charge difference between the In3+ and Zr4+ ions, which leads to displacements of the cations and to tilting of the (In/Zr)O-6 octahedra. On the basis of our results, we suggest that there is a threshold between x = 0.10 and x = 0.25 where the structural distortions propagate throughout the whole perovskite structure. Comparison of our spectroscopic data with the proton conductivity for the same materials indicates that the presence of extended structural distortions is favorable for fast proton transport.
|
|
| 5. |
- Agostini, Marco, 1987, et al.
(author)
-
A high-power and fast charging Li-ion battery with outstanding cycle-life
- 2017
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7:1
-
Journal article (peer-reviewed)abstract
- Electrochemical energy storage devices based on Li-ion cells currently power almost all electronic devices and power tools. The development of new Li-ion cell configurations by incorporating innovative functional components (electrode materials and electrolyte formulations) will allow to bring this technology beyond mobile electronics and to boost performance largely beyond the state-of-theart. Here we demonstrate a new full Li-ion cell constituted by a high-potential cathode material, i.e. LiNi0.5Mn1.5O4, a safe nanostructured anode material, i.e. TiO2, and a composite electrolyte made by a mixture of an ionic liquid suitable for high potential applications, i.e. Pyr(1),4PF6, a lithium salt, i.e. LiPF6, and standard organic carbonates. The final cell configuration is able to reversibly cycle lithium for thousands of cycles at 1000 mAg(-1) and a capacity retention of 65% at cycle 2000.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
