A5115602958- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advancements in Solid Oxide Fuel Cells
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Perovskite Materials and Applications
- Thermal Expansion and Ionic Conductivity
- Advanced Condensed Matter Physics
- Extraction and Separation Processes
- Nuclear materials and radiation effects
- Advanced Battery Technologies Research
- Supercapacitor Materials and Fabrication
- Solid-state spectroscopy and crystallography
- Conducting polymers and applications
- Physics of Superconductivity and Magnetism
- Catalytic Processes in Materials Science
- Chalcogenide Semiconductor Thin Films
- Chemical Synthesis and Characterization
- Semiconductor materials and devices
- Quantum Dots Synthesis And Properties
- Ferroelectric and Piezoelectric Materials
- Electron and X-Ray Spectroscopy Techniques
- Transition Metal Oxide Nanomaterials
- Electrocatalysts for Energy Conversion
- Inorganic Chemistry and Materials
University of Bath
2015-2024
The Faraday Institution
2021-2024
University of Oxford
2023-2024
Gunadarma University
2021
Centre National de la Recherche Scientifique
2020
Centre for Sustainable Energy
2017
Bath College
2014
University of Warwick
2011
University of Birmingham
2011
University of St Andrews
2011
Key issues relating to intrinsic defects, dopant incorporation, and lithium ion migration in the LiFePO4 electrode material have been investigated using well-established atomistic modeling techniques. Our simulation model shows good reproduction of observed olivine-type structure LiFePO4. The most favorable defect is Li−Fe "anti-site" pair which a Li (on M1 site) an Fe M2 are interchanged. This type anti-site or "intersite exchange" has olivine silicates. lowest energy found for pathway...
Two-dimensional transition metal carbides (termed MXenes) are a new family of compounds generating considerable interest due to their unique properties and potential applications. Intercalation ions into MXenes has recently been demonstrated with good electrochemical performance, making them viable electrode materials for rechargeable batteries. Here we have performed global screening the capacity voltage variety intercalation (Li(+), Na(+), K(+), Mg(2+)) large number M2C-based (M = Sc, Ti,...
The defect chemistry, doping behavior, and ion migration in olivine-type materials LiMPO4 (M = Mn, Fe, Co, N) are investigated by atomistic simulation techniques. most favorable intrinsic type is found to be the cation antisite defect, which Li M ions exchange positions. occur preferentially down [010] channels, following a curved trajectory. Defect association or binding energies for pair clusters composed of combinations lithium vacancies, cations, small polaron species investigated....
This article presents a survey of recent applications advanced computer modelling techniques in the study ion transport and defect properties ABO3 perovskite-structured oxides. The principal methodologies are outlined which include based upon both interatomic potentials (static lattice, molecular dynamics) quantum mechanical methods. scope contemporary perovskite oxides (such as LaBO3 AZrO3) is illustrated by accounts work on oxygen association, cation migration, and, finally, proton...
Tin perovskites have emerged as promising alternatives to toxic lead in next-generation photovoltaics, but their poor environmental stability remains an obstacle towards more competitive performances. Therefore, a full understanding of decomposition processes is needed address these issues. Herein, we elucidate the degradation mechanism 2D/3D tin perovskite films based on (PEA)
Polyoxyanion compounds, particularly the olivine-phosphate LiFePO4, are receiving considerable attention as alternative cathodes for rechargeable lithium batteries. More recently, an entirely new class of polyoxyanion based on orthosilicates, Li2MSiO4 (where M = Mn, Fe, and Co), has been attracting growing interest. In case Li2FeSiO4, iron silicon among most abundant lowest cost elements, hence offer tantalising prospect preparing cheap safe from rust sand! This Highlight presents overview...
The importance of exploring new low-cost and safe cathodes for large-scale lithium batteries has led to increasing interest in Li(2)FeSiO(4). structure Li(2)FeSiO(4) undergoes significant change on cycling, from the as-prepared γ(s) form an inverse β(II) polymorph; therefore it is important establish cycled material. In half LiO(4), FeO(4), SiO(4) tetrahedra point opposite directions ordered manner exhibit extensive edge sharing. Transformation polymorph cycling involves inversion SiO(4),...
Lithium-rich oxide electrodes with layered structures have attracted considerable interest because they can deliver high energy densities for lithium-ion batteries. However, there is significant debate regarding their redox chemistry. It apparent that the mechanism of lithium extraction from lithium-rich Li2MnO3 not fully understood, especially in relation to observed O2 evolution and structural transformation. Here, delithiation kinetic processes are investigated using ab initio simulation...
Abstract Metal oxides with a tunnelled structure are attractive as charge storage materials for rechargeable batteries and supercapacitors, since the tunnels enable fast reversible insertion/extraction of carriers (for example, lithium ions). Common synthesis methods can introduce large cations such potassium, barium ammonium ions into tunnels, but how these affect performance is not fully understood. Here, we report role tunnel in governing electrochemical properties electrode by focusing...
Perovskite solar cells containing a mixture of A-site cations show increased activation energies for iodide diffusion.
A detailed investigation on the effects of Mg substitution (0 ≤ <italic>x</italic> 0.2) in high voltage P2-Na<sub>2/3</sub>Ni<sub>1/3−x</sub>Mg<sub>x</sub>Mn<sub>2/3</sub>O<sub>2</sub> cathode materials for Na-ion batteries.
The efficiency and longevity of metal-halide perovskite solar cells are typically dictated by nonradiative defect-mediated charge recombination. In this work, we demonstrate a vapor-based amino-silane passivation that reduces photovoltage deficits to around 100 millivolts (>90% the thermodynamic limit) in bandgaps between 1.6 1.8 electron volts, which is crucial for tandem applications. A primary-, secondary-, or tertiary-amino-silane alone negatively barely affected crystallinity transport,...
Perovskite solar cell efficiency and stability are improved by π-conjugated aromatic additives that hydrophobic or hydrophilic due to strong binding with the perovskite.
Computer modelling techniques have been used to examine the mechanistic features of oxygen ion transport in La8Sr2Si6O26 and La9.33Si6O26 apatite-oxides at atomic level. The potential model reproduces observed complex structures both phases, which are comprised [SiO4] tetrahedral units La/O channels. Defect simulations examined lowest energy interstitial vacancy sites. results suggest that migration is via a mechanism with direct linear path between O5 Interstitial predicted for...
Materials displaying high oxide-ion conductivity have attracted considerable interest due to technological applications in solid oxide fuel cells (SOFCs), oxygen sensors and separation membranes. This has driven research into the identification of new classes conductors, this review, work on recently discovered apatite-type silicate/germanate conductors is presented. In contrast traditional perovskite- fluorite-based which conduction proceeds via vacancies, these apatite systems suggests...
Computer simulation techniques have been used to model cubic CeO2−ZrO2 solid solutions in the whole composition range. Aspects related with oxygen storage capacity of these materials are emphasized. The energetics Ce4+/Ce3+ bulk reduction reaction as well activation energy for migration lattice investigated and compared corresponding quantities pure CeO2. It is found that even small additions ZrO2 decrease Ce4+ values comparable those reported surface Activation calculations indicate an...
Advanced simulation techniques are used to provide atomic-scale insight into the surface structures and crystal morphologies of lithium battery cathode material LiFePO4. Relaxed energies reported for 19 low index planes. The calculated equilibrium morphology takes on a rounded, isometric appearance, with {010}, {201}, {011}, {100} faces prominent. Almost all energy surfaces lithium-deficient relative bulk lattice, requiring Li vacancies at surface. growth exhibits {101} faces, an elongated...
Computer simulation techniques have been used to investigate the defect and transport properties of zirconia (ZrO2) oxygen-ion conductor. First, a wide variety low-valent metal ions are substituted into zirconia, energetics solution investigated. Favourable dopants (on energetic grounds) calculated include CaO, Y2O3 , Gd2O3 ,and Sc2O3 in agreement with observation. Dopant-vacancy clusters also examined results revealing trends dopant ion size significant local atomic relaxation. These...
Atomistic simulation techniques are used to investigate the defect properties of anatase TiO(2) and Li(x)TiO(2) both in bulk at surfaces. Interatomic potential parameters derived that reproduce lattice constants anatase, energies defects surface structures calculated. Reduction involving interstitial Ti is found be most favorable reaction bulk, with a lower energy than either Frenkel or Schottky reactions. The binding selected clusters also presented: for Ti(3+)-Li(+) cluster, approximately...
MnO2 is attracting considerable interest in the context of rechargeable batteries, supercapacitors, and Li–O2 battery applications. This work investigates electrochemical properties hollandite α-MnO2 using density functional theory with Hubbard U corrections (DFT+U). The favorable insertion sites for Li-ion Na-ion are determined, we find good agreement measured experimental voltages. By explicit calculation phonons suggest multiple accessible dilute limit. Significant structural changes...