scholarly journals 1D to 2D Na-Ion Diffusion Linked to Structural Transitions in Na0.7CoO2

2014 ◽  
Vol 70 (a1) ◽  
pp. C363-C363
Author(s):  
Marisa Medarde ◽  
Mattia Mena ◽  
Jorge Gavilano ◽  
Ekaterina Pomjakushina ◽  
Jun Sugiyama ◽  
...  
Keyword(s):  
Solid State ◽  
Structural Similarity ◽  
Clean Energy ◽  
Rechargeable Batteries ◽  
Atomic Scale ◽  
Structural Transitions ◽  
Ion Diffusion ◽  
Energy Materials ◽  
Energy Devices ◽  
Neutron Powder Diffraction Data

One of the most important scientific problems faced by our society is how to convert and store clean energy. In order to achieve a significant progress in this field we need to understand the fundamental dynamical processes that govern the transfer of energy on an atomic scale. For many energy devices such as solid-state batteries and solid-oxide fuel cells, this means understanding and controlling the complex mechanisms of ion diffusion in solid matter. Because of the unusual evolution of correlated electronic properties (frustrated magnetism and superconductivity), the layered Co-oxide family NaxCoO2 (0<x<1), object of this work, has been extensively studied during the last decade. More recently it has also attracted the attention of applied sciences, mainly because of its structural similarity with LixCoO2, one of the most common Li-ion battery electrodes. In view of the larger abundance of Na in the earth crust with respect to Li, Na-ion batteries enjoy an increased attention. Hence we decided to investigate the Na-ion diffusion in this material, whose possible use as cathode for solid-state rechargeable batteries has recently been proposed [1]. The present study reports the observation of a crossover from quasi-1D to 2D Na-ion diffusion in Na0.7CoO2. High resolution neutron powder diffraction data indicate the existence of two structural transitions at T1=290K and T2=400K [2]. We present here evidence indicating that both transitions are closely related to changes in the Na-ion mobility. Analysis of the anomalies in the Na-Na distances, the Debye-Waller factors and the scattering density in the paths connecting neighbouring Na sites strongly suggest that Na-ion diffusion starts at T1, although for T1<T<T2 it occurs preferentially along quasi-1D paths. A fully isotropic diffusion is only observed for T>T2, coinciding with the equalization of all first-neighbor Na-Na distances in the structure [2]. These findings provide new insight on the subtle mechanisms controlling the Na-ion diffusion in the NaxCoO2 family and could be used for the design of related energy materials with improved functional properties. Fig. 1. Fourier difference maps of the z = 0.25 Na planes at T = 50, 320 and 450 K showing the evolution of the residual scattering density in the paths connecting the Na1 and Na2 sites (from ref.[2]).

scholarly journals Magnetism and ion diffusion in honeycomb layered oxide $${\hbox {K}_2\hbox {Ni}_2\hbox {TeO}_6}$$

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nami Matsubara ◽  
Elisabetta Nocerino ◽  
Ola Kenji Forslund ◽  
Anton Zubayer ◽  
Konstantinos Papadopoulos ◽  
...  
Keyword(s):  
Low Temperature ◽  
Muon Spin ◽  
Diffusion Mechanism ◽  
Diffusion Constant ◽  
Muon Spin Rotation ◽  
Oxide Material ◽  
Ion Diffusion ◽  
Energy Materials ◽  
Layered Oxide ◽  
Energy Devices

Abstract In the quest for developing novel and efficient batteries, a great interest has been raised for sustainable K-based honeycomb layer oxide materials, both for their application in energy devices as well as for their fundamental material properties. A key issue in the realization of efficient batteries based on such compounds, is to understand the K-ion diffusion mechanism. However, investigation of potassium-ion (K$$^+$$ + ) dynamics in materials using e.g. NMR and related techniques has so far been very challenging, due to its inherently weak nuclear magnetic moment, in contrast to other alkali ions such as lithium and sodium. Spin-polarised muons, having a high gyromagnetic ratio, make the muon spin rotation and relaxation ($$\mu ^+$$ μ + SR) technique ideal for probing ions dynamics in these types of energy materials. Here we present a study of the low-temperature magnetic properties as well as K$$^+$$ + dynamics in honeycomb layered oxide material $${\hbox {K}_2\hbox {Ni}_2\hbox {TeO}_6}$$ K 2 Ni 2 TeO 6  using mainly the $$\mu ^+$$ μ + SR technique. Our low-temperature $$\mu ^+$$ μ + SR results together with complementary magnetic susceptibility measurements find an antiferromagnetic transition at $$T_{\mathrm{N}}\approx 27$$ T N ≈ 27  K. Further $${\mu}^{+}$$ μ + SR studies performed at higher temperatures reveal that potassium ions (K$$^+$$ + ) become mobile above 200 K and the activation energy for the diffusion process is obtained as $$E_{\mathrm{a}}=121 (13)$$ E a = 121 ( 13 )  meV. This is the first time that K$$^+$$ + dynamics in potassium-based battery materials has been measured using $$\mu ^+$$ μ + SR. Assisted by high-resolution neutron diffraction, the temperature dependence of the K-ion self diffusion constant is also extracted. Finally our results also reveal that K-ion diffusion occurs predominantly at the surface of the powder particles. This opens future possibilities for potentially improving ion diffusion as well as K-ion battery device performance using nano-structuring and surface coatings of the particles.

scholarly journals Real-time powder diffraction studies of energy materials under non-equilibrium conditions

IUCrJ ◽  
2017 ◽  
Vol 4 (5) ◽  
pp. 540-554 ◽  
Author(s):  
Vanessa K. Peterson ◽  
Josie E. Auckett ◽  
Wei-Kong Pang
Keyword(s):  
Real Time ◽  
Powder Diffraction ◽  
Chemical Engineering ◽  
Atomic Scale ◽  
Energy Materials ◽  
Equilibrium Conditions ◽  
Energy Devices ◽  
Real Time Analysis ◽  
Sorbent Materials ◽  
Non Equilibrium

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage of energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function.

scholarly journals Atomic-scale tandem regulation of anionic and cationic migration for long-life alkali metal batteries

2021 ◽  
Author(s):  
Pan Xiong ◽  
Fan Zhang ◽  
Xiuyun Zhang ◽  
Yifan Liu ◽  
Yunyan Wu ◽  
...  
Keyword(s):  
Alkali Metal ◽  
High Performance ◽  
Rechargeable Batteries ◽  
Atomic Scale ◽  
Fast Diffusion ◽  
Ion Diffusion ◽  
Fast Transport ◽  
Na Ions ◽  
Long Life ◽  
Severe Growth

Abstract Atomic-scale regulation of both cationic and anionic transport is of great significance in membrane-based separation technologies. Ionic transport regulation techniques could also play a crucial role in developing high-performance alkali metal batteries such as alkali metal-sulfur and alkali metal-selenium batteries, which suffer from the non-uniform transport of alkali metal ions and detrimental shuttling of polysulfide/polyselenide (PS) anions. These obstacles can cause severe growth of alkali metal dendrites and the irreversible consumption of active cathodes, leading to capacity decay and short cycling life. Herein, we report long-life alkali metal batteries enabled by atomic-scale tandem regulation of the migration of both alkali metal cations (Li+/Na+) and PS anions using negatively charged Ti0.87O2 nanosheets with Ti atomic vacancies. The shuttling of PS anions has been effectively eliminated via a robust electrostatic repulsion between the negatively charged nanosheets and PS anions. The negatively charged nanosheets can also regulate the migration of Li+/Na+ ions to ensure a homogeneous ion flux through efficient but light adhesion of Li+/Na+ ions within the nanosheets. The atomic Ti vacancies act as sub-nanometre pores to provide fast diffusion channels for Li+/Na+ ions. Therefore, eradication of PS shuttling and stable Li/Na-ion diffusion without compromising the fast transport of Li+/Na+ ions has been achieved for long-life alkali metal-sulfur and alkali metal-selenium batteries. This work provides a facile and effective strategy to regulate the transport of both cations and anions for developing advanced rechargeable batteries by using two-dimensional vacancy-enhanced materials.

New insights in the mechanism of cation migration induced by cation-anion dynamic coupling in superionic conductors

2022 ◽  
Author(s):  
Siyuan Wu ◽  
Ruijuan Xiao ◽  
Hong Li ◽  
Liquan Chen
Keyword(s):  
Solid State ◽  
Lithium Batteries ◽  
Cation Vacancy ◽  
Diffusion Mechanism ◽  
Superionic Conductors ◽  
Ion Diffusion ◽  
Dynamic Coupling ◽  
Energy Devices ◽  
Cation Migration

Understanding the ion diffusion mechanism is one of the key preconditions for designing superionic conductors in solid state lithium batteries and many other energy devices. Besides single-cation vacancy/interstitial-assisted and multi-cation...

scholarly journals Solid-State Materials for Clean Energy: Insights from Atomic-Scale Modeling

MRS Bulletin ◽  
2009 ◽  
Vol 34 (12) ◽  
pp. 935-941 ◽  
Author(s):  
M. Saiful Islam ◽  
Peter R. Slater
Keyword(s):  
Solid State ◽  
Clean Energy ◽  
Proton Conductors ◽  
Atomic Scale ◽  
Computational Techniques ◽  
Rechargeable Lithium Batteries ◽  
Ion Migration ◽  
Global Challenge ◽  
Solid State Ionics ◽  
Energy Conversion And Storage

AbstractFundamental advances in solid-state ionics for energy conversion and storage are crucial in addressing the global challenge of cleaner energy sources. This review aims to demonstrate the valuable role that modern computational techniques now play in providing deeper fundamental insight into materials for solid oxide fuel cells and rechargeable lithium batteries. The scope of contemporary work is illustrated by studies on topical materials encompassing perovskite-type proton conductors, gallium oxides with tetrahedral moieties, apatite-type silicates, and lithium iron phosphates. Key fundamental properties are examined, including mechanisms of ion migration, dopant-defect association, and surface structures and crystal morphologies.

scholarly journals Towards the Digitalisation of Porous Energy Materials: Evolution of Digital Approaches for Microstructural Design

2021 ◽  
Author(s):  
Zhiqiang Niu ◽  
Valerie Pinfield ◽  
Billy Wu ◽  
Huizhi Wang ◽  
Kui Jiao ◽  
...  
Keyword(s):  
Energy Materials ◽  
Energy Devices ◽  
Essential Components ◽  
Microstructural Design

Porous energy materials are essential components of many energy devices and systems, the development of which have been long plagued by two main challenges. The first is the ‘curse of...

scholarly journals Cobalt Nanoparticle-Embedded Nitrogen-Doped Carbon Catalyst Derived from a Solid-State Metal-Organic Framework Complex for OER and HER Electrocatalysis

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1320
Author(s):  
Shaik Gouse Peera ◽  
Ravindranadh Koutavarapu ◽  
Chao Liu ◽  
Gaddam Rajeshkhanna ◽  
Arunchander Asokan ◽  
...  
Keyword(s):  
Solid State ◽  
Alkaline Medium ◽  
Glassy Carbon ◽  
Metal Organic Framework ◽  
Electronic Conductivity ◽  
Organic Ligand ◽  
Synthesis Process ◽  
Ni Foam ◽  
Shell Nanoparticles ◽  
Energy Devices

Electrochemical water splitting is considered a promising way of producing hydrogen and oxygen for various electrochemical energy devices. An efficient single, bi-functional electrocatalyst that can perform hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) is highly essential. In this work, Co@NC core-shell nanoparticles were synthesized via a simple, eco-friendly, solid-state synthesis process, using cobalt nitrate and with pyrazole as the N and C source. The morphological analysis of the resulting Co@NC nanoparticles was performed with a scanning and transmission electron microscope, which showed Co nanoparticles as the core and the pyrolysis of pyrazole organic ligand N-doped carbon derived shell structure. The unique Co@NC nanostructures had excellent redox sites for electrocatalysis, wherein the N-doped carbon shell exhibited superior electronic conductivity in the Co@NC catalyst. The resulting Co@NC nanocatalyst showed considerable HER and OER activity in an alkaline medium. The Co@NC catalyst exhibited HERs overpotentials of 243 and 170 mV at 10 mA∙cm−2 on glassy carbon and Ni foam electrodes, respectively, whereas OERs were exhibited overpotentials of 450 and 452 mV at a current density of 10 and 50 mA∙cm−2 on glassy carbon electrode and Ni foam, respectively. Moreover, the Co@NC catalyst also showed admirable durability for OERs in an alkaline medium.

Equilibrium and Kinetic Properties of Minerals

1998 ◽  
Vol 62 (5) ◽  
pp. 581-583
Author(s):  
Simon A. T. Redfern
Keyword(s):  
Solid State ◽  
Statistical Mechanics ◽  
Structural Features ◽  
Atomic Scale ◽  
Kinetic Properties ◽  
Computational Power ◽  
Equilibrium Thermodynamics ◽  
Bulk Properties ◽  
Scale Characteristics ◽  
Number Of Publications

How can the equilibrium and non-equilibrium thermodynamics of minerals be understood from their atomic-scale structural features? How can they be predicted, simply from models for the forces between atoms? Advances in analytical theory, statistical mechanics, experimental solid-state science, computational power, and the sophistication of a mineralogical approach that brings all of these together, means that these questions, once imponderable, are now realistically tractable. These questions have been exercising the minds of mineralogists over the last decade or so, and have motivated many developments in the science. Acting as way-markers along the path, there are a number of publications which have followed from meetings where these questions have been addressed. It is now twelve years since the publication of Microscopic to Macroscopic, an edition of Reviews in Mineralogy (Kieffer and Navrotsky, 1985) that sought to identify the fundamental controls on the bulk properties of minerals in terms of their atomic-scale characteristics.

Hydrogen Storage in Magnesium-Based Alloys

MRS Bulletin ◽  
1999 ◽  
Vol 24 (11) ◽  
pp. 40-44 ◽  
Author(s):  
R.B. Schwarz
Keyword(s):  
Energy Density ◽  
Hydrogen Storage ◽  
Alternative Energy ◽  
Distribution Systems ◽  
Electrical Energy ◽  
Clean Energy ◽  
Energy System ◽  
Liquid Hydrogen ◽  
Rechargeable Batteries ◽  
Oil Crisis

Magnesium can reversibly store about 7.7 wt% hydrogen, equivalent to more than twice the density of liquid hydrogen. This high storage capacity, coupled with a low price, suggests that magnesium and magnesium alloys could be advantageous for use in battery electrodes and gaseous-hydrogen storage systems. The use of a hydrogen-storage medium based on magnesium, combined with a fuel cell to convert the hydrogen into electrical energy, is an attractive proposition for a clean transportation system. However, the advent of such a system will require further research into magnesium-based alloys that form less stable hydrides and proton-conducting membranes that can raise the operating temperature of the current fuel cells.Following the U.S. oil crisis of 1974, research into alternative energy-storage and distribution systems was vigorously pursued. The controlled oxidation of hydrogen to form water was proposed as a clean energy system, creating a need for light and safe hydrogen-storage media. Extensive research was done on inter-metallic alloys, which can store hydrogen at densities of about 1500 cm3-H2 gas/ cm3-hydride, higher than the storage density achieved in liquid hydrogen (784 cm3/cm3 at –273°C) or in pressure tanks (˜200 cm3/cm3 at 200 atm). The interest in metal hydrides accelerated following the development of portable electronic devices (video cameras, cellular phones, laptop computers, tools, etc.), which created a consumer market for compact, rechargeable batteries. Initially, nickel-cadmium batteries fulfilled this need, but their relatively low energy density and the toxicity of cadmium helped to drive the development of higher-energy-density, less toxic, rechargeable batteries.

scholarly journals Suppressing Void Formation in All-Solid-State Batteries: The Role of Interfacial Adhesion on Alkali Metal Vacancy Transport

2021 ◽  
Author(s):  
Ieuan Seymour ◽  
Ainara Aguadero
Keyword(s):  
Solid State ◽  
Interfacial Adhesion ◽  
Void Formation ◽  
Rechargeable Batteries ◽  
Metal Anode ◽  
Solid State Batteries ◽  
Promising Solution ◽  
Metal Vacancy ◽  
All Solid State Batteries

All-solid-state batteries containing a solid electrolyte and a lithium (Li) or sodium (Na) metal anode are a promising solution to simultaneously increase the energy density and safety of rechargeable batteries....

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