scholarly journals An Idealised Approach of Geometry and Topology to the Diffusion of Cations in Honeycomb Layered Oxide Frameworks

2020 ◽  
Author(s):  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Layered Crystal ◽  
Quantum Geometry ◽  
Layered Oxides ◽  
Alkali Cations ◽  
Layered Oxide ◽  
Quantum Tunnelling ◽  
Coinage Metals ◽  
Curvature Deformation ◽  
Topological Phase Transitions

<div><p>Honeycomb layered oxides are a novel class of nanostructured materials comprising alkali or coinage metals intercalated into transition metal slabs. The intricate honeycomb architecture and layered framework endows this family of oxides with a tessellation of features such as exquisite electrochemistry, unique topology and fascinating electromagnetic phenomena. Despite having innumerable functionalities, these materials remain highly underutilised as their underlying atomistic mechanisms are vastly unexplored. Therefore, in a bid to provide a more in-depth perspective, we propose an idealised diffusion model of the charged alkali cations (such as lithium, sodium or potassium) in the two-dimensional (2D) honeycomb layers within the multi-layered crystal of honeycomb layered oxide frameworks. This model not only explains the correlation between the excitation of cationic vacancies (by applied electromagnetic fields) and the Gaussian curvature deformation of the 2D surface, but also takes into consideration, the quantum properties of the cations and their inter-layer mixing through quantum tunnelling. Through this work, we offer a novel theoretical framework for the study of multi-layered materials with 2D cationic diffusion currents, as well as providing pedagogical insights into the role of topological phase transitions in these materials in relation to Brownian motion and quantum geometry.<br></p></div>

scholarly journals An Idealised Approach of Geometry and Topology to the Diffusion of Cations in Honeycomb Layered Oxide Frameworks

2020 ◽  
Author(s):  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Layered Crystal ◽  
Quantum Geometry ◽  
Layered Oxides ◽  
Alkali Cations ◽  
Layered Oxide ◽  
Quantum Tunnelling ◽  
Coinage Metals ◽  
Curvature Deformation ◽  
Topological Phase Transitions

<div><p>Honeycomb layered oxides are a novel class of nanostructured materials comprising alkali or coinage metals intercalated into transition metal slabs. The intricate honeycomb architecture and layered framework endows this family of oxides with a tessellation of features such as exquisite electrochemistry, unique topology and fascinating electromagnetic phenomena. Despite having innumerable functionalities, these materials remain highly underutilised as their underlying atomistic mechanisms are vastly unexplored. Therefore, in a bid to provide a more in-depth perspective, we propose an idealised diffusion model of the charged alkali cations (such as lithium, sodium or potassium) in the two-dimensional (2D) honeycomb layers within the multi-layered crystal of honeycomb layered oxide frameworks. This model not only explains the correlation between the excitation of cationic vacancies (by applied electromagnetic fields) and the Gaussian curvature deformation of the 2D surface, but also takes into consideration, the quantum properties of the cations and their inter-layer mixing through quantum tunnelling. Through this work, we offer a novel theoretical framework for the study of multi-layered materials with 2D cationic diffusion currents, as well as providing pedagogical insights into the role of topological phase transitions in these materials in relation to Brownian motion and quantum geometry.<br></p></div>

scholarly journals An Idealised Approach of Geometry and Topology to the Diffusion of Cations in Honeycomb Layered Oxide Frameworks

2020 ◽  
Author(s):  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Layered Crystal ◽  
Quantum Geometry ◽  
Layered Oxides ◽  
Alkali Cations ◽  
Layered Oxide ◽  
Quantum Tunnelling ◽  
Coinage Metals ◽  
Curvature Deformation ◽  
Topological Phase Transitions

<div><p>Honeycomb layered oxides are a novel class of nanostructured materials comprising alkali or coinage metals intercalated into transition metal slabs. The intricate honeycomb architecture and layered framework endows this family of oxides with a tessellation of features such as exquisite electrochemistry, unique topology and fascinating electromagnetic phenomena. Despite having innumerable functionalities, these materials remain highly underutilised as their underlying atomistic mechanisms are vastly unexplored. Therefore, in a bid to provide a more in-depth perspective, we propose an idealised diffusion model of the charged alkali cations (such as lithium, sodium or potassium) in the two-dimensional (2D) honeycomb layers within the multi-layered crystal of honeycomb layered oxide frameworks. This model not only explains the correlation between the excitation of cationic vacancies (by applied electromagnetic fields) and the Gaussian curvature deformation of the 2D surface, but also takes into consideration, the quantum properties of the cations and their inter-layer mixing through quantum tunnelling. Through this work, we offer a novel theoretical framework for the study of multi-layered materials with 2D cationic diffusion currents, as well as providing pedagogical insights into the role of topological phase transitions in these materials in relation to Brownian motion and quantum geometry.<br></p></div>

scholarly journals An Idealised Approach of Geometry and Topology to the Diffusion of Cations in Honeycomb Layered Oxide Frameworks

2020 ◽  
Author(s):  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Three Dimensional ◽  
Quantum Geometry ◽  
Layered Oxides ◽  
Alkali Cations ◽  
Layered Oxide ◽  
Quantum Tunnelling ◽  
Quantum Properties ◽  
Curvature Deformation ◽  
Topological Phase Transitions

<div><p>Honeycomb layered oxides are a novel class of nanostructured materials comprising alkali or alkaline earth metals intercalated into transition metal slabs. The intricate honeycomb architecture and layered framework endows this family of oxides with a tessellation of features such as exquisite electrochemistry, unique topology and fascinating electromagnetic phenomena. Despite having innumerable functionalities, these materials remain highly underutilized as their underlying atomistic mechanisms are vastly unexplored. Therefore, in a bid to provide a more in-depth perspective, we propose an idealised diffusion model of the charged alkali cations (such as lithium, sodium or potassium) in the two-dimensional (2D) honeycomb layers within the three-dimensional (3D) crystal of honeycomb layered oxide frameworks. This model not only explains the correlation between the excitation of cationic vacancies (by applied electromagnetic fields) and the Gaussian curvature deformation of the 2D surface, but also takes into consideration, the quantum properties of the cations and their inter-layer mixing through quantum tunnelling. Through this work, we offer a novel theoretical framework for the study of 3D layered materials with 2D cationic diffusion currents, as well as providing pedagogical insights into the role of topological phase transitions in these materials in relation to Brownian motion and quantum geometry.<br></p></div>

A Heuristic Model for 3D Layered Materials with 2D Cationic Diffusion Currents from Their Honeycomb Lattice

2020 ◽  
Author(s):  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Three Dimensional ◽  
Layered Materials ◽  
Honeycomb Structure ◽  
Honeycomb Lattice ◽  
Heuristic Model ◽  
Layered Oxides ◽  
Alkali Cations ◽  
Quantum Properties ◽  
Curvature Deformation

<div><p>Honeycomb layered oxides are a novel class of materials generally exhibiting high ionic conductivity with battery applications. Owing to their honeycomb structure and layered framework, this class of materials is thought to harbor unique electrochemistry and physics. Here, a heuristic diffusion model of the charged alkali cations (such as lithium, sodium or potassium) in two-dimensional (2D) honeycomb layers within the three-dimensional (3D) crystal of honeycomb layered oxide is proposed. The model relates the excitation of cationic vacancies (by applied electromagnetic fields) to the Gaussian curvature deformation of the 2D surface. The quantum properties of the cations and their interlayer mixing through quantum tunneling are also considered. This work offers a novel theoretical framework for the study of 3D layered materials with 2D cationic diffusion currents, whilst providing pedagogical insights in the role of geometry in Brownian motion and quantum theory.</p><br></div>

A new lithium diffusion model in layered oxides based on asymmetric but reversible transition metal migration

2020 ◽  
Vol 13 (4) ◽  
pp. 1269-1278 ◽  
Author(s):  
Kyojin Ku ◽  
Byunghoon Kim ◽  
Sung-Kyun Jung ◽  
Yue Gong ◽  
Donggun Eum ◽  
...  
Keyword(s):  
Transition Metal ◽  
Diffusion Model ◽  
Layered Oxides ◽  
Layered Oxide ◽  
Reversible Transition ◽  
Lithium Diffusion ◽  
Metal Migration

We propose a new lithium diffusion model involving coupled lithium and transition metal migration, peculiarly occurring in a lithium-rich layered oxide.

Boosting Cycling Stability of Ni-rich Layered Oxide Cathode by Dry Coating of Ultrastable Li3V2(PO4)3 Nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Dongdong Wang ◽  
Qizhang Yan ◽  
Mingqian Li ◽  
Hongpeng Gao ◽  
Jianhua Tian ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Lithium Ion ◽  
High Energy ◽  
Cycling Stability ◽  
Next Generation ◽  
Layered Oxides ◽  
Dry Coating ◽  
Layered Oxide ◽  
Oxide Cathode

Nickel (Ni)-rich layered oxides such as LiNi0.6Co0.2Mn0.2O2 (NCM622) represent one of the most promising candidates for the next-generation high-energy lithium-ion batteries (LIBs). However, the pristine Ni-rich cathode materials usually suffer...

Revealing the role of spinel phase on Li-rich layered oxides: A review

2022 ◽  
Vol 427 ◽  
pp. 131978
Author(s):  
Huixian Xie ◽  
Jiaxiang Cui ◽  
Zhuo Yao ◽  
Xiaokai Ding ◽  
Zuhao Zhang ◽  
...  
Keyword(s):  
Spinel Phase ◽  
Layered Oxides

scholarly journals Modelling Cationic Diffusion in Nickel-Based Honeycomb Layered Tellurates using Vashishta-Rahman Interatomic Potential and Relevant Insights

2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Performance Enhancement ◽  
Interatomic Potential ◽  
Theoretical Studies ◽  
Layered Oxides ◽  
Ionic Radii ◽  
Diffusion Channel ◽  
Exponential Increase ◽  
Potential Parameters ◽  
Insight Into

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a refined set of inter-atomic potential parameters of <i>A</i><sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> (where <i>A</i> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the interatomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger interlayer distances. The simulations further demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> and Na<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> relative to Li<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub>. Whence, our findings connect lower potential energy barriers, favourable cationic paths and wider bottleneck size along the cationic diffusion channel within frameworks (comprised of larger mobile cations) to the improved cationic diffusion experimentally observed in honeycomb layered oxides. Furthermore, we explicitly study the role of inter-layer distance and cationic size in cationic diffusion. Our theoretical studies reveal the dominance of inter-layer distance over cationic size, a crucial insight into the further performance enhancement of honeycomb layered oxides.</b><br>

scholarly journals Role of Alkali Cations in Stabilizing Mixed-Cation Perovskites to Thermal Stress and Moisture Conditions

2021 ◽  
Vol 13 (36) ◽  
pp. 43573-43586
Author(s):  
Suresh Maniyarasu ◽  
J. Chun-Ren Ke ◽  
Ben F. Spencer ◽  
Alex S. Walton ◽  
Andrew G. Thomas ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Alkali Cations ◽  
Mixed Cation ◽  
Moisture Conditions

scholarly journals Modelling Cationic Diffusion in Nickel-Based Honeycomb Layered Tellurates using Vashishta-Rahman Interatomic Potential and Relevant Insights

2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese
Keyword(s):  
Performance Enhancement ◽  
Interatomic Potential ◽  
Layered Oxides ◽  
Ionic Radii ◽  
Diffusion Channel ◽  
Atomic Potential ◽  
Exponential Increase ◽  
Potential Parameters ◽  
Insight Into

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a reliable set of inter-atomic potential parameters of </b><i>A</i><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> (where </b><i>A</i><b> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the inter-atomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger inter-layer distances. The simulations demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> and Na</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> relative to Li</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b>. Whence, our findings connect lower potential energy barriers, favourable cationic paths and wider bottleneck size along the cationic diffusion channel within frameworks (comprised of larger mobile cations) to the improved cationic diffusion experimentally observed in honeycomb layered oxides. Furthermore, we elucidate the role of inter-layer distance and cationic size in cationic diffusion. Our theoretical studies reveal the dominance of inter-layer distance over cationic size, a crucial insight into the further performance enhancement of honeycomb layered oxides.</b><br>

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