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.

scholarly journals Atomic-scale regulation of anionic and cationic migration in alkali metal batteries

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pan Xiong ◽  
Fan Zhang ◽  
Xiuyun Zhang ◽  
Yifan Liu ◽  
Yunyan Wu ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Electrostatic Interactions ◽  
High Performance ◽  
Metal Electrode ◽  
Atomic Scale ◽  
Ion Diffusion ◽  
Alkali Ions ◽  
Anions And Cations ◽  
Polypropylene Separator ◽  
Coated Separator

AbstractThe regulation of anions and cations at the atomic scale 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 (e.g., Li+ or Na+) and detrimental shuttling effect of polysulfide/polyselenide anions. These drawbacks could cause unfavourable growth of alkali metal depositions at the metal electrode and irreversible consumption of cathode active materials, leading to capacity decay and short cycling life. Herein, we propose the use of a polypropylene separator coated with negatively charged Ti0.87O2 nanosheets with Ti atomic vacancies to tackle these issues. In particular, we demonstrate that the electrostatic interactions between the negatively charged Ti0.87O2 nanosheets and polysulfide/polyselenide anions reduce the shuttling effect. Moreover, the Ti0.87O2-coated separator regulates the migration of alkali ions ensuring a homogeneous ion flux and the Ti vacancies, acting as sub-nanometric pores, promote fast alkali-ion diffusion.

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 Highly crystalline nickel hexacyanoferrate as a long-life cathode material for sodium-ion batteries

RSC Advances ◽  
2020 ◽  
Vol 10 (45) ◽  
pp. 27033-27041 ◽  
Author(s):  
Ratul Rehman ◽  
Jian Peng ◽  
Haocong Yi ◽  
Yi Shen ◽  
Jinwen Yin ◽  
...  
Keyword(s):  
Cathode Material ◽  
High Performance ◽  
Electrode Materials ◽  
Rechargeable Batteries ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Nickel Hexacyanoferrate ◽  
Synthesis Strategy ◽  
Prussian Blue Analog ◽  
Long Life

A low-speed synthesis strategy was designed to fabricate Prussian blue analog based electrode materials for high-performance rechargeable batteries.

Mechanistic Study of Electrode Materials for Rechargeable Batteries beyond Lithium Ion by In-situ Transmission Electron Microscopy

2021 ◽  
Author(s):  
Shaojun Guo ◽  
yousaf Muhammad ◽  
Ufra Naseer ◽  
Yiju Li ◽  
Zeeshan Ali ◽  
...  
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Lithium Ion ◽  
Rechargeable Batteries ◽  
Electrochemical Process ◽  
Atomic Scale ◽  
Mechanistic Study ◽  
Electrochemical Reactions ◽  
Transmission Electron

Understanding the fundamental mechanisms of advanced electrode materials at the atomic scale during the electrochemical process is condemnatory to develop the high-performance rechargeable batteries. The complex electrochemical reactions involved inside...

Sulfurized Polyacrylonitrile for High-Performance Lithium Sulfur Batteries: Advances and Prospects

2021 ◽  
Author(s):  
Xiaohui Zhao ◽  
Chonglong Wang ◽  
Ziwei Li ◽  
Xuechun Hu ◽  
Amir A. Razzaq ◽  
...  
Keyword(s):  
Energy Density ◽  
High Performance ◽  
Specific Capacity ◽  
Rechargeable Batteries ◽  
Next Generation ◽  
Lithium Sulfur Batteries ◽  
Theoretical Specific Capacity ◽  
Lithium Sulfur

The lithium sulfur (Li-S) batteries have a high theoretical specific capacity (1675 mAh g-1) and energy density (2600 Wh kg-1), exerting a high perspective as the next-generation rechargeable batteries for...

Fe-F Co-doped NaTi2(PO4)3/C Anode Material for High performance and Long-life Aqueous Li-ion Battery

2021 ◽  
pp. 161007
Author(s):  
Xin Zhang ◽  
Haixin Chen ◽  
Hui Chen ◽  
Senlin Li ◽  
Yurong Zhang ◽  
...  
Keyword(s):  
Anode Material ◽  
High Performance ◽  
Li Ion Battery ◽  
Li Ion ◽  
Long Life ◽  
Co Doped

scholarly journals Ab initio molecular dynamics and materials design for embedded phase-change memory

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Liang Sun ◽  
Yu-Xing Zhou ◽  
Xu-Dong Wang ◽  
Yu-Han Chen ◽  
Volker L. Deringer ◽  
...  
Keyword(s):  
Phase Change ◽  
High Performance ◽  
Materials Design ◽  
Atomic Scale ◽  
Ab Initio Molecular Dynamics ◽  
Core Material ◽  
Structure Property ◽  
Switching Speed ◽  
Atomic Structures ◽  
Memory Applications

AbstractThe Ge2Sb2Te5 alloy has served as the core material in phase-change memories with high switching speed and persistent storage capability at room temperature. However widely used, this composition is not suitable for embedded memories—for example, for automotive applications, which require very high working temperatures above 300 °C. Ge–Sb–Te alloys with higher Ge content, most prominently Ge2Sb1Te2 (‘212’), have been studied as suitable alternatives, but their atomic structures and structure–property relationships have remained widely unexplored. Here, we report comprehensive first-principles simulations that give insight into those emerging materials, located on the compositional tie-line between Ge2Sb1Te2 and elemental Ge, allowing for a direct comparison with the established Ge2Sb2Te5 material. Electronic-structure computations and smooth overlap of atomic positions (SOAP) similarity analyses explain the role of excess Ge content in the amorphous phases. Together with energetic analyses, a compositional threshold is identified for the viability of a homogeneous amorphous phase (‘zero bit’), which is required for memory applications. Based on the acquired knowledge at the atomic scale, we provide a materials design strategy for high-performance embedded phase-change memories with balanced speed and stability, as well as potentially good cycling capability.

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