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Xiong P, Zhang F, Zhang X, Liu Y, Wu Y, Wang S, Safaei J, Sun B, Ma R, Liu Z, Bando Y, Sasaki T, Wang X, Zhu J, Wang G. Atomic-scale regulation of anionic and cationic migration in alkali metal batteries. Nat Commun 2021; 12:4184. [PMID: 34234123 PMCID: PMC8263716 DOI: 10.1038/s41467-021-24399-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/07/2021] [Indexed: 11/09/2022] Open
Abstract
The 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.
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Affiliation(s)
- Pan Xiong
- Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing, China
- Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia
| | - Fan Zhang
- Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia
| | - Xiuyun Zhang
- College of Physical Science and Technology, Yangzhou University, Yangzhou, China
| | - Yifan Liu
- Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing, China
| | - Yunyan Wu
- Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing, China
| | - Shijian Wang
- Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia
| | - Javad Safaei
- Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia
| | - Bing Sun
- Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia
| | - Renzhi Ma
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan
| | - Zongwen Liu
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Yoshio Bando
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan
| | - Takayoshi Sasaki
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan
| | - Xin Wang
- Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing, China
| | - Junwu Zhu
- Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing, China.
| | - Guoxiu Wang
- Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia.
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Gamba Z. Effective potentials and electrostatic interactions in self-assembled molecular bilayers II: The case of biological membranes. J Chem Phys 2009; 129:215104. [PMID: 19063584 DOI: 10.1063/1.3026662] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In order to study the electrostatic properties of a single biological membrane (not an stack of bilayers), we propose a very simple and effective external potential that simulates the interaction of the bilayer with the surrounding water and that takes into account the microscopic pair distribution functions of water. The electrostatic interactions are calculated using Ewald sums but, for the macroscopic electrostatic field, we use an approximation recently tested in simulations of Newton black films that essentially consists in a coarsed fit (perpendicular to the bilayer plane) of the molecular charge distributions with Gaussian distributions. The method of effective macroscopic and external potentials is extremely simple to implement in numerical simulations, and the spatial and temporal charge inhomogeneities are then roughly taken into account. As examples of their use, several molecular dynamics simulations of simple models of a single biological membrane, of neutral or charged polar amphiphilics, with or without water (using the TIP5P intermolecular potential for water) are included. The numerical simulations are performed using a simplified amphiphilic model which allows the inclusion of a large number of molecules in these simulations, but nevertheless taking into account molecular charge distributions, flexible amphiphilic molecules, and a reliable model of water. All these parameters are essential in a nanoscopic scale study of intermolecular and long range electrostatic interactions. This amphiphilic model was previously used by us to simulate a Newton black film, and, in this paper, we extend our investigation to bilayers of the biological membrane type.
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Affiliation(s)
- Z Gamba
- Department of Physics--CAC, Comisión Nacional de Energía Atómica, Avenida Libertador 8250, 1429 Buenos Aires, Argentina.
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Gamba Z. Macroscopic electrostatic potentials and interactions in self-assembled molecular bilayers: the case of Newton black films. J Chem Phys 2008; 129:164901. [PMID: 19045308 DOI: 10.1063/1.2996295] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We propose a very simple but "realistic" model of amphiphilic bilayers, simple enough to be able to include a large number of molecules in the sample but nevertheless detailed enough to include molecular charge distributions, flexible amphiphilic molecules, and a reliable model of water. All these parameters are essential in a nanoscopic scale study of intermolecular and long range electrostatic interactions. We also propose a novel, simple, and more accurate macroscopic electrostatic field for model bilayers. This model goes beyond the total dipole moment of the sample, which on a time average is zero for this type of symmetrical samples; i.e., it includes higher order moments of this macroscopic electric field. We show that by representing it with a superposition of Gaussians, it can be analytically integrated, and therefore its calculation is easily implemented in a molecular dynamics simulation (even in simulations of nonsymmetrical bi- or multilayers). In this paper we test our model by molecular dynamics simulations of Newton black films.
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Affiliation(s)
- Z Gamba
- Department of Physics, CAC, Comision Nacional de Energia Atomica, Av. Libertador 8250, 1429 Buenos Aires, Argentina.
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