Journal article
Molecular Dynamics Modeling of the Structure and Na + -Ion Transport in Na 2 S + SiS 2 Glassy Electrolytes
The journal of physical chemistry. B, Vol.122(30), pp.7597-7608
08/02/2018
Handle:
https://hdl.handle.net/2376/114814
PMID: 29924606
Abstract
Solid-state sodium batteries, a relatively safe and potentially cost-effective energy-storage technology, have attracted increasing scientific attention recently for application in stationary grid-scale energy storage. Identifying solid electrolytes with high electrochemical stability and high Na
-ion conductivity at room temperature is critically important to enable high energy densities with enhanced rate capabilities. We evaluated sodium sulfide-silicon sulfide, xNa
S + (1- x)SiS
, glasses as potential glassy solid electrolytes (GSEs) using molecular dynamics (MD) simulations. We employed ab initio MD to determine ion conduction mechanisms, to calculate energy barriers for ion hops, and to correlate these to the local short-range structure of 0.50Na
S + 0.50SiS
glass. To simulate much larger systems for accurately calculating the ionic conductivity, we parameterized empirical Buckingham-type potential and performed classical MD simulations. After validating these calculations by comparing the structure obtained from MD to that from X-ray scattering data, we calculated the ionic conductivity of these glasses for the range of 0.33 ≤ x ≤ 0.67 compositions. The calculated ionic conductivities at room temperature were in the range of ∼10
S/cm for the x = 0.50 composition and increased significantly with sodium sulfide ( x) content. These calculations provide theoretical insights into the role of Na
S content on the ionic conductivity of GSEs aiding in the selection of specific compositions to enhance the ionic conductivity.
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Details
- Title
- Molecular Dynamics Modeling of the Structure and Na + -Ion Transport in Na 2 S + SiS 2 Glassy Electrolytes
- Creators
- A Dive - School of Mechanical and Materials Engineering , Washington State University , Pullman , Washington 99164-2920 , United StatesC Benmore - Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United StatesM Wilding - Department of Chemistry , University College London , London WC1E 6BT , United KingdomS W Martin - Department of Materials Science and Engineering , Iowa State University , Ames , Iowa 50011 , United StatesS Beckman - School of Mechanical and Materials Engineering , Washington State University , Pullman , Washington 99164-2920 , United StatesS Banerjee - School of Mechanical and Materials Engineering , Washington State University , Pullman , Washington 99164-2920 , United States
- Publication Details
- The journal of physical chemistry. B, Vol.122(30), pp.7597-7608
- Academic Unit
- Mechanical and Materials Engineering, School of
- Publisher
- United States
- Identifiers
- 99900548343801842
- Language
- English
- Resource Type
- Journal article