Structural properties of amorphous Na3 OCl electrolyte by first-principles and machine learning molecular dynamics

Aug 5, 2026

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Solid-state electrolytes enable safer, more efficient electrochemical energy storage than conventional liquid systems, and amorphous antiperovskite Na3OCl is investigated here for its structural behavior. The study combines first-principles molecular dynamics with machine-learning interatomic potential simulations, covering models from 135 to 3645 atoms. Quantitative structural descriptors include X-ray and neutron structure factors, total and partial pair correlation functions, coordination numbers, and distributions of structural units. Results show only minimal, partially present size effects and confirm that the MLIP reproduces amorphous Na3OCl structure details at the FPMD level.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages25

Reading Time1 h 3 min

AccessFree to download

Introduction

Solid-state electrolytes and antiperovskite motivation

Computational approach: FPMD and MLIP

Structural metrics and size effects

arXiv :2404 . 11442v1 [ cond-mat .mtrl-sci ] 17 Apr 2024 Structural properties of amorphous Na3 OCl electrolyte by 􀀌rst-principles and machine learning molecular dynamics Tan-Lien Pham􀀃 and Young-Han Shin Multiscale Materials Modeling Laboratory, Department of Physics, University of Ulsan, Ulsan 44610, Republic of Korea Mohammed Guerboub, Steve Dave Wansi Wendj, Mauro Boero,† Carlo Massobrio,† and Guido Ori‡ Universit􀀓e de Strasbourg, CNRS, Institut de Physique et Chimie des Mat􀀓eriaux de Strasbourg, UMR 7504, F-67034 Strasbourg, France and ADYNMAT CNRS consortium, F-67034 Strasbourg, France Assil Bouzid Institut de Recherche sur les C􀀓eramiques, UMR 7315 CNRS-Univesit􀀓e de Limoges, Centre Europ􀀓een de la C􀀓eramique, 12 rue Atlantis 87068 Limoges Cedex, France Christine Tugene Universit􀀓e de Strasbourg, CNRS, Institut de Physique et Chimie des Mat􀀓eriaux de Strasbourg, UMR 7504, F-67034 Strasbourg, France Solid-state electrolytes mark a signi􀀌cant leap forward in the 􀀌eld of electrochemical energy storage, o􀀋ering improved safety and e􀀎ciency compared to conventional liquid electrolytes. Among these, antiperovskite electrolytes, particularly those based on Li and Na, have emerged as promising candidates due to their superior ionic conductivity and straightforward synthesis processes. This study focuses on the amorphous phase of antiperovskite Na3 OCl, assessing its structural properties through a combination of 􀀌rst-principles molecular dynamics (FPMD) and machine learning interatomic potential (MLIP) simulations. Our comprehensive analysis spans models ranging from 135 to 3645 atoms, allowing for a detailed examination of X-ray and neutron structure factors, total and partial pair correlation functions, coordination numbers, and structural unit distributions. We demonstrate the minimal, albeit partially present, size e􀀋ects on these structural features and validate the accuracy of the MLIP model in reproducing the intricate details of the amorphous Na3 OCl structure described at the FPMD level. 2 I. INTRODUCTION Solid-state electrolytes are a focal point in the advancement of electrochemical energy storage technologies, oﬀering the potential to address the safety and performance challenges inherent in traditional liquid electrolytes [1, 2] . Notably, antiperovskite electrolytes, rich in Li and Na with low melting points, have been identiﬁed as a promising category due to their superior ionic conductivity and expedited synthesis processes [3–7] . Antiperovskite electrolytes based on X3 OA (X= Li+ or Na+ ; A= halides (Cl 􀀀 , Br 􀀀 , I 􀀀 ) or other anions (BH , NO)) have been synthesized in various forms, including purely crystalline, glassy, and hybrid amorphous/crystalline phases [3, 8–17] . In particular, glassy Li3 OCl-and Na3 OCl-based antiperovskites have shown remarkable conductivities of approximately 􀀘 0.1 mS/cm at room temperature, with glass transition temperatures between 390 and 450 K [18–20] . Also, amorphous Li3 OCl has been used as a matrix to embed Li-La-Zr-Ta-O garnet-type oxide particles, resulting in high room-temperature conductivity of 0.2 mS/cm and an extensive electrochemical stability window up to 10 V. The amorphous phase acted as a binder and ﬁller, ensuring the formation of an integrated composite solid electrolyte with a continuous, widespread ionic conductive network. This signiﬁcantly reduces the interfacial resistance with lithium metal anodes [21–24] . However, despite such enormous potential for applications [3, 16, 25–28], a precise understanding of the structural and ion conduction mechanisms in these glassy antiperovskite electrolytes is not been achieved yet. Indeed, recent literature on antiperovskites for solid-state batteries has highlighted the limited scope of structural characterizations available, underscoring the urgent need for a quantitative structural assessment to prevent misinterpretation of the relationship between structure and performance [13] . W

FAQs

Why focus on the amorphous phase of Na3OCl antiperovskite electrolytes?

The amorphous phase is attractive for solid-state batteries, but its structural characterizations and ion-conduction mechanisms are not yet fully understood. This work provides a quantitative structural assessment for amorphous Na3OCl.

How are the structural properties of amorphous Na3OCl evaluated?

The study uses first-principles molecular dynamics and machine-learning interatomic potential simulations, then analyzes X-ray/neutron structure factors, pair correlation functions, coordination numbers, and structural unit distributions.

What do the results indicate about model size effects and MLIP accuracy?

The simulations show minimal size effects on the structural features, and the MLIP is validated by reproducing detailed amorphous Na3OCl structure comparable to the first-principles molecular dynamics level.

Aug 5, 2026

Upload by Liam