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Title: Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba- closo -borate Salts

Abstract

Solid lithium and sodium closo-polyborate-based salts are capable of superionic conductivities surpassing even liquid electrolytes, but often only at above-ambient temperatures where their entropically driven disordered phases become stabilized. Here we show by X-ray diffraction, quasielastic neutron scattering, differential scanning calorimetry, NMR, and AC impedance measurements that by introducing 'geometric frustration' via the mixing of two different closo-polyborate anions, namely, 1-CB 9H 10- and CB 11H 12-, to form solid-solution anion-alloy salts of lithium or sodium, we can successfully suppress the formation of possible ordered phases in favor of disordered, fast-ion-conducting alloy phases over a broad temperature range from subambient to high temperatures. Finally, this result exemplifies an important advancement for further improving on the remarkable conductive properties generally displayed by this class of materials and represents a practical strategy for creating tailored, ambient-temperature, solid, superionic conductors for a variety of upcoming all-solid-state energy devices of the future.

Authors:
 [1];  [2];  [3];  [3];  [3];  [3];  [4];  [5];  [6];  [7]
  1. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Center for Neutron Research; Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering
  2. Tohoku Univ., Sendai (Japan). Inst. for Materials Research
  3. Russian Academy of Sciences (RAS), Ekaterinburg (Russian Federation). Inst. of Metal Physics
  4. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Center for Neutron Research; National Renewable Energy Lab. (NREL), Golden, CO (United States)
  5. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  6. Tohoku Univ., Sendai (Japan). Inst. for Materials Research; Tohoku Univ., Sendai (Japan). WPI-Advanced Inst. for Materials Research
  7. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Center for Neutron Research
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Fuel Cell Technologies Office (EE-3F); National Science Foundation (NSF)
OSTI Identifier:
1315853
Report Number(s):
NREL/JA-5900-68062
Journal ID: ISSN 2380-8195
Grant/Contract Number:
AC36-08GO28308; AC04-94AL85000; DMR-0944772; 25220911; 15-03- 01114; 26820311
Resource Type:
Journal Article: Published Article
Journal Name:
ACS Energy Letters
Additional Journal Information:
Journal Volume: 1; Journal Issue: 4; Journal ID: ISSN 2380-8195
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; superionic conductivities; anions; ordered phases; disorder

Citation Formats

Tang, Wan Si, Yoshida, Koji, Soloninin, Alexei V., Skoryunov, Roman V., Babanova, Olga A., Skripov, Alexander V., Dimitrievska, Mirjana, Stavila, Vitalie, Orimo, Shin-ichi, and Udovic, Terrence J. Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba- closo -borate Salts. United States: N. p., 2016. Web. doi:10.1021/acsenergylett.6b00310.
Tang, Wan Si, Yoshida, Koji, Soloninin, Alexei V., Skoryunov, Roman V., Babanova, Olga A., Skripov, Alexander V., Dimitrievska, Mirjana, Stavila, Vitalie, Orimo, Shin-ichi, & Udovic, Terrence J. Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba- closo -borate Salts. United States. doi:10.1021/acsenergylett.6b00310.
Tang, Wan Si, Yoshida, Koji, Soloninin, Alexei V., Skoryunov, Roman V., Babanova, Olga A., Skripov, Alexander V., Dimitrievska, Mirjana, Stavila, Vitalie, Orimo, Shin-ichi, and Udovic, Terrence J. 2016. "Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba- closo -borate Salts". United States. doi:10.1021/acsenergylett.6b00310.
@article{osti_1315853,
title = {Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba- closo -borate Salts},
author = {Tang, Wan Si and Yoshida, Koji and Soloninin, Alexei V. and Skoryunov, Roman V. and Babanova, Olga A. and Skripov, Alexander V. and Dimitrievska, Mirjana and Stavila, Vitalie and Orimo, Shin-ichi and Udovic, Terrence J.},
abstractNote = {Solid lithium and sodium closo-polyborate-based salts are capable of superionic conductivities surpassing even liquid electrolytes, but often only at above-ambient temperatures where their entropically driven disordered phases become stabilized. Here we show by X-ray diffraction, quasielastic neutron scattering, differential scanning calorimetry, NMR, and AC impedance measurements that by introducing 'geometric frustration' via the mixing of two different closo-polyborate anions, namely, 1-CB9H10- and CB11H12-, to form solid-solution anion-alloy salts of lithium or sodium, we can successfully suppress the formation of possible ordered phases in favor of disordered, fast-ion-conducting alloy phases over a broad temperature range from subambient to high temperatures. Finally, this result exemplifies an important advancement for further improving on the remarkable conductive properties generally displayed by this class of materials and represents a practical strategy for creating tailored, ambient-temperature, solid, superionic conductors for a variety of upcoming all-solid-state energy devices of the future.},
doi = {10.1021/acsenergylett.6b00310},
journal = {ACS Energy Letters},
number = 4,
volume = 1,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1021/acsenergylett.6b00310

Citation Metrics:
Cited by: 8works
Citation information provided by
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  • Solid lithium and sodium closo-polyborate-based salts are capable of superionic conductivities surpassing even liquid electrolytes, but often only at above-ambient temperatures where their entropically driven disordered phases become stabilized. Here we show by X-ray diffraction, quasielastic neutron scattering, differential scanning calorimetry, NMR, and AC impedance measurements that by introducing 'geometric frustration' via the mixing of two different closo-polyborate anions, namely, 1-CB 9H 10- and CB 11H 12-, to form solid-solution anion-alloy salts of lithium or sodium, we can successfully suppress the formation of possible ordered phases in favor of disordered, fast-ion-conducting alloy phases over a broad temperature range from subambientmore » to high temperatures. Finally, this result exemplifies an important advancement for further improving on the remarkable conductive properties generally displayed by this class of materials and represents a practical strategy for creating tailored, ambient-temperature, solid, superionic conductors for a variety of upcoming all-solid-state energy devices of the future.« less
  • Li 2B 12H 12, Na 2B 12H 12, and their closo-borate relatives exhibit unusually high ionic conductivity, making them attractive as a new class of candidate electrolytes in solid-state Li- and Na-ion batteries. However, further optimization of these materials requires a deeper understanding of the fundamental mechanisms underlying ultrafast ion conduction. To this end, we use ab initio molecular dynamics simulations and density-functional calculations to explore the motivations for cation diffusion. We find that superionic behavior in Li 2B 12H 12 and Na 2B 12H 12 results from a combination of key structural, chemical, and dynamical factors that introduce intrinsicmore » frustration and disorder. A statistical metric is used to show that the structures exhibit a high density of accessible interstitial sites and site types, which correlates with the flatness of the energy landscape and the observed cation mobility. Furthermore, cations are found to dock to specific anion sites, leading to a competition between the geometric symmetry of the anion and the symmetry of the lattice itself, which can facilitate cation hopping. Finally, facile anion reorientations and other low-frequency thermal vibrations lead to fluctuations in the local potential that enhance cation mobility by creating a local driving force for hopping. In conclusion, we discuss the relevance of each factor for developing new ionic conductivity descriptors that can be used for discovery and optimization of closo-borate solid electrolytes, as well as superionic conductors more generally.« less
  • Both LiCB 9H 10 and NaCB 9H 10 exhibit liquid-like cationic conductivities (≥0.03 S cm –1) in their disordered hexagonal phases near or at room temperature. Furthermore, these unprecedented conductivities and favorable stabilities enabled by the large pseudoaromatic polyhedral anions render these materials in their pristine or further modified forms as promising solid electrolytes in next-generation, power devices.