Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba-Closo-Borate Salts

Published

September 1, 2016

Author(s)

Wan Si NMN Tang, Koji Yoshida, Alexei V. Soloninin, Roman V. Skoryunov, Olga A. Babanova, Alexander V. Skripov, Mirjana NMN Dimitrievska, Vitalie Stavila, Shin-Ichi Orimo, Terrence J. Udovic

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, differential scanning calorimetry, NMR, and AC impedance measurements, that by introducing "geometric frustration" via the mixing of two different closo-polyborate anions, namely, 1-CB₉H_{10- and CB}d11^H^d12-, 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 ally phases over a broad temperature range from sub-ambient to high temperatures. This result exemplifies an important advancement for further improving on the remarkable conductive properties generally, displayed by this class of materials, and represents a practice strategy tailored, ambient-temperature, solid, superionic conductors for the variety of upcoming all-solid-state energy devices of the future.

Citation

ACS Energy Letters

Volume

1

Issue

4

Pub Type

Journals

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Keywords

Closo-borates, Diffraction, Ionic Conductivities, Neutron Fixed-Window Scans, NMR, Reorientational Dynamics, Solid Solutions, Solid-State Conductors, Superionic

Citation

Tang, W. , Yoshida, K. , Soloninin, A. , Skoryunov, R. , Babanova, O. , Skripov, A. , Dimitrievska, M. , Stavila, V. , Orimo, S. and Udovic, T. (2016), Stabilizing Superionic-Conducting Structures via Mixed-Anion Solid Solutions of Monocarba-Closo-Borate Salts, ACS Energy Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921546 (Accessed October 3, 2025)