Unparalleled Lithium and Sodium Superionic Conduction in Solid Electrolytes with Large Monovalent Cage-like Anions
Wan Si NMN Tang, Atsushi Unemoto, Wei Zhou, Vitalie Stavila, Motoaki Matsuo, Hui Wu, Shin-Ichi Orimo, Terrence J. Udovic
Solid electrolytes with sufficiently high conductivities and stabilities are the elusive answer to the inherent shortcomings of organic liquid electrolytes prevalent in today's rechargeable batteries. We recently revealed a novel fast-ion-conducting sodium salt, Na2B12H12, which contains large, icosahedral, divalent B12H122- anions that enable impressive superionic conductivity, albeit only above its 529 K phase transition. Its lithium congener, Li2B12H12, possesses an even more technologically prohibitive transition temperature above 600 K. Here we show that the chemically related LiCB11H12 and NaCB11H12 salts, which contain icosahedral, monovalent CB11Hd12^ anions, both exhibit much lower transition temperatures near 400 K and 380 K, respectively, and truely stellar ionic conductivities (>}0.1 S cm-1) unmatched by any other known polycrystalline materials at these temperatures. With proper modifications, we are confident that room-temperatures-stabilized superionic salts in corporating such large polyhedral anion building blocks are attainable, thus enhancing their future prospects as practical electrolyte materials in next-generation, all-solid-state batteries.
, Unemoto, A.
, Zhou, W.
, Stavila, V.
, Matsuo, M.
, Wu, H.
, Orimo, S.
and Udovic, T.
Unparalleled Lithium and Sodium Superionic Conduction in Solid Electrolytes with Large Monovalent Cage-like Anions, Energy & Environmental Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=919083
(Accessed December 10, 2023)