From High‐ to Low‐Temperature: The Revival of Sodium‐Beta Alumina for Sodium Solid‐State Batteries

Abstract

Sodium‐based batteries are promising post lithium‐ion technologies because sodium offers a specific capacity of 1166 mAh g−1 and a potential of −2.71 V vs. the standard hydrogen electrode. The solid electrolyte sodium‐beta alumina shows a unique combination of properties because it exhibits high ionic conductivity, as well as mechanical stability and chemical stability against sodium. Pairing a sodium negative electrode and sodium‐beta alumina with Na‐ion type positive electrodes, therefore, results in a promising solid‐state cell concept. This review highlights the opportunities and challenges of using sodium‐beta alumina in batteries operating from medium‐ to low‐temperatures (200 °C–20 °C). Firstly, the recent progress in sodium‐beta alumina fabrication and doping methods are summarized. We discuss strategies for modifying the interfaces between sodium‐beta alumina and both the positive and negative electrodes. Secondly, recent achievements in designing full cells with sodium‐beta alumina are summarized and compared. The review concludes with an outlook on future research directions. Overall, this review shows the promising prospects of using sodium‐beta alumina for the development of solid‐state batteries.

Low Na-β′′-alumina electrolyte/cathode interfacial resistance enabled by a hydroborate electrolyte opening up new cell architecture designs for all-solid-state sodium batteries

“…Such high current densities meet fast-charging requirement [17], making Na-β ′′alumina a promising candidate for all-solid-state batteries. In addition to demonstrated fast-charging capabilities, Na-β ′′alumina ceramics exhibit a sodium-ion conductivity competitive with typical liquid electrolytes (1.2 mS cm −1 at room temperature), a wide electrochemical stability window (>3 V), and proven chemical stability against sodium metal [18][19][20][21].…”

Pressure‐ and Temperature‐Dependent Interface Kinetics in Na3Zr2Si2PO12‐Based All‐Solid‐State Na Metal Battery

“…The CCD at which the metal-SSE cell fails is normally associated with metal (Na or Li) dendrites that initiate at the elec-trode|SSE interface and propagate through the SSE, eventually connecting the electrodes and resulting in a "hard" short circuit. [29][30][31] High current density affects the nucleation and growth of Na dendrites. Morphological instabilities arise when nuclei are induced at the Na|SSE interface that lead to rapid Na void accumulation and poor interfacial kinetics.…”

Promoting Mechanistic Understanding of Lithium Deposition and Solid‐Electrolyte Interphase (SEI) Formation Using Advanced Characterization and Simulation Methods: Recent Progress, Limitations, and Future Perspectives

“…The stability of beta‐alumina against molten Na recently spurred interest in using this solid electrolyte also at lower temperatures. [ 112 ] The driving force for reactions between Li and solid electrolytes, however, is generally larger. Overall, it turned out that the chemical stability window of solid electrolytes is quite limited, and may decompose upon direct contact with lithium.…”