From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

Abstract

SummaryResearch devoted to room temperature lithium–sulfur (Li/S8) and lithium–oxygen (Li/O2) batteries has significantly increased over the past ten years. The race to develop such cell systems is mainly motivated by the very high theoretical energy density and the abundance of sulfur and oxygen. The cell chemistry, however, is complex, and progress toward practical device development remains hampered by some fundamental key issues, which are currently being tackled by numerous approaches. Quite surprisingly, not much is known about the analogous sodium-based battery systems, although the already commercialized, high-temperature Na/S8 and Na/NiCl2 batteries suggest that a rechargeable battery based on sodium is feasible on a large scale. Moreover, the natural abundance of sodium is an attractive benefit for the development of batteries based on low cost components. This review provides a summary of the state-of-the-art knowledge on lithium–sulfur and lithium–oxygen batteries and a direct comparison with the analogous sodium systems. The general properties, major benefits and challenges, recent strategies for performance improvements and general guidelines for further development are summarized and critically discussed. In general, the substitution of lithium for sodium has a strong impact on the overall properties of the cell reaction and differences in ion transport, phase stability, electrode potential, energy density, etc. can be thus expected. Whether these differences will benefit a more reversible cell chemistry is still an open question, but some of the first reports on room temperature Na/S8 and Na/O2 cells already show some exciting differences as compared to the established Li/S8 and Li/O2 systems.

Von Lithium‐ zu Natriumionenbatterien: Vorteile, Herausforderungen und Überraschendes

“…Ein umfassender Vergleich zu diesem Thema findet sich an anderer Stelle. [12] Wieo ben erwähnt, werden regelmäßig Übersichtsartikel Grundsätzlich lassen sich also auch mit Natriumionenbatterien hohe Spannungen erzielen. Betrachtet man Lithium und Natrium im Vergleich, so sollte Natrium aufgrund der geringeren Kohäsionsenergie Zellspannungen ermçglichen, die sogar um 0.53 Vh çher liegen.…”

Electrolyte-controlled discharge product distribution of Na–O2batteries: a combined computational and experimental study

“…[1][2][3][4][5][6][7][8][9][10] The composition of discharge products can be regulated by tuning their reaction conditions such as adding redox mediators [11][12][13][14][15][16][17][18] and changing electrochemical environment. [19][20][21][22][23] Some monovalent discharge products such as LiOH 18 and LiO 2 23 could be formed by adding some mediators and controlling electrode structures.…”

“…3,9,24,25 However, there exist a large debates on discharge product such as NaO 2 , Na 2 O 2 , and Na x O 2 (1<x<2) in Na-O 2 batteries duo to very close equilibrium voltages. 9,20,25,26 Based on ex situ analysis of the carbon cathode, Fu et al reported Na 2 O 2 as the major discharge product with use of either carbonate or ether electrolytes.…”

Polymers for energy storage

“…However, the relatively poor performance of the existing battery concepts represents the major bottleneck for the further developments of "mobile energy". The currently most common technologies are based on lithium compounds (also a substitution with sodium is intensively discussed) [6]. However, the application of LiCoO 2 as the cathode-active material leads to problems in terms of thermal stability as well as cost, toxicity, and availability of the raw-materials [1].…”