The current status of sodium metal anodes for improved sodium batteries and its future perspectives

Abstract

Sodium-ion batteries with evident merits in resource abundance and expenditure are emerging as a more suitable alternative to lithium-ion batteries for fulfilling the voracious energy demand of human activities. As the integral component of the battery, the exploration of anode materials suited to the electrochemical system during the last few decades has been never suspended, and the sodium metal anode successfully stands out with its high theoretical capacity and low redox potential. However, a huge gap exists between the direct usage of the sodium metal anode and the large-scale applications, as the uncontrollable sodium dendritic growth during cycling brings about serious concerns (i.e. infinite volume change, unstable solid electrolyte interphase, and safety issues) on battery performance losses. Although a few review articles on high-performance sodium metal anode have been already published, new research on solving the aforementioned challenges is still in progress. Therefore, we herein summarize the recent progress on the high-energy sodium metal anode from four aspects (protective layers, electrolyte additives, three-dimensional framework current collectors, and alloy materials) together with the detailed discussion and analysis in this Perspective. Furthermore, the potential directions and prospects of future research on constructing high-performance sodium metal anodes are also proposed.

Synergistic theoretical and experimental study on the ion dynamics of bis(trifluoromethanesulfonyl)imide-based alkali metal salts for solid polymer electrolytes

“…Furthermore, demand for higher energy density, increased sustainability, abundant and economically viable energy storage systems have led to a surge in the exploration for alternative battery technologies beyond LIBs in recent years. [5][6][7] Post-lithium-ion batteries (post-LIBs), such as lithium-metal batteries (LMBs), [8][9][10][11] sodium-ion batteries (NIBs), 4,12,13 potassium-ion batteries (KIBs), [14][15][16][17] and cesium-ion batteries (CIBs) [18][19][20] are gaining momentum. Numerous advantages of these post-LIB technologies include higher redox potentials; Li + /Li (À3.04 V vs. SHE), Na + /Na (À2.71 V vs. SHE), K + /K (À2.93 V vs. SHE), and Cs + /Cs (À3.03 V vs. SHE), along with superior theoretical specific capacities, 21 an abundance of both sodium and potassium in the Earth's crust posing an attractively low cost alternative to lithium, and the higher diffusion coefficients (low diffusion barrier) of cesium-based electrodes resulting in hindered dendrite formation for cesium-ion batteries.…”

On the Reversible Sodium Plating/stripping Reaction in Porous SiCN(O) Ceramic: A Feasibility Study

“…[11] In particular, 3D framework current collectors show perspective results and broad application prospects in improving sodium metal anodes. [12] 3D porous materials have been widely studied as functional hosts leading to uniform nucleation based on the interaction between sodium ions and a matrix structure. [9,13] Most studies have attributed porous matrix structures to be beneficial to uniform sodium metallic deposition since pores can induce the initial nucleation by concentrating the ion flux.…”

“…This concept is based on a direct plating/stripping of the metal thus avoiding kinetically slower insertion [10] or alloying processes [11] . In particular, 3D framework current collectors show perspective results and broad application prospects in improving sodium metal anodes [12] . 3D porous materials have been widely studied as functional hosts leading to uniform nucleation based on the interaction between sodium ions and a matrix structure [9,13] .…”

Slope-Dominated N/S Co-Doped Carbon Anode Derived from Pitch for Sodium-ion Batteries

“…Sodium has the advantage of being abundantly available and relatively inexpensive, making it a promising alternative to lithium for use in batteries. − However, the larger ionic radius of sodium (1.02 Å) compared to lithium (0.76 Å) hinders the direct use of graphite anodes for sodium-ion batteries, despite the commercial availability of such anodes for lithium-ion batteries. , To address this issue, various anode candidates for sodium-ion batteries have been explored including carbon, alloy, metal oxides/sulfides, and organic materials. Among them, carbon materials are currently considered the most promising candidates for commercial anode applications in sodium-ion batteries. , Pitch-based carbon materials are widely used in the preparation of hard carbon anode materials for sodium-ion batteries due to their stable structure, amorphous configuration, large layer spacing, and low cost. In hard carbon, sodium storage is governed by capacitive control processes (>0.2 V) and solid diffusion control processes (<0.2 V) .…”

“…Among them, carbon materials are currently considered the most promising candidates for commercial anode applications in sodium-ion batteries. 7,8 Pitch-based carbon materials are widely used in the preparation of hard carbon anode materials for sodium-ion batteries due to their stable structure, amorphous configuration, large layer spacing, and low cost. In hard carbon, sodium storage is governed by capacitive control processes (>0.2 V) and solid diffusion control processes (<0.2 V).…”