Electrocatalysis in Room Temperature Sodium‐Sulfur Batteries: Tunable Pathway of Sulfur Speciation

Abstract

Benefiting from the merits of natural abundance, low cost, and ultrahigh theoretical energy density, the room temperature sodium‐sulfur (RT NaS) batteries are regarded as one of the promising candidates for the next‐generation scalable energy storage devices. However, the uncontrollable sulfur speciation pathways severely hinder its practical applications. Recently, various strategies have been employed to tune the conversion pathways of sulfur, such as physical confinement, chemical inhibition, and electrocatalysis. Herein, the recent advances in electrocatalytic effects manipulate sulfur speciation pathways in advanced RT NaS electrochemistry are reviewed, including the promotion of the nearly full conversion of long‐chain polysulfides, short‐chain polysulfides, and small sulfur molecules. The underlying catalytic modulation mechanism that fundamentally tunes the electrochemical pathway of sulfur species is comprehensively summarized along with the design strategies for catalytic active centers. Furthermore, the challenge and potential solutions to realize the quasi‐solid conversion of sulfur are proposed to accelerate the real application of RT NaS batteries.

Enhanced Polysulfides Adsorption and Conversion for High Coulombic Efficiency Sodium‐Ion Batteries

“…The conversion of insoluble short‐chain NaPSs (such as Na 2 S 2 and Na 2 S) is another additional intermediate for the slow electrochemical reactions [6c,e] . In above reaction, this difficult conversion of Na 2 S exists, corresponding to the first peak potential during charging, while the reaction potential of CoS 2 NP@3D‐NC is 0.23 V ahead of that of CoS 2 /NC.…”

Recent Advances in Transition‐Metal‐Based Catalytic Material for Room‐Temperature Sodium–Sulfur Batteries

“…Additionally, metal-based host materials with enhanced catalytic and active sites, such as Febased, Co-based, Ni-based, and V-based materials, have been found to chemisorb NaPSs and facilitate the redox reactions of S species, thus improving the utilization of the S cathode and reaction kinetics. [15,[33][34][35][36] Although several excellent reviews have discussed the research progress of catalytic materials used in RT Na-S batteries, there is a lack of insight into the overview of TM-based host materials. Therefore, this review provides a comprehensive summary of TM-based host materials, including their principle of synthesis methods, working mechanisms, and electrochemical kinetics.…”

Dredging sodium polysulfides using a Fe3C electrocatalyst to realize improved room-temperature Na–S batteries

“…25 In contrast to blocking, dredging NaPSs via sulfiphilic electrocatalysts is a notably better strategy, which does not only capture these soluble polysulfides via polar interactions but also promotes their further redox conversions (i.e., both inhibiting polysulfide shuttling and preventing the formation of dead S). 26,27 This strategy usually requires the used materials to possess multifunctionalities with reasonable adsorption capacity, fast electron conduction, and robust electrocatalysis.…”

“…, both inhibiting polysulfide shuttling and preventing the formation of dead S). 26,27 This strategy usually requires the used materials to possess multifunctionalities with reasonable adsorption capacity, fast electron conduction, and robust electrocatalysis.…”