Sulfur in Amorphous Silica for an Advanced Room‐Temperature Sodium–Sulfur Battery

Abstract

The room-temperature (RT) Na/S battery is apromising energy storage system owingt os uitable operating temperature,h igh theoretical energy density,a nd lowc ost. However,ithas apoor cycle life and low reversible capacity.In this work, we report al ong-life RT-Na/S battery with amorphous porous silica as as ulfur host. The sulfur is loaded into amorphous silica by ad ipping method;t he optimal sulfur loading is up to 73.48 wt %. Molecular dynamics simulation and first-principles calculations suggest that the complex pores, acting as micro-containers and the formation of Na-O chemical bonds between amorphous silica and sodium polysulfide,g ive the electrodes as trong ability to inhibit sodium polysulfide shuttle.This would give rise to effectively avoiding the loss of active sulfur,c orresponding to as uperior capacity and an excellent cyclability even at 10 Ag sulfur À1 (nearly 100 % coulomb efficiency and high reversible capacity of 955.8 mAh g sulfur À1 after 1460 cycles).

In situ implanting MnO nanoparticles into carbon nanorod-assembled microspheres enables performance-enhanced room-temperature Na–S batteries

“…7,8 Heteroatom doping, represented by N atoms, is a good strategy to boost the chemical affinity of carbons via defect sites and facilitate chemical bonding with terminal Na ions of polysulfide chains (i.e., Na-N bonds), thus relieving the shuttle effect to some extent; 9,10 however, the extremely limited doping level cannot completely eradicate the negative effect of polysulfide shuttling. 11,12 Impressively, polar metal oxides, for examples, TiO 2 , 13 SiO 2 , 14 and MoO 2 15 etc., are shown to hold abundant surface sites (i.e., functional oxygen-containing groups), which enable chemical bonding with dissolved polysulfides via polar-polar interactions. 16,17 These metal oxides are widely utilized as adsorbents in cathode materials or building blocks for adsorptive interlayers to trap soluble polysulfides for reducing their shuttle effect.…”

Cellulose nanofiber‐derived carbon aerogel for advanced room‐temperature sodium–sulfur batteries

“…[16][17][18] Aiming to resolve the aforementioned inherent drawbacks, considerable efforts have been devoted toward improving the electrochemical performance of RT/Na-S batteries using conductive host materials, functional separators or interlayers, and optimized electrolytes. [15][16][17][18][19][20][21][22][23] Inspired by the research on Li-S batteries, quite a few non-polar materials (e.g., porous carbon materials, 16,[23][24][25] covalent sulfur materials, 26 and conducting polymer 27 ) and polar materials (such as metal oxides, [28][29][30] metal sulfides, 18,[31][32][33] metal carbides, 34,35 and transition metals 15,17,[36][37][38][39] ) have been investigated to immobilize NaPSs through physical confinement and/or chemical anchoring, thus increasing the sulfur utilization and suppressing the polysulfide shuttling. Impressively, another effective strategy is to use innovative electrolytes, such as a "cocktail optimized" electrolyte, 22 an ionic liquid electrolyte, 23 a gel polymer electrolyte, 40 and a ceramic solid electrolyte, 41 which can restrain the dissolution/migration of NaPSs.…”