Room temperature sodium-sulfur (RT NaS) batteries have gained remarkable attention due to their high theoretical capacity, low cost, and rich raw material sources. Nevertheless, the shuttle effect and the low sulfur content still limit the further development of RT NaS batteries. Here, micro-mesoporous carbon materials derived from cedarwood sawdust are synthesized through a simple annealing process with KOH activation as sulfur-carriers applied for RT NaS batteries. The micro-mesoporous carbon materials with high specific surface area (1411.63 m2 g−1) which achieve high sulfur content (61 wt%) and quite high sulfur loading (2.5 mg cm−2). Micropores structure is used for inhibiting the shuttling behavior of sodium polysulfides to realize a quasi-solid reaction of sulfur. Besides, mesoporous and macropores promote the diffusion and penetration of electrolytes. The assembled NaS battery achieves splendid initial capacity (1700.54 mAh g−1) and exhibits fantastic cycle performance at 0.2 A g−1 (724 mAh g−1, 100 cycles) even at sulfur loading up to 2.5 mg cm−2. Moreover, the NaS battery demonstrates a retained discharge specific capacity of 497.78 mAh g−1 (500 cycles) at current densities of 2 A g−1. The cedarwood sawdust-derived micro-mesoporous carbon characterized by a high sulfur content offers a practicable strategy for the synthesis of promising sulfur cathodes.

Link:Cedarwood sawdust derived micro-mesoporous carbon as sulfur host with high-sulfur-content for room-temperature NaS batteries - ScienceDirect