Jiang Yu, Yu Zuxi, Zhou XueFeng, Cheng Xiaolong, Huang Huijuan, Liu Fanfan, Yang Yaxiong, He Shengnan, Pan Hongge, Yang Hai, Yao Yu, Rui Xianhong, Yu Yan
Hefei National Research Center for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, China.
Adv Mater. 2023 Feb;35(8):e2208873. doi: 10.1002/adma.202208873. Epub 2022 Dec 29.
The practical application of the room-temperature sodium-sulfur (RT Na-S) batteries is hindered by the insulated sulfur, the severe shuttle effect of sodium polysulfides, and insufficient polysulfide conversion. Herein, on the basis of first principles calculations, single-atom vanadium anchored on a 3D nitrogen-doped hierarchical porous carbon matrix (denoted as 3D-PNCV) is designed and fabricated to enhance sulfur reactivity, and adsorption and catalytic conversion performance of sodium polysulfide. The 3D-PNCV host with abundant and active V sites, hierarchical porous structure, high electrical conductivity, and strong chemical adsorption/conversion ability of V-N bonding can immobilize the polysulfides and promote reversibly catalytic conversion of polysulfides toward Na S. Therefore, as-fabricated RT Na-S batteries can achieve a high reversible capacity (445 mAh g over 800 cycles at 5 A g ) and excellent rate capability (224 mAh g at 10 A g ). The electrocatalysis mechanism of sodium polysulfides is further experimentally and theoretically revealed, which provides a new strategy to develop the highly stable RT Na-S batteries.
绝缘硫、多硫化钠严重的穿梭效应以及多硫化物转化不足阻碍了室温钠硫（RT Na-S）电池的实际应用。在此，基于第一性原理计算，设计并制备了锚定在三维氮掺杂分级多孔碳基质上的单原子钒（表示为3D-PNCV），以提高硫的反应活性以及多硫化钠的吸附和催化转化性能。具有丰富且活性的V位点、分级多孔结构、高电导率以及V-N键强大的化学吸附/转化能力的3D-PNCV主体能够固定多硫化物，并促进多硫化物向Na₂S的可逆催化转化。因此，所制备的室温钠硫电池能够实现高可逆容量（在5 A g⁻¹下800次循环中为445 mAh g⁻¹）和优异的倍率性能（在10 A g⁻¹下为224 mAh g⁻¹）。进一步通过实验和理论揭示了多硫化钠的电催化机理，这为开发高度稳定的室温钠硫电池提供了一种新策略。
