Colombo Roberto, Versaci Daniele, Amici Julia, Bella Federico, Para Maria Laura, Garino Nadia, Laurenti Marco, Bodoardo Silvia, Francia Carlotta
Department of Applied Science and Technology (DISAT), Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
Nanomaterials (Basel). 2023 Jul 24;13(14):2149. doi: 10.3390/nano13142149.
Lithium-sulfur technology is a strong candidate for the future generation of batteries due to its high specific capacity (1675 mAh g-1), low cost, and environmental impact. In this work, we propose a facile and solvent-free microwave synthesis for a composite material based on doped (sulfur and nitrogen) reduced graphene oxide embedded with zinc sulfide nanoparticles (SN-rGO/ZnS) to improve the battery performance. The chemical-physical characterization (XRD, XPS, FESEM, TGA) confirmed the effectiveness of the microwave approach in synthesizing the composite materials and their ability to be loaded with sulfur. The materials were then thoroughly characterized from an electrochemical point of view (cyclic voltammetry, galvanostatic cycling, Tafel plot, electrochemical impedance spectroscopy, and Li2S deposition test); the SN-rGO/ZnS/S8 cathode showed a strong affinity towards polysulfides, thus reducing their loss by diffusion and improving redox kinetics, allowing for faster LiPSs conversion. In terms of performance, the composite-based cathode increased the specific capacity at high rate (1 C) from 517 to 648 mAh g-1. At the same time, more stable behavior was observed at 0.5 C with capacity retention at the 750th cycle, where it was raised from 32.5% to 48.2%, thus confirming the beneficial effect of the heteroatomic doping process and the presence of zinc sulfide nanoparticles.
锂硫技术因其高比容量（1675 mAh g-1）、低成本和环境影响小，是下一代电池的有力候选者。在这项工作中，我们提出了一种简便的无溶剂微波合成法，用于合成一种基于掺杂（硫和氮）的还原氧化石墨烯并嵌入硫化锌纳米颗粒（SN-rGO/ZnS）的复合材料，以提高电池性能。化学物理表征（XRD、XPS、FESEM、TGA）证实了微波法在合成复合材料及其负载硫能力方面的有效性。然后从电化学角度对材料进行了全面表征（循环伏安法、恒电流循环、塔菲尔曲线、电化学阻抗谱和Li2S沉积测试）；SN-rGO/ZnS/S8阴极对多硫化物表现出很强的亲和力，从而减少了它们因扩散造成的损失并改善了氧化还原动力学，使LiPSs转化更快。在性能方面，基于复合材料的阴极在高倍率（1 C）下的比容量从517提高到了648 mAh g-1。同时，在0.5 C下观察到更稳定的行为，在第750次循环时容量保持率从32.5%提高到了48.2%，从而证实了杂原子掺杂过程和硫化锌纳米颗粒存在的有益效果。
