Lodovico Lucas, Varzi Alberto, Passerini Stefano
Helmholtz Institute Ulm (HIU), Ulm, Germany.
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Front Chem. 2020 Jan 10;7:893. doi: 10.3389/fchem.2019.00893. eCollection 2019.
Lithium sulfide-based materials have been considered as potential positive electrodes for the next generation batteries. Lithium sulfide is the fully lithiated form of sulfur, i.e., they share the same high theoretical capacity. However, it has the benefit of already containing lithium, which allows making cells with lithium-free negative electrodes. Lithium sulfide, however, shares with sulfur the polysulfide dissolution drawback upon cycling. One possible solution to this problem is to envelop the active material particles with carbonaceous materials. In this work, we investigate the effect of a nitrogen-rich carbon coating on lithium sulfide particles. The effect of such coating on the surface properties and electrochemistry of lithium sulfide cathodes is investigated in details, in particular, regarding its interaction with fresh vs. aged electrolyte. The polymerization of dioxalane (DOL) due to aging is found to affect the electrochemistry of lithium sulfide and, interestingly, to improve the cycling performance.
基于硫化锂的材料被认为是下一代电池的潜在正极材料。硫化锂是硫的完全锂化形式，也就是说，它们具有相同的高理论容量。然而，它的优势在于已经含有锂，这使得可以制造无锂负极的电池。然而，硫化锂与硫一样，在循环过程中存在多硫化物溶解的缺点。解决这个问题的一种可能方法是用含碳材料包裹活性材料颗粒。在这项工作中，我们研究了富含氮的碳涂层对硫化锂颗粒的影响。详细研究了这种涂层对硫化锂阴极表面性质和电化学的影响，特别是关于其与新鲜电解液和老化电解液的相互作用。发现由于老化导致的二氧戊环（DOL）聚合会影响硫化锂的电化学，有趣的是，还会改善循环性能。
