Okotrub Alexander V, Fedorenko Anastasiya D, Makarova Anna A, Sulyaeva Veronica S, Fedoseeva Yuliya V, Bulusheva Lyubov G
Nikolaev Institute of Inorganic Chemistry, SB RAS, 630090 Novosibirsk, Russia.
Physical Chemistry, Institute of Chemistry and Biochemistry, Free University of Berlin, 14195 Berlin, Germany.
Beilstein J Nanotechnol. 2025 Jun 10;16:847-859. doi: 10.3762/bjnano.16.64. eCollection 2025.
Hybrid materials consisting of molybdenum disulfide (MoS) and graphitic-like carbon have great potential for practical application as anodes in high-performance sodium-ion batteries. In this work, to reveal the effect of carbon coating on the interaction of sodium with the MoS layers located vertically relative to the substrate, model experiments were carried out using synchrotron-radiation-induced X-ray photoelectron spectroscopy (XPS). Sodium vapor obtained by heating a sodium source was simultaneously deposited in vacuum on the surfaces of MoS, pyrolytic carbon, and a hybrid sample obtained by transferring a pyrolytic carbon film onto the MoS film. According to XPS data, sodium easily penetrates into the space between the vertical layers of the uncoated film, and its interaction with MoS leads to the transformation of the original hexagonal structure into a distorted tetragonal one. Under the experimental conditions, sodium is unable to diffuse through the carbon film consisting of horizontally oriented graphene domains and is almost completely removed by annealing the sample at 773 K in ultrahigh vacuum. The presence of the underlying MoS film facilitates the diffusion of sodium through the graphitic coating, but not all of the deposited sodium reaches MoS. As a result, the sodium-induced rearrangement of the carbon-coated MoS is less than that of the free MoS film, and annealing of the sodiated sample restores its structure. The obtained results demonstrate the important role of the graphitic coating in the development of viable MoS-based electrodes for energy storage systems.
由二硫化钼（MoS）和类石墨碳组成的混合材料在高性能钠离子电池中作为阳极具有巨大的实际应用潜力。在这项工作中，为了揭示碳涂层对钠与相对于基底垂直排列的MoS层之间相互作用的影响，使用同步辐射诱导X射线光电子能谱（XPS）进行了模型实验。通过加热钠源获得的钠蒸气在真空中同时沉积在MoS、热解碳以及通过将热解碳膜转移到MoS膜上得到的混合样品的表面。根据XPS数据，钠很容易渗透到未涂层膜的垂直层之间的空间中，并且它与MoS的相互作用导致原始的六边形结构转变为扭曲的四边形结构。在实验条件下，钠无法扩散穿过由水平取向的石墨烯域组成的碳膜，并且通过在超高真空下于773 K对样品进行退火处理，钠几乎被完全去除。底层MoS膜的存在促进了钠通过石墨涂层的扩散，但并非所有沉积的钠都能到达MoS。结果，钠诱导的碳包覆MoS的重排比自由MoS膜的小，并且对含钠样品进行退火处理可恢复其结构。所获得的结果证明了石墨涂层在开发用于储能系统的可行的基于MoS的电极中的重要作用。
