Transition metal disulfide/graphene nanocomposites for Na-ion batteries: design and electronic interactions

用于钠离子电池的过渡金属二硫化物/石墨烯纳米复合材料：设计和电子相互作用

• 批准号: 449561509
• 负责人: Professor Dr. Clemens Laubschat
• 金额: --
• 依托单位: Russian Foundation for Basic Research
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/449561509?language=en
• 关键词: Transition; metal; disulfide; graphene; nanocomposites

The proposal addresses electronic interactions in heterostructures of transition metal disulfides (TMD) and graphene. Two-dimensional layer-structures, weak interlayer interactions and large surface-to-volume ratio of TMDs offer a great potential to act as advanced anode materials for sodium ion batteries, which are a promising alternative to lithium ion batteries due to the low cost and abundance of sodium. The poor electrical conductivity and high agglomerate risk of pure TMD electrodes can be overcome by interspersing nanocarbon phases within the composite material. The synergetic interactions of TMD and graphene nanohybrid materials for superior electrochemical performance in lithium and sodium ion batteries have been demonstrated in a quickly increasing number of scientific publications in recent years, most of which report on efficient electrochemical parameters in terms of capacity and cyclability. This proposal aims on the study of the physical processes occurring upon sodium ion intercalation in TMD/graphene composites and detailed understanding of the relationship between (micro-) structure - properties - electrochemical performance of these composite materials. We focus on disulfides of three transition metals - molybdenum, tungsten and vanadium - and their composites with graphene. The project comprises (i) elaborating synthesis procedures of these composites, (ii) characterisation of their morphology, structure and electronic properties, and (iii) studies of the effects of Na intercalation. A combination of experimental and theoretical approaches including high-resolution microscopy, optical spectroscopy, x-ray photoelectron and absorption spectroscopy using laboratory and synchrotron sources, and a theoretical quantum chemistry approach will be applied in this project. Furthermore, to improve the Na ion diffusion mobility and accessibility of active sites, we will introduce vacancy and heteroatom defects into TMD composites, and investigate the effects of this modifications on the structural, electronic and conducting properties. Finally, the TMD/graphene materials will be tested as electrodes for Na ion batteries at variable electrochemical cycling conditions. Chemical stability of electrodes will be evaluated by exposure to air. The reaction products of discharged composite-containing electrodes and effects of Na intercalation will be studied by solid-state NMR. The results will be analysed towards electrical conductivity characterized by electrochemical impedance measurement. It is anticipated that design of TMD/graphene composites elaborated in the project based on tuning their (micro-)structure and electronic properties will contribute to development of advanced electrode materials for Na ion batteries with high capacilty and stable cycling.

该提案解决了过渡金属二硫化物（TMD）和石墨烯异质结构中的电子相互作用。二维层状结构、弱的层间相互作用和大的表面积与体积比为钠离子电池提供了巨大的潜力，由于钠的低成本和丰富的钠，钠离子电池是锂离子电池的有前途的替代品。纯TMD电极的差的导电性和高的附聚风险可以通过在复合材料内散布纳米碳相来克服。TMD和石墨烯纳米杂化材料的协同相互作用在锂和钠离子电池中具有上级电化学性能，近年来已经在数量迅速增加的科学出版物中得到证实，其中大多数报道了容量和循环性方面的有效电化学参数。该提案旨在研究钠离子嵌入TMD/石墨烯复合材料时发生的物理过程，并详细了解这些复合材料的（微观）结构-性能-电化学性能之间的关系。 我们专注于三种过渡金属的二硫化物-钼，钨和钒-以及它们与石墨烯的复合材料。该项目包括（i）详细说明这些复合材料的合成程序，（ii）表征它们的形态、结构和电子性质，以及（iii）研究钠插层的影响。实验和理论方法的结合，包括高分辨率显微镜，光谱学，x射线光电子和吸收光谱使用实验室和同步辐射源，以及理论量子化学方法将应用于该项目。此外，为了提高Na离子的扩散迁移率和活性中心的可及性，我们将在TMD复合材料中引入空位和杂原子缺陷，并研究这种修饰对结构，电子和导电性能的影响。最后，TMD/石墨烯材料将在可变电化学循环条件下作为Na离子电池的电极进行测试。将通过暴露于空气来评价电极的化学稳定性。放电复合含电极的反应产物和钠嵌入的效果将通过固态NMR进行研究。将对结果进行分析，通过电化学阻抗测量表征电导率。预计该项目中基于调整其（微）结构和电子性能的TMD/石墨烯复合材料的设计将有助于开发具有高容量和稳定循环的钠离子电池的先进电极材料。