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.

该提案涉及过渡金属二硫化物（TMD）和石墨烯异质结构中的电子相互作用。 TMD的二维层结构，较弱的层间相互作用和较大的表面体积比，具有充当钠离子电池的高级阳极材料的巨大潜力，这是锂离子电池的有希望的替代品，这是由于低成本而导致的钠的丰度。可以通过在复合材料中散布纳米碳相，可以克服纯TMD电极的较差的电导率和高的聚集风险。近年来，TMD和石墨烯纳米杂化材料在锂和钠离子电池中具有出色的电化学性能的协同相互作用已在近年来的迅速增加的科学出版物中得到证明，其中大多数报告在能力和环保方面报告了有效的电化学参数。该建议旨在研究TMD/石墨烯复合材料中钠离子插入时发生的物理过程，并详细了解（微 - ）结构 - 特性 - 这些复合材料的电化学性能。 我们专注于三种过渡金属的二硫化物-Motybdenum，Tungsten和Vanadium-及其与石墨烯的复合材料。该项目包括（i）阐述这些复合材料的合成程序，（ii）其形态，结构和电子特性的表征以及（iii）Na互插的影响的研究。在该项目中，将采用实验和理论方法（包括高分辨率显微镜，光谱，X射线光电子以及使用实验室和同步源源的吸收光谱）的组合，并将在该项目中采用理论量子化学方法。此外，为了改善活性位点的NA离子扩散迁移率和可及性，我们将在TMD复合材料中引入空置和杂原子缺陷，并研究这种修饰对结构，电子和导电性能的影响。最后，在可变电化学循环条件下，TMD/石墨烯材料将作为NA离子电池的电极进行测试。电极的化学稳定性将通过暴露于空气来评估。固态NMR将研究排出的含复合电极的反应产物和NA插入的效果。将分析以电化学阻抗测量为特征的电导率的结果。可以预计，基于调整其（微）结构和电子性能在项目中详细阐述的TMD/石墨烯复合材料的设计将有助于开发高能力和稳定循环的NA离子电池的高级电极材料。