In situ NMR spectroscopic investigations of ion adsorption mechanisms on nanoporous carbon materials

纳米多孔碳材料由于其优异的材料性能，如高电导率、化学和热稳定性，特别是由于其大的电解质可接近的内表面，在电化学能量储存方面获得了越来越多的兴趣。NMR光谱方法越来越有助于理解电池和电极材料中的分子过程。除了材料和表面表征，NMR光谱研究还可以研究电极材料和电解质分子之间的相互作用。同时，这甚至可以通过带电器件的原位NMR光谱来完成。在本项目中，将合成具有典型孔径分布和表面功能的定义明确的理想化模型材料，用于识别吸附离子的特征NMR签名。与创新的原位表征技术相结合，这将导致详细的机制的结论，在电吸附过程中发生的分子过程。计划的研究包括：（i）制备和表征具有定制孔径和表面功能（例如，具有或不具有极性表面官能化等的具有单或多峰孔径分布的碳材料）。(ii)固态核磁共振光谱表征碳材料表面和电解质分子之间的相互作用，有和没有施加电压。(iii)使用定量液态NMR光谱分析孔隙填充机制（吸附等温线）。此外，深入了解动力学和吸附动力学将获得。这些分子机制的理解将有助于获得合理的设计原则，为超级电容器和其他电化学储能装置的改进电极的制造。

Nanoporous carbon materials have gained increasing interest for electrochemical energy storage due to their outstanding materials properties such as high electrical conductivity, chemical and thermal stability, and especially due to their large electrolyte-accessible internal surfaces. NMR spectroscopic methods increasingly contribute to the understanding of the molecular processes in battery and electrode materials. In addition to materials and surface characterization, NMR spectroscopic studies also allow investigating the interactions between electrode materials and electrolyte molecules. Meanwhile, this can be even done by in situ NMR spectroscopy of charged devices. Within the present project, well-defined, idealized model materials with typified pore size distributions and surface functionalities will be synthesized for the identification of characteristic NMR signatures of adsorbed ions. Combined with innovative in situ characterization techniques, this will lead to detailed mechanistic conclusions concerning the molecular processes taking place during electro-adsorption. The planned investigations include: (i) Preparation and characterization of defined model materials with tailored pore sizes and surface functionalities (e.g., carbon materials with mono- or multimodal pore size distribution, with or without polar surface functionalization etc.). (ii) Solid-state NMR spectroscopic characterization of the interactions between the surface of the carbon materials and electrolyte molecules with and without applied voltage. (iii) Analysis of the pore filling mechanisms (adsorption isotherms) using quantitative liquid-state NMR spectroscopy. Moreover, insights into dynamics and adsorption kinetics will be gained. The understanding of these molecular mechanisms will contribute to derive rational design principles for the fabrication of improved electrodes for supercaps and other electrochemical energy storage devices.