Central subproject: Preparation and characterization of technical silver electrodes

气体扩散电极（GDE）是燃料电池和金属空气电池等相关电化学过程的关键部件，对能源周转具有根本重要性。在拟开展的研究单元中，将以碱性电解液中银基GDE上的氧还原为例进行研究。这些GDE的制备方法必须确保高的电催化活性、低的电子电阻以及高的化学和机械稳定性。GDE孔系统的形态对于这些要求起决定性作用，因为只有亲水性和疏水性的适当组合才能引起液体电解质、气态氧和电催化剂之间的紧密接触。到目前为止，GDE的详细描述只是部分可能的。这是由于复杂的相互作用的过程，缺少空间解决的方法在现场和操作中的观测使用工作GDE，以及有限的可用性模型与健全的物理化学基础。拟议的研究单位应结合联合收割机在电极制备，断层扫描，相分布和运输，微电化学以及分析和建模的微观和宏观动力学在所有相关尺度领域的能力。因此，运输和反应过程的复杂相互作用可以理解和定量描述。在拟议的中心项目中，将为所有合作伙伴进行电极的制备和表征以及半电池的制造。

Gas-diffusion electrodes (GDE) are key components for several relevant electrochemical processes such as fuel cells and metal-air batteries with fundamental importance for the energy turnaround. In the proposed research unit, the oxygen reduction over silver-based GDE in alkaline electrolyte shall be studied as an example. The preparation methods for these GDE must ensure high electro-catalytic activity, low electronic resistance as well as high chemical and mechanical stability. The morphology of the GDE pore system plays a decisive role for these requirements, since only a proper combination of hydrophilic and hydrophobic properties gives rise to intimate contact between liquid electrolyte, gaseous oxygen and the electro-catalyst. A detailed description of GDEs has been until now only partially possible. This is caused by the complex interplay of processes, missing methods for spatially resolved in situ and in operando observations using working GDEs, and the limited availability of models with sound physico-chemical basis. The proposed research unit shall combine competencies in the fields of electrode preparation, tomography, modeling of phase distribution and transport, micro-electrochemistry as well as analysis and modeling of micro- and macro-kinetics on all relevant scales. Thus, the complex interaction of transport and reaction processes can be understood and quantitatively described. In the proposed central project, the preparation and characterization of electrodes as well as the manufacture of half cells will be conducted for all partners.