Drying influence on binder distribution in electrodes for Lithium ion batteries - Mechanistic insight into the progress of component distribution

锂离子电池电极的性能主要是由其复杂的微观结构决定的。它由颗粒活性物质和功能添加剂在整个薄膜中的局部分布来定义。在第一个资助期进行的工作中，研究了参数、干燥速度和干燥温度对薄膜结构的影响。作为本次调查的一个主要结果，发现这两个参数的影响是不同的，因此必须分开考虑。这些结果形成了开发预测干燥模型的基础，该模型允许描述组分分布的演变和膜结构的形成。该方案的目的是详细阐述薄膜的固化机理。对结构发展的时间顺序的检查需要具有高局部和时间分辨率的单一组分在薄膜高度上的分布的特定测量技术。在相关和定义的边界条件下，这些技术不适用于干燥过程。因此，阐述了几个关于特征、中间膜状态的假设，并将通过附着力测量、能谱分析和其他方法进行验证，这些方法已在初步实验中成功应用。此外，应用了一种新颖、创新的实验方法，该方法允许根据干膜性质揭示特定膜性质的时间演变。

Properties of electrodes used in lithium-ion batteries are mainly defined by the complex micro structure of the active layer. It is defined by the local distribution of the particulate active material and functional additives throughout the film. Within the work conducted in the first funding period the influence of the parameters drying rate and drying temperature on the film structure was investigated. As a major outcome of this investigation both parameters were found to impact differently and have, therefore, to be considered separately. The results form the basis for the development of a predictive drying model that allows for description of the evolution of the component distribution and formation of the film structure. The objective of this proposal is the detailed elaboration of the film solidification mechanism. The examination of the chronological sequence of the structural development requires specific measurement techniques with a high local and chronological resolution of the distribution of single components over the film height. These techniques are not available for the drying process at relevant and defined boundary conditions. Therefore, several hypotheses concerning characteristic, intermediate film states were elaborated that will be checked up on by means of adhesive force measurements, EDS and additional methods that have been successfully applied in preliminary experiments. In addition, a novel, innovative experimental approach is applied that allows for revelation of the chronological evolution of specific film properties on the basis of the dry film properties.