December 2017

To enable large industrial application of next generation batteries several problems have to be solved. In the case of all-solid-state batteries such problems are for example a bad cycling stability and capacity fading. In this context, a deeper understanding of the degradation mechanisms is necessary to improve the battery performance. Investigations regarding the interface between the cathode and the electrolyte are typically based on electrochemical studies, diffraction methods, microscopic investigations and computational methods. In contrast, the measuring possibilities of analytical methods such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) are yet not fully exploited.The image shows 3D tomography studies of uncoated and coated Li[NixCoyMnz]O2 (x + y + z = 1) particles which were performed with ToF-SIMS. Ideally, coating the cathode material should lead to an improved battery performance and the coating should be homogeneously distributed on the surface. The image shows clearly that ToF-SIMS is a valuable tool for investigations regarding the coating of battery materials. The signals of the particles can be easily distinguished from the coating signals, which allows a characterization of the coating morphology. ToF-SIMS provides structural and chemical information simultaneously with a high lateral resolution (~ 100 nm) which is not easily accessible through other techniques. (Picture submitted by Felix Walther.)