The project „InSEIde – Aritifical SEI: Understanding and manipulating interfaces in lithium ion batteries” deals with the development and optimization of electrochemical energy storage materials for lithium ion batteries. The project focusses on new anode materials based on silicon carbon composites (Si/C) as well as artificial electrode protection layers.

One of the biggest challenges with respect to using Si/C composites as negative electrode materials is located at interface between electrode and electrolyte. At this interface, the solid electrolyte interface (SEI) is formed from as a result of electrolyte decomposition. This is connected to irreversible capacity losses, as the charges consumed in the electrolyte decomposition cannot be recovered. However, the ideal SEI should protect the electrode surface from continuous unwanted side reactions consuming the battery electrolyte.

The fundamental processes during the SEI formation as well as its behavior during battery operation are very complex and up to know not yet fully understood. Therefore, we will use state-of-the art surface and interface characterization techniques to identify the main criteria of stable SEI layers to be able to drive a knowledge-based development of artificial SEI layers.

The long-term goal is to establish Si/C composites as next generation negative electrode materials in Li ion batteries.