New insights towards better Li and Na ion/metal batteries : diffusion, plating and electrolytes

This work focuses on the negative electrode of lithium ion batteries and so-called beyond lithium ion technologies, as well as the related interactions with the electrolyte. The first approach is a direct one, where we propose a new type of electrode architecture. The thereby encountered limitation in form of inept diffusion rates of lithium in copper, has implications for the general use of copper in lithium ion batteries. The diffusion is thus subjected to close investigation. This marks our second approach as a more fundamental one, focusing on uncovering underlying phenomena of the respective applications. The influence of often neglected parameters on the cycling of sodium metal as another type of negative electrodes is thoroughly studied. Building upon this base, we finally construct the principle of electrolytes that do not form a solid electrolyte interphase as a potential solution to many of the encountered issues. In the search for such an electrolyte, suitable analytical protocols are developed.