The future changes to our transportation systems and societal consumption patterns demand the development and improvement of reliable and safe high-energy storage systems for both mobile and stationary applications. In recent years, Lithium metal batteries (LMBs), e.g. O2ǁLi cell chemistries have been under investigation as promising beyond-lithium ion candidates in mobile applications, mainly due to their superior theoretical specific energy densities. Moreover, research focus has shifted towards efforts to enable “low-excess” or “zero-excess” batteries, in which the availability of excess Lithium is strongly limited. In such cell chemistries, galvanic corrosion can be regarded one of the often-neglected failure mechanisms.
This project is based on previous studies, in which the ionic liquids Pyr14TFSI, Pyr13TFSI, Pip14TFSI and N1114TFSI were systematically investigated for their tendency to be affected by galvanic corrosion.
Four different principles for the prevention of galvanic corrosion have been proposed: Application of adequate sealings, sufficiently high concentrations of conductive salts, such as LiTFSI or others, chemical additives leading to surface layers on current collector and electrodes, as well as artificial coatings reducing the active contact area between current collectors and the electrolyte. In this poster, we present practical examples for these four strategies. It could be shown that conductive salt concentration and the addition of SEI-forming additives proved most effective for the limitation of galvanic corrosion. These findings are supported by different analytical techniques, such as 1H-NMR, XPS and ion chromatography. Electrochemical tests (galvanostatic cycling) revealed influences of the applied prevention methods to the cycling performance of the investigated electrolytes.
 A. Kolesnikov, M. Kolek, J.F. Dohmann, F. Horsthemke, M. Börner, P. Bieker, M. Winter, M.C. Stan, Adv. Energy Mater. 10 (2020) 2000017.
 J.F. Dohmann, F. Horsthemke, V. Küpers, S. Bloch, Y. Preibisch, A. Kolesnikov, M. Kolek, M.C. Stan, M. Winter, P. Bieker, Adv. Energy Mater. 11 (2021) 2101021.