Improved Interfaces of Mechanically Modified Lithium Electrodes with Solid Polymer Electrolytes

Liebenau D, Jalkanen K, Schmohl S, Stan M, Bieker P, Wiemhöfer H-D, Winter M, Kolek M

Abstract

The combination of mechanically modified lithium electrodes and solid polymer electrolytes (SPEs) is investigated. So far, modified lithium electrodes, e.g., via structuring, are successfully used in combination with liquid electrolytes like ionic liquid‐based and organic solvent‐based ones. Specific SPEs have proven to be well compatible with lithium metal, even better than with liquid electrolytes. Nevertheless, the interface between lithium and SPEs is a complex issue. In this work, the challenge of the adequate wetting of the lithium electrode surface, especially a structured lithium surface, with a solid polymer is faced to successfully improve the interfacial properties and thus the performance, by a new method for the coating of such electrodes. The wetting of the micropatterned lithium surface by the SPE and the directed lithium electrodeposition in the patterns are verified by scanning electron microscopy analysis. The electrochemical properties of Li|SPE assemblies are investigated on the basis of constant current cycling and impedance experiments.