Electrodeposition of Lithium/Polystyrene Composite Electrodes from an Ionic Liquid: First Attempts

One challenge in the use of metallic lithium in secondary lithium ion or lithium air batteries is the dendritic growth of lithium upon repeated cycling which might either lead to a short circuit or at least to an uneven current distribution and bad cycling stability. In the present paper we present our first results on the electrodeposition of lithium from an ionic liquid within the voids of a polystyrene opal structure on copper. For this purpose polystyrene spheres with an average diameter of about 600 nm were applied onto a copper sheet by a simple dipping process resulting in a layer thickness of about 10 μm. Lithium can be deposited within this polymer structure without damaging it and the subsequent dissolution of the polystyrene spheres delivers a macroporous lithium film, proving that a mechanically stable composite electrode is feasible.