Wetting of nanostructured germanium electrodes by polyethylene oxide

One of the crucial factors that affects the performance of solid electrolyte - lithium-ion batteries is the electrode/electrolyte contact characteristics. Better contact implies greater ion transfer efficiency, leading to improved charge/discharge characteristics, and higher-power densities. In this study, the authors investigate the contact characteristics, viz. wettability, of germanium nanorod thin films initially by water, followed by polyethylene oxide (PEO)/water solution and PEO melt. The authors demonstrate that the electrode surface is hydrophilic, and considerably wettable, as evidenced by the contact angle for PEO/water solution and PEO melt, which are both below 25-. Electron microscopy was used to investigate the electrode/electrolyte contact area, and our results showed that PEO melt efficiently penetrates the inter-rod space, which is a further indication of considerable increase in the contact area.