Schottky field emission gun

Focused ion beam cross‐sectional SEM was performed using a Dual Beam Helios NanoLab G3 instrument (FEI, USA). Platinum deposition was conducted prior to observation. High‐resolution scanning electron microscopy (HR‐SEM) was carried out using a Zeiss Ultra Plus high‐resolution scanning electron microscope equipped with a Schottky field‐emission gun (Carl Zeiss, Germany) operating at an acceleration voltage of 1 kV. For HR‐SEM imaging, sample fixation was performed at the end of the 2 h growth assays with 2.5% glutaraldehyde, followed by overnight soaking in PBS at 4 °C. Then a series of dehydration steps were conducted in 10%, 25%, 50%, 75%, and 100% ethanol solutions (20 min in each solution). Selected HR‐SEM images were false‐colored using Adobe Photoshop software CS3.

SEM images were obtained using an Auriga field emission scanning electron microscope (FE‐SEM) Crossbeam workstation equipped with a Schottky field emission gun by Carl Zeiss AG using an acceleration voltage of 3 kV, an in‐lens secondary electron detector, and a working distance of 5 mm. For the SEM measurements, the cycled graphite electrodes measured by ex‐situ Raman spectroscopy were used. To remove the electrolyte surface film, the electrodes were washed with DMC (2×0.5 mL) and transferred to the SEM device in a sealed container without moisture contact.