Cypher es microscope

AFM measurements were performed on a Cypher ES microscope (Asylum Research, Oxford Instruments, CA/USA) with the tip fully immersed into the solution. The AFM was equipped with photothermal excitation of the cantilever (blue drive) for better stability and the sample’s temperature was kept constant at 25 °C in a sealed, in situ cell. The imaging was performed in Amplitude Modulation mode (AM-AFM) driving the cantilever close to its resonance frequency. We used ArrowUHFAuD cantilevers (Nanoworld, Germany) with a nominal spring constant of ~2 N/m and resonance frequencies varying between 400–430 kHz in liquid. Each cantilever was calibrated using the thermal method54 and we used cantilevers from the same batch for all samples for better comparison.

In situ AFM measurements were performed in a tapping mode using Cypher ES microscope (Asylum Research, Oxford Instruments) installed inside an Ar filled glove box (MBraun) with O₂ < 0.1 ppm and H₂O < 0.1 ppm. A Si cantilever with 140 kHz resonance frequency and 0.6 N/m spring constant was mounted in a liquid perfusion cantilever holder and installed in an environmental sample cell. Before measurements the cantilever was washed with acetone and deionized water. An external potentiostat/galavanostat (BioLogic SP 150) was connected to the microscope. The samples were connected as working electrodes and a Li foil was connected as a reference and a counter electrode in a two electrode configuration. The cantilever was brought to a distance of 100 µm from the sample surface. Commercial battery grade electrolyte solution (1 M LiPF₆ in EC/DMC = 50/50 (v/v)) (Sigma Aldrich) was injected between the sample and the cantilever holder by a syringe via a polyethylene tubing until it formed a meniscus between the sample and the fused silica window of the cantilever holder. After that the cantilever was lander on the sample surface and the measurements were performed with 512 × 512 pixels resolution. The detailed setup is illustrated in Supplementary Fig. 8.
AFM images were processed using Gwyddion software.

Visualization of the nanofiber structures and determination of their respective dimensions were carried out by AFM. For this purpose, the supernatant of the suspension was subjected to ultrasound for five minutes. Then, an aliquot of the new supernatant was diluted (1:4), and 10 μL was deposited on mica fixed on a metal disc and air-dried at room temperature. The analysis was conducted on a Cypher ES Microscope (Asylum Research, Santa Barbara, CA, USA), with controlled humidity (40–45%) and temperature (22 °C). A silicon AC240TS tip was used for the scans at a frequency of 70 Hz, and the force constant was set to 2 N min⁻¹. Scans were performed in different areas ranging from 10 × 10 μm to 1 × 1 μm at a speed of 1.5 Hz (lines s⁻¹). The scanning mode was intermittent contact (Tapping Mode). The acquired images were processed using the manufacturer’s software, AR, version 16.