Imagine it’s rush hour in Roma. You’re waiting for the subway, and when the train finally arrives, it’s packed. You try to squeeze in, but there’s barely any space. Passengers are frustrated, some push, some give up. Oddly, you notice that half the seats are empty, but for some reason, they’re out of reach. This daily struggle mirrors what potassium (K) atoms experience when they try to enter few-layer graphene. Despite plenty of “free seats,” local deformations make many spots inaccessible. The frustration for these atoms must be immense.
This is more than just a metaphor: in our recent study published in Nano Energy, we explored how K atoms move inside few-layer graphene using ultra-high vacuum micro-Raman spectroscopy. We discovered that, in few-layer graphene, K atoms don’t spread out evenly. Instead, they form domains with sharp boundaries, suggesting a collective, edge-driven process. Understanding this process is crucial to develop better batteries and energy storage devices.

Authors: D.Marchiani, N. Jimenez-Arevalo, M. Sbroscia, C. Mariani, M. G. Betti e R. Frisenda