From Aluminum Dissolution in Supercapacitors to Electroplating: A New Way for Al Thin Film Deposition?

The present work addresses a new finding observed while performing aluminum dissolution experiments for supercapacitors (SCs) stability investigation. Supercapacitor (SC) electrodes based on carbon‐coated aluminum foils are electrochemically cycled in harsh conditions into bis‐trifluoromethylsulfonyl imide (TFSI)‐based electrolyte and using Acetonitrile (ACN) as solvent. Dissolution of aluminum is observed with subsequent plating on the carbonaceous surface of counter electrodes. Moreover, the same process can be reproduced also on standard SC activated carbon electrodes. This mechanism can open the way to an effective strategy to achieve Al film deposition by electroplating becoming competitive with the most common copper counterpart. A new discovery concerning aluminum deposition by electroplating is presented. The process involves dissolving aluminum foils in a TFSI‐based electrolyte in acetonitrile solvent. The method is safer and cost‐effective and can be implemented on different substrates. The discovery also opens up opportunities for developing aluminum‐based electrochemical energy storage devices and deeper insights into the deposition mechanism on carbon surfaces.