Ultrafine nanoporous aluminum by electrolytic dealloying of aluminum-magnesium alloys in glyme-based electrolytes with recovery of sacrificial magnesium

Air-free electrolytic dealloying using non-aqueous electrolytes is a sustainable method for creating nanoporous Al (NP-Al) with highly reactive nanoscale-sized ligaments from Al-Mg parent alloys while simultaneously recovering the sacrificial Mg. However, this synthesis strategy is limited in versatility by the low number of available non-aqueous electrolytes that can conduct Mg ions and has so far only been proven to work with all-phenyl complex (APC) electrolyte derived from in situ reaction between two equivalents of Lewis base C6H5ClMg and one equivalent of Lewis acid AlCl3 in tetrahydrofuran (THF) solvent. Here we demonstrated that a new electrolyte consisting of MgCl2/AlCl3/Mg(TFSI)(2) (or MACT) in glyme-based solvents recently introduced in the Mg-ion battery community can also be used to create NP-Al. This alternative electrolyte exhibits higher electrochemical performance than APC and can create ultrafine NP-Al with approximate to 6-14 nm ligament size, which is smaller than the approximate to 10-20 nm ligament size commonly achieved using APC.