3D-Printed AlSi10Mg lattice anodes in aluminum-air batteries: Effects of electrolyte and structure

This work investigates the influence of lattice geometry on the electrochemical corrosion behaviour of porous AlSi10Mg alloys, which are potential anodes for aluminium batteries. Lattice-structured alloys, including diamond, lidinoid, gyroid, and split-P, were designed using nTopology optimisation and fabricated via selective laser melting. Electrochemical corrosion performance was evaluated in aggressive 2 M NaOH, 2 M KOH, and 2 M NaCl electrolytes using cyclic voltammetry, linear sweep voltammetry, and potentiodynamic polarization. In 2 M NaOH, gyroid and split-P lattices develop stable passive films with minimal hysteresis, whereas lidinoid shows unstable oxide growth and rapid dissolution. In 2 M KOH, split-P and lidinoid lattices form thick, durable oxides with pronounced hysteresis, while diamond and gyroid produce thinner, less protective films. In 2 M NaCl, split-P and diamond lattices achieve rapid, high-current passivation, while gyroid and lidinoid display incomplete film formation and increased dissolution. The diamond and gyroid have slower corrosion in alkaline media, whereas lidinoid and split-P are more stable in chloride media. The maximum corrosion rates and weight loss occur in NaOH and KOH, with complete dissolution for the diamond lattice, attributed to higher surface area, and minimal loss for the lidinoid lattice in KOH due to stable oxide formation.