Adjustable and low-cost production of magnesium alloys using a liquid metal cathode

Abstract

Magnesium (Mg) alloys are known for their exceptional properties and versatile applications but suffer from inherent challenges in production including complex processes, high energy consumption, limited alloy tunability, and costly electrolytes. Herein, we present an efficient electrolysis approach for direct Mg alloy production with precisely adjustable composition from LiCl-free molten salts using a liquid Sn cathode. Liquid Sn effectively captures reduced Mg, enabling the successful preparation of Mg₆₀Sn₄₀, Mg₇₀Sn₃₀, and Mg₈₀Sn₂₀ alloys with uniformly distributed compositions. This method not only eliminates the need for expensive electrolytes, lowering production costs, but also achieves significant energy savings, estimated at 1.2 kW h kg⁻¹ Mg and 1.32 kg CO₂/kg Mg less than conventional primary Mg electrolytic production. By addressing key challenges in traditional Mg alloy production, this electrolysis technique provides a sustainable, energy-efficient, and cost-effective solution, with broad industrial applicability and considerable environmental benefits. This advancement represents a transformative step toward the greener production of Mg alloys.