A novel magnesium-based alloy is described. The alloy is particularly suitable for the construction of electrodes, especially anodes, that can be used for an electrochemical process, such as the synthesis of struvite. The magnesium-based alloy is an AZXY alloy in which A is aluminium and Z is zinc, X represents the content, expressed in wt. %, of the first element, and Y the content, expressed in wt. %, of the second element. The AZXY alloy according to the invention has 2%≤X≤4% and 0.5%≤Y≤2%, and an iron (Fe) content of less than 0.005%, and preferably less than 0.003%. The anodes constituted by this novel alloy have a much slower corrosion speed and improved performances compared to existing anodes. An electrode cartridge comprising said alloy and suitable for being inserted into an electrolytic reactor so as to form, once assembled, an electrocoagulation unit, is also described.