Fabricating Mg powder electrodes via the traditional way enhances its suitability for next-generation Mg battery prototypes

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Typically, Mg batteries use Mg foil as an anode with a thickness of 100–250 μm. Producing ultra-thin foils (< 50 μm) is challenging because of Mg's hardness and brittleness. Alternatively, Mg powder based anode may be a better option for Mg batteries because it is cheaper and easier to shape into electrodes. Mg powder can be combined with conductive additives such as carbon and binding polymers and subsequently cast as a slurry, allowing precise regulation of areal capacity to correspond with that of the cathode. However, Mg metal reacts with moisture and oxygen over time, forming oxide layers. In this work, a new organic acid-based etching process was developed to remove oxide and carbonate layers from the Mg particles. Subsequently, an etched Mg powder-based electrode was prepared using traditional methods consisting of a slurry and electrode coating process. The compatibility of the etched Mg powder electrodes was in several electrolyte systems, including APC (all-phenyl complex), Mg(TFSI) 2 , and Mg[B(hfip) 4 ] 2 . In a symmetrical cell using APC electrolyte, the etched Mg powder electrode maintained stable cycling over 1000 cycles with low overpotential at current densities of 0.1 and 1 mA cm −2 . The Mg powder/APC/Mo 6 S 8 full cell achieved a high capacity of about 70 mAh g −1 with nearly 98% coulombic efficiency, sustained over 2000 cycles at 1C. It also demonstrated excellent C-rate performance, delivering 50 mAh g −1 at 10C. Notably, a cell using a low-active-material-loading Mg powder anode and a high-active-material-loading Mo 6 S 8 cathode was assembled, achieving the lowest N/P ratio of 2 for Mg systems to date. This etched Mg powder cell outperformed traditional Mg foil-based cells by performing better, being cheaper, more scalable, and having a lower N/P ratio. The study also demonstrated, for the first time, a cost-effective magnesium powder anode in a pouch-cell configuration. This work developed an acid-based etching method to remove the native contaminated oxide layer from Mg particles, serving as a preliminary step for creating protective coatings on Mg powder. Additionally, it aims to establish a scalable manufacturing process for next-generation, commercially viable Mg-based energy storage systems technologies.