Study of microstructure and discharge performance in fine-grained AZ31 magnesium alloy air battery anodes produced via single-pass large strain rolling

This study utilized single-pass large strain rolling technology to prepare fine-grained AZ31 magnesium alloy anodes with excellent discharge properties. We systematically examined the microstructural evolution , electrochemical behavior, and discharge characteristics of these materials through EBSD , laser confocal three-dimensional morphology analysis, SEM, electrochemical testing, and constant current discharge experiments. The findings highlighted the interplay between the material's recrystallization and its discharge characteristics, along with the corrosion mechanisms active during discharge. Experimental results showed that increased rolling deformation improved both the degree of recrystallization and the anodes' overall discharge performance. Recrystallized grains that were fine and evenly distributed mitigated the depth of corrosion pits , resulting in a smoother electrolyte interface . This structural alteration reduced the chunk effect, enhancing the stability of the discharge process. Notably, anodes deformed by 80 % demonstrated optimal comprehensive discharge performance. At a discharge current of 20 mA·cm -2 , these anodes achieved an efficiency, discharge capacity, and specific energy of 68.88 %, 1538.46 mA h·g -1 , and 1764.11 mW h·g -1 respectively, showing an increase of 16.67 %, 16.67 %, and 17.67 % over the base material. Such results confirm the significant benefits of single-pass large strain rolling technology in developing fine-grained magnesium alloy anode materials , offering new avenues for advancing high-performance magnesium-air battery anodes.