From Mill Scale to Hematite: Processing and Electrophoresis Deposition Coating for Sustainable Secondary Battery Electrodes

Mill scale is a by-product of hot rolling steel generated in a rolling mill and has the potential to be transformed into hematite. Owing to hematite's many uses; mill scale has a high economic value and may be used as a battery anode. The impact of CaCO3 pellet quantity and calcination time on hematite purity, as well as the effect of deposition duration and voltage on coating thickness. The calcination duration has a considerable effect on the purity of the resulting hematite, while the addition of CaCO3 pellets lowered the purity by around 6%. Attaining the thickest hematite coating on an aluminium surface required a 40 V treatment and a deposition time of 30 minutes. Alternately arranged aluminium ions (Al3+) and oxide ions (O2-) form an ionic connection. Whereas aluminium ions on the surface of aluminium are positively charged, oxide ions are negatively charged in order to generate an electrostatic interaction. During the discharge phase, the voltage decreased from 1.02 to 0.70 V. This research contributes to the development of more efficient and effective manufacturing procedures for hematite and its battery anode applications.