Flow Field Design for Inhibiting Heterogeneous Deposition in Electrolytic Ironmaking at Ambient Temperature

Electrolytic production of iron exhibits prospective potential toward the global aim of carbon neutrality under the rapid development of renewable energy, whereas uniform morphology of deposited iron from electrolysis in acidic solution is critical due to the intrinsic solid/liquid interface and side reaction of hydrogen evolution. This study demonstrates the advantage of introducing flow field design with three patterns of bottom-top, center-symmetric, and multi-inlet, reflected in the optimization of reaction resistance, cell voltage, and current efficiency for electrolysis in aqueous solution of ferrous sulfate (FeSO4). Specifically, the multi-inlet design leads to a superior decrease of 47.42% on reaction resistance and 2.04 V on cell voltage, accompanied by an increase of 14.40% on current efficiency, which is attributed to efficient mitigation of concentration polarization and dendritic growth confirmed by multiphysics simulation, resulting in uniform deposition with a roughness of 0.96–3.8 μm after 48 h continuous electrolysis under a flow rate of 40 mL·min–1.