Ms. Katerina Bogomolov - Ph.D. Candidate
23/07/2026
אודיטוריום ע"ש דויד וואנג, בניין מידן, קומה 3
13:30
Iron-based materials are promising active materials for rechargeable battery anodes, with a theoretical specific capacity of 960 mAh g⁻¹, low cost, high abundance, and established recycling procedures. Yet, practical systems are limited by parasitic hydrogen evolution and passivation. This study addresses these limitations through electrode composition and structural modifications, while challenging the current mechanistic framework proposed for dissolved LiOH as an electrolyte additive.
Composition was modified by pre-lithiation of magnetite anodes to decouple the role of Li ions as a LixFe3O4 solid additive and as dissolved LiOH in the electrolyte. Pristine and lithiated magnetite electrodes were evaluated in 7 M KOH with 0–2 M LiOH. Lithium hydroxide reduced conductivity, increased viscosity, and shifted the hydrogen evolution onset. Lithium pre-intercalation demonstrated HER catalysis and changed the discharge pathway, showing that intercalated Li ions and dissolved LiOH impose distinct reaction pathways. The transient effect of pre-lithiation is linked to Li ion instability, but can be improved by adjusting equivalency in the host. These findings indicate that Li ion intercalation is complex under aqueous alkaline conditions, and that dissolved LiOH functions through interfacial water rearrangement rather than intercalated intermediates.
Physical structure was modified using fused filament fabrication and laser powder bed fusion. LPBF parameters were optimized by adjusting laser power and scanning speed to improve structural control, reduce porosity, and limit defects. Pillar and lattice electrodes were compared with planar disks to evaluate the effect of increased surface area per volume and improved bulk utilization. For FFF, iron-PLA composite filaments were developed, followed by de-binding and sintering optimization to fabricate light, porous, and scalable electrodes. Optimized electrodes reached >90% coulombic efficiency with 200 mAh g⁻¹ over 100 cycles.