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Title: Reversible Disorder-to-Order Transition Induced By Aqueous Lithiation in Vanadate Electrode Materials
ID: 709571
My research investigates the interfacial chemistry between electrodes and aqueous electrolytes, focusing on two key areas: electrocatalytic reactions and energy storage via lithium intercalation.
(1) In the field of electrocatalysis, I studied the urea electrooxidation reaction (UOR) using Ni/Co binary catalysts. The synergistic interaction between Ni and Co significantly improved catalytic performance, leading to a lower onset potential, enhanced reaction kinetics, and higher selectivity against the competing oxygen evolution reaction (OER). These bimetallic catalysts outperform monometallic references (NiO, NiOOH, Co3O4) and commercial Pd catalysts. Electrochemical techniques (LSV, CV, SCV, CA) combined with material characterizations (XRD, XPS, XAS, TEM-EDS) revealed that Ni2+ and Co3+ species dominate at low anodic potentials, promoting UOR, while the formation of Ni3+ at higher potentials favors OER. These findings provide insights for rational catalyst design.
(2) In the area of energy storage, I explored the lithium intercalation behavior of a disordered vanadate material (LiV3O8) in aqueous electrolytes. Using CV, CP, GITT, XRD, XAS, TEM-EDS, and Debye scattering simulations, I observed a reversible disorder-to-order transition during (de-)lithiation. This transition proceeds via a sequential interlayer and intralayer lithium insertion mechanism, which mitigates the phase distortions common in conventional vanadium oxide cathodes. This unique chemistry enhanced structural stability and improved energy storage capacity.
Together, these studies advance our understanding of electrode–electrolyte interactions in aqueous systems, with implications for both sustainable catalysis and battery material development.