(163a) In Operando Study of Zinc and Proton Co-Intercalation in Disordered Sodium Vanadate for Aqueous Zinc Ion Batteries
AIChE Annual Meeting
2020
2020 Virtual AIChE Annual Meeting
Materials Engineering and Sciences Division
Poster Session: Materials Engineering & Sciences (08D - Inorganic Materials)
Thursday, November 19, 2020 - 8:00am to 9:00am
Disordered sodium vanadate (NaV3O8) cathode materials are synthesized and used in aqueous zinc-ion battery (ZIB) and showed a high capacity of 265 mAh g-1, a high energy density of 371 Wh kg-1, and a good cyclability by retaining 78% of the capacity after 2000 cycles at 0.4 A g-1 in full cell test. Synthesized NaV3O8 is abundant with structural vacancies in its framework with large interlayer distance of 9.35 â«, allowing enough space for ion storage and flexibly adjusting its own structure as an excellent cathode material. In this work, the synergistic sequential co-intercalation of zinc cations and protons was analyzed via in operando x-ray diffraction spectroscopy (XRD) and x-ray absorption spectroscopy (XAS) technique. During discharging, 0.2 Zn2+ ions and 0.24 protons are inserted per vanadium atom in sequence and reversely extracted during cycling, consequently yielding 0.63 electron charge transfer per vanadium atom. This co-insertion is expected to address the sluggish ionic transport issue that is common in multivalent battery systems. This study will further expand the fundamental understanding of the structure-dependent dynamics in ZIBs.