Browsing by Author "Gualpa Suco, Gabriel Alexander"

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    Evaluación del desempeño electroquímico del prototipo de una celda de flujo redox con electrolitos de hierro a escala de laboratorio
    (Universidad de Cuenca. Facultad de Ciencias Químicas, 2026-02-20) Gualpa Suco, Gabriel Alexander; Montero Izquierdo, Iván Andrés
    Redox flow batteries (RFBs) based on iron electrolytes represent a promising alternative for large-scale energy storage due to their low cost, material abundance, and enhanced environmental sustainability. However, their efficiency is limited by transport phenomena and electrolyte physicochemical stability. This work evaluated the performance of an RFB employing iron–gluconate and potassium ferrocyanide redox pairs in alkaline medium (KOH 1.0 mol·L⁻¹) to identify energy loss mechanisms and operational degradation. The methodology involved electrolyte synthesis at 0.32 mol·L⁻¹ and assembly of a prototype with Nafion NR212 membrane, graphite felt electrodes, and acrylic plates. Physicochemical characterizations were performed using UV–Vis spectrophotometry and atomic absorption, along with galvanostatic charge (0.1 A) and resistive discharge (10 Ω) tests over 20 cycles, operating between 10% and 90% state of charge. Results revealed a 31% capacity loss, decreasing from 0.539 to 0.372 Ah·L⁻¹. Voltage efficiency remained stable (~81%), while coulombic efficiency dropped from 64.6% to 52.5%. This behavior was attributed to species crossover through the membrane and resulting stoichiometric imbalance, evidenced by massive water transport (catholyte: 0.32 to 2.55 mol·L⁻¹) and severe anolyte conductivity decrease (71.8%). Stable pH at 13 confirmed absence of irreversible chemical degradation. Technical viability requires optimized membranes and higher operating current density.