Evaluación de desempeño y comportamiento electroquímico del níquel como electrodo en la recuperación de hidróxido de litio a partir de cloruro de litio empleando una membrana catiónica.
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Date
2025
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Publisher
Universidad de Concepción
Abstract
La creciente demanda del litio, debido a su uso en almacenamiento de energía, ha llevado a la necesidad de desarrollar nuevos procesos de recuperación de este, con la finalidad de tener procesos más eficientes y sostenibles. Este trabajo tiene como objetivo estudiar el desempeño del níquel como material de electrodos en el proceso de electrodiálisis con una celda tipo H para la recuperación de hidróxido de litio, con el uso de herramientas de análisis microscópico y electroquímico para caracterizar la morfología y el comportamiento de los electrodos de níquel previo y posterior al proceso de electrodiálisis. En los ensayos, se evaluó el impacto que tenía el tiempo y la densidad de corriente en la recuperación de litio, la mayor recuperación (15,48%) se obtuvo a 3 horas y 35,6 A/m2, mientras que las más bajas (6,52% y 7,08%) se tienen a ambas densidades de corriente, en 1 hora de operación, concluyendo que el tiempo es el parámetro que más influye en la recuperación. Se utilizo SEM-EDS y espectroscopia Raman para caracterizar fisicoquimicante los electrodos, en la cual, el ánodo presentó corrosión por picadura y pérdida de masa (0,645 g) asociada al desprendimiento de β-Ni(OH)2 como producto de corrosión. Todo esto debido a la aplicación de un sobrepotencial, favoreciendo la disociación del agua y oxidación del níquel. Por otro lado, el cátodo se comportó de manera estable, sin signos de corrosión o cambio superficiales, colocándolo como una alternativa adecuada para cumplir este rol. Se utilizó voltametría cíclica, ruido electroquímico y curvas de polarización para caracterizar electroquímicamente los electrodos. El ánodo presento inestabilidad, cinética más lenta y aumento en la resistencia a los procesos redox, relacionado con los procesos corrosivos sufridos durante la electrodiálisis (ED). Mientras, el cátodo no presento modificaciones considerables, confirmando la estabilidad presentada en las pruebas anteriores.
The growing demand for lithium, driven by its use in energy storage, has led to the need to develop new recovery processes, to have more efficient and sustainable processes. The objective of this work is study the performance of nickel as an electrode in the electrodialysis process using an H-type cell for the lithium hydroxide recovery, using microscopic and electrochemical analysis to characterize the morphology and the behavior of the electrodes before and after the electrodialysis. In the experiment, the effect of time and current density was evaluated on lithium recovery. The highest recovery (15.48%) was obtained at 3 hours and 35.6 A/m2, while the lowest (6.52% and 7.08%) were obtained at both current densities, in 1 hour of operation, concluding that time is the parameter that most influences recovery. SEM-EDS and Raman spectroscopy were used to characterize the electrodes physicochemically. The anode exhibited pitting corrosion and a mass loss of 0.645 g associated with the release of β- Ni(OH)2 as a corrosion product, attributed to overpotential, which promoted water dissociation and nickel oxidation. On the other hand, the cathode showed stable behavior with no signs of corrosion or surface changes, making it a suitable alternative for this role. Cyclic voltammetry, electrochemical noise and polarization curves were used to characterize the electrodes. The anode showed instability, slower kinetics, and increased resistance to redox processes, related to the corrosive processes during ED. Meanwhile, the cathode did not show significant modifications, confirming the stability shown in previous tests.
The growing demand for lithium, driven by its use in energy storage, has led to the need to develop new recovery processes, to have more efficient and sustainable processes. The objective of this work is study the performance of nickel as an electrode in the electrodialysis process using an H-type cell for the lithium hydroxide recovery, using microscopic and electrochemical analysis to characterize the morphology and the behavior of the electrodes before and after the electrodialysis. In the experiment, the effect of time and current density was evaluated on lithium recovery. The highest recovery (15.48%) was obtained at 3 hours and 35.6 A/m2, while the lowest (6.52% and 7.08%) were obtained at both current densities, in 1 hour of operation, concluding that time is the parameter that most influences recovery. SEM-EDS and Raman spectroscopy were used to characterize the electrodes physicochemically. The anode exhibited pitting corrosion and a mass loss of 0.645 g associated with the release of β- Ni(OH)2 as a corrosion product, attributed to overpotential, which promoted water dissociation and nickel oxidation. On the other hand, the cathode showed stable behavior with no signs of corrosion or surface changes, making it a suitable alternative for this role. Cyclic voltammetry, electrochemical noise and polarization curves were used to characterize the electrodes. The anode showed instability, slower kinetics, and increased resistance to redox processes, related to the corrosive processes during ED. Meanwhile, the cathode did not show significant modifications, confirming the stability shown in previous tests.
Description
Tesis presentada para optar al título de Ingeniero/a en Civil Químico/a.
Keywords
Minería, Litio, Electrodos, Níquel, Electroquímica