ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-09142021-194941


Tipo di tesi
Tesi di laurea magistrale
Autore
IMPALA', GIULIA
URN
etd-09142021-194941
Titolo
Mathematical Modelling of the Discharge Process of Lithium-Air Batteries with Redox Mediators
Dipartimento
INGEGNERIA CIVILE E INDUSTRIALE
Corso di studi
INGEGNERIA CHIMICA
Relatori
relatore Prof. Bertei, Antonio
relatore Ing. Lagnoni, Marco
controrelatore Prof. Nicolella, Cristiano
Parole chiave
  • lithium-air batteries
  • redox mediators
  • mathematical modelling
  • diffusion in porous media
Data inizio appello
01/10/2021
Consultabilità
Non consultabile
Data di rilascio
01/10/2024
Riassunto
The main objective of this work is to develop a mathematical model for a non-aqueous Li-Air battery, capable to simulate the discharge process in presence of a Redox Mediator based on experimental evidence, and to define how the design of the cathode should be modified to enhance the discharge process in this condition.

After thorough analysis of experimental evidence, and based on an existing mathematical framework, a mathematical model was developed for a Li-Air battery. The mathematical model comprehends original additions to be able to take into account for the morphology evolution during the discharge process. This model was validated against experimental data, before being used to perform the design optimisation simulations. The dynamic behaviour of cathode porosity was determined by numerical solution of the governing, transport and reaction equations. The microscopic behaviour included the local mass transfer and the change in morphology related to the growth of Li2O2 particles driven by the mediator mechanism. The effect of the deformation given from the current collector was also included in the model. Simulations were performed first in 1D to calibrate the model parameters, which were used for the validation of the 2D model against experimental data. Then, 2D simulations were performed to achieve the design optimisation of the cathode geometry with embedded micro-channels to enhance oxygen supply.
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